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COMPARISON OF SELF-FED WET/DRY AND HAND-FED LACTATING
SOW FEED-WATER SYSTEMS

presented by
Jiajiang Peng

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COMPARISON OF SELF-FED WET/DRY AND HAND-FED LACTATING SOW
FEED-WATER SYSTEMS

By

J iajiang Peng

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
For the degree of

MASTER OF SCIENCE
Department of Animal Science

2005

ABSTRACT

CONIPARISON OF SELF-FED WET/DRY AND HAND-FED LACTATING SOW
FEED-WATER SYSTEMS

By

Jiajiang Peng

A study was conducted to determine the performance of multiparous lactating sows
when feed and water were made available using either a self-fed wet/dry (SFWD) or a
hand-fed (HF) feed-water system. Research methods and equipment were developed for
the measurement of sow water disappearance, the collection and measurement of wasted
feed and water, and the determination of actual feed and water intakes of lactating sows.
Sows (n = 120) were assigned to treatments based on parity and genotype. Total feed
disappearance per sow during lactation (120.7 i 2.58 kg vs. 110.2 i 2.46 kg for SFWD and
HF, respectively) and piglet weaning weight (6.56 d: 0.10 vs. 6.15 i: 0.10 kg for SFWD and
HF, respectively) were greater (P < 0.01) with SFWD sows than with HF sows. The
SFWD sows had greater (P = 0.02) weight gains during lactation than HF sows (6.5 i 1.60
vs. 1.2 :1: 1.53 kg for SFWD and HF, respectively). Sows with SFWD wasted less water (P
< 0.01) than those with HF (15 :t 9.5 vs. 227 i 12.9 L for SFWD and HF, respectively).
However, sow average daily water intake and total feed wastage during lactation did not
differ (P = 0.48 and P = 0.58, respectively) between treatments. In conclusion, use of a
self-fed wet/dry feed-water system in lactation, that provides sows choices of when to eat,
how much to eat, and if the dry feed should be mixed with water before consumption,

enhances sow appetite and improves litter growth performance.

This thesis is especially dedicated to my advisor, Dr. Dale Rozeboom, and his
family.
This thesis is also dedicated to my beloved parents and grandparents, to my

brothers and sisters, and to my wife and her parents and sister.

iii

ACKNOWLEDGEMENTS

I would like to thank everybody who has contributed to the realization of this
thesis. Especial appreciation goes to my advisor, Dr. Dale Rozeboom, for his guidance
and financial support during my time as a graduate student in the Department of Animal
Science. I am grateful for his insight, experience, and enthusiasm in training me. I am
also grateful for the guidance and support from my committee members, Dr. Roy
Kirwood, Dr. Nathalie Trottier, and Dr. Steve Bursian, whose doors were always open to
me. I am indebted to the members of the committee for reviewing my thesis and for their
excellent suggestions. The combination of my committee members’ critical eyes and Dr.
Rozeboom’s general view of the project have contributed largely to the final appearance
of my thesis.

Special thanks also go to Dr. Robert Tempelman for his excellent statistical
advice and support and Dr. Adroaldo Zanella and Dr. Karen Chou for their admirable
encouragement. Sincere thanks also go to the other faculty in the Department of Animal
Science for their expertise, frankness, generosity, and outstanding good humor.
Regarding to the statistical advice and support, genuine appreciation also goes to Purdue
University faculty (Department of Animal Science and Department of Statistics), Dr.
Kristofer Jennings, Dr. Michael Zhu, and Mr. Mark Einstein.

Special appreciation goes to the acting department chair, Dr. Margaret Benson,
and the department graduate coordinator, Dr. Steve Bursian, for their even-handed and
strong support through both good and hard times. I would like to thank office and lab
support staff Jackie Christie, Jane Link, Dewey Longuski, Dave Main, Julie Moore, Ron

Southwick, Barb Sweeney, and Jackie Ying for their help and encouragement.

iv

Special appreciation goes to the agricultural engineer team. I thank Dr. Gary Van
Ee, Mr. Richard Ledebuhr, Mr. Richard Wolthuis, Nick Tipper, and other students for the
pleasant help and teaching they offered during my work in the agricultural engineering
shop. I thank both Richards and Dr. Van Be for their advice on the design of the waste
collection pans and water tanks. I want to express my gratitude to these colleagues for
creating a stimulating work environment. The act of research consists mainly of two
elements: using one’s powers of conception and creating an atmosphere in which the
mind functions at its best. I think my life changed dramatically when the water tanks and
collection pans turned out to be mechanically flawless. My life has been enriched by the
acquaintance with the engineering people. I am especially grateful to Nick, who brought
my wife and myself to tour his uncle’s farm, where my interests both in agriculture and
engineering were further developed. I also thank Nick for his voluntary and critical
reading of part of this thesis.

Special appreciation also goes to Mr. Al Snedegar and Mr. Lance Kirkpatrick
from Michigan State University Swine Teaching and Research Farm for their great help.

Appreciations go to Mr. Berry and his family for the generous support for this
study. Thanks the company for providing the feeders and farm training to me during the
study.

I also have to give appreciation to my undergraduate helpers, Jessica Scrimger,
Steve Grow, Mark Labar, Mark Hartzler, and Mellisa Ryan. Without their hard work my
studies would not be accomplished so efficiently.

I would like to thank my fellow graduate students, Barry Bradford, Pooi-see

Chan, Laurie Davis, J iayou Han, Jayne Kalbfleisch, Mike Jacobsen, Juliana Perca-

Laspiur, Mike Rincker, Jason Rowntree, Carissa Wickens, and Lan Xiao for their smiles
and help. These people demonstrated excellence in all facets of their life and shared their
gifts with me. I am thankful to have shared good times with them. I am grateful for the
many other friends that have supported me, too many to mention them all.

My final thanks go to my family. My parents, Kezi and Penxiang, brothers, J iahai
and Jiayang, and sisters, Fulian and Hualian, have demonstrated through the example of
their lives what it is to be a good person. Some of us in this world take a while longer to
reach full maturity. If not for their love, encouragement and solid support, I would not
have the privilege of submitting this thesis. I believe growing up in such a lively,
stimulating and therefore inspiring family life has been of considerable influence on my
conduct in life. Knowing I could always rely on the warm family has strengthened my
decision to retreat for a few years of study and research at an academic institution. I am
forever indebted to my wife, Xiaotao, who worked with me throughout the project both at
home and on the farm. With her forever trust, love, and support, I was able to finish this
thesis strongly. I am also indebted to her parents, Shangqian and Meiyue, and her sister’s
family, Xiaolan and Weidong, who supported me the best during my graduate study at
Michigan State University.

I understand now that Science is so much more than research alone, and
perseverance is equally important as insightfulness.

Thank you God. Good luck to everyone.

vi

TABLE OF CONTENTS

LIST OF TABLES ..................................................................................................... x
LIST OF FIGURES .................................................................................................... xi
INTRODUCTION .................................................................................................... 1
CHAPTER 1
LITERATURE REVIEW
FEED AND WATER USAGE IN LACTATING SOWS ......................................... 3
Introduction .................................................................................................... 3
Definitions of nutrient disappearance, intake, and wastage .......................... 4
Factors affecting lactating sow feed intake ................................................... 5
Ambient temperature ........................................................ 5
Health ........................................................................ 6
Genotype ..................................................................... 6
Parity ......................................................................... 6
Litter size .................................................................... 7
Body size and body condition ............................................. 8
Lactation stage .............................................................. 8
Dietary formulation ......................................................... 8

vii

Previous feeding level ...................................................... 9

Feeding systems ............................................................ 10
Feeder design ............................................................... 1 1
Other factors ................................................................. l 1

Factors affecting lactating sow water disappearance,

wastage, and intake ................................................................... 12

Water disappearance ........................................................ 12

Water wastage ............................................................... 13

Factors affecting lactating sow water intake ............................ 14

Summary ..................................................................................................... . 14
CHAPTER II

CUSTOM EQUIPMENT SYSYTEM TO ASSESS
LACTATING SOW FEED AND WATER USAGE, WASTAGE

Abstract .......................................................................................................... 16
Introduction ................................................................................................... 16
Water tank design .......................................................................................... 17
Building materials and process ........................................... 17
Water tank functionality .................................................... 22
Waste feed and water collection system design .......................................... . 23
Building materials and process ........................................... 23
Waste feed and water collection system functionality ................. 27
Observations and recommendations .............................................................. 28

viii

Conclusion ..................................................................................................... 3 1

CHAPTER III

COMPARISON OF SELF-FED WET/DRY AND HAND-FED
LACTATING SOW FEED-WATER

Abstract ....................................................................................................... . 32
Introduction .................................................................................................... 33
Materials and Methods .................................................................................. 35
Results and Discussion .................................................................................. 47
Conclusion ............................................................................ 58
Implication ........................................................................... 58
LITERATURE CITED .............................................................................................. 59

ix

LIST OF TABLES

Table 1. Water usage for the lactating sow (Ud) ................................................ 13
Table 2. Building materials for each water tank .................................................. 19

Table 3. Water holding capability (L) of the top and bottom caps of each
water tank ....................................................................... 23

Table 4. Water flow rate (mUmin) of the waterer nipples for each crate in the

two lactation rooms ............................................................ 29
Table 5. Composition of the lactation and gestation diets (as-fed basis) ......... 36
Table 6. Effect of lactation feed-water system on sow performance .............. 48
Table 7. Effect of lactation feed-water system on piglet performance ............ 51
Table 8. Effect of lactation feed-water system on sow feed and water

disappearance, wastage, and actual intake .................................. 53

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

Figure 6.

LIST OF FIGURES

Schematic drawing (not to scale) of water tank ........................

Schematic drawing (not to scale) of farrowing crate and air
pressure supply line in the two farrowing rooms ........................

Schematic drawing (not to scale) of collection units’ position under
the farrowing crates .........................................................

Self-fed wet/dry system (BerryTM Feeding System) ....................

Hand-fed system (Circle BTM feeding system) .......................... '

Average daily high and low ambient temperatures during this trial..

xi

18

21

25

38

39

41

INTRODUCTION

Lactation is a metabolically demanding time while sows need to consume enough
feed and water for maintenance and milk production. Feed and water intake are major
factors influencing sow and litter performance (Trottier and Johnston, 2001; Thacker,
2001). Many other factors also affect feed intake of lactating sows, including method of
feed and water presentation (O’Grady and Lynch, 1978; Pettigrew et a1, 1985; Peterson
et al., 2004).

Significant amounts of wasted feed and water in swine production are
accumulated in manure, resulting from animal feeding behavior and equipment design.
Improper feeder design can cause feed wastage by sows (Taylor and Curtis, 1988; Taylor,
1990). For sows in individual feeding stalls, the method of feed provision (hand-fed or
self-fed access to feed) influences the amount of wastage by the animal (Taylor, 1990).
The relationship between feed and water wastage and the feed-water system used for the
lactating sow has seldom been examined under commercial conditions and is not
commonly known by producers. Minimizing feed and water wastage may decrease
manure volume and manure management costs, and protect against environmental
poflufion.

The Berry Feeding SystemTM is a new commercially available self-fed wet/dry
(SFWD) lactating sow feed-water system. This feeding and watering system provides
sows with ad libitum access to feed and water, and the freedom to make choices relative
to when they want to eat, how much they want to eat, and how moist the feed they eat
may be. The impact of this new feeding and watering system on sow performance and

environment effect has not been evaluated. The present research was designed to

evaluate this feed-water feeding system in comparison to a conventional hand-fed (HF)
dry feed system.

The research hypothesis was that sows provided with feed and water using an ad
libitum self-fed wet/dry feed-water system during lactation would consume more feed,
better conserve body tissue, wean heavier litters, waste less feed and water, and
experience shorter wean-to-estrus intervals postweaning.

The overall purpose of this research was to determine the effect of two lactation
feed-water systems (i.e., feed and water presented with different feeder and drinker
combinations) on sow and litter performance during lactation. Sow lactation feed and
water apparent usage (i.e., disappearance), feed and water wastage, and actual feed and
water intake from the two different feed-water feeding systems were measured using

custom-built equipment.

CHAPTER I
LITERATURE REVIEW

FEED AND WATER USAGE IN LACTATING SOWS

Introduction

Genetics, environment, and management can influence sow lactation performance
(i.e., nutrient consumption, milk production, body tissue conservation, and subsequent
timely continuation of reproductive function). Genetic selection has resulted in sow lines
that produce large quantities of milk. This results in significant nutrient requirements
during lactation. Lactating sows need to consume enough feed to meet their daily energy
and protein requirements for maintenance and milk production. If this does not happen,
sows must mobilize body tissues to meet the nutrient deficits (W hittemore et al., 1980,
1988; ARC, 1981). Current feeding recommendations for lactating sows are calculated to
minimize live weight and backfat losses and to increase weaning litter weight. It has
been shown that sows with a greater lactation feed intake mobilize less body tissues
during lactation (Reese et al., 1982; Pettigrew et al., 1985; Armstrong et al., 1986), have
greater litter weight gain (Eissen et al., 2003), shorter wean-to-estrus intervals (Johnston
et al., 1989; Koketsu et al., 1996b), and greater viable embryo numbers in subsequent
pregnancies (Kirkwood et al., 1987). Restriction of feed intake during lactation has
resulted in greater sow weight loss comparing to full-fed sows (Gall, 1980; Matzat,
1990). In addition, restrict-fed lactating sows have smaller subsequent litter sizes and

more unsuccessful pregnancies (Baidoo et al., 1992).

The primary purpose of this review is to discuss the factors that affect feed intake
in lactating sows. Water usage by lactating sows is also discussed. The definitions of

disappearance, intake, and wastage are provided at the beginning.

Definitions of Nutrient Disappearance, Intake, and Wastage
To give us a common understanding and a context for the remainder of this
thesis, the definitions of nutrient intake, disappearance, and wastage are defined as
follows:

Disappearance. ‘Disappearance’ of feed or water is the amount provided to the
animal in a given period of time that appears to be consumed. Disappearance includes
the amount actually consumed and the amount of waste caused by the animal.

Intake. ‘Intake’ of feed or water is the amount actually consumed by the animal.
It is determined by accounting for that amount remaining in the delivery device and that
amount wasted by the animal.

Wastage. ‘Wastage’ of feed or water is the amount presented to the animal that is
spilled or scattered by the animal during consumption or other activities. Wastage is feed
or water that was not consumed, nor did it remain in the delivery device after the selected
period of time.

Although many researchers measured feed and/or water ‘disappearance’, most of
them inappropriately use the terminology ‘intake’ in their reports. Most of these
researchers should have used nutrient ‘disappearance’ because they did not measure those
nutrients wasted by the animals. Feed wastage is mainly due to feeder design and animal

eating habits (Taylor, 1990). Taylor and Curtis (1988) examined 10 different types of

sow feeders and they found feed wastage ranged from 0.1% to 38% of the total feed
disappearance. A well-designed feeder prevents feed accumulation in the comers of the

feeder, which can cause stale or spoiled feed hence increasing wastage.

Factors Affecting Lactating Sow Feed Intake

The aim of lactation feeding is to maintain sow body condition, maximize piglet-
weaning weights, and minimize weaning-to-service intervals. Environmental factors
(e.g., ambient temperature), animal factors (e. g., health, genotype, parity, litter size, body
size and body condition, and lactation stage), dietary factors (e. g, dietary formulation,
previous feeding level, and feeding systems,) and feeder factors (e. g., feeder design) can
affect sow feed intake.

Ambient temperature. Lactating sows adjust their feed intake according to
temperature, with low temperatures stimulating feed intake and high temperatures
reducing feed intake (Matzat, 1990). The NRC (1998) model considers a temperature of
20°C as thermoneutral and predicts that the lactating sow will consume 310 kcal of
dietary ME (323 kcal of DE) more, or less, per day for every 1° below or above 20°C,
respectively. Black et a1. (1993) and Spencer et al. (2003) demonstrated that ambient
temperatures above the evaporative critical temperature caused lactating sows to decrease
feed intake, which resulted in decreased milk yield, reduced weaning litter weight, and
increased sow weight loss. During winter months, sows increase feed intake in order to
produce more heat to maintain body temperature. It is important to ensure that a warm
microenvironment (e.g., 30 to 34 °C) is available for piglets while the room is kept at a

temperature low enough to ensure adequate feed intake for the sows. Proper ventilation,

with an adequate supply of clean fresh air, is required for sow comfort and performance.
Modern swine producers try to maintain a comfortable environment all year round in
order to achieve less interruption in production and greater economic benefits.

Health. Diseases may affect sow appetite and hence decrease sow lactation feed
intake. For example, the mastitis, metritis and agalactia (MMA) syndrome is a problem
for some lactating sows. Constipation, along with depressed appetite and reduced water
intake, may accompany MMA (Smith et al., 1992). It may take days for a sow to recover
from the farrowing process and return to a normal body water balance. In general, if a
sow consumes an adequate quantity of water during the first few days post farrowing, the
remaining portion of the lactation period is considered to be relatively safe from
dehydration related problems (susceptibility to constipation, catabolism of body tissues,
decreased milk production). Lameness is another problem that leads to depressed sow
lactation feed intake confounded by severity of pain or discomfort (O’Grady et al., 1985).

Genotype. Sow feed intake varies between genetic lines such as Meishan
synthetic and European White (Sinclair et al., 1999), Meishan and Dutch (Van der Steen
and de Groot 1992), and Meishan synthetic and Large White (Farmer et al., 2001).
Meishan sows are known to have a greater number of functional teats, larger litter size at
birth, and lower piglet mortality during lactation than western breeds. Nevertheless, they
also have a low feed intake during lactation. Therefore, further genetic selection is
required to increase their lactation feed intake while maintaining high productive
performance.

Parity. Multiparous sows consume more feed during lactation than primiparous

sows, with daily feed intake increasing as parity advances (O’Grady et al., 1985; Koketsu

et al. 1996a; Moeller et al., 2004). Noblet et al. (1998) indicated that sows lactating for
five weeks consumed 6.2, 6.8, 7.3, and 7.7 kg/d feed for parity one through parity four,
respectively. Mahan (1998) also observed an increasing trend and reported that parity
one average daily feed intake was 4.66 kg and then increased to 6.37, 6.70, 6.43, and 7.08
kg for parity two through five, respectively. Although sows consumed more feed as their
parity increased, they still mobilized body fat to meet the energy requirement for milk
production. Older breeding herds are characterized by a greater percentage of thin sows
and deficient body condition with advancing sow parity may be an indication of dietary
energy deficiencies during lactation. Therefore, stimulating older lactating sows to
consume more feed is warranted.

Litter size. Selection for greater feed consumption during lactation should
accompany genetic improvements in litter size and heavier litter weight. Lactating sow
feed intake increases with the number of pigs being nursed (O’Grady et al., 1985),
reflecting the need for greater milk production. The relationship between energy required
for milk production and litter size has been described by Noblet and Etienne (1989) as:
Energy required for milk production (kcal/d) = (4.92 x ADG - 90) x pigs. Where, ‘ADG’
is average daily gain and ‘pigs’ represents the number of pigs in the litter.

According to O’Grady et al. (1985), the increase in sow feed intake for nursing an
additional piglet is more significant for small litters than that of large litters (e.g., 145 and
65 g/d for 5 and 10 piglets/litter, respectively) and becomes negligible above 12 piglets.
However, in the literature review of Noblet et al. (1998), other studies have failed to

show an effect of litter size on lactating sow feed intake.

Body size and body condition. Larger and heavier sows need to consume more
feed to provide energy for maintenance (O’Grady et al., 1985; Matzat, 1990). However,
if sows are too large or fat upon entering the farrowing house, they will have lower feed
intakes during lactation (O’Grady et al., 1985; Dourmad, 1991; Weldon et al., 1994b). In
the study of O’Grady et al. (1985), fatter sows ate 0.15 kg/d less feed than thinner sows
during lactation. Koketsu et al. (1996a) found that greater body fat decreased sow
lactation feed intake by delaying the attainment of peak lactation feed intake and by
leading to a transient drop (commonly referred to as the feed intake ‘crash’) in daily feed
intake.

Lactation stage. Immediately postpartum, sows vary in their desire to consume
feed but as time progresses appetite increases (Koketsu et al., 1996a). Sows that lactated
for only 10 days had a lower average daily feed intake (4.1 kg/d) than those that had an
18-day lactation period (4.9 kg/d) (Koketsu et al., 1996a). Farmer et al. (2001) and
Sinclair et al. (1996) also saw an effect of lactation stage on sow feed intake with feed
consumption increasing as lactation advanced, reaching a plateau shortly before weaning.
In addition, in order to avoid the incidence of acute feed intake depressions, a step-up
feeding practice (feeding a small amount of feed during the first several days postpartum
and then increasing that amount to fiill-fed gradually within the first week) for lactating
sows has been frequently recommended by veterinary practitioners and nutritionists.

Dietary formulation. Sow feed intake is influenced by the energy concentration
of the diet (O’Grady et al., 1985; Kirkwood et al., 1988; Noblet et al., 1998), with higher
energy densities decreasing feed intake. Greater dietary energy density is used to

enhance lactation performance of younger sows and of all sows during warmer seasons.

In a study by Gatlin et al. (2002), adding fat to lactation diets decreased sow lactation
daily feed intake by more than 10%, but did not lessen lactation ME intakes.

Feed intake during lactation may be influenced by the consumption of other
feedstuffs, varied nutrient densities of these feedstuffs, and the use of these feedstuffs
during the prior gestation period as well as during lactation. For example, Hagen et al.
(1987) and Nelson (1996) both observed an increased lactation feed intake when sows ate
greater amounts of fiber during gestation. These researchers speculated that fiber might
expand the stomach of the sow, enabling her to consume larger amounts of feed during
the lactation period.

Previous feeding level. Studies have shown that daily feed intake of sows during
the gestation immediately preceeding lactation is inversely related to feed intake during
lactation (Dourmad, 1991; Weldon et al., 1994a, 1994b). Ifthe difference in feed intake
is small, this relationship may not hold true. Mahan (1998) found that gilts that had been
fed 0.13 kg/d more feed than the control group during gestation did not consume less feed
during their first lactation, but feed intake during the first week postpartum of subsequent
parities was improved with additional feed in first gestation. Additionally, Mahan
(1998) reported that greater protein concentration in the gilt gestation diet led to an
increase in lactation feed intake. Kusina et al. (1999) supported this finding by observing
that inadequate protein intake by gilts in gestation led to inferior feed intakes in lactation.

Recent evidence suggests that nutrition further in advance than just the preceeding
gestation may also influence lactation feed intake. Lyvers (2000) reported that pre-
pubertal gilts fed to experience periods of compensatory gains by feeding high fiber diet

during a 16-week rearing period had higher lactation feed intakes in parity one. This is

the only known scientific evidence of such an influence of rearing nutrition and why it
occurred is also unknown.

Feeding systems. There are three common commercially-used sow lactation
feeding systems in the swine industry. A dry feeding system provides only dry feed
(about 10 to 12% moisture) with the water supplied separate from the feeder. Additions
of dry feed are made to sow feeders by hand, two to three times daily. Liquid feeding
systems thoroughly mix water or whey or other liquid by-products with dry ingredients in
a dedicated mixing tank and subsequently transport the gruel to the sows. European
studies have shown that pigs more readily consume liquid feed over dry feed (Jensen and
Mikkelsen, 2001). Liquid feeding has been studied with lactating sows by mixing
pelleted feed with water in a 1:2 ratio to make a flesh or fermented wet form of feed
(Demeckova et al., 2002). This feeding system is costly and is not as popular as dry
feeding system within the United States. Thirdly, wet/dry feeding systems provide feed
and water separately inside the feeder allowing sows to add water to the dry feed at the
bottom of the feeder. A nipple drinker is typically mounted above the bowl-shaped
bottom of the feeder. The term ‘wet/ dry’ is used because sows have control over the
amount of water mixed with the feed, as contrasted with situations where wet/dry is not a
choice of the sow. Sometimes, water additions may just be sows inadvertently spilling
water as they drink or the intentional wetting of the dry feed in the feeder by the
herdsperson.

Far less common in commercial swine production, and studied only sparsely, are
feeding systems called self-fed and systems that are a combination of self-fed and

wet/dry. Peterson et al. (2004) reported a 7% improvement in the total lactation feed

10

disappearance when lactating sows were fed using a self-feeder. Koketsu (1994)
observed an 11% improvement of daily feed intake by lactating sows with wet feeding
systems. Pettigrew et al. (1985) found that lactating sows had greater feed consumption
when using a self-fed, wet/dry feeding system as compared to a conventional hand-fed
dry feeding system. Crystal Spring Hog Equipment, Ltd. (Ste. Agatha, MB, Canada)
manufactures a self-fed wet/dry feed-water system and on their website
(www.crystalgarirrgh_oggcom/cs_crate.html) claim 0.2 to 0.45 kg heavier pigs at three wk
weaning and a 50% reduction in water waste.

Feeder design. Feeder design, the structural shape or form of the feeder, is a
major factor that influences feed intake, animal productivity, health, and well-being of
sows (Taylor, 1990). The design of a feeder influences eating behavior, nutrient intake,
the amount of nutrients wasted, and consequently the cost of production. Taylor (1990)
observed evidence of considerable variation in feed spillage by gilts and sows due to
differences in feeder design. Feeders should be free of protruding bolts, nuts, and sharp
edges in order to reduce animal body injuries, and ideally allow feed delivery at a rate so
that sows can eat comfortably. The feeders should meet the sows’ spatial requirements
for normal posture and eating movements.

Other Factors. Feed quality, water quality, and water availability also influence
sow lactation feed intakes. Sows should be provided with mycotoxin-free fresh feed and
clean water during lactation. Adding specialty ingredients, sweeteners, aromatic
compounds, and certain natural ingredients (e.g., flavoring agents) to lactation diets at
low levels may increase voluntary feed intake by the sow. Sucrose has been used as

appetite enhancers in swine diets (NCR-89, 1990). Johnston et al. (2003) provided dried

ll

porcine solubles (1.5% or 3%) to lactating sows and found that these sows had a higher
feed intake than those of the control group. These treatment differences highlight the

importance of offering palatable feed to lactating sows.

Factors Affecting Lactating Sow Water Disappearance, Waste, and Intake

Water content of the empty body of the gilt and mature sow is about 47 to 48 %
(Rozeboom et al., 1996). Water is important for the movement of feed through the
digestive system, nutrient and waste transportation, lubrication, and temperature
regulation.

Water disappearance. Insufficient water consumption can affect sow lactation
performance. Lactating sows with low water intake have low milk production and piglet
weight gains (Fraser and Phillips, 1989). A lactating sow can produce 15 to 18 kg of
milk per day during lactation peak and more than 75% of milk is water (Darragh and
Moughan, 1998). It is suggested that sows can become dehydrated during lactation if
they do not drink enough water (Thacker, 2001). Drinking enhances mastication and
swallowing, the excretion of metabolic wastes, the production of milk, the prevention of
constipation, and post-partum rehydration. Although water is an essential nutrient for
pigs, swine nutritionists have not studied it as extensively as other nutrients because it is
abundant and cheap (Mroz et al., 1995). However, desires to reduce the amount of water
wastage and manure volume from swine production, and to improve animal well-being,
are motivating scientists to reestablish the actual water requirement of the lactating sow.
An allowance of between 8 and 25 L/d for the lactating sow’s average daily water usage

has been suggested based on twelve studies (Fraser et al., 1990). Furthermore, Thacker

12

2001) has suggested a requirement in the range of 15 to 35 L per day. A summary of the

studies evaluating water usage for the lactating sow is presented in Table 1.

Table 1. Water usage for the lactating sow ('L/d)a

 

Wastage
Author Range Averag collection
Lightfoot, 1978 12-40 18 3’
Riley, 1978 - 25 -
Bauer, 1982 - 20 -
Cleary, 1983 18-23 - -
Anderson et al., 1984 18-23 - -
Lightfoot and Armsby, 1984 - 18 -
Gill, 1989 8-12 - No
Fraser and Phillips, 1989 - 6 and 14 c Yes
Fraser et al., 1990 8-25 - -
Phillips et al., 1990 12-17 d - Yes
Pederson, 1994 25-35 - No
Klopfenstein et al., 1994 - 20 -
Seynaeve et al., 1996 - 12 and14 e No
Lumb,1998 15-30 - -
Farmer et al., 2001 12 No

 

’ Data of Lrghtfoot (1978), Riley (1978), Bauer (1982), Cleary (1983),
Anderson et al (1984), Lightfoot and Armsby (1984), and Klopfenstein et al.
(1994), Pederson (1994), and Lumb (1998) were derived from Thacker (2001).

bWater wastage determination was not indicated.

°On the day of farrowing water usage averaged 6 L; from d 4 postpartum to
weaning water usage averaged 14 L
d Data were collected between (1 4 to d 14 postpartum.

cDietary salt concentrations were 0.1 and 0.85 % for the 12 L and 14 L water
intakes, respectively.

Water wastage. Increasing water costs, less manure volume, and public policies
are encouraging the swine industry to minimize water wastage. Nipple drinkers are
commonly used for sows housed in farrowing crates. If these drinkers are not adjusted
correctly, then water wastage increases. Small orifices and high pressure may cause

water to spray if sows play with the nipple drinkers. A satisfactory flow rate using large

13

orifices in nipple drinkers and low water pressure will reduce the chance of spraying and
wastage. One goal of swine production is to reduce the amount of slurry or manure by
limiting water wasted by the animals without limiting water consumption. Because water
wastage was not taken into account, previous publications about sow water usage
generally give overestimates (Seynaeve et al., 1996; Farmer et al., 2001).

Factors aflecting lactating sow water intake. Water requirements can be affected
by feed intake, litter size, stage of lactation, environment temperature, dietary salt
concentrations, and sow health status (Fraser and Phillips, 1989; Gill, 1989, Seynaeve et
al., 1996). Water management during lactation should ensure unlimited water intake
through accessible drinkers and an appropriate flow rate. A low nipple drinker water
flow rate (70mL/min) caused a lower water intake compared to a nipple drinker water
flow rate of 700mL/min (Leibbrandt et al., 2001). Phillips et al. (1990) found that
lactating sows consumed similar amounts of water when drinker water delivery rate was

between 600 mL/min and 2000 mL/min.

Summary
Stimulating lactating sow feed intake, maximizing litter weight at weaning, and
minimizing sow weight loss are important goals for the swine production and well-being
of the animals. Many factors affect feed intake of the lactating sow, including the
system(s) selected to provide feed and/or water. The combination of self-fed and wet/dry
feeding (Berry Feeding System”) recently has become commercially available and is of
current interest to producers. However, so far, there are no published data available to

guide them in making a decision on whether or not to adopt such feed-water technology.

14

Increases in efficiency of feed and water usage by choosing the new feed-water system
may improve the economics of pig production and environment friendly. Therefore,
further information of the impact of this self-fed, wet/dry feed-water system on sow
lactation feed and water consumption and it effect on lactation performance would be

beneficial for swine producers.

15

CHAPTER II

CUSTOM EQUIPMENT SYSTEM TO ASSESS LACTATING SOW FEED AND

WATER USAGE, WASTAGE, AND ACTUAL INTAKE

Abstract

To determine the feed and water wastage in lactating sows, a novel and practical
system was designed and installed at the Michigan State University swine research and
teaching farm. Thirteen PVC (polyethylene vinyl crystalline) water tanks and twelve
stainless steel waste feed and water collection units were built during the summer of 2003.
The water tanks and waste collection units were installed in two identical farrowing rooms.
The custom feed and water waste collecting equipment was effective in the accurate
evaluation of sow lactation feed and water wastage, thus allowing an assessment of a novel
feed—water system. One indirect objective of this study was examined the feasibility of
introducing a new feed-water system as a possible waste minimization option for the
commercial swine industry.

Key words: Sow, Lactation, Feed, Water, Waste

Introduction
Significant amounts of wasted feed and water in swine production are accumulated
in manure, because of the animal’s feeding behavior and equipment design (Taylor, 1990).
For sows in individual feeding stalls, the method of feed provision (hand-fed or self-fed

access to feed) influenced the amount of feed wastage (Taylor, 1990). Very little is known

16

about how water wastage is related to the water delivery system available to lactating
sows. Agriculture engineers are challenged to design facilities and equipment suitable for
both animal production profit and environment friendly. Minimizing feed and water
wastage will decrease manure volume and manure management costs, and protect against
environmental pollution.

In order to accurately measure feed and water wastage associated with feed-water
systems during lactation, water tanks and waste feed and water collection units were
designed and made to be fitted into a sow farrowing facility. Consequently, the actual feed
and water intake of lactating sows could be assessed in a research facility operated with

commercially available equipment.

Water Tank Design
Building materials and process. Thirteen PVC (15.24 cm in inside diameter)
cylindrical water tanks, averaging 2.3 meter in height, were built during July and August in

2003 (Figure l). The materials used to build each tank are listed in Table 2.

17

Figure 1. Schematic drawing (not to scale) of water tank.

Air supply

Water input supply

    
   
  
  
  

Top volume /

/ Sight tube

 

<3
Air exhaust

\

Animal
water

/ supply

 

Bottom volume

 

Drain opening

Note: 0 = on/off valve or stopcock

18

Table 2. Building materials for each water tanka

Item Quantity
PVC pipe, 15.24 cm (6 inch, ID) x 304.8 cm (10 feet), white 1
PVC cap, 15.24 cm (6 inch, ID), white

Wood board, 4 x 6 x 210 cm, painted white

Nylon cable tie, 80 kg maximum tensile strength, white
Adhesive-backed paper tape, millimeter units, 100 cm long
Sight vinyl plastic tubing, 0.95 cm (3/8 inch, OD), 200 cm, clear
Vinyl plastic tubing, 1.27 cm (1/2 inch, OD), 200 cm, clear

Air tubing, 0.60 cm (DD), 30 cm, clear

Air tubing adapter, white

PVC elbow, white

Hose barb, white

PVC Threaded coupling adapter, white

PVC Tee, white

PVC Valve, white

aPVC, polyethylene vinyl crystalline ; ID, inside diameter; OD, outside diameter.

NHAQr—Iu—it—It—du—INNHN

 

To begin the construction of each tank, the PVC pipe was cut to 230 cm in length.
Each of the two ends of the pipe were covered and glued with a PVC cap (15.24 cm in
diameter) by using PVC primer and heavy-duty cement. In order to protect against
leaking, the cap-pipe seam was sealed again by using Poxy Marine epoxy (Power Poxy,
Sussex, WI).

Two holes (0.95 cm in diameter) were drilled near the ends of the same side of the
PVC pipe. The distance between the two holes was 220 cm. These two holes were used to
secure the ends of a sight tube, which allowed monitoring of water disappearance. Also
connected to the bottom hole was the tubing going to the sow drinker and a short tube to
drain for emptying the tank occasionally to avoid the accumulation of stale water. Another
hole (0.95 cm in diameter) was drilled in the cap near the top to fill the tank with water. A
fourth hole (0.95 cm in diameter) was drilled on the top cap of the tank, and fitted to be

used to pressurize the tank while in operation, to bleed air, and to serve as a ‘firll’ indicator

l9

when filling the tank with water. All holes in the tank were threaded to accept their
respective fittings. Teflon tape was applied to threads prior to securing each fitting.

A wood board which had an indented U-shaped grove (1 cm in width) running
lengthwise down the middle, was painted white and fastened parallel to each PVC tank
using two nylon cables. The purpose of the notched wood board was to host and straighten
the sight plastic tube. A calibrated adhesive-backed paper tape ruler was fastened to the
straight plastic sight tube, and used to calculate the water disappearance from the water
tank.

The top of each water tank was connected to the existing water supply at the farm.
Each water line running to a tank featured a stopcock to control the water input. An air
compressor (Westward, Model: 3JR70, Grainger International, Inc., Lake Forest, IL)
supplied air to the tanks through polyethylene air tubing (0.60 cm in outside diameter).
The air compressor was adjusted to provide a water pressure of 41 to 48 kPa to twelve
nipple drinkers used by sows housed in two different farrowing rooms (room 3 and room
4). The air tubing of the six water tanks in the same farrowing room were connected in
parallel with the air compressor through an on/off valve (Figure 2). This allowed

independent operation of the water system in each farrowing room.

20

Figure 2. Schematic drawing (not to scale) of farrowing crates and air pressure supply

lines in the two farrowing rooms.

Air compressor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Room 4 Room 3
< O 0—>
_, Crate 12 I _’ Crate 12
Front + Crate 11 Back I Front _’ Crate 11 Back
" Crate 10 I " Crate 10
_’ Crate 9 I " Crate 9
“’ Crate 8 " Crate 8
it” Crate 7 m 1!, Crate 7
Crate 6 I Crate 6
Crate 5 l Crate 5
Crate 4 I Crate 4
Crate 3 I \ Crate 3
Crate 2 I Wall Crate 2
Crate 1 I Crate 1
North

I East

Note: Q = on/off valve or stopcock

21

Water tank fimctionality. After assembling each water tank, the water-holding
capacity of each water tank, which ranged from 42 to 43 liters, was determined.

Twelve of the water tanks were placed in two rooms (six each in rooms 3 and 4). The
extra tank was kept at the farm in case another tank malfiinctioned. The water tanks were
assigned to individual sow farrowing/lactation crates or stalls in each room. Each water
tank was suspended in front of the individual sow crate by hanging it on an iron bar, which
had been fixed to ceiling trusts. When filling the water tanks for a room, the air pressure
valve was turned off and water stopcocks and the air exhaust openings on each tank were
opened. Water coming through an air exhaust opening was an indication that the tank was
full. Then, the water stopcock and the air exhaust opening were closed. All tanks in the
same room were filled before opening the valve to establish water pressure.

The water volumes of the top and bottom cap ends of each water tank (V, and Vb,
respectively, L), where the sight tube did not apply, were manually measured by using a
graduated cylinder (Table 3). The level of the water (Le, cm) in the cylinder proper was
measured with the sight tube and represented the volume of water in that portion of the
tank. The level of the water was read against the calibrated adhesive-backed paper ruler,
which went from 0 to 200 cm, from top to bottom of the tank. Because sow use of water
seldom reached the bottom of the sight tube, the volume of the bottom of the tank (Vb) was
not a concern. The water usage per day (V, L) of an individual sow was calculated as the
following:

V=V,+an2><Le

(R = radius of 7.62 cm)

22

Table 3. Water holding capacity (L) of the top and bottom cap ends of each water

 

 

 

 

tankat
Crateb
7 8 9 10 11 12

Room 3

Tank IDc 1 2 3 4 5 6

Top capacity 3.84 4.00 3.79 4.22 3.86 4.04

Bottom capacity 2.20 2.19 2.18 2.42 2.15 2.58
Room 4

Tank ID 7 8 9 10 11 12

Top capacity 4.07 4.16 3.91 4.09 3.92 3.97

Bottom capacity 1.90 1.98 2.16 2.35 1.75 2.24

 

a The top and bottom water holding capacity represent the water volume of the top

and bottom caps from each tank, which could not be measured by reading the water

level in the sight tube.

b Crates are numbered from 1 to 12 in each farrowing room (Room 3 and Room 4, for

hand-fed and self-fed wet/dry feed-water systems, respectively).

° Identification number of each tank used.

Tanks were refilled when the amount of water remaining in the tank was projected

to be less than that needed on a half-day (12 h) basis by sow. This was judged by
estimating that a minimum of 30 liters should be available during a 12 h interval.

Generally, water tanks were less than half fiill after 12 h and water was added at that

frequency.

Waste Feed and Water Collection System Design
Building materials and process. Twelve feed and water waste collection units were
built during a period from May to August in 2003. The design for the collection unit was
developed with the following considerations. Farrowing rooms were equipped with a
single row of crates set on Tri-BarTM flooring (Nooyen, Chicago, H.) suspended over a

shallow pit, which had been engineered to accommodate a liquid-solid separating scrapper

23

system. Clearances between the pit floor, the top of the scrapper blade, and the underside
of the Tri-BarTM flooring and its suspension rods were measured. These measurements
were critical in determining the maximum height of the collection unit. The width of the
farrowing crate (side panels 60 cm apart) was considered when deciding the length of the
collection unit (perpendicular in relation to the width of the crate), which extended beyond
the sow space by 30 cm on either side. The maximum distance a sow could move when
backing away from the headgate and feeder was considered when deciding the width of the
collection unit. These dimensions were important if all waste feed and water were to be
collected (Figure 3).

Collection units were designed to consist of three main parts: a screen, a pan, and a
carboy. The screen sat in the pan while the carboy was held under the pan. This allowed
for the separation and collection of both wasted feed and water. The intent was that the
wasted water would pass through the screen, collect in the pan, and drain into the carboy
while wasted feed would remain collected on the screen.

The majority of building materials for the pans and screens were stainless steel
sheet metal (0.9 mm in thickness, Alro Steel Supply, Dayton, OH) and stainless steel
woven wire cloth (20 x 20 mesh and 0.04 mm in diameter, McMaster-Carr Supply Co.,

Cleveland, OH).

24

Figure 3. Schematic drawing (not to scale) of collection units’ position under the

farrowing crates.

Front of the sow crate
30 cm 120 cm 15 cm

Collection pan l‘ _______ + .................. + - -’|

 

 

 

 

 

 

Steel bar \
I I I a I T
I i I I 1 I i
I I I . I i
l I 1 .' I . :
I I I I j
I I I I I
I I I I 200 :Cm
I I I I I
I I I I :
l l 1* ------- +1 :
I I I I j
I I I I :
Crate I | Crate | . :
I l I I I
4 - - - _'_

 

 

 

 

1
G
O
O
B

j.

Crate panels

Back of the sow crate

25

Sheets of stainless steel were cut and pressed to form a pan (5 x 64 x 120 cm)
having a 10% sloped bottom surface, and edges to secure a screen. Both side edges of the
bottom surface of the pan were also 10% sloped to its centerline. A circular hole (3 cm in
diameter) was cut in the center of the bottom surface of the pan. With this shape, any
liquid would automatically flow toward the hole when the pan was on a level surface. A
‘U’ shaped piece of metal was welded to each comer of the pan. Two holes drilled in this
metal piece accommodated a garage door wheel, which allowed the pan to move freely on
a horizontal garage door track hung beneath the farrowing crate floor. A stainless steel
frame was welded under the lower end of the pan to hold a carboy for waste water
accumulation (20 x 37 x 37 cm, Nalge Company, Mfg, Rochester, New York). The
carboy was secured into a frame below the pan. The mouth of the carboy was positioned
below the hole of the pan for catching the liquid from the pan. A rubber calf nipple (large
side opening: 5 cm in diameter) was used to make a tight connection between the carboy
mouth and the hole in order to lead all the liquid into the carboy. A 30 cm bungee cord
was used to fix each carboy to the flame so that the mouth of the carboy would not move
away from the hole of the pan when the system was moving. The water holding capacity
of each carboy was 15 liters.

The screen (1 x 63 x 119 cm) was made of stainless steel woven wire cloth. On the
rectangle perimeter of the screen, a l-cm high 90° angle stainless steel strip was welded.
This gave the screen rigidity and placed it a small distance away from the pan edge when
inserted. Each screen had a handle welded on one end for picking up the screen from the

pan. After the pans and screens were built, the rough and sharp surfaces and comers were

26

ground smooth. The seams at the bottom of the pans were all sealed with JB weld (JB
Weld Company, Sulphur Springs, Texas) in order to avoid any possible leaking.

Waste feed and water collection system functionality. A collection unit was
installed under each of the six crates in each of the two sow farrowing rooms. Collection
units were positioned under the front part of the farrowing crates on horizontally-hung
garage door track. This track was attached under the Tri-BarTM flooring of the farrowing
crates, to the cement wall of the shallow pit and to the Tri-BarTM flooring support rods.
Each collection unit had garage door track wheels, which allowed easy movement when
pushing and pulling the pans in and out of the track. Collection units were connected to
adjacent units by a steel bar (30 cm). Each pan, screen, and carboy was labeled in order to
match the same crate during the whole lactation period.

In both rooms, concrete walkways (1.2 m in width) were in front and behind a
single row of 12 farrowing crates, which were placed side-by-side (sharing a common side
wall between them). The slotted Tri-BarTM flooring sections upon which sows stood was
suspended between the walkways. The flooring extended about 150 cm beyond the first
and last sow crate in the row. The northern end of this flooring was lifted daily and set
aside so that pans on the track below the floor could be accessed and wasted feed and
water accounted for. This access area was approximately 150 cm wide. The track was
extended to this area, connected to two support pieces of angle iron, and affixed to the wall

of the shallow pit beneath the row of individual sow crates.

27

Observations and Recommendations

The slotted Tri-BarTM flooring, with 50% opening, allowed wasted feed and water
from the sows to easily fall through the flooring. There was no accumulation of feed
residue on the flooring.

None of the water tanks experienced leaks during the experiment. The water level
in the tanks was easily read. In order to obtain an accurate measurement of the water level
near the top of the tank, a short ladder was used. The adhesive-backed paper ruler tape
was accurate and convenient to read, with a length of 55 mm representing a volume of one-
liter volume. Using the custom built water tanks to measure water usage of sows was less
expensive than use of the water meters, especially those manufactured for the extremely
low pressure and flow rates as would he usually observed in water lines connected to
individual sow drinkers. Obviously using individual water tanks to assess water intakes of
groups of animals is not commercially practical, but using water meters would be.

Water flow rate ranged from 965 to 1350 mL/min under a water pressure of 41 to
48 kPa (Table 4). Wasted water was collected twice a day (0800 and 1600 h) and wasted
feed on a 1 to 3-d basis (0800 or 1600 h) during each lactation period. A parastatic pump
(Masterflex, Model U-07019-43, Dayton Electric Mfg, Co. Niles, IL) was used to suck the
water out from the carboys when the collection system was not pulled out from underneath
of the crates. In this case, the pump was connected to a small inflexible PVC pipe (0.95
cm in outside diameter), which went on a slot in the Tri-BarTM flooring and reached inside
of the carboy by passing through the hole of the pan and mouth of the carboy together.

The use of this pump saved multiple hours of labor required for the waste water

quantification.

28

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29

Because of a poor connection between the mouth of the carboy and the hole of the
collection pan during the first feed and water wastage collection period, the waste water of
two sows dripped off of the collection pans, instead of falling into the carboy. To solve
this problem, rubber nipples were used to make a tight connection between the carboy
mouths and the holes. This directed all the waste water into the carboy and corrected the
problem.

The carboy volume of 15 liters proved inadequate for some sows. Sows playing
with their water nipples caused large amounts of water wastage during short periods of
time, which caused the carboys to overflow during very short intervals. It was difficult to
collect total water wastage for these sows. To compensate for this kind of drinking
behavior, fixture experiments should have containers with larger water volume capacities or
collection must occur more frequently to prevent the carboy from overflowing.

Predominant areas of spilled feed in the collection pan were observed. Care was
taken to avoid collection of piglet and mice feces, although some contamination was
unavoidable. In order to have an accurate waste feed collection, rodent populaton was
reduced by using poisoned bait and traps. The pans and screens were scraped clean of
manure after each collection to minimize contamination errors on the following day. After
each collection, the waste collection units were repositioned under the sows for the next
day’s waste water and feed accumulations.

Some waste feed powder residual accumulated on the pan. This part of waste feed
was wet and more difficult to collect. Slight amounts of fine feed residue moved with the
water into the water collecting containers. The waste feed collected in this study was dried

to correct for the waste water content and then converted back to an as-fed basis. Weight

30

of the water in the wet waste feed (except that in 88% DM feed) was mathematically added
back to the total water amount collected from the carboy to calculate the final total water

wastage.

Conclusion
Accurate measurement of water usage by individual lactating sows was
accomplished using custom built pressurized PVC tanks. Complete collection of waste
feed and waste water from under farrowing room equipment was accomplished.
Accuracy of water waste collection was influenced by carboy capacity or timeliness of
vacuum removal of waste water before the carboy overflowed. All equipment appeared

durable and available for long-term use.

31

CHAPTER III

COMPARISON OF SELF-FED WET/DRY AND HAND-F ED LACTATING SOW

FEED-WATER SYSTEMS

Abstract

A study was conducted to determine the performance of multiparous lactating
sows when feed and water were made available using either a self-fed wet/dry (SFWD)
or a hand-fed (HF) feed-water system. The feeders in both systems were made of
stainless steel and mounted to the head-gates of individual farrowing crates. The bottom
of the SFWD feeder included a flat surface located below a plastic hopper and a sow-
operated feed dispensing mechanism, and a shallow bowl area located below a water
nipple drinker. Sows were given the opportunity to drop fresh feed when desired and
consume it at any wetness. The bottom of the HF feeder was J-shaped from side—to—side
and water was provided using a nipple—cup combination drinker located independent of
the feeder. Sows (n = 120) were assigned to SFWD or HP treatments based on parity and
breed, and moved into farrowing rooms 7 d or less prior to parturition. A system for
collection of wasted feed and water was designed and installed under half of the SFWD
and HF farrowing crates, which also had individual custom-built water tanks for
measuring sow water intake. Cross-fostering was used when necessary to standardize
litter size at a minimum of 10 by d 3 of lactation. Average lactation length did not differ
between treatments (P = 0.73). Total feed disappearance per sow during lactation (120.7

d: 2.58 kg vs. 110.2 i 2.46 kg for SFWD and HF, respectively) and piglet weaning weight

32

(6.56 d: 0.10 vs. 6.15 d: 0.10 kg for SFWD and HF, respectively) were greater (P < 0.01)
with SFWD sows than with HF sows. The SFWD sows had greater (P = 0.02) weight
gains during lactation than HF sows (6.5 :1: 1.60 vs. 1.2 d: 1.53 kg for SFWD and HF,
respectively). Backfat depth change during lactation did not differ (P = 0.29) between
treatments. Sows displaying estrus by d 11 postweaning did not differ (P = 0.97)
between treatments. Sows with SFWD wasted less water (P < 0.01) than those with HF
(15 i 9.5 vs. 227 i 12.9 L for SFWD and HF, respectively). However, sow average daily
water intake and total feed wastage during lactation did not differ (P = 0.48 and P = 0.58,
respectively) between treatments. In conclusion, use of a self-fed wet/dry feed-water
system in lactation, that provides sows choices of when to eat, how much to eat, and if
the dry feed should be mixed with water before consumption, enhances sow appetite and

improves litter growth performance.

Key words: Sow, Lactation, Feed Intake, Water Intake

Introduction
Sow feed and water intakes during lactation provide most of the nutrients required
for milk production while protecting sow body tissue stores for subsequent reproductive
success. The primary goal in commercial production is to encourage the lactating sow to
eat and drink as much as possible. Sow feed and water intakes are influenced by a
number of factors including ambient temperature, genotype, parity, sow health, lactation

stage, and litter size (O’Grady et al., 1985; Matzat, 1990; Farmer et al., 2001).

33

Wetness of feed and the self-fed or hand-fed provision of feed are factors that
may influence sow feed and water intakes. Studies have documented that lactating sows
provided with wet feed tend to eat more feed compared to sows given dry feed (O’Grady
and Lynch 1978; Koketsu, 1994; Lynch, 2001). Peterson et al. (2004) reported an
improvement in the total lactation feed disappearance when sows were fed using a self-
feeder instead of a feeder requiring manual feed additions. Pettigrew et al. (1985) found
that lactating sows fed using a self-fed, wet/dry feeding system and given the ability to
control meal frequency, meal size, and moisture content of the feed being consumed,
respond with improved feed intakes, less weight loss, and heavier litters as compared to
sows fed using a hand-fed system. The positive effect of the self-fed wet/dry feeding
system on lactating sows performance was observed only during the summer season.

Agriculture engineers are challenged to design facilities and equipment suitable
for animal production, profitability, and environmental compliance, especially those
associated with intensive animal feeding operations. The Berry Feeding SystemTM is a
commercially-available self-fed wet/dry lactating sow feed-water system. This feeding
and watering system provides sows with ad libitum access to feed and water, and the
freedom to make choices relative to when they want to eat, how much they want to eat,
and how moist the feed they eat should be. The impact of this new feed-water system on
animal performance and the environment has not been evaluated. The objective of the
present study was to determine if lactating sows would consume more feed, better
conserve body tissue, wean heavier litters, waste less feed and water, and experience

shorter wean-to-estrus intervals postweaning, if fed and watered using a self-fed wet/dry

34

feed-water feeding system as compared to using a conventional hand-fed dry feed

system.

Materials and Methods

Animal Use and Care. The experimental procedures in this study were approved
by the All University Committee on Animal Use and Care at Michigan State University
(AUF number: 11/01-176-00).

Animals and Diets. Multiparous Yorkshire (n = 28) or Yorkshire x Landrace (n =
92) sows were randomly assigned based on parity and breed to one of two feed-water
systems during January and February 2002, and from September 2003 to January 2004.
The study consisted of seven replications that farrowed and lactated during the fall and
winter seasons. Sow parity ranged from one to nine.

Sows were moved into farrowing rooms and individual crates (0.6 x 2.0 m) 7 d or
less prior to parturition. Sows were fed a com-soybean meal based lactation diet from
that time until weaning, and a com-soybean meal based gestation diet from weaning to
estrus. Both diets were in mash form and met or exceeding NRC (1998)
recommendations for the lactating sow (Table 5). At weaning all sows were moved into
individual crates in a breeding room, managed to stimulate estrus and to service sows for

another pregnancy. All sows were treated similarly after weaning.

35

Table 5. Composition of the lactation and gestation diets (as-fed basis)“

 

 

 

 

Diets
Ingredient, % Lactation Gestation
Corn 63.53 67.91
Soybean meal, 48% CP 29.01 14.63
Wheat bran - 10.00
Calcium phosphate (Mono calcium), 21% P 2.06 1.90
Limestone 0.50 0.66
Vitamin premixb 0.60 0.60
Trace mineral premix“ 0.50 0.50
Sow pac“ 0.30 0.30
Salt 0.50 0.50
Choice white grease 3.00 3.00
Calculated analysis
Lysine, % 1.00 0.65
Calcium, % 0.90 0.90
Phosphorus, % 0.80 0.80

 

“ Diets formulated to meet or exceed the NRC Requirements for Swine
(1998)

“ Supplied per kilogram of diet: 5,511 IU of vitamin A; 551 IU of vitamin D;
60 IU of vitamin E; 4.4 mg of vitamin K; 4.4 mg of riboflavin; 17.6 mg of
pantothenic acid; 26.4 mg of niacin; 33 pg of B12; 33 pg of thiamin; and 990
11g of B6 .

“ Supplied per kilogram of diet: 11.00 mg of Mn; 11.00 mg of Fe; 11.00 mg
ofCu; 150 11g ofI; 100 mg onn, and 300 11g of Se.

“ Supplied per kilogram of diet: 2,756 IU of vitamin A; 386 mg of choline;
220 mg of biotin; and 1.65 mg of folic acid.

36

F eed- Water Systems. Treatments consisted of two different systems to provide
sows with feed and water. The term ‘system’ is used herein to describe the combination
of different feeding and drinking equipment. One of the treatments was a self-fed
wet/dry system (SFWD; with the nipple drinker inside the feeder). The second treatment
was a stainless steel feeder for hand-fed (HF; dry feed additions made manually) and a
nipple-cup combination drinker independent of the feeder. The equipment composing
both systems is described in detail in the following paragraphs.

The bottom of the SFWD feeder (Berry Feeding System11“, Keith and Brian
Berry, Greencastle, IN; manufactured by Lou Mfg, Inc, Austin, MN) included a flat area
located below a plastic hopper and sow-operated feed dispensing mechanism, and a
shallow bowl area located below a water nipple (Figure 4). This allowed the sow to
choose between dry and wet feed. The sow-operated feed dispenser of the SF WD system
included a rolling ball, the agitating mechanism that the sow “used,” and a knob, which
was inaccessible to the sow and used by the researchers to adjust the amount of feed
flowing with each agitation by the sow, to control the amount of feed that dropped with
sow agitation. Feed passed from the hopper into the feeder when the sow moved the
rolling ball dispensing mechanism. The SFWD system was made of three materials, the
feeder was made of stainless steel, the dispenser was made of PVC, and the hopper was
made of poly plastic. The dimensions of the SFWD feeder were: height 54.6 cm without
hopper or 102.9 cm with hopper, width 41.6 cm, depth 29.2 cm, lip to floor 20.3 cm,

bottom of feed trough from floor 6.4 cm.

37

Figure 4. Self-fed wet/dry system (BerryTM feeding system).

 

38

The bottom of the HF feeder (Circle Bm Mfg, Inc, Three Rivers, M1) was J-
shaped and free of comers where feed could accumulate and spoil (Figure 5). All parts of
the HF feeder that came in contact with the sow or feed were made of stainless steel. The
dimensions of the HF feeder were: height 69.2 cm, width 36.2 cm, depth 34.3 cm, lip to

floor 26.7 cm, bottom of feed trough from floor 4.0 cm.

Figure 5. Hand-fed feeder (CircleTM B feeding system).

 

39

In both systems, feeders were mounted to the head-gate of individual farrowing
crates. Ad libitum access to drinking water was available in both systems. The nipple
drinker (Jalmarson # 1720-180A, Eskilstuna, Sweden) was about 8.0 cm above the
shallow bowl pressed into the steel bottom of the feeder used in the SF WD system.
Water for HF sows was provided using a nipple-cup combination, with the nipple fixed
into the mounting wall of the cup. The nipple drinker (Edstrom # 1000-0743, Waterford,
WI) for the HF systems was located 10.0 cm above the Tr'i-BarTM flooring, and to the left
front side of each sow (10.0 cm from the feeder). The HF watering equipment was
mounted to the left panel of the sow crate.

General Management. Two adjacent farrowing rooms were used and were
identical in every aspect of structured animal environment, except for the feed-water
systems used in each room. The SFWD system was installed in all 12 crates of one room
and the HF system was installed in all 12 crates of the other room. Within a room, crates
were in a single row and numbered 1 through 12, going from south to north, or from the
entrance to the far end of the room.

The two feed-water systems were assigned to different farrowing rooms in order
to avoid possible behavioral responses of SFWD sows to the daily, twice-a-day, hand
feeding of sows on the HF treatment. This would have possibly violated the true ‘self—
fed’ intent of the SFWD system. In a preliminary study, we had observed that sows on
the SFWD systems stood and ate when neighboring HF sows were being fed in the
morning and in the afternoon.

The environmental temperatures in the two sow farrowing rooms were maintained

with thermostatically-controlled heating and ventilation. The farrowing room

40

temperatures were set at 18 to 22°C for the study period and monitored daily. The
thermostat was set at 22°C when farrowing began and was reduced gradually until it
reached 18°C by the end of the first week of lactation, where it remained for the
remainder of lactation. Minimum and maximum temperatures were monitored daily
(0830 h) at 30 cm above the floor. Within each replication, the temperatures in the two
farrowing rooms were similar. Daily high and low temperatures for the two farrowing
rooms during the trial are shown in Figure 6. Average daily high and low ambient
temperatures across all replicates during the trial were 223°C and 201°C, respectively.
In addition to temperature, the lighting, piglet microenvironments, and all structural
components were identical in both rooms.

Figure 6. Average daily high and low ambient temperatures within each replication
during this study. (HP is hand-fed stainless steel J-shape rounded bottom feeder plus

nipple-cup combination drinker independent of the feeder; SFWD is self-fed wet/dry
system with nipple drinker inside the feeder.)

 

I HF low E SFWD high I SFWD low

   
   

Celsius

Jan, 02 Feb, 02 Sep, 03 Oct, 03 Nov, 03 Dec, 03 Jan, 04
Replicate

 

 

41

 

During the lactation period, a heat pad (50 x 90 cm, Standfield'm, Osborne
Industries, Inc., Model: RS2B40, Osborne, KS) was provided on the floor on one side of
the sow in each crate for piglet warmth. A 24-h lighting regimen was used throughout
the study in both rooms, with lighting from fluorescent bulbs during daytime (0700 to
1700 h) and lighting from incandescent bulbs during night (1700 to 0700 h).

Feeding Management. All sows were offered 2.0 kg of lactation diet once a day
from entry into the farrowing room until parturition. They were offered the same
amount, but twice a day for the first 3 d postpartum. Thereafter, sows were feed to-
appetite until weaning.

After d 3 postpartum, feed was manually added to the hoppers of the SFWD
systems 1 or 2 times (0800 and 1600 h) daily so that fresh feed was constantly available.
Fresh feed was placed in the hopper of SFWD system when the quantity of feed
remaining would potentially limit sow intake in the following 12 h. The HF sows were
fed ‘to-appetite’ (an amount slightly exceeding the feed disappearance in previous
meals), twice each day (0800 and 1600 h).

Feed additions were weighed and the amounts recorded in the morning and
afternoon on each day for each individual sow during lactation. If feed accumulated (dry,
wet, and beginning to spoil) in the bottom of a feeder over 36 h it was removed, weighed,
dried, and reweighed. All residual feed in the feeder, including the feed in the hopper of
SFWD system, was collected and weighed in order to determine total feed disappearance
from d 0 to 6, d 7 to 13, and d 14 to weaning. Sows were fed 2.3 kg gestation diet once a

day from weaning to estrus.

42

Sow Performance. Total feed disappearance was determined over the entire
lactation period for each sow. Sows were weighed within 24 h after parturition, at 7, 14 d
postpartum, and at weaning. Sow backfat depths were measured using a digital backfat
indicator (Lean Meater, Renco Corp, Minneapolis, MN) on d 0 and at weaning at 5 cm
off the left and right midline at the 10th rib. Standing heat in the presence of a boar was
used as an indication of postweaning estrus.

Piglet Growth Performance. By (1 3 postpartum, litters were standardized to have
a minimum of 10 piglets per sow by cross-fostering. Cross-fostering was used only when
necessary, and consequently not all litters experienced fostering. Number of piglets
within a litter and piglet weights (BW) were recorded at birth, at cross-fostering, d 7, d
14, and at weaning. The coefficient of variation (CV) for individual piglet BW within
litter was calculated for each litter for each weigh day to evaluate the effect of treatment
on piglet grth variation within litter. No creep feed was provided before weaning.

Actual Feed and Water Intake. To document the actual feed and water intakes of
lactating sows, custom-built water tanks and feed and water waste collecting systems
were used to record water disappearance and collect feed and water wastage. The
features and installation of these water tanks and collection units have been reported
previously (Chapter 2 of this thesis). In each of the five replications studied from
September 2003 to January 2004, six sows from a treatment group in a replication were
randomly allotted to crates 7 to 12 of each room and used to determine actual feed and
water intakes.

The water supply to crates 1 through 6 in both farrowing rooms was via standard

plumbing within the barn (41 to 48 kPa). Sows in crates 7 through 12 received their

43

water from individual pressurized (41 to 48 kPa) water tanks, which were designed to
hold 42 to 43 L water and allowed measurement of water disappearance for sows in those
crates. Water disappearance was recorded at 0800 and 1600 h daily. The water tanks
were refilled after each measurement of disappearance had been taken.

Custom fabricated systems to collect wasted feed and water were installed under
the Tri-BarTM flooring of crates 7 through 12 in both farrowing rooms. Each crate had a
separate collection unit, which consisted of a screen, a pan, and a carboy. The screen was
set in the pan and the carboy was fitted under the pan. This allowed separation of wasted
water from the wasted feed for each sow. Wasted water drained through the screen, onto
the pan, and where it then followed a designed slope into the carboy. Collection units
were mounted on garage door track under the feeding and watering areas of the sow and
against the wall of the shallow pit beneath the crate.

Wasted feed was collected on a 1 to 3 (1 basis (0800 h) throughout lactation, with
wasted water collected twice a day (0800 and 1600 h). Carboys containing wasted water
were weighed at the farm immediately after collection and emptied. Wasted feed was
collected and transferred to labeled aluminum pans. The labeled aluminum pans were
covered and transported to the lab where waste feed was dried to zero moisture but
extrapolated back to 12% moisture thereafter. Care was taken to avoid collection of
piglet and mice feces, although minor contamination was unavoidable. After each
collection, waste collection equipment was scraped, brushed to clean off residue,
reassembled, and placed back under the crates.

Actual average daily feed intake was calculated as total lactation feed

disappearance per sow minus total lactation feed waste per sow divided by lactation

44

length. Total lactation feed waste as a percentage of the total feed disappearance was
also calculated for each sow. Actual average daily water intake was calculated as total
lactation water disappearance per sow minus total lactation water waste per sow divided
by lactation length.

Statistical Analysis. Of the 120 sows originally allotted to treatments, 114 (n = 57
and 57 for HF and SFWD, respectively) were included in the data analyzed. Two sows
from HP were removed from the study because of dystocia. A total of four SFWD sows
were not included in the analysis, including two sows that experiencing dystocia, one sow
that had been inadvertently weaned early (d 14), and another sow that had gave birth to
only seven piglets at a time when no piglets of similar age were available for
crossfostering.

Sow feed disappearance and lactation performance data were collected for all
sows (n = 114). Actual feed and water intake and wastage data were collected on a
subset of those sows (n = 29 per treatment). Although piglet weight was intended to be
recorded at birth and cross-fostering, these weights were not analyzed because the exact
date of weighing was inadvertently not recorded for several litters. As a result, piglet
growth performance was evaluated using weights recorded on d 7, 14, and at weaning.
Because of unexpected water wastage in excess of carboy capacity, thirteen of the sows
on the HF feeding system were not included in the analysis of the water wastage and
average daily water intake data. It is interesting that no water wastage in excess of
carboy capacity occurred with the SFWD system. Two outliers were detected using the
studentized outlier test for the feed wastage data but both data were included in the final

analysis because biological reasons for the removal were lucking.

45

Data were analyzed by generalized least squares analysis of variance (ANOVA)
using the PROC MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) for a completely
randomized design, with the sow or piglet serving as the experimental unit. The models
of PROC MIXED for sow feed and water disappearance, wastage, and intake, as well as
litter size, piglet survival, CV of piglet weight within litter, backfat, and wean-to-estrus
interval included the main effects of treatment, replicate, and parity. Lactation length
was included as a covariate in models analyzing sow total lactation feed disappearance,
water disappearance, feed wastage, water wastage, d 14 to weaning feed disappearance,
CV of piglet weight within litter, and wean-to-estrus interval. Litter size was included as
a covariate in models analyzing feed disappearance, water disappearance, feed wastage,
water wastage, feed intake, water intake, weaning backfat depth, backfat depth change
during lactation, wean-to-estrus interval, piglet survival, and CV of piglet weight within
litter. The model of PROC MIXED for sow weight at d 0 included the main effects of
treatment, replicate, and parity. The models of PROC MIXED for sow weights at d 7,
14, and weaning, as well as sow weight change during lactation included the main effects
of treatment, replicate, parity, and litter size. Lactation length was included as a covariate
for sow weaning weight and sow weight change from d 0 to weaning. Sow weight at d 0
was included initially as a covariate for sow feed and water disappearance, wastage, and
intake as well as subsequent sow weight. However, it was backwards eliminated in the
final analyses because statistically nonsignificant (P > 0.10).

The models of PROC MIXED for piglet weight at d 7, l4, weaning, piglet weight

gain from d 7 to 13, and d 14 to weaning included the main effects of treatment, replicate,

46

parity, litter size, and sex. Lactation length was included as a covariate for piglet
weaning weight and piglet weight gain fi'om d 14 to weaning.

The PROC MIXED analysis initially included all two way interactions among
those main effects for all the models mentioned above. Where appropriate, statistically
nonsignificant interactions (P > 0.10) were backwards eliminated in the final analysis
model. The random effect in the PROC MIXED procedure included sow x (replicate x
treatment x parity) as the error term.

Chi-square analysis was used to evaluate the effects of feed-water system on the
occurrence of estrus by d 11 postweaning. All means presented are least square means.

Differences were considered significant at the level of P < 0.05.

Results and Discussion

Sow Lactation Performance

Average parity and lactation length were similar for the HF and SFWD sows
(Table 6). Average lactation total feed disappearance of the SFWD feeding system was
greater (P < 0.01) than that of the HF feeding system. The difference between the two
treatments was nearly 11 kg. When lactation was divided into discreet periods, daily feed
disappearance for sows on SFWD feeding system was greater (P < 0.02) than those on
the HF system for the d 14 to weaning period. In other periods of lactation, d 0 to 6 and d
7 to 13, daily feed disappearances were numerically greater for SFWD sows. The results
of this study are consistent with those of Pettigrew et al. (1985) who also observed
greater (15%) daily feed usage when sows were provide feed and water with a self-fed,

wet/dry system (Hen-Way, no longer manufactured). Furthermore, Peterson et al. (2004)

47

reported a 7% improvement in the total lactation feed disappearance when lactating sows
were given ad libitum access to dry feed using a self-feeder. In that study, a similar self-
dispensing mechanism as used in the present study was mounted above a stainless bowl-

type dry feeder with the drinker located separately outside of the feeder.

Table 6. Effect of lactation feed-water system on sow performance “b

 

Feed-water system

 

 

Item I-IFc SFWDd P value
Number of sows at farrowing 57 57
Average parity 2.73 i 0.24 2.80 :t 0.23 0.84
Lactation length 20.0 i 0.23 20.1 i 0.24 0.73
Feed disappearance, kg
Average daily (1 0 to 6 3.86 i 0.13 4.05 i 0.13 0.27
Average daily d 7 to 13 6.25 i 0.21 6.68 i 0.22 0.16
Average daily (1 14 to weaning 6.86 i 0.16 7.40 i 0.17 0.02
Total (1 0 to weaning 110.2 i 2.46 120.7 i 2.58 0.01
Weight, kg
d 0 205.9 i 2.73 198.2 i 2.87 0.05
d 7 211.0 i 2.39 204.7 i 2.50 0.06
d 14 210.5 i259 206.0i2.71 0.21
Weaning 207.4 i 2.46 203.9 i 2.58 0.31
Change d 0 to weaning 1,2 4; 1,53 6.5 i 160 0.02
Backfat depth, mm
(10 15.5 i055 16.4:056 0.25
Weaning 14.7 i 0.53 14.2 i 0.55 0.49
Change (I 0 to weaning -l.30 1r 0.28 -1.69 i 0.27 0.29
Wean-to-estrus interval“, (1 5.66 i 0.16 6.00 i 0.17 0.14
Sows displaying estrus“, % 94.6 94.4 0.97

 

“ Values were least square means i standard error.

“ d 0 is defined as farrowing date.
““ HP is hand-fed stainless steel J-shape rounded bottom feeder plus nipple-cup

combination drinker independent of the feeder; SFWD is self-fed wet/dry system with

nipple drinker inside the feeder.

“ For sows that displayed estrus by d 30 postweaning.
“ For sows that displayed estrus by d 11 postweaning.

48

O’Grady and Lynch (1978), Koketsu (1994), and Lynch (2001) also have reported that
lactating sows ate 12%, 11%, and 7%, respectively, more feed per day when the feed was
wet. In those studies, sows were not given a ‘self-feeding’ option. Based on those
previous studies, the 10% improvement in feed usage observed in the present study with
the SFWD system was likely a consequence of sows having both the choice of when to
eat and the choice of how wet the feed should be when eaten.

As noted above, Pettigrew et al. (1985) reported a 15% increase in feed usage
with a self-fed, wet/dry feeder. This was the average response across all seasons of the
year, but a season by feed-water system interaction was observed in that study, where
feed usage was greater in summer months but similar in the other seasons. An increase in
feed disappearance with the SFWD systems was observed in the fall and winter seasons
of the present study, which was also conducted in a northern state of the United States.
Thus, the results of the present study are not in full agreement with those of Pettigrew et
a1. (1985). An explanation for the disagreement between the two studies is not apparent.

Postpartum (d 0) sow weight on the SFWD feeding system was lower (P = 0.05)
than those on the HF feeding system (Table 6). Sow weights at d 7, 14, and weaning
were not different. Both groups of sows gained weight during lactation, with those on the
SFWD system gaining more from d 0 to weaning (P = 0.02). Sows in both groups lost
weight between d 14 and weaning, suggesting a metabolic use of body tissues and the
inability of either feed-water system to provide sufficient nutrients for milk production
and litter growth at the end of lactation. Pettigrew et al. (1985) observed less weight loss
with the use of a self-fed, wet/dry system, in agreement with the present study. Peterson

et al. (2004) reported no difference in sow weight change when comparing self and hand

49

feeding. The studies of Whittemore et al. (1988), Mahan (1998), and Spencer et al.
(2003), although not designed to compare methods of feed and water provision, likewise
observed sows gaining weight during lactation, when weight change was calculated using
weights taken immediately postpartum and at weaning.

Although weight change in the present study suggests differing amounts of body
tissue mobilization during lactation, subcutaneous backfat depth at weaning and backfat
change from d 0 to weaning were not different between treatments. In contrast, Peterson
et al. (2004) reported less backfat loss during lactation with greater feed intakes when
using of the self-fed mechanism. Conservation of sow body weight or tissue during
lactation is thought to be important, as it is related to the culling of highly productive
sows because of postweaning anestrus or failure to conceive after weaning. However,
despite the greater weight gains of SFWD sows in the present study, feed-water system
did not influence wean-to-estrus interval or the percentage of sows that displayed estrus
postweaning. The present study only included one lactation and the impact that the
SF WD system may have on long-term reproductive performance over multiple parities is

worthy of further investigation.

Piglet Growth Performance

Litter sizes at cross-fostering, d 7, d 14, and weaning were not different between
HF and SFWD treatments (Table 7). Likewise, feed-water system had no influence on
litter survival from cross-fostering to weaning or on the CV for piglet weight within litter

at any time from cross-fostering to weaning.

50

Table 7. Effect of lactation feed-water system on piglet performance“
Feed-water system

 

 

 

Item HF“ SFWD“ P value
Number of litters 57 57
Litter size
Cross fostering 10.16 i 0.12 10.03 i 0.12 0.40
‘17 10.15 :013 99532013 0.24
d 14 1007:013 9.95 20.13 0.50
Weaning 10.07 i 0.13 9.90 i 0.13 0.34
Survival crossfoster to wean, % 99.1 i 0.47 98.7 i 0.48 0.52
Piglet wt, kg
d 7 2.87 i 0.06 2.90 i- 0.06 0.70
n = 579 n = 571
d 14 4.67 i‘ 0.08 4.84 i 0.09 0.14
n = 573 n = 569
Weaning 6.15 :010 6.56i0.10 0.01
n = 573 n = 564
CV piglet wt within litter
C1058 fOStefing 18.6 i 1.23 17.8 :r 1.20 0.48
‘17 20,311.17 20.4i1.13 0.88
(“4 21.5i1.19 21.12115 0.73
Weaning 20.4 i 1.17 18.6 i 1.15 0.09
Piglet average daily gain, g
d 7 1° 13 256.4 i 5.84 2757 i 5.99 0.02
d 1410 weaning 256.8 i 7.42 291.2 i 7.62 0.01

 

“ Values were least square means i standard error.
““ HF is hand-fed stainless steel J-shape rounded bottom feeder plus nipple-cup
combination drinker independent of the feeder; SFWD is self-fed wet/dry
system with nipple drinker inside the feeder.
Piglet weight and piglet average daily gain were used to assess the effect of feed-
water system on the transfer of nutrients from feed and water into product (weaned pigs).
Piglet weight on d 7 was not different. On d 14, piglet weight was 0.17 kg heavier and

tended to be greater (P = 0.14) for the SFWD piglets compared to those of the HF. At

weaning, the SFWD piglet weight was 0.41 kg greater (P < 0.01) than that of the HF

51

piglets. Because of similar litter size between treatments at weaning as mentioned above,
one can conclude that SFWD sows wean heavier litters than HF sows. When piglet
growth performance was evaluated using piglet average daily gain during discreet
lactation periods, piglet nursed by SFWD sows gained more weight per day from d 7 to
13 and from d 14 to weaning (P< 0.02 and P < 0.01, respectively) compared to those
nursed by HF sows. Average daily gains of HF piglets were 256.4 and 256.8 g/d for the
two periods, indicating that milk production of sows on this treatment did not further
promote piglet average daily gain in the later period of lactation. However, average daily
gains of SFWD piglets were greater in the d 14 to weaning period than in the d 7 to 13
period.

Treatment differences in piglet grth reflected similar treatment differences in
feed disappearance, suggesting that the SFWD sows were producing increasing amounts
of milk as lactation progressed. Pettigrew et al. (1985) also observed an improvement in
litter growth performance during lactation when using a self-fed wet/dry feeding system
in the summer season. In that study, the better litter grth performance on the self-fed,
wet/dry feeding system was also accompanied by greater lactation feed consumption.
However, the same litter growth benefit did not appear during other seasons in that study,
nor in the studies of O’Grady and Lynch (1978) and Koketsu (1994). The later two
research studies reported no improvement in litter growth when feed and water
presentation involved wet feeding system despite observing an increase in apparent feed

consumption by sows.

52

Actual Feed Intake

For the subset of 58 sows, total feed wastage per sow during lactation for the two
feed-water systems was not different. With no difference in feed wastage and a large
difference in feed disappearance, actual feed intake was greater (P < 0.03) for the
lactating sows on the SFWD feed-water system as compared to those on the HF feed-
water system (Table 8).

Table 8. Effect of lactation feed-water system on sow feed and water
disappearance, wastage, and actual intake“

Feed-water system

 

 

Item HF“ SFWD“ P value
Number of sows at farrowing 29 29
Lactation length, d 20.0 i 0.23 20.1 i 0.24 0.73
Feed
Total feed disappearance, kg 110.0 i 3.61 122.3 i 3.9 0.02
Total feed wastage“, kg 2.0 i 0.61 2.5 i 0.66 0.58
Range, kg (0.1 - 25.0) (1.0 - 8.1) -
Average daily feed intake, kg 5.39 i 0.18 5.94 i 0.19 0.03
Water
Total water disappearance, L 675 i 250 380 i 272 0.01
Range, L (410 - 1080) (148 - 545) -
Total water wastage“, L 227 i 12.9 15 i 9.5 0.01
Range, L (137 - 577) (2 - 44) -
Average daily water intake“, 1. 17.7 i 0.90 17.0 a 0.65 0.48

 

“ Value were least square means i standard error.

b“ HF is hand-fed stainless steel J-shape rounded bottom feeder plus nipple-cup
combination drinker independent of the feeder; SFWD is self-fed wet/dry
system with nipple drinker inside the feeder.

“ Values are total feed wastage during a whole lactation period per sow (as-fed
basis).

“ Values are total water wastage during a whole lactation period per sow,
number of sow on HF and SF WD was 16 and 29, respectively.

“ Number of sow on HF and SFWD was 16 and 29, respectively.

53

Sows on the HF feed-water system had a wider range of feed wastage than those
on the SFWD feed-water system. The maximum amount of 25 kg of feed waste in the
HF feed-water system is the equivalent of almost 21% of the total feed offered to that
sow during the 20-d lactation period. Taylor (1990) documented a range of sow feed
wastage from 0.1 to 38% when several different models of individual sow feeders were
evaluated. The greater range of feed wastage with the HF system was due to the ‘gulping
or wolfing’ eating behavior of two sows. The feed wastage of all other HF sows during
each lactation period was less than 8 kg and similar in range to those of the SF WD
system.

Our subjective observations indicated that SFWD sows were quieter during the
feeding period and were not motivated to move their head upward and toss feed above
the crate because of their greater interest in operating the system’s dispensing device that
dropped small amounts of fresh feed from the hopper into the feeder. Feed was released
in small amounts from the SFWD systems, allowing the animals to develop a head-down
eating position in order to pick up small amounts of feed rather than a head-up position,
which happened more frequently in the HF feeding system because of the greater
amounts of feed placed in the feeder twice each day.

We also observed that the wasted feed in the SF WD group consisted of smaller
particles or was more ‘powder-like.’ This may have resulted from the meal feed falling
from the dispensing device to the platform surface, and possibly from feed falling on the
face of the sow each time she moved the rolling ball dispensing mechanism. Sows on the
HF feed-water system moved frequently from the feeder to drinker during feeding bouts,

which may have led to both feed and water wastage with this system.

54

The average feed wastage per sow during a lactation period for the two feed-water
systems was about 2% of the total lactation feed disappearance on an as-fed basis. This
wastage would be greater than 12 metric tons of feed per year in a production unit of

2400 sows using either the HF or SFWD feed-water feeding system.

Actual Water Intake

Both total water disappearance and water wastage of the HF feeding sows were
greater (P < 0.01) than those of the SFWD feeding sows (Table 9). However, average
daily water intakes on the two treatments were not different, with sows consuming an
average of 17.7 and 17.0 L water per day for HF and SFWD, respectively. The method
of providing water to the lactating sows can have an important influence on actual water
disappearance and water wastage. Ample access to drinking water can improve sow feed
intake and decrease sow weight loss compared to restricted sows (Leibbrandt et al.,
2001).

Thacker (2001) has summarized previous sow lactation studies and lists a range of
15 to 35 L for required daily water intake. The results of the present study are within this
range, but are much closer to the smaller requirement suggested. The wide range of
values, and particularly the higher estimated requirements, are likely the consequence of
several studies reporting water disappearance and not actual intake. Frequently, water
wastage has gone unreported. For example, Seynaeve et al. (1996) reported ‘water
intake’ but did not measure water wastage. They assumed there was minimal water

wastage when the drinker was located inside the sow-feeding trough and did not measure

55

water wastage. Likewise, Farmer et al. (2001) used water bowls with a float to avoid
lactating sow water wastage instead of nipple drinkers and assumed minimal wastage.

The amount of water wastage of the HF sows was more variable than that of the
SFWD sows. In our study, drinkers located inside the SFWD feed-water system resulted
in an average of 15 L of waste water per sow during the 20-d lactation period.
Comparatively, 15 times greater or 227 L of waste water was accumulated by each sow
on the HF watering system, which was a nipple-cup combination located independent of
the feeder. In commercial production, this large amount of waste water would increase
manure volume, which may increase the cost of manure storage and distribution. A
2400-sow production unit would waste more than 1362 metric tons of water per year
using the HF feed-water feeding systems compare to using the SFWD systems.

It has been recommended that the water nipple should be set at approximately the
same height as the sow’s shoulder in order to decrease water wastage if the water nipple
was separated away from the feeder (Gill, 1989). In the HF feed-water system, the water
nipple was located inside the crate and only set 10 cm above the floor in order to supply
water for the sow and baby pigs together. This lower height allowed sows an opportunity
to play with the nipple drinkers even when they were lying down. This greater water
wastage of the HF sows may also be consistent with the less feed disappearance, as they
may possibly spent less time eating feed and more time playing with nipple drinkers. It
may be better to have separate water nipples for the piglets and sow if using a feeding
system with separated feeding and watering equipment. The water nipples for the sows

could be moved according to each sow’s height to reduce water wastage while the water

56

nipples for the piglets could be set at an appropriate height but not accessible by the

SOWS.

Sow Well-Being

Although the measures recorded in the current study were limited to production
parameters, the increased feed intake and weight gain of the lactating sows combined
with greater litter weight gain in the SFWD treatment indicate empirically improved sow
well-being compared to the HF treatment. For the current study, we hypothesized that
SF WD sows would be more active than HF sows, due to being required to operate the
self-fed wet/dry systems’ dispensing device and mix feed and water to achieve desired
feed moistness preferences. Increased feeding activity in SFWD sows may also improve
well-being. Allowing for more time to stand up and forage may avoid the problems
associated with constipation and decrease stereotypic behavior, respectively. To better
assess the impact of SFWD feed systems on animal well-being, filture investigations
should involve measures such as time budgets, stereotypic behavior, physiological

changes, injuries, and other well—being assessment.

57

Conclusions

Method of feed and water provision influenced lactating sow feed intakes. Use of
the self-fed wet/dry feed-water system allowed lactating sows to achieve and maintain
greater feed consumption, which was positively related to body weight conservation
during lactation. Litter growth performance was also improved by using of the self-fed
wet/dry feed-water system, presumably due to greater sow milk production. The self-fed,
wet/dry-feeding system did not result in less feed wastage for lactating sows. However,
water wastage of lactating sows was less with the drinker located inside the feeder of the
self-fed, wet/dry system than that of sows using a nipple-cup combination drinker within

the hand-fed system.

Implications

Provision of feed and water using a self-fed wet/dry feed-water system during
lactation may enhance pork production efficiency and profitability through increased sow
feed consumption and litter growth. Additionally, such a system may contribute to
improved sow well-being as a result of conservation of body tissue stores and greater
longevity. Lastly, use of this self-fed, wet/dry feed-water system may allow producers to
be more environmentally compliant, in that there would be less water waste, less total
manure, and reduced risk of spillage or discharge during storage, transport, and

application to cropland.

58

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