(0—3
_\_\

 

'-I
I
.moo—s

THESIS

Date

0-7639

This is to certify that the

thesis entitled

Renewed Use of Underutilized Species
of Great Lakes Fish for Animal Feed

presented by

Thomas C. Hornshaw

has been accepted towards fulfillment
of the requirements for

Master oLScienceJegreeinIisheniELand Wildlife

7/’ L :3: L L /j<;/:. k);"£:1, 1;": 1v"
May/r professor

/'</?1’ 33/51

 

lllllllllllllllllll ‘

OVERDUE FINES:
25¢ per day per Hem

RETURNIKE LIBRARY MATERIALS:

lecibokretumtorem remev
cha urge from crct ulatton records

 

j RPBfér-fi @733

RENEWED USE OF UNDERUTILIZED SPECIES

OF GREAT LAKES FISH FOR ANIMAL FEED

BY

Thomas C. Hornshaw

A THESIS

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

MASTER OF SCIENCE

Department of Fisheries and Wildlife

1981

ABSTRACT

RENEWED USE OF UNDERUTILIZED SPECIES
OF GREAT LAKES FISH FOR ANIMAL FEED

BY

Thomas C. Hornshaw

Great Lakes fish stocks, once an abundant and inexpensive
feed ingredient for Mid-western mink ranchers, have been unsuit~

able for mink feed since the mid-1960's due to toxic contami-
Since PCB

nants, primarily polychlorinated biphenyls (PCBs).
residues in Great Lakes fish have declined steadily since the

mid-1970's, this study was initiated to determine if they
The results indicate

might once again be safely fed to mink.
that growth and furring were normal for all species tested.

However, mink fed carp failed to reproduce and reproductive

performance of mink fed perch, Whitefish, and sucker was sub-

optimum. Reproductive performance of mink fed alewife fish
PCB residues (as Aroclor 1254)

meal was equivalent to controls.
accumulated in subcutaneous body fat as much as 38 times, while
It was estimated

some congeners accumulated up to 200 times.
that at least 100 days were required for elimination of 50% of

the body fat PCB burden.

ACKNOWLEDGEMENTS

I wish to express my deep appreciation to my wife Elena
for her love, understanding, and support throughout my course
of study.

I would also like to thank Dr. Howard E. Johnson, Advisor,
for his encouragement, guidance, technical assistance, and
personal interest during this project.

I am deeply indebted to Dr. Richard J. Aulerich, principal
investigator, for his advice, encouragement, friendship, and
many hours of assistance over the course of this project.

I wish to thank Dr. Niles R. Kevern for reading the
thesis and serving on my committee.

I would like to thank Mr. Angelo Napolitano, Mr. Michael
Bleavins, and Ms. Paulette Queener for their technical advice
and assistance.

I am indebted to the Michigan Sea Grant Program for
providing the funds necessary for this research, and the
Bayport Fish Company for providing the fish used in this project.

I am also indebted to Ms. Carolyn Daniel for her assis-

tance in typing the manuscript.

TABLE OF CON TENTS

 

me;

List of Tables ............ . ............................ iv
List of Figures ... ..... ........... ..................... v
Renewed Use of Underutilized Species

of Great Lakes Fish for Animal Feed ............... ..... 1
Methods and Materials .... .............................. 3
Results ..... . ................... . ...................... 10
Discussion ....... ...................................... 22
PCBs in Fish, Mink Fat, and

Mink Milk .. ........... . ......... . ...................... 23
Reproduction ....... .................................... 29
Liver Weights ........................... . .............. 33
Elimination .... ....... . ......... . ...................... 34
Other Observations .............................. . ...... 35
Conclusions .. .................... . ................... .. 37
References .................. . ....................... ... 41

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

10.

11.

12.

13.

14.

LIST OF TABLES

Composition of Basal Diet ...............

Fat Content of Fish or Fish
Products and Amount of Added

Corn Oil

Growth of Mink

PCB Residue Levels in Fish

and Diets

PCB Residue Levels in Mink Fat

Reproductive Performance of
Female Mink Fed Diets that
Contained Various Fish or

Fish Products

Average Body Weights and Biomass
of Kits at Birth and at 4 Weeks
(First Year) or 3 Weeks (Second
Year) of Age ............................

PCB Residue Levels in Mink Milk

Liver Weights of Mink Fed Diets
that Contained Various Fish or
FiSh PrOdUCtS 000............OOOOOOOOOOOO

Chlorobiphenyls Eluting at or
Near Retention Times of Peaks

A:

D:

and I

PCB Bioaccumulation Factors for
various SpeCieS ......O.........OOOOOOOOO

Total Dietary PCB Intake of
Female Mink Fed Diets that
Contained Various Fish or

Fish Products

Rate of Elimination of PCBs from
Adipose Tissue of Various Species .......

Body Weight Changes of Mink Fed
the Carp, Sucker, and Whitefish

Diets, December 14,

January 15,

1979 and

1980’......OOOOOOOOOOOOOOOOOO

11

13

14

15

16

l8

19

24

28

31

36

38

Figure

Figure

Figure

Figure

Figure

1.

LIST OF FIGURES

 

Gas Chromatograph Tracings of
Aroclor 1254 Standard and Mink
Fat from a Male Fed 30% Carp ..............

Elimination of Total PCBs
from Mink Fat Over a 16
Week Withdrawal Period ....................

Elimination of Peaks A, D,
and I from Mink Fat Over a
16 Week Withdrawal Period .................

Gas Chromatograph Tracings

of Aroclor 1260 Standard

and Mink Fat from a Male

Fed 30% Carp ..............................

Gas Chromatograph Tracings
of Natural Dark and Pastel
Mink Fed 30% carp ......OOOOOOOOOOOOOOOO...

20

21

27

39

Renewed Use of Underutilized Species of
Great Lakes Fish for Animal Feed

For many years Great Lakes fish stocks provided an
abundant and inexpensive supply of fish and fish products for
the mink ranching industry of the Midwest. Since the late
1960's, however, these fish stocks have proven unsuitable for
feeding most animals due to toxic contaminants, forcing the
mink industry to rely on more costly marine fish and fish
products to meet its feed demands.

Laboratory analyses and mink feeding experiments have
shown polychlorinated biphenyls (PCBs) to be the toxic factor
present in Great Lakes fish (Aulerich gt 31., 1971, 1973;
Ringer et 31., 1972) and in Baltic herring (Jensen gt 31.,
1977). Subsequent studies (Platonow and Karstad, 1973;
Aulerich and Ringer, 1977; Bleavins 32 31., 1980) have shown
that mink are extremely sensitive to certain PCBs.

Since PCB use has been greatly curtailed in the U.S.,
residue levels in most Great Lakes fish species have declined
steadily, falling below the 5 ppm limit currently deemed safe
for human consumption in most species and below the 2 ppm
level for certain species (Michigan Department of Natural
Resources, personal communication). Noting this decline,
mink ranchers have expressed an interest in once again utilizing
some of these species if they can be shown to be safe for
animal consumption.

Although monitoring PCB concentrations in fish can pro—

vide a good indication of general pollution trends, it is much

more difficult to attempt to predict the degree of toxicity
associated with such concentrations due to variations in the
chemical and biological properties of the many PCB congeners*.
Most animal feeding studies have involved the addition of
specific commercial grade PCBs (which contain a specific
amount of chlorine by weight and a relatively limited number
of congeners) to the diet, which does not take into account
the much wider array of congeners normally present in environ-
mentally contaminated fish, the other potentially toxic
pollutants often found in conjunction with PCBs, nor the toxi?
city of the metabolized or selectively retained PCBs in the
fish. Some studies have shown marked differences in the toxi—
city of the various commercial PCBs when fed to mink (Aulerich
and Ringer, 1977; Bleavins gt_gt., 1980) and to other species,
for example rabbits (Villeneuve gt gt., 1971a; Koller and
Zinkl, 1973), leghorn chickens (Lillie gt gt., 1974), and
various aquatic organisms (Meyer gt gt., 1972). Research
results also indicate that once PCBs have been exposed to
biological processes the resultant changes in the ratio of the
congeners may result in substantially altered toxicity
(Platonow and Karstad, 1973; Biocca gt gt., 1976; McKinney,
1976). Therefore, feeding trials were deemed necessary to
determine the safety of Great Lakes fish and fish products for
animal consumption. Experiments were designed to evaluate the

growth, furring, and reproductive performance of mink when fed

 

209 different congeners are possible, containing 1-10
chlorine atoms. Of these, over 100 have been identified in
various commercial PCB mixtures (Sissons and Welti, 1971).

various species of Great Lakes fish, in order to assess the
suitability of these fish species for use by commercial mink
ranchers. The experiments were initiated at the Michigan

State University Fur Animal Project on August 15, 1979.

Methods and Materials

 

During the first year of the study, 96 sub-adult mink were
randomly assigned to one of six dietary groups, with the
exception that litter-mates were not assigned to the same
group. Each diet group consisted of 4 males and 12 females
(2 males and 6 females each of the natural dark and pastel
color varieties) which were fed gg libitum a basal diet (Table
l) differing only in the type of fish or fish product which
comprised 30% of the diet. Five fish or fish products were

selected for trial, including whole carp (Cyprinus carpio),

 

whole white sucker (Catastomus commersoni) (both species taken

 

from Saginaw Bay, Lake Huron), yellow perch (Perca flavescens)

 

scraps (taken from northern Lake Erie), lake Whitefish

(Cgregonus clupeaformis) racks (taken from Big Bay de Noc,

 

Lake Michigan), and alewife (Alosa pgeudoharengus) fish meal

 

(taken from Green Bay, Lake Michigan). The fish portion of the
control diet consisted of ocean fish scrap mix, which included
cod, haddock, and flounder trimmings.

Each fish or fish product was assayed for fat content,
and since the fat contents varied widely, corn oil was added
to all fish or fish products except carp to approximately
equalize the energy contents of the various diets (Table 2).

In addition, the carp, sucker, and Whitefish were cooked by

Table 1. Composition of Basal Diet.

 

 

 

 

Ingredient Wgt (kg) Percentage
Commercial Mink Cereal* 13.3 13.3
Whole Chicken 16.0 16.0
Fish/Fish Products 30.0 30.0
Beef Tripe 5.3 5.3
Beef Liver 2.7 2.7
Beef Lungs 2.7 2.7
Beef Trimmings 2.7 2.7
Cooked Eggs 2.7 2.7
Added Water 24.7 24.7
Total 100.1 100.1

 

*
XK-40 Grower, XK Mink Foods, Thiensville, WI.

Table 2. Fat Content of Fish or Fish Products and Amount of
Added Corn Oil.

 

 

 

Diet % Kg Oil/Fish Added Corn

Group Fat Portion of Diet Oil (kg)
Carp 21.2 6.4 0
Whitefish 16.6 5.0 1.4
Perch Scraps 8.8 2.6 3.7-
Sucker 2.7 0.8 5.5
Alewife Fish Meal 10.6 0.5 5.9
Control 3.8 1.1 5.2

 

placing them in sealed containers in 95°C water for approxi-
mately 2 hours to inactivate thiaminase. (Thiaminise is an
antimetabolite of thiamine present in certain fish species
which, if not denatured prior to feeding to mink and foxes,
can cause a muscular paralysis known as Chastek's paralysis).
During the second year of the study, beginning July 2,
1980, 28 sub-adult (kit) female mink were assigned to either
a Great Lakes fish diet group or a control (marine fish) diet
group. The assignments were made as follows: 5 pastel and
2 natural dark kits raised by dams fed the perch, sucker, or
Whitefish diet during the first year of the study (all that
remained after mortalities and sacrifices) plus 5 pastel and
2 natural dark kits selected at random from ranch stock were
assigned to the Great Lakes fish diet group, while 5 pastel
and 2 natural dark (randomly selected) kits raised by dams
fed the control or alewife fish meal diet during the first
year plus 5 pastel and 2 natural dark kits selected at random
from ranch stock were assigned to the control group. The
Great Lakes fish diet group was initially fed the perch and
sucker (uncooked) diets, as in the first year of the study but
without added corn oil, on alternate days. However, after 4
months several mink exhibited signs of Chastek's paralysis,
so the sucker diet was fed only every third day after November
6, 1980. The control group received the basal diet, but with
the fish portion comprising only 12.5% of the diet instead of

30% as in the first year, and also without added corn oil.

Routine ranch procedures were followed in the feeding,
care, and breeding of the animals. A11 mink were vaccinated
as kits against botulism, virus enteritis, and canine distemper.
Body weights were recorded at the beginning of each year's
trial and monthly thereafter until the breeding season (in
March).

During the first year of the study, the females were mated
to males within the same diet group, while during the second
year the females were mated to males from ranch stock. All
matings were verified by the presence of normal, motile
spermatozoa in a vaginal smear taken after copulation.

Mated females were checked daily for kits during the
whelping period. Kits were counted and weighed on the day of
birth and at 4 weeks of age the first year and at 3 weeks the
second year (due to a change in ranch record-keeping).

All fish and fish products were analyzed for PCB content
(Food and Drug Administration, 1975). In addition, 4 females
from each of the first year Great Lakes fish diet groups and
8 females from the control group were randomly selected and
anesthetized with Tilazol®*, an incision was made in the
inguinal area, and a fat sample (approximately 1 g) was taken
for PCB analysis (Food and Drug Administration, 1975). Fat
samples were taken in November (at the time of greatest fat
deposition) and in February (at the time of least fat deposi-

tion). A 500 mg sample of milk was collected (Jones gt_gt.,

 

it
Parke Davis Co., Ann Arbor, MI.

1981) for PCB analysis from the females previously fat-sampled
and lactating in May. These milk samples were extracted by a
modification of the method of the Food and Drug Administration
(1975), because the milk curdled upon addition of the extracting
solvent acetonitrile and had to be ground in a mortar and pestle
to break up the curds. Additionally, in an attempt to deter-
mine the rate of PCB elimination from the body fat stores of
mink, 4 males that had been fed the carp diet (equivalent to

1.5 ppm as Aroclor 1254) since August 15, 1979 were placed on
the control ration (equivalent to 0.04 ppm as Aroélor 1254)

on July 8, 1980. Fat biopsies from the inguinal area of these
males were taken for PCB analysis at the time of the dietary
change, and at 2 week intervals thereafter for the next 16
weeks.

Extracts from all samples were injected into a MicroTek
Model MT-220 gas chromatograph equipped with a 63Ni high tempera-
ture electron capture detector and a 6 foot glass column packed
with 3% SE-30 on 60-80 mesh Gas-Chrom Q. The following condi-
tions were maintained for all injections:

Column temperature = 180

Inlet temperature = 210

Detector temperature = 300

Flow rate = 40 m1 Nz/minute

Attenuation = 10 x 128
The approximate limit of detection for this analytical system
was 0.1 ppm Aroclor 1254. Quantitation was based on Aroclor
1254, using the area of peaks A (retention time = 2.0 minutes),

D (retention time = 3.0 minutes), and I (retention time = 6.6

minutes) as shown in Figure l. Recoveries for the various

.Ausmflmv mumo won com mam: m soum
umm xcfiz can Aummnv cumccmum vmma uoHoonm mo mmcflomua ammumoumfiougo mmo .H cunmfih

.. _ , 1‘
_ _ _ _ a

_ , 1
_ A r m l r m L
_ I _ _ L _
I _ _ I
. _

_

      

  

...l.
_

   

I . 1:1
_ __ L
_

f,
_ .
_ _, ,_

 

 

10

samples ranged from 72% to 95%, and all reported values are
unadjusted. All values are reported as ppm Aroclor 1254.

The contributions of peaks A, D, and I to the total calculated
PCB residue for the various samples are included for compari-
son.

Following weaning of the kits in early July, all females
previously biopsied plus one of their kits (if any were still
surviving) were sacrificed by cervical dislocation. The
weights of brain, kidneys, liver, and spleen were recorded.

The data were analyzed by Dunnett's "t"-test for the

difference between means of the control and treatment group.

Results

Growth (Table 3) and furring of mink on all diets were
normal in both years. Average weight gains by mink fed all
Great Lakes fish diets were not significantly different from
the control diet. There were, however, mortalities due to
Chastek's paralysis in mink fed the carp and sucker diets
during the first year (due to insufficiently cooked fish) and
in mink fed the alternated perch and sucker diet in the second
year. During the first year, 3 females and 1 male (natural
dark) were added to the carp and sucker diet groups on
January 8, 1980 to replace mortalities. Previous research
(Leonard, 1966) had indicated that feeding a diet containing
thiaminase with a diet lacking thiaminase on alternate days
resulted in no harm to mink, but we found this not to be the
case, at least with the sucker diet during the second year

feeding trial.

Table 3. Growth of Mink.

 

 

Average Weight Gain (9)

 

Diet August 15, 1979-

Group March 15, 1980
(First Year)

Control 321

Carp 225

Sucker 234

Perch Scraps 360

Whitefish Racks 299

Alewife Fish Meal 265
(Second Year) July 6, 1980-February 6, 1981

Control 429

Perch & Sucker 440

 

11

12

The PCB residue levels in the Great Lakes fish or fish
products and in the total diets for the first and second
years, shown in Table 4, range from 1.6-5.0 ppm and 0.2-1.5
ppm, respectively, for the first year and are 2.2 and 0.7
ppm, respectively, for the second year. The PCB content of
the total diets for the first year was calculated on the basis
of 30% fish in the ration for the control, carp, sucker,
Whitefish, and perch diets, and on the basis of 6.5% for the
alewife fish meal diet (1 kg of fish meal is equivalent to
6.2 kg of whole fish on a dry weight basis). For the second
year, the PCB content of the perch and sucker diet was
calculated by averaging the PCB contents of the 30% perch
and sucker portions, while the PCB content of the control
diet was calculated on the basis of 12.5% fish in the diet.

The PCB residue levels in the mink fat samples taken in
November, 1979 and February, 1980, shown in Table 5, indicate
that PCBs are more concentrated in fat at the end of winter
than at the beginning. A bioaccumulation factor (residue
level in the fat divided by the residue level in the total
diet) has been calculated for these samples, which also shows
an increase from November to February.

The reproductive performance of females in the various
groups is summarized in Table 6 for both years. No live off-
spring were produced by females fed the carp diet in the first
year, and no kits whelped by females fed the perch and sucker

diet in the second year survived to 3 weeks. Table 7 shows

.mmsHm> cmumasoamo m

.«mma Hoaooufi no cmmmm H

 

Ahm.oumm.ouho.ov ww.o Aom.oun.oauvm.ov m.m Hoxosm w soumm
Aao.onmo.ouao.ov vo.o Amo.ouma.oumo.ov m.o Houucoo
Ammo» ccoommv
Amo.ouma.oumo.ov Hm.o Amm.oumw.auvm.ov m.m HMO: nmflm OMH3OH¢
Aeo.oumm.ouoo.ov mv.o Ama.oumm.auma.ov w.H mxomm SMAMODH£3
Amm.ouHm.oumo.ov mm.o Amo.Humo.Hnom.ov m.N mmmuom SUHmm
AHN.ouvm.oumo.ov mo.o AHh.ouNH.HubN.ov H.N meosm
Ava.oumb.oumm.ov om.a Amv.oumm.mumm.av o.m ammo
Aao.oumo.oumo.ov mo.o Amo.ouma.oumo.ov m.o HOHHGOU

Ammo» uwuflmv

 

 

H xmmmun Hmuoe AH xmmmuo acuoa swam
xmmmufl xcmmN‘ Mommud xmmflV‘
(NDOHQ aH nmwm CH

 

Aammv Ham>mq oscflmmm mom

 

 

.mumfln can nmwm GA mHm>wq mscflmmm mum .v manna

1Q

.mmHuHHmuuoz mUMHmmm op ommH .mumsccb CH coccm MGHS N mmczHocH

 

 

 

.cwuccHEmucoo mHmEcm H M

.umHo Hmuoe cH Hm>mH mschmM\umm cw Hm>mq mschmm m

.vmmH H0H00H4 co commm H
Av.mmHum.omum.mv v.mm AmH.mu~m.~umm.oV H.m v Hmmz smHm wMHzmHm
Ao.momum.~Hum.mv m.b~ AmH.muom.vuom.ov m.MH v mxomm smemanz
Am.mmum.OHum.hv m.mH Ans.mumH.mumv.ov m.MH w mmcuom noucm
Ao.omuv.mum.mHv H.mH Amm.muHm.Huom.Hv m.m we meosm
Ao.hmuH.mum.mHv ~.bH Amm.hnoh.Humm.Hv m.0H N meosm
Am.mmHum.mHuH.mv m.vm Amm.mmumm.mumm.~v m.mm ev mumo
Am.momum.mHuv.mv m.mm Amm.mmuvm.muo>.mv m.~v N mucu
Am.mmHuH.HNu>.ov o.mm Amh.HuwH.Hu~o.ov m.m m Honucou

lemma .sumaunmmv
Am.mvum.oHuo.mv H.mH Ahv.Huvo.mumv.ov o.v e Hmmz anm wMHzde
Am.mmuo.mum.mv v.NH Anv.mumm.mumm.ov 0.0 v mxomm anmmuch
Am.mHum.muo.hv m.0H Amv.quh.mumw.ov m.> v mmcuom nonmm
Am.mmuH.muv.vv v.Hm Amv.HHuOh.Humm.ov m.MH v meosm
Av.mmum.0HuH.mv w.mH Amn.mHumm.mumm.mv m.¢m v ammo
Am.moHum.HHum.vv m.mH Amm.ouvm.o”MH.ov n.H mu Honucoo

_ Aman .Hmn8m>ozv
AH xmmmua Hmpoe AH xmmmun Hence : moons
(Mcmmufi xmmmv xcmmum xcmmv umHQ

 

N

uouocm coHuMHnfisoomon AEmmv HHm>mH mschmm mum c002

 

 

.umm gag: an mam>mq mseflmmm mom

.m mHQcB

1A

 

 

 

 

.lHo. w my Houpcoo cane mmmg saucmOHMHamHm m
.AHoo. w mv Honucoo cmsa mmmq wHuQMOHMHGmHm H
Ho mm.o mo.H v we m\v meosm w noumm
mm v.w m.m m we VH\NH Honucou
Amxmm3 m on nuHHmv Ammo» ccoommv
Hm m.v m.m m mm NH\oH Hmwz amHm wMH3wH¢
mm N.m o.v 5 mm 0H\m mxomm QmHmwuHQB
mm o.m h.m NH mm Haxm mmmuom comma
ow m.~ m.m «H mm Ome umxosm
Ho Ho Ho m Ho HH\m mHMO
mm m.m N.¢ HH mm 0H\m Houucou
Anew» umuHmv
Amxwm3 e cmumz cmmHmnz cmco m>HH< cope: macho
on nuuHmv mamsmm\muflx cmmHorz \cmmHmrz umHo
Hm>H>Hsm m>Hq .oz muHM .oz mmHmem
uHM w mommm>¢ .OZ

 

 

.muosconm SmHm Ho anm
mDOHHc> cmchucou Heap mumHo com xcHz oHcEmm mo mocmfiuomumm m>Huosconmmm .m manB

.mchEmm mcHnmuomq mo HwQEDZ\mpH& m>HH HHc mo pamHmB ch09 I mmmEon

 

 

 

 

1E

 

 

N
.cmmHmaz acne memEmm mo HmQEDZ\muHM w>HH HHc mo uzmHmz Hmuoa I mmchHm H
0.0 o.o v.5 n.n noxosm a noumm
m.mom «.mm o.mv o.m Houpcov
wxmmz m nuHHm Ahmmw uncommv
m.me v.v~H m.vv v.m Hmmz AmHm mMHsmHm
m.Hmm H.5OH H.vm m.m mxocm stmmuHsz
m.vmm m.mm s.mm H.m mmmuom noumm
«.mmH H.HHH o.vm >.m meosm
o.o o.o o.o o.o ammo
m.mmm m.mmH h.mm v.m Houucou
Ammo» umHHmv
Ame Ame luv “mo msouo
qmmcfimmm .umz .m>¢ HmmmEon .umz .m>< umHa
c mxmmz a - npuflm

 

 

.wm¢ mo Ammo» ccoommv mxwmz M AC Hummw
umnHmv mxmmz w an can auHHm um muHM mo mmmEon can muanmz atom mmmuw>¢

17

the average kit body weights and biomass (total weight of all
live kits per female that whelped) at birth and at 4 and 3 weeks
for the first and second years, respectively.

The PCB residue levels in the mink milk samples, shown in
Table 8, are in the range of 0.4-1.0 ppm for all Great Lakes
fish diet groups. Due to the small number of females still
lactating on the various diets and the relatively wide range
of numbers between groups it was deemed inappropriate to
analyze the milk data statistically.

Gross examination of the organs taken at the time of
sacrifice revealed no abnormalities, with the exception of
some hemorrhages found on the spleens of one of the control
females and her kit. Liver weights, expressed as average
liver weights, as well as % of brain weight and % of body
weight, are shown in Table 9. Livers from mink fed the carp
and Whitefish diets were significantly larger than the controls,
although there were only 2 individuals sacrificed from the
Whitefish diet. No significant differences were found when
the weights of the other organs taken were compared with
controls.

The elimination of PCBs from male mink is illustrated in
Figure 2 (total PCBs) and Figure 3 (peaks A, D, and I). Over
the 16 weeks of observation 60.3% of the total PCB burden in
the subcutaneous body fat was eliminated. Of the individual
peaks, 87.2% of peak A, 88.9% of peak D, and 55.4% of peak I

was eliminated.

.vmmH H0H00H¢ no commm

 

 

H

so.H-ms.o Aoa.o"~m.ouma.ov sm.o Ham: nmflm mmflzmHa
--- lov.ouom.ouaa.oc om.o mxomm amHmmanz
Ho.Hnmm.o Amw.ouam.ouma.ov ma.o mmmuom noumm
ma.o-ms.o lam.oumfl.ouoa.oo Hm.o umxosm
m~.o-HH.o AHH.oumo.oumo.ov N~.o Houuaoo
Afimmv AH xmmmuo Hmuoa muonw
omcmm xcwmufl xmwmv umHQ

 

Afimmv HHm>mH mschmm mum

 

 

.xHHz MGHS CH mHm>mH mschwm mom .m manB

 

 

 

 

.Amo. w my Homecoo cane “mummno sHucmonHcmHm N

.AHo. w my Houucou acne nmummuo mHucmoHMHcmHm H
on.m m.mmm hm.vm v Hmmz amHm mqumH¢
Nvm.¢ Hm.mmv Hmo.hm m mxomm anmmuch
AH.m s.mom on.mm v mmmuom comma
HH.m m.vmm mm.mm v meosm
mHo.v mm.mmm va.om v mumu
mh.m m.Hm~ em.Hm n Houpcoo
.umz .umz Amv c QSOHG
mcom chHm .umz Hm>HH umHQ

w w momum>¢
.muoscoum
anm no cmHm msoHHm> cmchucou awn» mumHa com xcHz mo muanmz nm>HH .m mHQmB

1O

38

34

 

 

28

 

26

24

22

20

PCI concentration (ppm)

18

16

 

14

12

10

 

 

l—u—r—F-r-l—I—r—r—J—

7/8 7/22 8/5 8/19 9/2 9/16 9/3010/1510/28
Dot.

Figure 2. Elimination of Total PCBs From Mink Fat Over a 16 Week
Withdrawal Period.

20

PCB concontrotion; Pool: I (0) (ppm)

30

25

20

15

10

W3

Figure 3.

A

7/22 8/5 8/19 9/2 9/15 9/3010/15 10/28

Do to

Elimination of Peaks A, D, and I From Mink Fat Over a

16 Week Withdrawal Period.

5.0

4L0

3.0

243

L0

PCB concontrotion; Pooh A and D (c) (ppm)

22

Discussion

 

The primary objective of this study was to assess the suit-
ability of Great Lakes fish and fish products for mink feed.
With this in mind, an attempt was made, where possible, to
simulate the "worst possible" set of circumstances a commer-
cial mink ranch might encounter using Great Lakes fish or
fish products. Thus, the relatively high level of 30% fish
or fish products was used in the diets, since some commercial
mink ranches routinely utilize this level of fish in their
diets. Also, whenever possible the fish or fish products
were procured from relatively polluted environments such as
Saginaw Bay, Green Bay, and the western basin of Lake Erie.
Finally, in the second year of the study as many offspring
of first year dams as possible were used in the Great Lakes
fish diet group to provide maximum exposure to the PCBs
derived from Great Lakes fish or fish products.

Before discussing the results of the study, the reader
should be aware that compounds other than PCBs, most notably
chlorinated dibenzofurans (CDFs) and chlorinated dibenzo-
dioxins (CDDs), have been found to have many of the same
effects on laboratory animals as PCBs, and usually at much
lower levels (Vos, 1972, Gupta gt gt., 1973; Moore gt gt.,
1976). These compounds have been identified as contaminants
of some commercial PCB mixtures (Vos gt gt., 1970; Porter and
Burke, 1971; Bowes gt gl., 1975), and, in addition, may be
present in certain environments, especially Saginaw Bay, as

a result of industrial activities (unpublished research,

23

Pesticide Research Center, Michigan State University). Thus,
it is possible that effects attributed to PCBs in this study
may be due to the presence of CDFs and/or CDDs in the fish or
fish products used. However, since the effects of these
compounds on mink have not been studied, and since these com-
pounds were not analyzed in the fish or fish products, it will
be assumed that the effects noted are due to PCBs.

The reader should also be aware that problems exist with
the handling of environmental PCB samples. Various methods
are recommended for the extraction, clean-up, chromatography,
and confirmation of environmental PCB samples, as well as for
methods of quantitation*. In this study the 3 peaks used for
quantitation were chosen for the lack of known interfering
compounds at the respective retention times of these peaks and
for the relative prominence of these peaks in the fish, fat,
and milk samples. A list of some of the Chlorobiphenyls
known to elute at or near the retention times of peaks A, D,

and I is shown in Table 10.

PCBs in Fish, Mink Fat, and Mink Milk

 

PCBs are readily stored in mink adipose tissue from
dietary exposure. Previous research (Iwamoto, 1973) has shown
that PCB residues reach levels approximately 25 times those
in the diet, then plateau after 8 weeks. Examination of the

data in Table 5 shows that the total PCB residue levels in

 

See Duinker gt gt., 1980 for a discussion of some of the
problems involved with quantitation of environmental PCB
samples.

Table 10. Chlorobiphenyls Eluting at or Near Retention Times
of Peaks A, D, and I.

 

 

 

Major Minor
Peak Component Components
A 2,5,2',5' Tetra-CB1 2,4,2',5' Tetra-CB1
D 2,3,6,2',5' Penta-CB1 ,4' Tetra-CB1 2

2,5, 3'

2, 4, 3' ,4' Tetra-CBl
I 2,4,5,2',4',5' Hexa-CBl 4,

4,

' ,4' Penta- CB2
' ,3', 6' Hexa-CB2

 

1 From Webb and McCall, 1972.

2 From Sissons and Welti, 1971.

24

25

mink fat in February were approximately double the levels in
November for all diet groups except sucker (which unexplain-
able drOpped from the November level), and in the range of
17-38 times the dietary level, indicating that, as fat stores
are mobilized during cold weather, PCB residues are concen-
trated in the fat depots. This is consistent with results
obtained with pigeons which, after reaching plateau levels of
Aroclor 1254 in adipose tissue, approximately doubled the
concentraton of PCB in adipose tissue after exposure to 1
week of cold temperature and starvation (DeFreitas and
Norstrom, 1974).

Of particular interest are the bioaccumulation factors
for peaks A, D, and I. Comparison of these values for
November and February shows that peaks A and D accumulated to
approximately the same levels at both sampling times, while
peak I accumulated in February to approximately twice the
November level (again, the sucker diet group is the exception).
This indicates that there is net movement out of the fat depot
for some (or all) of the Chlorobiphenyls comprising peaks A
and D, since the bioaccumulation factors would be expected to
rise in response to a shrinking of the fat depot. This net
movement could be due to relocation of the Chlorobiphenyls to
other tissues, metabolism. and elimination of the chloro-
biphenyls, or, perhaps, a combination of both processes.
Similar results have been found in robins (Sodergren and
Ulfstrand, 1972), which relocate PCBs (primarily to brain and
breast muscle), and in pigeons (DeFreitas and Norstrom, 1974),

which relocate the extensively metabolize PCBs.

26

The bioaccumulation factors for peak I also illustrate
the relatively high concentrations that can be attained by
the more highly chlorinated PCB congeners in mink fat. In
fact, the gas chromatographic patterns of the adipose tissue
extracts more closely resembled the pattern of Aroclor 1260
than Aroclor 1254. This PCB mixture was not, however, used
for quantitation, since the few peaks in the fish extracts
with retention times that corresponded to major peaks in the
Aroclor 1260 mixture were too small for reliable quantitation.
Nevertheless, these "1260" peaks were very prominent in all
adipose tissue samples (Figure 4).

The total PCB residue levels in adipose tissue are
consistent with published data (Odsjo, 1973) which show levels
of 45 ppm Aroclor 1254 in adipose tissue of mink whose diets
included Baltic Sea fish. PCB bioaccumulation factors for
several other animal species are listed in Table 11 for
comparison.

No trends were evident when the concentration of PCBs
in the milk samples were compared with either the dietary or
adipose tissue PCB levels, although the small numbers of milk
samples make generalizations based on these values unreliable.
The most notable observation from these values was the rela—
tively high PCB concentration in the milk samples taken from
females in the alewife fish meal diet group. These values
were equivalent to those of the other diet groups (in fact,

the highest individual PCB concentration in milk was found in

w Eoum pmm xcHz can

.57....

____.__.’ __ --- _. -..—

.._-____ _'__._._, _.
t

a
I

1..--.. _i_-. -

 

 

7—7

 

4M._l_,

J

J- -_~__._____ __._. _ _ _
l

—-_ ,.__.i

l
4
_.

- ) .._-.—~ -- -_ .

r1. ._ ..

~--4—___-‘_.- ___.-—_,- ___.,,,- _

._- _.-_. --..

1...- .-_ _- ..

 

 

__+__.__._~._ _-_

 

 

.lpnmflmv mumo mom can mam:

Auwoqv pHMQQMHm ommH HOHOOHH mo mmcHocHB smcumoumfionno mmw

 

i
my
_,
W:
+

 

- ~_-_l-‘_-, - _ _.

 

 

rrr— ‘
+—-—-——-:-—

 

___g_ .

 

_..__x_..L_‘_L

l

_ _.4__, -- .._.._.__4- --....

a -r-

L

_..-. ._._... ...l_._
.

 

9'7

.cmHmHommm uoz u mz

 

 

 

 

 

 

m
.kucz CH CoHucHHCooCoo\>pom mHOCS CH Hm>mH mCUHmmm u *
.umHC Hmuoe CH COHumnquoCoo\umm CH Hm>mH mCCHmwm u a H
«Has ..Hm_ww uwsmz N lemmas s moa x s.~ A.mm msuonomnov mmon
mesa ..Hm mm umsmz H lemmas 4 MOH x m.m (C.mm xmasoc oustmoz
NHmH ..Hm_ww “mam: m AsmmHv * MOH x m.m l.mm mmucosomammo msHusm mmmau
msma ..Hm_mm “mam: m.o Asmmav * moa x m.m mamas mflcammn
NHmH ..Hm mm umsmz N AsmmHv # mOH x m.m A.mm msumssmwv comHnms<
NHmH ..Hm pm umsmz m lemmav * HOH x m.o l.mm mmuomcoouov amfimsmuo
II.|I mmz loomflv # moH x H.~
mums ..Hm um momma mmz Amvmflv * moa x N.H soacHz ommaumm
abelwcmmcmm mm Amvmav 4m.m cmflmumo Hwacmno
vsmH ..Hc pm mxmoe mmz AvmmHv «H Aumwcnv CwMOHCU
II II m lemmas 4m.mus.a
onH ..Hm um :mmcmm m Amvmav 4m.~-o.a AumHHoum mamzv cmxoflso
m Asmmav .o.m
msmfl .cmmcmm m INVNHV 4m.~ mlmzv cmxoflno
SH lemmas 4m.H
msma .aomcmm SH Imvao «m.o mmmsm
ma lemmas 4m.H
msmfl .cmmcmm ma Amvmav 4m.o mafism
II II mm ANGNHV .om
msma ..Hm pm :mHHa mm AHmNHV 40H lsmHsmaumsmmumm .mHmzv pom
mesa .cmHH< m Imemfiv 4m Imsmmnmv masses
mousom Amxmmzv AmHCmomxm mmHommm
5mmUMHm HOHUOHCV Hnouocm
HHuCD mEHB CoHucHCECOOMOHm

 

 

.mOHOOQm mSOflHMNV HON MHO#OM..m COHHMHSEDOOMOflm mUm

.HH OHQCB

’)Q

29

this group), even though the dietary and adipose tissue PCB
concentrations of the alewife fish meal diet group much more
closely approximated those of the control group. Also notable
is the fact that the concentraton of PCBs in the mink milk

was comparable to the concentration of PCBs in the diet,
whereas in cows the milk concentration was approximately 4

times the dietary level (Fries gt gt., 1973).

Reproduction

 

The detrimental effects of PCBs on mink reproduction are
well documented. Aulerich and Ringer (1977) have shown that
diets supplemented with as little as 2 ppm of Aroclor 1254
result in near total reproductive failure. Platonow and
Karstad (1973) have shown that "metabolized" PCBS are even
more detrimental to mink reproduction, since beef products
from cows which had been dosed with Aroclor 1254 and fed to
mink at levels as low as 0.64 ppm (as Aroclor 1254) had
severe effects on mink reproduction. The list of animal
species found to suffer reproductive problems upon exposure to
PCBS is extensive; see, for example, the reviews of Stendell
(1976) and Kimbrough (1978).

The results of this study further illustrate the dele—
terious effects of PCBs on mink reproduction, especially PCBs
which have been exposed to biological processes before being
fed to mink. During the first year of the study, females fed

the carp diet, with the equivalent of 1.5 ppm Aroclor 1254,

30

produced no offspring which survived to 24 hours, while those
fed the perch, sucker, and Whitefish diets, with the equiva-
lent of 0.69, 0.63, and 0.48 ppm Aroclor 1254, respectively,
showed reduced reproduction, as measured by average litter
size and kit survival to 4 weeks (Table 6). However, the
kit survival of all groups, including the control group, was
below that which would be deemed acceptable on a commercial
mink ranch. (Perhaps the addition of the corn oil to the
first year diets had a negative effect on kit survival. Thus,
the elimination of added corn oil from the second year diets).
During the second year of the study, females fed the alter-
nated perch and sucker diets, with the equivalent of 0.66
ppm Aroclor 1254, showed significantly reduced reproduction and
100% mortality at 3 weeks. The Second year results are nearly
identical to the results of Platonow and Karstad (1973),
including dietary PCB level, average litter size, and kit
survival.

Assuming that adult female mink consume an average of
150 g of feed per day (Schaible, 1970; Bleavins and Aulerich,
1981), the total amount of PCBS consumed by the females to
the beginning of whelping can be calculated. These values,
based on 250 days exposure in the first year and 290 days in
the second, are shown in Table 12. Comparison of these
results with the results of Aulerich and Ringer (1977)
further illustrate the difference between adding technical
PCB mixtures to a mink diet and adding environmentally derived

PCBs to a mink diet. At a level of 2 ppm Aroclor 1254 in the

Table 12. Total Dietary PCB Intake of Female Mink Fed Diets
that Contained Various Fish or Fish Productsl.

 

 

Diet Group Intake (mg)

 

(First Year)

Control 3.4
Carp 56.2
Sucker 23.6
Perch Scraps 25.9
Whitefish Racks 18.0
Alewife Fish Meal 7.9

 

(Second Year)
Control 1.7

Perch & Sucker 28.7

 

1 Based on an Assumed Feed Consumption of 150 g/Day.

31

32

diet for 9 months (the lowest level which Aulerich and Ringer
found to have a significant effect on reproduction) the females
consumed approximately 61 mg of PCB. In the second year of
this study, similar results were obtained from females which
consumed approximately 29 mg of PCB, while in the Platonow
and Karstad (1973) study (0.64 ppm PCB for 160 days) similar
results were obtained after consumption of about 15 mg of PCB.

Enhanced toxicity of biologically modified PCBS can be
explained by an increased toxicitycfifmetabolized forms of
PCBs, by selective retention of the more toxic (usually the
more highly chlorinated) congeners of a PCB mixture within an
animal, by interactions of PCBs with other compounds present
within an animal, or by combinations of these factors.
Whatever the causative factor(s) may be, it would appear that
biologically modified PCBs are more toxic to mink than
corresponding technical mixtures.

In contrast to the poor results obtained with whole
fish and fish by-products, the results from the first year
of this study (and those of a commercial mink ranch) with
alewife fish meal are encouraging. In this study reproduction
and survival of kits were comparable to that of controls
(although, as noted above, kit survival was sub-optimum for
both groups). Furthermore, a large commercial mink ranch in
Illinois which used the same alewife fish meal fed in this
study in some of their diets reports satisfactory mink growth

and reproduction on these diets (personal communication,

33

Northwood Fur Farms, Inc.). The results of this study also
suggest the possibility of using other underutilized Great
Lakes fish stocks for making fish meal.

Comparison of the results of the first and second years
of this study (Tables 6 and 7) reveal an interesting possi-
bility. Since the Great Lakes fish diets for both years
differ only in the amount of oil in the diets, yet the
reproduction, biomass, and kit survival are dissimilar, it
is possible that the addition of corn oil to the first year
diets may have lessened the effects of the PCBS on the mink.
Similarly, Hansen gt gt. (1976) have reported a small positive
effect on PCB elimination in a high fat diet fed to broiler

cockerels.

Liver Weights

 

Increased liver weight and/or fatty degeneration of the
liver has been associated with PCB exposure in practically
all species studied. Rats (Grant gt_gl., 1971; Kimbrough gt
gt., 1972; Allen and Abrahamson, 1973; Cecil gt_gt., 1973;
Grant and Phillips, 1974; Allen gt gt., 1976), mice (Orberg
and Lundberg, 1974), rabbits (Villeneuve gt gl., 1971b;
Koller and Zinkl, 1973), swine (Hansen gt_gt., 1975), monkeys
(Allen gt gl., 1974), pigeons (Bailey and Bunyan, 1972),
quail (Bailey and Bunyan, 1972; Cecil gt gt., 1973), pheasants
(Dahlgren gt gl., 1972), and chickens (Iturri, 1974) have all
shown liver enlargement due to exposure to various PCB

ndxtures. Mink are no exception, showing increased liver

34

weight when fed Aroclor 1254 at 5 ppm for 9 months (Aulerich
and Ringer, 1977). In this study, female mink fed the carp
and Whitefish diets for 9 months also exhibited significantly
enlarged livers, at levels equivalent to 1.5 and 0.5 ppm
Aroclor 1254, respectively (Table 9). Livers of females fed
the other Great Lakes fish diets were also slightly enlarged,
but not significantly different from the controls. These
results again point to increased toxicity of biologically

modified PCBs to mink.

Elimination

 

Elimination of PCBS from fat stores in mink has been
studied (Iwamoto, 1973), although the rate of elimination was
based on relatively few samples. In an effort to provide
more information on the rate of PCB elimination from mink,

4 males that had been on the carp diet for 11 months were

fat biopsied biweekly and the samples analyzed for PCB concen-
tration. The results (Figure 2) indicate that first order
decay occurred over the length of the study (16 weeks; the
study was terminated after the 16th week). Regression analy-
sis of the data gave an estimate of 199 days for elimination
of PCBs from adipose tissue and 98.4 days for 50% removal

(r = -0.985). These results are underestimates, however,
since the study was terminated before second order elimination
could occur. Nevertheless, the estimate of 98 days for 50%
elimination may provide a gauge by which mink ranchers can
judge whether mink which have been accidentally or uninten-

tionally exposed to PCBS should be pelted or kept for breeding.

35

The results (Figure 3) also indicate that rates of

elimination for individual PCB congeners can vary widely.

Peak A exhibited second order decay throughout the study,

peak D exhibited first order decay for the first week after,
removal of the carp diet followed by second order decay to
termination, and peak I exhibited first order decay throughout
the study. (Since peak I dominated the composition of the
total PCB residue, the rate of elimination for total PCBS was
first order also).

The relatively fast elimination of peak I (primarily 2,
4,5,2',4',5'-hexachlorobiphenyl) indicates the high level of
activity of mink mixed-function oxidase enzyme systems. This
PCB congener, which has an apparent half-life of infinity in
the rat (Hutzinger gt gt., 1972; Matthews and Anderson, 1975),
pigeon and brook trout (Hutzinger gt gt., 1972), was undoubt-
edly among the congeners eliminated during the course of the
elimination of peak I. The rate of elimination of PCBS from

various species is shown in Table 13 for comparison.

Other Observations

 

Certain observations in this study suggest that natural
dark and pastel mink are not completely equivalent metaboli-
cally. First, 9 of 10 deaths during the study due to Chastek's
paralysis occurred to natural dark mink. Re-examination of
the monthly weight records for December and January of the
first year of the study, when the first year deaths occurred,

further illustrates the different susceptibility of natural

.HowCmHQOHOHComxmmI.m..e..m.m.v.m

 

 

H
msmH .qmmcmm Hmomnmvm m.om
mHmH .cmmqmm wmmH noHooum ¢.mm
vsmH ..Hm_mm mxmma vaH uoHooua m.om HumHMHV :mHoHno
NHmH .cmsasm new smHHmm NHNH uoHooua mNH
NHmH ..Hm mm HmmcHuusm Hmomnmem commHm
mHmH ..Hm mm ummcHNusm Hmomumvm Hsoua xooum
msaH ..mm mm ummcHuusm Hmomumem
mHmH .aomumcca cam msmsuumz Hmomumem Hem
mHmH .ammcmm Hmomumvm ommA
mHmH .emmcmm vmmH HoHoofiH m.mm~ mcHsm
monsom cmpmma Ammcov mmHommm
mom «HHHumHmm

 

 

.mmHommm mCoHHm> mo msmmHB

mmomHUC Eoum wmum mo COHCMCHEHHm mo wumm .MH mHQMB

‘1‘

37

dark and pastel mink to thiaminase. The records for the carp,
sucker, and Whitefish diet groups, which are summarized in
Table 14, indicate that weight loss, which results from reduced
food intake due to the reduced mobility associated with
muscular paralysis, is greater for natural dark mink than for
pastels in all groups except the December 14 Whitefish group.
The PCB gas chromatographic patterns of natural dark and
pastel mink show several differences between the two color
varieties. Figure 5 shows representative gas chromatographic
tracings of 2 male mink fat samples, one of the natural dark
and one of the pastel variety, taken at the initiation of the
elimination study. If the tracings are superimposed so that
peaks L, M, N, and O coincide, it will be apparent that peaks
A, E, F, G & H, J, and K differ in their relative heights.
Note especially the difference between peaks A, E, and G & H
in the 2 tracings, as well as the difference between peak K
in relation to peak L. These differences were most pronounced
in the elimination study (so pronounced, in fact, that it

was possible to identify the color variety of a sample with—
out it being labelled, by inspecting the gas chromatographic
trace), but they were also evident in several of the February

biopsy samples.

Conclusions

 

Based on the results of this study, the following conclu-

sions were made:

Table 14. Body Weight Changes of Mink Fed the Carp, Sucker,
and Whitefish Diets, December 14, 1979 'U3 January

 

 

 

15, 1980.

Average Wgt.

Change (9)
Diet Color December 14, 1979

Group Variety January 15, 1980

Carp Dark - 96 -137
Pastel - 29 - 30
Sucker Dark -113 -210
Pastel - 48 - 74
Whitefish Racks Dark — 51 - 48
Pastel - 64 + l

 

38

luanmv xcHz Hmummm can AuHmHV sumo

 

.v——~—--~4,-- 1.1..

T
.— -...—
‘1‘..."—

L_.___._-_- __

... _ -..—....

 

 

A
Y

, -_ --.~h...-—.——~O-.- ...—.—
l
- _».___._~__4—_. _. .._' — - W...

F

'_ - -... —————.4.——~—-.—. .— -—
n

l _

t - .—.—.-————~ .__.4- ...———.—-.—._. ——‘———--——— ——~——- .-
l

 

 

 

 

 

 

 

J
- _ . ' 1.
.___.-__ - -___+__--

”7"“ ‘m‘JJ'—”‘"‘_ ‘
:3
r ,
__1__.._ if.-- --__,.____

 

._l._

i
'

 

 

 

.-—-f— —-—~~—.—-——r

l“
-.-.

t'tliflt 1715'

‘I.3-DE .1. C O.)

 

.mumo mom
Hmusumz mo mmCHomua nmmumoumeounu

 

 

YI.l—-.G .1 C PD.

 

‘20

40

(1) Whole Great Lakes fish or fish products are currently
unsafe for use as mink feed when fed at a level of 30% of the
diet.

(2) Alewife fish meal may be safe for use in mink diets
at levels up to the equivalent of 30% whole fish. Further
study would be helpful in determining its safety.

(3) Mink can accumulate PCBs as much as 38 times the
dietary level, and can accumulate individual congeners as
much as 200 times the dietary level.

(4) It is estimated that at least 100 days are required
for mink to eliminate 50% of the adipose tissue burden of
PCBS.

(5) Environmentally derived PCBS appear to be more toxic

to mink than corresponding technical mixtures.

 

REFERENCES

Allen, J.R., 1975. Response of the non-human primate to poly-
chlorinated biphenyl exposure. Fed. Proc. 34:1675.

Allen, J.R. and L.J. Abrahamson, 1973. Morphological and
biochemical changes in the liver of rats fed polychlorinated
biphenyls. Arch. Environ. Contam. Toxicol. 1:265.

Allen, J.R., L.A. Carstens, and L.J. Abrahamson, 1976.
Responses of rats exposed to polychlorinated biphenyls for
fifty-two weeks. I. Comparison of tissue levels of PCB and
biological changes. Arch. Environ. Contam. Toxicol. 4:404.

Allen, J.R., D.H. Norback, and I.C. Hsu, 1974. Tissue modifica-
tions in monkeys as related to absorption, distribution, and
excretion of polychlorinated biphenyls. Arch. Environ.

Contam. Toxicol. 2:86.

Aulerich, R.J. and R.K. Ringer, 1977. Current status of PCB
toxicity to mink, and effect on their reproduction. Arch.
Environ. Contam. Toxicol. 6:279.

Aulerich, R.J., R.K. Ringer, and S. Iwamoto, 1973. Reproductive
failure and mortality in mink fed on Great Lakes fish. J.
Reprod. Fert. Suppl. 19:365.

Aulerich, R.J., R.K. Ringer, H.L. Seagran, and W.G. Youatt,
1971. Effect of feeding coho salmon and other Great Lakes
fish on mink reproduction. Can. J. Zool. 49:611.

Bailey, S. and P.J. Bunyan, 1972. Interpretation of persis-
tence and effects of polychlorinated biphenyls in birds.
Nature 236:34.

Biocca, M., J.A. Moore, B.N. Gupta, and J.D. McKinney, 1976.
Toxicology of selected symmetrical hexachlorobiphenyl isomers.
I. Biological responses in chicks and mice. Proc. Natl. Conf.
on Polychlorinated Biphenyls. Nov. 19-21, 1975, Chicago, IL
pp. 67272.

Bleavins, M.R. and R.J. Aulerich, 1981. Feed consumption and
food passage time in mink (Mustela vison) and European ferrets
(Mustela putorius furo). Lab. AnimaI Sci. 31:268.

 

 

Bleavins, M.R., R.J. Aulerich, and R.K. Ringer, 1980. Poly-
chlorinated biphenyls (Aroclors 1016 and 1242): Effects on
survival and reproduction in mink and ferrets. Arch. Environ.
Contam. Toxiéol. 9:627.

41

42

Bowes, G., M. Mulvihill, B.R.T. Simoneit, A.L. Burlingame,
and R.W. Risebrough, 1975. Identification of chlorinated
dibenzofurans in American polychlorinated biphenyls. Nature
256:305.

Cecil, H.C., S.J. Harris, J. Bitman, and G.F. Fries, 1973.
Polychlorinated biphenyl-induced decrease in liver vitamin A

in Japanese quail and rats. Bull. Environ. Contam. Toxicol.
9:179.

Dahlgren, R.B., R.J. Bury, R.L. Linder, and R.F. Reidinger,
Jr., 1972. Residue levels and histopathology in pheasants
given polychlorinated biphenyls. J. Wildlife Mangt. 36:524.

DeFoe, D.L., G.D. Veith, and R.W. Carlson, 1980. Effects of
Aroclor 1248 and 1260 on the fathead minnow (Pimephales
promelas). J. Fish. Res. Board Can. 35:997.

 

DeFreitas, A.S. and R.J. Norstrom, 1974. Turnover and metabo-
lism of PCBs in relation to their chemical structure and the
movement of lipids in the pigeon. Can. J. Physiol. 52:1080.

Duinker, J.D., M.T.J. Hillebrand, K.H. Palmork, and S.
Wilhelmsen, 1980. An evaluation of existing methods for
quantitation of polychlorinated biphenyls in environmental
samples and suggestions for an improved method based on measure-
ment of individual components. Bull. Environ. Contam. Toxicol.
25:956.

Environmental Protection Agency, 1976. Proceedings of
National Conference on Polychlorinated Biphenyls, November
19-21, 1975, Chicago, IL. Report No. EPA-560/6-75-004.
Washington, D.C.

Food and Drug Administration, 1975. FDA Pesticide Analytical
Manual, Vol. I. 1968 (rev. 1975).

Fries, G.F., G.S. Marrow, and C.H. Gordon, 1973. Long-term
studies of residues retention and excretion by cows fed a
polychlorinated biphenyl (Aroclor 1254). J. Agric. Food Chem.
21:117.

Grant, D.L. and W.E.J. Phillips, 1974. The effect of age and
sex on the toxicity of Aroclor 1254, a polychlorinated biphenyl,
in the rat. Bull. Environ. Contam. Toxicol. 12:145.

Grant, D.L., W.E.J. Phillips, and D.C. Villeneuve, 1971.
Metabolism of a polychlorinated biphenyl (Aroclor 1254)
mixture in the rat. Bull. Environ. Contam. Toxicol. 6:102.

Gupta, B.N., J.G. Vos, J.A. Moore, J.G. Zinkl, and B.C. Bullock,
1973. Pathological effects of 2,3,7,8,-tetrachloro-p-dioXin in
laboratory animals. Environ. Health Perspect. 5:125.

43

Hansen, L.G., 1979. Selective accumulation and depletion of
polychlorinated biphenyl components: Food animal implications.
Ann. N.Y. Acad. Sci. 320:238.

Hansen, L.G., G.S. Byerly, R.L. Metcalf, and R.F. Bevill, 1975.
Effect of polychlorinated biphenyl mixture on swine reproduc-
tion and tissue residues. Am. J. Vet. Res. 36:23.

Hansen, L.G., D.W. Wilson, R.L. Metcalf, and M.E. Welborn,
1976. Residues of polychlorinated biphenyl components in
broiler cockerels receiving two Aroclors in three dietary
variations. J. Agric. Food Chem. 24:256.

Hutzinger, 0., D.M. Nash, S. Safe, A.S.W. DeFreitas, R.J.
Norstrom, D.J. Wildish, and V. Zitko, 1972. Polychlorinated
biphenyls: metabolic behavior of pure isomers in pigeons, rats,
and brook trout. Sci. 178:312.

Iturri, S.J., 1974. The effects of various chlorinated hydro-
carbons on the cardiovascular physiology and hematology of the
domestic fowl. Ph.D. Thesis, Department of Poultry Science,
Michigan State University, East Lansing, MI 144 pp.

Iwamoto, S., 1973. The effects of polychlorinated biphenyls
and coho salmon on mink. M.S. Thesis, Department of Poultry
Science, Michigan State University, East Lansing, MI 73 pp.

Jensen, 8., J.E. Kihlstrom, M. Olsson, C. Lundberg, and J.
Orberg, 1977. Effects of PCB and DDT on mink (Mustela vison)
during the reproductive season. Ambio 6:239.

 

Jones, R.E., R.K. Ringer, and R.J. Aulerich, 1980. A simple
method for milking mink. Fur Rancher 60:4.

Kimbrough, R., J. Buckley, L. Fishbein, G. Flamm, L. Kasza,
W. Marcus, S. Shibko, and R. Teske, 1978. Animal toxicology.
Environ. Health Perspect. 24:173.

Kimbrough, R.D., R.E. Linder, and T.B. Gaines, 1972. Morpho-
logical changes in livers of rats fed polychlorinated biphenyls.
Light microscopy and ultrastructure. Arch. Environ. Health
25:354.

Koller, L.D. and J.G. Zinkl, 1973. Pathology of polychlorinated
biphenyls in rabbits. Am. J. Pathol. 70:363.

Leonard, A., 1966. Modern Mink Management. Ralston Purina Co.,
St. Louis, MO 206 pp.

Lillie, R.J., H.C. Cecil, J. Bitman, and G.F. Fries, 1974.
Differences in response of caged White Leghorn layers to various
polychlorinated biphenyls (PCBS) in the diet. Poultry Sci.
53:726.

44

Matthews, H.G. and M.W. Anderson, 1975. Effect of chlorina-
tion on the distribution and excretion of polychlorinated
biphenyls. Drug Metab. Disp. 3:371.

McKinney, J.D., 1976. Toxicology of selected symmetrical
hexachlorobiphenyl isomers: II. Correlating biological
effects with chemical structure. Proc. Natl. Conf. on Poly-
chlorinated Biphenyls, Nov. 19-21, 1975, Chicago, IL pp.
73-76.

Meyer, F.L., P.M. Mehrle, and H.G. Sanders, 1972. Residue
dynamics and biological effects of polychlorinated biphenyls
in aquatic organisms. Proc. 164th Natl. Meeting Amer. Chem.
Soc., New York, N.Y., 1972.

Moore, J.A., B.N. Gupta, and J.G. Vos, 1976. Toxicity of
2,3,7,8-tetrachlorodibenzofuran - preliminary results. Proc.
Natl. Conf. on Polychlorinated Biphenyls, Nov. 19-21, 1975,
Chicago, IL pp. 77-80.

Odsjo, R., 1973. PCB in some Swedish terrestrial organisms.
In PCB Conference II Nat. Swedish Environ. Protection Board
Publications: 4E. pp. 45-58.

Orberg, J. and C. Lundberg, 1974. Some effects of DDT and
PCB on the hormonal system in the male mouse. Environ.
Physiol. Biochem. 4:116.

Platonow, N.S. and L.H. Karstad, 1973. Dietary effects of
polychlorinated biphenyls on mink. Canad. J. Comp. Med. 37:391.

Porter, M.S. and J.A. Burke, 1971. Separation of three
chlorodibenzo-p-dioxins from some polychlorinated biphenyls
by chromatography on an aluminum oxide column. J. Assoc.
Offic. Anal. Chem. 54:1426.

Ringer, R.K., R.J. Aulerich, and M. Zabik, 1972. Effect of
dietary polychlorinated biphenyls on growth and reproduction
in mink. 164th Natl. Meeting, Amer. Chem. Soc. 12:149.

Schaible, P.J., 1970. Nutrition and Feeding. Sect. III.
In: The Blue Book of Fur Farming. Milwaukee, WI, Editorial
Service Co.

Sissons, D. and D. Welti, 1971. Structural identification of
polychlorinated biphenyls in commercial mixtures by gas-liquid
chromatography, nuclear magnetic resonance, and mass spectro-
metry. J. Chromatogr. 60:15.

Sodergren, A. and P. Ulfstrand, 1972. DDT and PCB relocate
when caged robins use fat reserves. Ambio 1:36.

45

Stendell, R.C., 1976. Summary of recent information regarding
effects of PCBS on birds and mammals. Proc. Natl. Conf. on
Polychlorinated Biphenyls, Nov. 19-21, Chicago, IL pp. 262-
267.

Teske, R.H., B.H. Armbrecht, R.J. Condon, and H.J. Paulin,
1974. Residues of polychlorinated biphenyl in products from
poultry fed Aroclor 1254. J. Agric. Food Chem. 22:900.

Villeneuve, D.C., D.L. Grant, K.Khera, D.J. Clegg, H. Baer,
and W.E.J. Phillips, 1971a. The fetotoxicity of a poly-
chlorinated biphenyl mixture (Aroclor 1254) in the rabbit
and in the rat. Environ. Physiol. 1:67.

Villeneuve, D.C., D.L. Grant, W.E.J. Phillips, M.L. Clark,

and D.J. Clegg, 1971b. Effects of PCB administration on
microsomal enzyme activity in pregnant rabbits. Bull. Environ.
Contam. Toxicol. 6:120.

Vos, J.G., 1972. Toxicology of PCBS for mammals and for birds.
Environ. Health Perspect. 1:105.

Vos, J.G., J.H. Koeman, H.L. Van Der Maas, M.C. Ten Noever de
Brauw, and R.H. DeVos, 1970. Identification and toxicological
evaluation of chlorinated dibenzofuran and chlorinated
naphthalene in two commercial polychlorinated biphenyls.

Food Cosmet. Toxicol. 8:625.

Webb, R.G. and A.C. McCall, 1972. Identities of polychlori-
nated biphenyl isomers in Aroclors. J. Assoc. Offic. Anal.
Chem. 55:746.

"11111111111414?