‘J‘;.{3 Hiltsldv H LLEICI' CORRELA'HON OF CERTAlN FHYSiC"L.(f)SILK",7. CHARACTERISTICS OF HEN-f?» WRTH EGG PRODUCTION Thesis for the Degree of M, S. MlCl’NGAN STATE COLLEGE Arthur S. Totten 1940 CORRELATION OF CERTAIN PHYSIOLOGICAL CHARACTERISTICS OF HENS WITH EGG PRODUCTION by Arthur Sylvester Tatten .A THESIS Submitted to the Graduate School of Michigan State College of Agriculture and.Applied Science in partial fulfilment of the requirements for the degree of MASTER OF SCIENCE Department of Poultry Husbandry 191:0 THESIS ACKNOWLEDGMENT The writer expresses appreciation to Dr. E. I. Henderson. .Assistant Professor of Poultry Husbandry, for his valuable suggestions and to Mr. J. Li Northam of the Mathematics Department for his assistance with statistical Operations. 1274.83 TABLE OF CONTENTS Chapter Page I INTRODUCTION 000000000...00.000.000.000. 1 II REVIEW OF LITERATURE ................... 2 III mERImrTAL 00000000000000000000000000. 8 Purpose Oeeeeeeeeeeeeeeeeeeeeeeeeesee 8 Procedure eeeeeeoeeeeeeeeeeeeeeeeeeee 8 Methods of Measuring Body Temperature ................. 8 Methods of Measuring Temperament ...................... 9 Bedyweight eeeeeeeeeeoeeeeeeeeeeeeeo 10 StOCk 00000000000000.0000...000000000 10 Rewts eeeeeeeeeeeeeeeeeeeeeeeeeeeee 10 IV DISCUSSION 0000000000000000000000000000. 19 v CONCLUSIONS ooeoooooeeeeoeeeeeeee0000000 21 VI SUM 0000000000000eeeooseeeseeeeeoeeo 22 VII LITERATURE CITED 00000000000000.0000000. 23 INTRODUCTION The selection of fowl for egg production by an examination of physical characteristics popularly accepted as related to egg produc- tion has been practiced for many years. There are,however, few re- liable experimental data that substantiate such practices. It is possible that a great amount of such work is empirical. At present, many breeders favor the use of external observations in estimating the egg laying ability of a hen, but experimental re- sults cast doubt on the validity of such pepular opinions. The sig- nificant experimental data encourage the use of physiological char- acters that a laying hen exhibits for estimating her laying ability. Physiological characters might conveniently be classed as those characters that are associated with the functions of an organism. -1- REVIEW OF LITERATURE In searching the literature. no work of the earlier breeders was found that mathematically related hen characteristics with egg production. Hogan (lSlh) promoted four particular body measurements as indi- cating the production value of fowl. These measurements were: thick- ness of pubic bones, width of the pelvic arch.as indicated by the spread of pubic bones, the span of the abdomen as measured by the distance between pubic bones and the keel bones, and shape of the skull as indicating prepotency. lycoff (1891) based his criteria of egg production upon: 1. Body type as exemplified by large bones. rather long in leg and neck; long on back. deep up and down behind. with legs set well apart: breast bones somewhat prominent; flesh :zid. strong, and muscular: in good condition but not too 2. Head type as indicated by comb above the average size, eyes bright and full. 3. Temperament: disposition lively. more inclined to crowd about the attendant. Sharp (1891) advanced the theory that the egg laying type of fowl should be squarely built, blocky, well proportioned. wide on the back. and with legs well apart, the legs and neck of medium length. These descriptions of characters which were thought by earlier ob- servers to indicate production qualities apparently were significant, even though they are not well explained. Seely (1896) observed that a yearling hen would always molt - 2- _ rev-er'F—v earlier than a two or three—year-old hen and that the earlier molter did not produce so many eggs as a late molter. His observations support the theory that yearling hens are poorer layers than twoqyear- old hens. a theory which is greatly contradicted by present writers. Within the last thirty years. work has been published that mathe- matically relates head characters. body form or type. anatomical measurement. and certain physiological characters with egg records. Waters (1927) in studying head characters with 200 single-comb white leghorns found that the correlation between width of cranium and egg production was -0.l9020.05. and between depth of head and egg production was 0.10010.05. Both correlations are very low. the lat- ter having less significance. Steup (1928) claimed that certain head characters are associated with egg production.yet he does not present data to substantiate his head point culling system. Miller and Carver (1933) from a study of 319 white leghorn hens found no significant relationship between head and body measurements and egg production. However. a multiple correlation coefficient of .39113.056 was obtained between the head measurements; depth of head. rear skull width. and length of head and egg production. As a contribution toward a solution of the problem as to the sig- nificance of certain head measurements of live birds in relation to egg production. Jull and Quinn (1933) presented data obtained from 50 leghorns and 50 Rhode Island reds that were killed and the skin and appendages removed from the skull. The data showed positive cor- relations but low in value. The correlation between length of skull and egg production was 0.130¢0.09. Breadth of skull was 0.083.09 and depth of skull was 0.0830.09. Pew investigators show any significant relation between body measurements and production. The data observed by the various inves- tigators pertaining to body form in its relation to egg production are summarized in Table I. TABLE I SIMPLE CORRELATION COEFFICIENTS BETWEEN BODY MEASUREMENTS AND EGG PRODUCTION IN WHITE LEGHORNS AS OBSERVED BY VARIOUS INVESTIGATORS. Correlation between egg production and the following criteria Tear Investigator Back 1°QEEB, Back width Front depth. Keel length 1921 Asmundson .. 0.36:0.oht 0.25:.oh' 0.03:0.0h 1922 Sherwood -- - - 03130.06"I 1923 Hall -0.1630.07 0.0310.07 -0.310.07 0.1510.07 1927 Waters 0.03*0.05 -- 0.0310.05 ~O.0710.05 1928 Sherwood Godbey 0.1730.07 0.2330.06‘ O.h230.06‘ -- 1933 Jull Quinn 0.2330.09 0.138.10 0.133.10 -O.2330.09 'Significant correlations There are several observations to be drawn from the data pre- sented in Table I. l. 2. 30 Considerable lack of uniformity among the observation of the different investigators is evident. Some obtained positive correlations and others negative core relations for the same measurements. 0f the 15 correlations determinations. only four have any significance. h. All correlations are relatively low. Prom measurements taken. Scholten (1927) concluded that body measurements are of no practical value in selecting the most produc- tive bird. Whitaker (1918) reported trials of the Hogan system in which width of pelvic arch and production. and shape of skull and produc- tion were .061*.lO. .0179*.06. and .0187*0.09 respectively. Knox (1933) studying 131 general purpose birds obtained data indicating a significant negative correlation between initial body weight and total number of eggs laid. His correlation was 0.105 which is too low to have much value in predicting performance. Knox (1933) also reported a correlation of 0.08% between the total number of eggs and average egg weight. Platt (1927) made a study of seasonal weight calculated by aver- aging two weights taken at the beginning and middle of each season respectively. In assembling the tables. seasonal weights were corre- lated with seasonal production. The correlations reported are sum- marized in Table II. TABLE II CORRELATION BETWEEN EGG PRODUCTION AND BODY WEIGHTS IN WINTER. SPRING. SUMMER, FALL. AND FOR THE YEAR S eason Correlation Winter .09721.O3 Spring .2279$.O3 Summer-Tall -.02111.O3 For the Year -.0633.03 .A study of the table reveals only one significant correlation and that is between body weight in the spring and egg production. {Atwood (l92h) found no significant correlation between number of eggs laid and mean egg weight. His correlations are all positive but do not substantiate the belief that the heavy layers tend to lay smaller eggs than the average of the flock. Hays (1932) in studying weights at sexual maturity and egg pro- duction found a positive correlation of .326*.03. Sherwood (1922) published data showing high correlation between egg production and characters; color of shank. color of beak. pli- abilitycf pubic bones. handling quality. and number of primary wing feathers melted. The correlations observed were -.6221.037. -.603 2138. Antone. .h31t.ol+8 and 5223.015 respectively. He reports that no distinctly significant correlation is town between capacity. depth of body. width of pelvic arch. and length of keel on the one hand. and egg production on the other. "The fact that there is such a distinct difference in the size of the correlhtion of the two classes of characters shows that the classification is not an arbi- trary one. but is based upon a real fundamental difference and that egg production itself is largely a physiological rather than an anatomical character.“ Knox and Quinn (193h) made a study of 228 single comb white leg- horns. Eighteen characters were chosen: type of feathers. body type. size of comb. quality of comb. head shape. quality of head. shape of eye. quality of eye. shape of shank. quality of shank. body depth. size of abdomen. quality of abdomen. width of back. quality of pubic bones. molt. pigment of beak and pigment of shank. Only two of the characters reported had no correlation with egg production. They were. uality of shank. -0.016. and the quality of pubic bones. -0.0lO. The body depth correlation was fairly significant. .177. Knox and Quinn (193%) also reported a multiple correlation coeffi- cient of .M9h which is not significantly different from the simple correlation of -.hh8 between shank color and egg production. Foreman (1922) in discussing criteria for selecting hens for egg production. refers to temperament as “the magneto of the pro- duction machinery. This character of hens is hard to measure due partly to lack of standard description. but it is an important factor in selecting hens for egg production.‘I Blakeslee (1918) said “high egg production is an example of the chemical efficiency of an organism. During the year a 150 egg bird weighing three or four pounds may store more fat than twice her own weight of fatty and nitrogenous substances in eighteen to nineteen pounds of eggs which she lays.“ Considering this statement and other citations. it appears that physiological characters (those characters that are altered by changes in the body function) may be the limiting factors for selection of hens for production. EXPERIMENTAL Purpose :The purpose of this study was to determine the relationship between the variables. normal body temperature. temperament. body weight. and the egg records of Rhode Island Red hens. Procedure It is commonly known that fowl are highly nervous and easily excited. Any data taken under conditions other than normal would be of little value. In order that birds might be studied.under normal conditions, free from excitement. observations were begun early in November 1939 to familiarize the hens with the presence of a person other than the regular attendant. Methods of Measuring Body Temperature In January 19h0 a series of observations of body temperatures were determined with a clinical thermometer. The temperatures were recorded in the mornings and afternoons of the days in which the ob- servations were made. The experimental conditions varied consider- ably with regards to environmental temperatures. It was thought that possibly this would make a difference in the body temperature. -8- however there was no pronounced difference in body temperatures taken under environmental temperatures between 32° and ”6° 7. The body temperatures (determined by inserting the bulb of the thermometer well into the vent and allowing it to remain for three minutes) ranged between 10h° and 108° F. under all conditions. The average temperature of each hen was computed and used to calculate the cor- relation. Methods of Measuring Temperament Temperament is logically the sum total of the reactions of a hen. In this s.udy. temperament was estimated on the basis of the hen's activity and tameness. A11 birds were given a score of from one to five according to their relative merit on the temperament scale estimate. The birds receiving a score of one were extremely active (not excited) with very bright and full eyes. a smart. alert. and intelligent expression. with a firm quick stride when walking and upon handling‘were friendly but revealed a quick Jerking motion of the head. The birds receiving a score of two were very similar in all previously mentioned characters common to those given a score of one. All birds scored three exhibited a lower index of nervous organization. characterized by being less active. somewhat sluggish in movement and habit. Birds given a score of four. were birds that exhibited a nervous organization that reached the point of excitable- ness in contrast to the friendly agreesiveness of the other scored birds. A score of five was given all birds that were slow and languid in movement. showing no outward expression of nerve action and were 10 not sensitive to changes or responsive to conditions. The writer's skill in scoring the birds according to classifi- cations of temperament as set up was verified by comparing repeated trials of scoring. Correlations ran as high as .8871.O3. as shown in Table I. which indicates that the scoring was reliable. Body Weight Body weight at the time the first egg was laid was taken from the record books kept by the College Experimental Plant. Stock The stock used in making this uudy were 90 Rhode Island Red hens obtained from the Michigan State College Experimental Poultry Plant. Except for a few individuals (about 10) they were all at the point of completing their first year's production. All hens were trap- nested; thus a record of their egg production. from the time of lay- ing the first egg. was made available. The record. however. was not inspected by the writer until all data had been compiled. An inter-class correlation with all variables studied was cal- culated. and a multiple correlation is presented in addition to the simple correlation. Results All the data that are treated statistically are presented in Table III; in Table IV. the correlation between body weight and egg 11 production: in Table V. correlation between temperature and egg pro- duction; in Table VI. temperament and egg production; in Table VII. temperature and body weight: in Table VIII. temperature and temperap ment: in Table II. body weight and temperament; in Table 1. trials of estimation of temperament: and Table XI. summary of correlations. TABLE III MEAN. RANGE. AND STANDARD DEVIATION FOR THE SEVERAL CHARACTERS STUDIED W Character - Range Mean Standard ‘ Deviation Temperature 0 Degrees :- 105.5 - 107.5 106332.026 .037 Production 61 - 267 166.31.09 13.00 Body Weight Pounds 3.“ - 6.0 3.71.01 .17 Temperament Score 1 - 5 2062,0001 e} TABLE IV GOWION DEW EGG PRODUCT ION AND BODY WEIGHT 12 Produc- tion Body Weight 3.6 3-3 h.0 M2 mu h.6 ”.8 5.0 5-2 5.“ 5-6 5-3 6.0 Total 250 230 220 210 190 180 170 160 150 lilo 130 120 110 100 80 70 I-‘l-‘HH PH p I" ummmrmrmm'm-qu-Immw Total 11 10 10 35 r = 0.00230e07 TABLE V 13 CORRELATION BETWEEN EGG PRODUCTION AND BODY TEMPERATURE w Egg Pro- duc- tion Body Temperature 105.5 105.7 105.9 106.1 106.3 106.5 106.7 106.9 107.1 107.3 107.5 Total 260 250 2&0 230 220 210 190 180 170 160 150 1ho 130 120 110 100 80 70 h‘ h‘ kiln r0 be P‘ P‘ NHHN 1 HHHmI—‘mt—‘t’wmmbfi no F‘ P‘ P‘ (hi-0 N-C'm hate #0:: Humrmmmmm Total 11 11 23 11 13 85 r 3 .05810.06 TABLE VI CORRELATION BETWEEN EGG PRODUCTION AND TEMPERAMENT Egg Temperament Production | 1 2 3 PM 5 Total 260 1 1 250 2ho 1 1 230 220 210 200 190 180 170 160 150 1&0 130 120 1 110 100 \u .c'xn to up \u an F'\fl id id to hi to F‘ F“ h‘-='\N \u or P‘ r: n) h‘ P‘ x» In us .=’-='