Variation and correlations of the organs of single comb white leghorn cockerels.код для вставкиСкачать
AUTHOR'S ABSTRACT OF THIS PAPER ISSUED B Y THE BIBLIOGRAPHIC SERVICE. NOVEMBER 19 VARIATION AND CORRELATIONS O F T H E ORGANS O F SINGLE COMB WHITE LEGHORN COCKERELS' ARTHUR JOHN SOUBA Section of Animal Nutrition, Division of Agricultural Biochemistry, University of Minnesota, St. Paul ONE PLATE The writer, having collected considerable data on the size of organs of single comb white Leghorn cockerels in connection with a nutrition study, deems it advisable to make a brief report because extensive data on the subject are lacking. Two hundred cockerels of uniform weight and appearance were selected at the age of 34 days from a hatch of 609 chicks. These cockerels were of line bred ancestry for several generations back and the data of only those birds that showed a normal growth to the age of 100 to 120 days are reported here. The data which are presented here, comprise the data of pens A and B of a previous publication (Souba, '23). Pel1 A formed a group of fifty birds receiving a regular poultry ration of grain, grain mash, and green roughage. Pen B formed a group of fifty birds receiving a synthetic diet of starch, casein, butterfat, lard, salt mixture, and yeast product. That the rations were of approximately relative equal value was shown in the publication of the above reference, for there existed no significant difference in the mean, standard deviation or coefficient of variation of the weights of the birds of these two pens. The slight differences which were not significant and which were observed in the mean, standard deviation and co-efficient of variation of the weight and size The writer wishes to express his indebtedness to the Minnesota Agricultural Experiment Station for the privilege of collecting the data presented in this paper. 291 THE ANATOMICAL RECORD, VOI.. 26, NO. 4 292 A R T H U R J O H X SOUBA of organs may be attributed to the fact that the data werz collected on a small number of individuals and to randoiri sampling. Po r t e r ('05) observed a coefficient of variation of 10.8 to 17.8 per cent in the weight of boys between the ages of 1 2 to 16 years, which corresponds to the age of puberty in boys. This is a period of life in which the variation of growth is the greatest f o r inost organisms. White Leghorn cockerels between the ages of 100 to 120 days show a coefficient of variation of 19.6982 1.203. Latimer ( '22) has already ~ 1 1 0 ~ ~ 7 1 1 that a 100 to 120 day old white Leghorn cockerel falls in tlie period of greatest growth, ancl accounts thus for the relative variation in the weight of these cockerels. Jackson ( '13) reports a coefficient of variation in the body weights of albino rats of 13.6k0.99 at birth, 28.4t3.00 a t twenty (lays of age and 18.5t2.0 a t five montlis. Tlie coefficient of variations given in table 1 is in fair agreement with the corresponding coefficients that Jackson ('13) found f o r rats twenty days of age. I n all cases his coefficients are larger with the exception of weight of testes, in which lie also found the largest variation. I n the data for the testes, tlie cockerels showed the greatest coefficient of variation, which was extremely high, ancl doubtless due to the age a t which the birds were Billed ancl autopsied. A t the age of 100 to 120 days, not only do we find a large coefficient of variation due to the fact that the birds grow the fastest during this period, but it is also during this period that the testes of wliite Legborn cockerels begin to grow very rapidly. Tlie coefficient of variation in the length and heiglit of combs of single comb white Leghorn cockerels is less than the coefficient of variation for the absolute weight of the comb. Tlie observed coefficients were as follows : Length of combs, 18.68721.141 ; height of combs, 24.787k1.513 ; and weight of combs, 57.221 k3.490. On account of the large coefficient of variation in tlie weight of rats and the weight of their organs, Jackson ('13) pointed 1 I I Grams ST.~NDAKD DEVIATIOS i 1 j Per rent CO~FFIC,RNT i , , I ' 1 ___-- - -- 3 0 . 1 7 t 2 . 9 4 to 4 3 . 4 7 ~4.32 14.72 c 1.404 to 23.74 T 2.36 11.70+-1.16 to 19.40-c 1.85 l t i . 2 6 t 1 . 0 1 to 2 0 . 9 4 t 2.04 15.10 i1.41 to 23.30 _c 2.31 8 3 . 7 0 ~ 7 . 9 8t o 1 2 2 . 9 0 t 1 2 . 2 2 iRAXkE OF COEFFICIENTS OF VARIATION 1 s CilWUPS OF COCKEREIS OF PENS A AND B 2 1 The various statistical constants-mean, standard deviation, coefficient of variation and probable errors-were obtained by employing the usoal formnlas (Pearson's) as given by Ynle ('11) 'The various groups consisted of 25 individunls. . . . . ... 1 1 0.47 t .023 ! 3 5 . 8 7 8 2 1.i56 5.128 t 251 21.858 & 1.069 .083 1.205- .059 19.185tO.V39 .@B 0 . 4 1 6 t .0"0 18.705t0.916 .N9 0.709 1 . .03j 20.32i & 0.994 .024 I 3.48 t .017 111.182t5.438 164.22 I8.04 19.N t 0 . 9 3 2 -1- Grams 1.31 C .033 23.46 L .355 Kidneys ....... G.281= Pancreas ...... 2 . 2 2 4 t Hearts . I 3.488 1. Testes .........! 3 . 1 3 O t Spleen . ... ....1 - TABLE I Variation in the weight of organs of single comb white Leghorn c~wkerrl~ 100 observations u? P B m M w 0 3 0 9 Z u 294 ARTHUR J O H N SOUBA out a ‘spurious correlation’ factor in connection with his work with albino rats and f o r this reason said that the coeffjeients of correhtion were too high. In most cases he found a much higher coefficient of correlation in albino rats than I have found in single comb white Leghorn cockerels. However, with the large coefficient of variation in the weight of birds and the weights of the various organs, especially the testes, one is suspicious of any correlation as being due to heterogeneity of material. Theref ore, in working up t.hese data it seemed desirable first t o correlate the various groups of cockerels which were of the same age or the same weight. F o r these preliminary calculations, the weight of the birds and the weight of the testes were used, and correlation coefficients ranging from .4335 to .8002 were obtained f o r pen A, pen B, groups of cockerels 100 and 120 days old, and groups of cockerels which varied only within 100 grams in weight. This is likewise true f o r the other organs. This has lead me to conclude t h a t a n actual correlation exists between the weight of the testes or other organs and the weight of the bird, though the value of the coefficient may not be the exact or true coefficient, because of the cockerels’ unequal growth and the scatter of the body weights and organ weights. TABLE 21 of birds and the weight of COEFFICIENT OF organs. 100 observations COP.REI.ATION Weight of bird and weight of testes.. ............................. .521 +- ,050 .671 _t .038 Weight of bird and weight of spleen.. ......................... Weight, of bird and weight of liver. ................. 2301 r+ .024 Weight of bird and weight of kidneys.. ...................... .568 .047 Weight of bird and weight of pancreas ............................ .523 c .050 Weight of bird and weight of heart ............................... .776 i- .027 (b) Correlations between the weight of organs and the length of organs. 61 observations Weight of comb and length of comb.. ........................ Weight of testes and length of testes. .......................... (c) Correlations between the weight of organs and the cuhe of the length of organs. 61 observations ....... .9289 c .0119 Weight of comb and length of comb cubed.. ..... Weight of testes and length of testes cubed ....... . . . . . . . .9816i- .W32 (a) Correlations between the weight The statistical constantcoefficient of correlation-was ing the formulas given by Yule (’11). obtained by employ- VARIATION A N D C O R R E L A T I O N S IN C O C K E R E L S 295 Correlation coefficients of larger magnitude a r e further noted i n the weight of the organs and the length of the organs. Theoretically, if the shape of the organ remained constant there should be a perfect correlation between the weight of the organs and the cube of one of the linear dimensions. Any difference should be an index of the change in the shape of the organ. It would appear therefore that the comb changed its shape more than the testes. The comb of a bird has been known for some time to be a secondary sex-character. Capons do not develop combs like those of normal male birds, showing that some relation exists between the comb and sex organs, and this has been attributed to the internal secretion. The comb of a hen has been used by poultrymen as a character indicative of the hen’s reproductive activity. I n fact both fancy and utility judges pay considerable attention to the size and shape of combs. However, in my search of the literature no statement regarding the correlation between comb and testes has been found. I n the following table (p. 6) a r e given the simple, partial, and multiple correlation coefficients between the weight of the birds, weight and length of the testes and the weight and length of the combs. It is very interesting to note the correlation coefficient between the weight of testes and weight of combs as corrected f o r the weight of the birds, as well as the correlation coefficient between the length of testes and length of combs corrected for the weight of the birds. A study of the standard deviation of the second order and the regression equations justifies the statement that such a correlation exists. It is also interesting to note the relationship of the development of the testes upon the development of the comb and growth or increase in body weight. Thus from a knowledge of the body weight and development of the comb one can predict the sexual clevelopment of single comb white Leghorn cockerels. '796 ARTHUR J O H N SOUBA TABLE 3' (a) Sitttple, partial, and multiple correlations betqeen the weight of birds, the ileiglit of testep, and tlie weight of combs Kninber of obscrrations, 61 \ AIIIABI F. \\'eight of bird Wcight of testes IYcight of comb Y S1 s2 s3 5 T 4 S I ) A K D DE\'IATION WF.4N 8R2.200 c 15.174 3.204t 11.950 -c 0.336 0.590 175.730 c 10.732 3.877 & 0.236 6.838 Z!Z 0.418 (1)) Pimplc, partial, and multiple correlations between the \wiglit of birds, the length of testes, and the length of combs Kiunibrr of observations, ti1 V,\ K I A B1.E ]\'right of bird Length of testes I m g t l i of comb Y S1 x2 ss >"AN 892.800 c 15.174 2 . 1 4 6 c 0.067 8.594 + 0.139 ST.\SI).\I:L) I)I?vixrios 175.750 t 10.732 O.773f 0.047 1.rjoii t 0.098 The statistical constants were obtained by employing the forninlae gircn b y Tlllc ( ' 1 1 ) . LITERATURE CITED C . M. 1913 Postnatal growth in the albino rat. Anier. Jonr. h a t . , vol. 15. LATIMER, €I. B. 1922 The postnataI growth of body, systems and organs of tlie single comb white Leghorn chicken. Thesis, Univ. of Alinn. Lib. PORTER, W. T. 1905 Growth of St. Louis children. Trans. St. Louis Acad. of Sciences, vol 6. SOUBA, A. J. 1923 Influence of the antineuritic vitamin upon the internal organs of single comb white Leghorn cockerels. Am. Jo. of Physiol., vol. 44. PULE, G . U. 1911 An Introduction t o the Theory of Statistics. London and Philadelphia. JACKSOS, VARIATION AND CORRELATIONS I N COCKERELS PLATE 1 ARTHUR JORK SOUBA This plate shows the combs and testes of a group of white Leghorn cockerels which were of the same age, approximately the same weight and differing in the size of combs.