Abstract:
Pre-Natal Growth of Cattle By A. G. LYNE:` : SUMMARY A comparative study has been made of the pre-natal linear dimensions and body weights of 22 foetuses and three new-born calves of B. indicus X B, ta' urus,, and 33 foetuses and ` new-born 7 calves of B. tauras. The linear equivalence (cube root of the body weight) is used as an overall measure of size against which the parts of the body The body weights and linear measurements are are compared. similar in the two types. The only exception is the ear length which is longer in the crossbreds, and the difference is apparent as early as 100 days of foetal life. INTRODUCTION The pre-natal growth of European cattle (Bos taurus) has been described by a number of investigators (Winters, Green and Comstock 1942; Postma 1947; Swett, Matthews and Fohrman 1948; and others) but I believe that the following observations are the first to be pub' lished on this phase of growth for Brahman crossbreds (B. indicus X B. taurus). For comparison, observations on B. tauras are included! in this study. MATERIAL B. indicus X B. taarus .-Twenty-two foetuses and three newborn calves were obtained from the National Cattle Breeding S,tation, Rockhampton, Queensland. The dams were Hereford and Shorthorn which had been inseminated with semen from a single Brahman (Zebu) bull. The ages of all specimens were therefore accurately known. The same specimens were the subject of a study of the development of skin and hair (Lyne and Heideman 1960). B. taums.-Twenty-five foetuses were obtained from the State Abattoir, Homebush, N.S.W., and a, further eight foetuses and seven The new-born calves were collected from localities near Sydney. ages of most of these animals were determined from information ,on the insemination or last service date of the dam. The majority of these specimens, also used in a study of hair development (Lyne and Heideman 1959), were from dairy breeds. MEASUREMENTS For all specimens the body weights, obtained before fixation, and the linear measurements,. taken as illustrated in Figure 1, are given in Tables I and II. In Talble II the details, of the new-born calves and some of the foetuses of B. talurus are not given be,cause the ages were estimated or only the body weights were recorded. * C.S.I.R.O., Division of Animal Physiology, The Ian Clunies Ross Animal Research Laboratory, P.O. Box 144, Parramatta, N.S.W. 153 CROWN-RUMP LENGTH HIND-LEG HEIGHT AT WITHERS FORELEG LENGTH LENGTH Fig. 1. Positions of foetal measurements. 154 155 156 Body weight changes (Fig. 2) .-The changes in body weight of the B. indicus X B. taurus specimens follow a similar pattern to the B. taurus specimens which are also similar to the data published by Winters, Green and Comstock (1942) and Swett, Matthews and Fohrman (1948). The observations of these authors are included in Figure 2. Marked changes in body weight occur during the late stages of pregnancy but the data are inadequate to show breed differences. 42 3200 0 I 0 . . 38 2800 I 2600 Bos taurus Bos mdlcus X 00s A N 40 3000 + o- 36 . 0 34 2400 - l o 32 2200 - taurus D COMSTOCK * x WINTERS.G R E E N + SWETT. M A T T H E W S A N D FOHRMAN 30 2000 0 28 !i c7 +. s . 0 *o 0 00 a ,. x . 26 1600 24 1400 z $ a a !i Y w z si 8 22 1200 O0 . 0 20 1000 1 0 e . , 18 BOO * + M 0 * 16 600 x x . . 14 400 12 2oo LI y---J& lrw?cX~l i4 0 I 1 ' IO 20 40 60 80 100 120 140 160 . + 8 x 6 .b 0 . r 20 40 60 80 100 AGE 120 140 160 180 200 220 240 260 280 t t 300 CONCiPTlON (days) FROM CONCEPTION Fig. 2.-Relation between body weight and foetal age in B. indicus X B. taurus and B. taurus. T' data of Winters, Green and Ctomstock (1942, Table 3), and he Swett, Matthews and Fohrman (1948, averages for all breeds in Table 1) are shown. 157 Dimensional changes .-I n order to compare the growth of various parts of the body with the body as a whole, the linear equivalence is used as a standard in a manner similar to that used by Lyne and Verhagen (195' for the marsupial Trichosurus vulpecula. 7) The linear equivalence is defined as the length of the side of a cube whose volume is equal to that of the animal. In actual practice the cube root of the body weight is substituted for body volume. In the cattle specimens examined in the present study there is a straight line relation between linear equivalence and age. However, when the changes in linear equivalence from conception to adulthood are considered the growth curve is sigmoid (Lyne and Verhagen 1957). Of the twelve linear dimensions recorded in this study (Fig. 1) ths relative (changes of only seven are illustrated in Figures 3, and 4. To avoid unnecessary duplication the other measurements are omitted, the results obtained for these measurements following substantially similar trends. Some measurements, such as the straight crownrump length, show a straight line relation when plotted against the l Bta uru s .. x ataurus EAR LENGTH 0 0 alndlcus . 0 . 0. 0 . 0 . HIND LEG . 0 LENGTH ' . . . 0 0 0 . 8 00 0 cP 0 00 0 B .'O O HEIGHT WITHERS AT 8 %+f+ OL 0 Oc I 5 I IO LINEAR I 15 EQUIVALENCE I 20 (cm) 1 25 I 30 Fig S.--Linear dimensions plotted against linear equivalence (3 &dy weight) in B. indicus X B. taurus and B. taurus. 158 linear equivalence, whereas other measurements, such as those shown in Figures 3 and 4, show a change in relative magnitude linear dimension (i.e. - ) of the part concerned. Although the data linear equivalence are concerned with pre-natal growth a maximum relative magnitude comparison of occurs only once for each part. It is obvious from a ` Figures 3 and 4 that the head reaches this maximum earlier than the limbs. In all measurements, except ear length, no difference bletween the Brahman crossbreds and B. taurus can be detected. The difference in ear length between the two types is apparent in all but the smallest f oetuses examined. 35 30 B.taurus 0 l 0 0 a l . X BtaUrUS t LENGTH 0 Bindtcus 25 HEAD l (CU MD) 20 0 0 l 0 l 0 l 0 l . . 0l l l IS 5 ? :: 20 0 HEAD LENGTH (STRAIGHT) 0 0 l # W 3 IO IS 09 00. . 0 0 0 5 IO IS co l l 0 0 0l 0 . O . 0 IO . HEAD WIDTH 00 O0 ,8' . 5 - LINEAR EQUIVALENCE (cm) Fig. 4.--IAncar dimensions plotted against linear equivalence (:I Jbody weight) i n B. indicus B. taurus a n d B. taurus. I X 159 DISCUSSION In the present study the gestation period of the B. taurus newborn calves was taken to be 2801 days but the mean duration of gestation varies with the breed and the range of the breed means is from 278-290 days (Asdell) 1946). *The recorded age of each foetus was found to be in close agreement with Postma' (1947) body sS weight and body length data for black and white and red and white cattle! in Holland, and the body weight data of Winters, Green and Comstock (1942) and Swett, Matthews and Fohrman (1948) for various European breeds in the U.S.A. In studies on growing animals it may sometimes be an advantto make certain body measurements, in addition to observations ekles (1920) was of the opinion that the growth on body weight. E' of an animal cannot be properly represented either by body weight or any body measurement alone. The height at withers, which was the linear measurement chosen by Eckles in his studies of the normal growth of dairy cattle, has the' disadvantage that it is only an approximate measure of height when applied to a foetus. In Figure oetuses 3 it is seen that it tends to be more variable in advanced f' than either foreleg or hind-leg length. The scatter of the points shown in Figures 3 and 4, and in the data. in Tables I and II, indicates that some dimensions are more accurate measures of growth than others. The straight head length, for example, has the advantage of being easier to take than the curved head length and it shows less variation. Probably the most interesting feature of this study is the similarity in the rate of growth between Brahman crossbred foetuses, which have a common sire, and the European foetuses from, a heterogeneous group of cows. The changes in body weight and linear measurements, except ear length, are closely similar in the two types. Studies on the pre-natal development of skin and hair (Lyne and Heideman 1959, 1960) also show that the two types are very similar. Hair follicle initiation on the midside begins at about 80th day of gestation and extends to about the 170th to 180th day. It is clear that the commonly observed longer ear length of Brahman cattle is also consistenily -z1, feature of Brahman first crosses with European breeds and therefore it is genetically controlled. It is most interesting, however, to note that this difference develops at a very early age; that is at about 100 days of gestation when the foetus weighs less than 400 g. age ACKNOWLEDGEMENTS The author is particularly indebted to Mr. J. F. Kennedy, Belmont' , Officer-in-Charge, National Cattle Breeding Station, ' Rockhampton, Queensland, Mr. R. H. Hayman, Officer-in-Charge, F. D. McMaster Field Station, Badgery Creek, N.S.W., and Mr. P. Brydon, State Abattoir, Homebush, N.S.W., for most of thei material. The technical assistance of Mr. J. W. Elfick? Miss M. J. Heideman, Mr. A. M. Sharp, and Mr. E. W. Taylor is gratefully acknowledged, REFERENCES Asdell, S. A. (1946).- 'Patterns of Mammalian Reproduction' (Comstock Publishing Co., Inc., New York). Eckles, C. H. (1920) .-The normal growth of dairy cattle. Res. Bull. MO . Exp. Sta. No. 36. Lyne, A. G., and Heideman, Margaret J. (1959 ).-The pre-natal development of skin and hair in cattle Bos ta urus L. . Aust. J. Biol. hi. 12: 72-95. 160 Lyne, A. G., and Heideman, Margaret J. (1960).--' rhe pre-natal development of skin and hair in cattle II. Bos indicus L. X B. taurus L. Aust. J. Biol. Sci. 13: (in press). Lyne, A. G., and Verhagen, A. M. W. (1957).-Growth of the marsupial Trichosurus vuilpecula and a comparison with some higher mammals. Growth 21 : 167-95. Postma, C. (1947) .-Die Ouderdomsbepaling bij Runder Foetus. Tijdschr. Diergeneesk. 72 : 463-531. Swett, W. W., Matthews, C. A., and Fohrman. M. H, (1948) .-Development of the fetus in the dairy ,cow. U.S. Agr. Dept. Technical Bull. No. 964. Winters, L. M., Green, W. W., and Comstock, R. E. (1942).-Prenatal development of the bovine. Tech. Bull. Minn. Agric. Exp. Sta. No. 151.