Body measurements and body weights of special-fed Holstein veal calves.
Changes in various body dimensions of special fed veal calves were measured and correlated with body weight (BW) at three specific times during the growth period as contemporaries and over the entire feeding period as noncontemporaries. The calves (n = 826) were weighed and measured for body length, heart girth, wither height, and hip width at 2, 8, and 16 wk after arrival at the veal farms. Each of the four measurements, expressed as ratios to BW, decreased over the feeding period; decline in the ratio of hip width to BW was less than the decreases in the other ratios. Linear models to predict contemporary BW within each age group based on all body measurements were developed; R2 values for models for 2, 8, and 16 wk were 0.72, 0.77, and 0.76, respectively. Within each of the three age classes, a model including linear, quadratic, and cubic terms of heart girth yielded the highest R2 values of any single measurement (0.46, 0.63, and 0.67 for data for 2, 8, and 16 wk, respectively). The addition of heart girth as a second linear measurement to three-term models containing only one other measurement increased the R2 more than did the addition of any other single linear expression, except for the equation based on body length. When all records on all calves were combined and the observations were treated as noncontemporaries, the R2 was 0.97 for a linear model that included all four measurements. However, this R2 was essentially the same as the R2 from a three-term model using only heart girth. The cubic models in descending order of R2 values were heart girth, body length, hip width, and wither height. These results suggest that BW can be predicted accurately in a group of noncontemporary male veal calves ranging from 2 to 16 wk after the start of the feeding period. However, the BW of calves within contemporary groups (2, 8, and 16 wk) cannot be predicted accurately according to R2 values.
Wilson
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Department of Dairy and Animal Science, Pennsylvania State University, University Park 16802, USA.
Egan
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Terosky
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D000375:Aging; D000821:Animal Feed; D000818:Animals; D001699:Biometry; D001835:Body Weight; D002417:Cattle / Q000033:anatomy & histology*; D008297:Male; D012044:Regression Analysis; D015430:Weight Gain