Birthweight was very important for growth until 12 months of age, particularly in bull calves which were heavier fed than heifer calves. Correlation between birthweight and bodyweight in bull calves was ± 0.5.The early first calving of heifers in the Netherlands (24 months of age) decreased birthweight of the first calf considerably, being 5 kg less than of calves born of cows. This difference in calfweight increased to 24 kg at 12 months of age. Autumn calves were at birth 2.5 kg heavier than spring calves. This difference increased in the first year of life to 48 kg, presumably through the difference in environmental conditions.Average weight, diameter and length of calves' hair at birth fluctuated between years. The sire had a definite influence on coat characters of offspring. The cattle breeds used in this study, Friesian and the Meuse-Rhine-Yssel, differed in coat type: the Friesians had a thinner shorter fibre with less medullation. The differences between coat types at birth were not significant.
|Qualification||Doctor of Philosophy|
|Award date||6 Mar 1964|
|Place of Publication||Wageningen|
|Publication status||Published - 1964|
- dairy breeds
- genetic variation