“I think we can claim to have succeeded in this in that the only older cows that require assistance at birth are those whose calf is presenting abnormally. Where the heifers are concerned it is exceptional for those having a heifer calf to require assistance although in some seasons anything up to 10 % of those having bull calves might have difficulty.
We might be able to avoid this by using sires with very low birth weight EBVs but one of the objects of the exercise is to challenge the heifer to have a calf within the normal weight range before she qualifies as a permanent member of the herd. Needless to say the cow is expected to feed and care for its calf until they are separated at weaning.”