THE INCORPORATION OF HEALTH TRAITS INTO CATTLE-BREEDING PROGRAMS

Hereditary defect genes are found in all populations. A steadily decreasing breeding base implies a possible dangerous accumulation of individual hereditary defects. Pathogenetic monitoring, especially of test bulls, is therefore indicated. Prior to testing, all potential A. I. bulls must be subjected to a molecular genetic examination for BLAD- and DUMPS-defective genes. Bulls with one or more defective genes should no longer be used for testing but should be prematurely slaughtered. Fertility and udder health traits are antagonistically linked to milk performance. Despite their low heritability, their incorporation in the breeding process is already justified today. Especially in the case of A. I. bull selection it is true to say that sires with shortcomings in this respect should be identified and discriminated against in the breeding process. The identification of these sires presupposes the conduct of routine breeding value checks for these traits. Apart from recording the progress made by calves, routine breeding value records for sires (A. I. bulls) should also include calf deaths. They should also take into account not only perinatal deaths, but also post-natal ones (in the first two weeks of life). Additional attention paid to animal health traits pays dividends, especially where the marginal utility of milk is low. As a rise in milk prices is most unlikely in the long term, systematic additional incorporation of such traits is already urgently to be recommended.