PERFORMANCE CAPACITY OF BEEF-COWS AFTER TWINNING

Studies were made with 330 dams of twins and 757 dams of single calves of different beef genotypes, supplying confirmatory evidence that both dam groups show almost equal live weight and withers height growth up to the third calving season. As a tendency, however, dams of twins were slightly superior on two of the four test farms. After twinning cows exhibited partly considerable reproductive disturbances, which could however be minimized by intensive care post partum. Since twin dam show no disadvantages after calving of singles, their overall reproductive result is hardly imparied. The superiority of twin dams is revealed by their lifetime performance. They get much older than single-calf dams and produce 1.5 to 2 calves more during their reproductive life. In view of their lifetime performance twin dams belong to the most efficient animals of beef populations too, deserving therefore special attention. With regard to their genetic merit for twinning they may be of particular interest for systematic dam breeding.