The effect of supplementation on reproduction and weight in extensively managed beef cattle in the Eastern Kalahari bushveld

A cow’s lifetime productivity is influenced not only by breed and age at first calving, but also by feeding conditions and appropriate supplementation. The objective of the study was to determine the effect of two different lick supplementation strategies between weaning and first conception on the calving percentage and weight over the first three calving seasons. In the study, 24 Bonsmara heifers were divided into two groups of 12 animals each after weaning. The two heifer groups received the same mineral lick during summer. During winter months (April – September), the one group received a protein rich winter lick (400g/kg protein) while the second group received a production lick (winter lick supplemented with yellow maize in a ratio of 2:1). The heifers were bred naturally at 24 months during a three-month summer breeding season (December – February). Calving percentage and reconception rate of the group which received production lick in the winter was 92%, 50% and 58% for the first, second and third calving seasons. This was significantly higher than the calving percentage of 67%, 42% and 33% for the group which received only winter lick. Cow weight at calving and calf 205 day corrected weaning weight were higher over the three consecutive calving seasons for the heifers receiving production lick during winter. These results indicate that it may be worthwhile to provide good supplementation before the first breeding season for the incentive of a better calving percentage and higher calf weaning weights up to the third calving season.