Influence of Cow Body Condition Score and Late Gestation Protein Supplementation on Subsequent Calf Health, Performance, and Future Productivity
We conducted a 2-yr study to evaluate the influence of cow BCS and dried distillers grains (DDGS) supplementation during late gestation on cow and calf productivity. The experimental design was a 2 X 2 factorial; 2 BCS (4 or 6) and supplemented or not supplemented. Approximately 12.7 kg/cow of low quality meadow hay (6.4% CP) was provided each day and supplemented cows received 1.81 kg/cow of DDGS every Monday and Wednesday and 2.72 kg/cow on Friday. On each supplementation day, supplemented cows were gathered and sorted into pens based on their respective blocking structure. After completing consumption of their allocated supplement, cows were returned to a common pasture. Performance data and binomial data were analyzed as a Randomized Complete Block using PROC MIXED and PROC GLIMMIX in SAS, respectively. Calf birth weight was greater with BCS 6 cows compared with BCS 4 (P = 0.002) and for supplemented compared with unsupplemented cows (P = 0.05). In addition, weaning weight was greater for BCS 6 compared with BCS 4 (P = 0.05) and calf weaning weight and ADG to weaning were greater for the offspring of supplemented compared with unsupplemented cows (P ≤ 0.02). We noted no differences in post-weaning calf performance or carcass characteristics (P > 0.10). However, BCS 6 cows had approximately 10% more live calves at birth and at weaning (P < 0.001) compared with BCS 4 cows. Also, pregnancy rate was 91% for BCS 6 compared with 79% for BCS 4 cows (P = 0.005). Supplementation during late gestation resulted in an estimated net return of $7/cow if calves were sold at weaning compared with not supplementing. More importantly, because of additional weaned calves, the estimated net return for BCS 6 cows at weaning was $71/head more than BCS 4. Likewise, with retained ownership, BCS 6 cows yielded a net return of $130/head more than BCS 4 cows. This research demonstrates the potential consequences of not maintaining cows in good BCS (> 5) at calving; greater calf losses, less weaned calves, decreased pregnancy rate, and lower economic return.