Cow-calf reproduction systems and effect of concentrate supplement at pre- and post-partum on reproductive performance of cross-bred Brahman cows raised in households in Binh Dinh Province

The objective of this study was to evaluate (1) cow-calf reproduction system and (2) effects of concentrate supplement at pre- and post-partrum on reproduction performance of Brahman cows. Total 66 cattle raising households (10%) in Tay Giang commune, Tay Son District, Binh Dinh province) were surveyed. In addition, 255 Cross-bred Brahman cows were evaluated for reproductive performance, and 163 calves were weighted from birth to 6 months of age. On-farm experiment and demonstration of the effect of pre- and post-partum supplementary feeding on cow-calf performance were conducted from January 2014 to December 2016. The survey results showed that the cow-calf system in the communes has been moving from extensive to semi-intensive one. Cows accounted for 50% of cattle surveyed, of which 90% were Zebu crossbred. Cow feeding systems were mostly grazing and stall feeding (97%). A long calving interval (15.9 months), lack of nutrition for cows at pre- and post-partum, and poor feeding management were identified. The experiment showed that improved supplementation for cows at pre- and post-partum could shorten calving to conception interval from 212 to 176 days (P < 0.05). The on-farm demonstration confirmed that post-partum supplementation can reduce calving interval and the techniques were well accepted by farmers in the region.