Produtividade e eficiência de vacas Nelore em pastagem de Brachiaria decumbens Stapf nos Cerrados do Brasil Central

The productivity of Nelore cows on Brachiaria decumbens Stapf pasture was measured during four years, in a soil initially improved with limestone and fertilizer and with free access to a mineral mixture. Pregnancy rate (PR), calving rate (CR), weaning rate (WR), calves weaning body weight (BWC), productivity (P = kg of calf/cow) and efficiency (E= P/100 kg of cow) per cow, productivity per area (AP = calves kg/ha), as well as cow body weight and body condition before the calving season (CLW and CBC), at the middle of the mating season (MLW and MBC) and at weaning (WLW and WBC) were evaluated. Mean PR, CR and WR of 87.5, 81.7 and 77.2%, respectively, were observed. Mean LWC of 170 ± 21.89 kg and mean weaning age of 202 ± 16.48 days were observed. Significant effect of calving order (CO) on LWC was detected. Cows between CO3 and CO9 weaned the heaviest calves. Values of 130 kg and 32.19 kg were observed for P and E, respectively, with AP of 192 kg/ha. The CLW and CBC, MLW and MBC, and WLW and WBC were of 471 + 19.67 kg and 4.45 + 0.30; 405 + 21.48 kg and 3.32 + 0.44; 410 + 9.35 and 3.54 + 0.19, respectively. The correlation between body weight and body condition was of 0.66. Nelore cows maintained on a tropical pastures of Brachiaria decumbens Stapf, in an initial fertilized soil, had high reproduction level and productivity. Cows with medium calving order had higher productivity than primiparous and older cows.