Data_EffectOfBodyConditionScore....xlsx

The objective was to evaluate the effect of body condition score (BCS), at the beginning of the fixed-time insemination (TAI) protocol, on ovary score (OS) and pregnancy per TAI (P/TAI) in Nellore females. Non-pregnant females (1,790) classified according to the parity (n= 586 heifers, 421 primiparous and 786 multiparous), were assigned to a TAI protocol. Cow BCS [1-very thin to 9-very fat] and OS [1-ovary with small follicles (<5 mm); 2-ovary with large follicles (>7 mm); 3-ovary with corpus luteum] evaluations were performed. TAI protocol, based on estrogen and progesterone, started 30 days after parturition of last cow in each group and cows were inseminated with semen from Angus, Nellore, Charolais and Brangus breeds. Pregnancy was diagnosed at 30 days after TAI. Data were analyzed by logistic regression and analysis of variance, including in the model the effects of the BCS, animal category and possible interactions. Significance was established as P≤0.05 and trend as 0.050.05), but in primiparous cows a tendency (P=0.063) and an effect in heifers (P<0.05) were detected. Primiparous cows and heifers with better BCS showed greater P/TAI. Effect of BCS (P<0.05) was detected on the OS in all categories evaluated, and females with higher BCS (≥6.50) also had higher OS. In conclusion, BCS at the beginning of the TAI program influences the OS in all categories analyzed and the P/TAI in primiparous and heifers.