PSV-B-18 Effect of Puberty Induction on Embryonic Loss in Precocious Nellore Heifers

Abstract This study aimed to determine if heifers induced puberty had damage in reproductive performance compared with that reach naturally. Nellore (n = 210) were weaned at 8 ± 0.7 mo of age assigned 42 feedlot pens according BW (184 1 kg). The diet was compounded by Tifton-85 haylage (18% CP; 55% TDN) ad libitum and supplement (4g/kg BW; 25% 60% TDN). Puberty growth assessed weekly. At 14 age, 46 reached naturally (precocious heifers; PH) 164 non-pubertal submitted induction progesterone (P4) insert for 10 days estradiol cypionate (0.5 mg) P4 removal (puberty induction; PI). After fourteen days, all TAI. Heifers considered pregnant 20 (P20) after AI when CL blood flow < area (Power-Doppler). Pregnancy rate also determined 30 (P30) 60 (P60) embryo detection. Early (P20 – P30) late (P30 P60) embryonic loss determined. Reproductive data analyzed GLIMMIX, using repeated measures over time (MIXED; SAS 9.3). PH heavier than PI from 16 which 296 285 3 kg respectively. beginning TAI, 88% a CL. similar (P > 0.05) between treatments, pregnancy 20, or 65, 47 43% 61, 53 48% PI, (26 vs 14%) (9 9%) In summary, natural pubertal performance.