Conception Rate of 11 Months Old Dairy Heifer Following Artificial Insemination with Natural Estrus and PGF2 Treatment

The aim of this study was to evaluate the conception rate of 11-months old dairy heifer following artificial insemination with natural estrus or treated with PGF2 at PT. Ultra Peternakan Bandung Selatan. A case study was applied in this study involving all data of 700 records for date of birth, body weight and reproduction status. Sample was selected according the complete records with criteria of age was 11±3 months, body weight >300kg, having normal reproduction organs detected by rectal palpation. The results showed that from observation of selected 300 samples out of 700 heifers, 25 heifers of them were natural estrus (Control), 50 estrus after single PGF2 injection (PG), 95 following single PGF2 and left to normal estrus after 21 days (PG-N), 50 after double PGF2 (2PG), and the rest of 80 heifers showed estrus following double PGF2 - Natural estrus (2PG-N) with the conception rate (CR) of 17/25(68%), 44/50(88%), 42/50(84%), for the respective groups. None of heifers in PG-N and 2PG-N groups became pregnant after first insemination. The body weight (BW) was classified into Low (336-347kg), Medium (348-359kg) and High (360-372kg). The total conception rate was 34%. The CR for Low, Medium and High BW were 41%, 32% and 31%, respectively. The conclusion, the 11-months old heifer was possible to become normal pregnant following insemination without and with PGF2 injection when reached body weight over 300 kg. To ensure the higher number animal exhibiting estrus, double PGF2 injections should be applied.