Dairy Breeding Management: The Effect of Body Weight on Conception Rate of Yearling Heifer with PGF2 Induced Estrus Following Artificial Insemination

Abstract

This study was to evaluate the conception rate of yearling dairy heifer at PT. Ultra Peternakan Bandung Regency following artificial insemination with PGF2-induced estrus. A total of 100 heifer records selected randomly from 700 heifers based on body weight (>300 kg) and has normal reproduction were used for this study. Non estrus animal during one day observation was then injected with PGF2 for estrus induction. The animal showing estrus within 11 days observation post PGF2 injection, was inseminated, nevertheless was reinjected for second PGF2, and the estrus animal was inseminated according to the standard procedure. The results showed that following first PGF2 injection, 50 heifers showed estrus, while 50 non-estrus others were re-injected PGF2. All 50 animals showed estrus following second PGF2 injection within 11 days thereafter. Body weight was divided into 3 groups, Low (<341 kg), Medium (341-355 kg), and High (>355 kg). There were significant difference (P<0.05) for Service per Conception, S/C (1.94±0.86, 1.60±0.74 and 1.78±0.87), and Conception Rate, CR (39%, 54% and 50%), respectively for Low, Medium and High body weight of yearling heifer. It was concluded that yearling dairy heifers were possible to breed and result pregnancy when reached body weight more than 300 kg.