We evaluated the effects of two estrus synchronization protocols on blood metabolic profile, progesterone levels, and reproductive performance of dairy goats. Forty mature does were assigned into two groups: Protocol 1 (10 Alpine and 10 Saanen goats received two injections of PGF2α; 10 mg/goat on Days 1 and 11) and Protocol 2 (10 Alpine and 10 Saanen goats received 10 mg PGF2α on Day 1, GnRH 43 μg on Day 9, and 10 mg PGF2α/goat on Day 11). Estrus was monitored and natural mating was performed 24-36 h post-second PGF2α injection. Estrus response was higher for Protocol 1 (70%) than for Protocol 2 (60%). Alpine goats showed higher (p ≤ 0.05) estrus response than Saanen ones. Pregnancy rates tended to be higher for Protocol 1 (78.5%) than for Protocol 2 (66.7%). Progesterone concentration was higher (p ≤ 0.05) for Protocol 1 on Day 3 post-breeding (PB). Blood cholesterol and glucose levels were higher (p ≤ 0.05) for Protocol 2 on Days 12 and 21 BP, respectively. No differences were observed in kidding rates and kids' birth weights between the two protocols or between the breeds. In conclusion, PGF2α alone was more effective for estrus synchronization of dairy goats than PGF2α + GnRH.
Kolikapongu et al. (Thu,) studied this question.