The effect of GnRH to litter size, colostrum and milk production in Nulliparous Sapera goat synchronized by PGF2α

Abstract

Estrous synchronization could become as an alternative to increase the efficiency of reproduction such as PGF2α can be combined with GnRH to optimize reproduction. The objective of this study was to evaluate the effect of GnRH hormone to litter size, colostrum and milk production of Sapera goat synchronized by PGF2α hormone. The study used 14 nulliparous Sapera does at the age of one yr. old after reaching sexual maturity. Estrous synchronization was treated by two intramuscular injections using PGF2α (Lutalyse®) at a dose of 1 mL. The treatments were conducted for two different hormone regimens. Group one was injected twice with PGF2α within an 11-d interval (n=6 heads). While group two was injected with GnRH (Ningbo Sansheng Pharmaceutical Co. Ltd) at a dose 0.25 mL on the 9th d. after the 1st injection of PGF2α and before the 2nd injection of this hormone within 11 d. interval (n=8 heads). Then all goats were mated by natural mating. The research design was by Completely Randomized Design, in which the variables were observed for litter size, colostrum and milk production. The results showed that the does treated with GnRH compared to untreated GnRH resulted in the averages of litter size by 1.33±0.51 vs 1.25±0.46, colostrum production by 350.55±227.06 ml vs 528,33±209.20 mL, and milk production by 624.90±195.43 ml vs. 654.61±166.27 ml, respectively. The conclusion was that there was no significant difference of both of the does treated with GnRH and without the addition of GnRH on litter size, colostrum, and milk production.