Assessment of estrous synchronization protocols and pregnancy specific protein B concentration for the prediction of kidding rate in Lezhi black goats

Abstract

• The onset of estrus is earlier in CIDR + cPGF 2α + eCG. • GnRH treated at CIDR removal showed similar reproductive performance as CIDR + eCG. • PSPB detected with ELISA can identify does carrying four fetuses. The objectives of this study were to assess the efficacy of estrous manipulation protocols and pregnancy specific protein B (PSPB) levels to determine kid number at birth in Lezhi black goats. Eighty-eight does were randomly allocated to three treatments. The PPe group (n = 29) was treated with Controlled Internal Drug Release devices (CIDR) for 7 days and 300 IU eCG and 0.2 mg PGF 2α at the time of CIDR removal. The PPG group (n = 28) was treated with a CIDR for 7 days and 0.2 mg PGF 2α at the time of CIDR removal and 15 μg GnRH at the onset of estrus. The GPG group (n = 31) was treated with 15 μg GnRH (day 0) and 0.2 mg PGF 2α on day 7, and a second GnRH treatment at the onset of estrus. Does at estrus were hand-mated using proven bucks. Estrous response ranged from 80.6%–89.7 %. The onset of estrus for the PPe, PPG and GPG groups was 38.4 ± 1.9, 45.6 ± 1.9 and 53.8 ± 1.4 h (P < 0.05), respectively. Mean kidding rates (205.9 %–227.8 %) and kidding percentages (112.9 %–146.4 %) were not different in the three treatments. At day 85 of gestation, does carrying quadruplets had a greater (P < 0.01) plasma PSPB level than does that delivered one to three kids. In conclusion, PPG may be a useful estrous synchronization protocol in goats. PSPB concentration at day 85 of gestation could be a potential diagnostic tool for predicting quadruplets.