Evaluation of out-of-season estrus induction protocols in progesterone-primed mix-breed dairy goats using eCG, GnRH and E2 Carrillo Evaristo1, Meza-Herrera César A.2, Luna-Orozco Juan R.3, Delgado-Gonzales Ramón A.4, Aleman Leticia R. Gaytan4, Ángel-Garcia Oscar4, Véliz Francisco G.4, Contreras-Villarreal Viridiana4,* Universidad Autónoma Agraria Antonio Narro, Departamento de Ciencias Médico Veterinarias, Torreón, Coahuila, México 1Instituto Tecnologico de Torreón, Torreón, Coahuila, México 2Universidad Autónoma Chapingo, Unidad Regional Universitaria de Zonas Áridas, Bermejillo, Durango, México, 35230 3Centro de Bachillerato Tecnológico Agropecuario, Nº 1, Torreón, Coahuila, México 4Universidad Autónoma Agraria Antonio Narro, Departamento de Ciencias Médico Veterinarias, Torreón, Coahuila, México *Corresponding author's e-mail: dra.viridianac@icloud.com
Abstract Different out-of-season estrus induction protocols were evaluated using a single progesterone (P4) priming 24h prior the use of eCG, GnRH or E2. Adult anestrus mix-breed dairy goats (n=32) were P4-primed (20 mg i.m.) and randomly assigned (n=8) to: a). E2: 1mg i.m. estradiol+0.2ml cloprostenol 24h later, b). E2+GnRH: E2+2.5ml GnRH 24h later, c). E2+eCG, E2+100 IU i.m. eCG 24h later, and d). eCG, 250IU i.m. eCG. Response variables considered the percentages of estrus (ES%, detected by sexually active males), ovulation (OV%), and pregnancy (PR%, diagnosed 45d after estrus detection). All treatments achieved high ES% (>87%) and OV% (>50%), yet, E2+GnRH reached 88% of OV% and PR%. E2 alone had the lowest PR% (p<0.05; 12.5%) and the highest interval from estrus to ovulation. The largest PR% (p<0.05; 81.5%, average) were observed in E2+GnRH and E2+eCG. Results indicate the feasibility of a simple synchronization protocol based in a single i.m. progesterone-priming plus E2+GnRH. Top Keywords Anestrous season, Estrus percentage, Exogenous hormones, Ovulation induction, Ovulation percentage. Top |