Abstract #W480

# W480
Reproductive efficiency of anovulatory goats through bucks treated with testosterone and (or) estrogenized females in northern México.
Juan M. Guillén-Muñoz1, César A. Meza-Herrera2, Rafael Rodríguez-Martínez1, Pedro A. Robles-Trillo1, Carlos Leyva-Orasma1, Evaristo Carrillo3, Francisco Gerardo Veliz1, Gerardo Arellano-Rodríguez*1, 1Universidad Autónoma Agraria Antonio Narro, Torreón, Coahuila, México, 2Universidad Autónoma de Chapingo, Bermejillo, Durango, México, 3Instituto Tecnologico de Torreon, Torreón, Coahuila, México.

The aim of this study was to evaluate the effect of treated males with testosterone and (or) estrogenized female upon reproductive efficiency in anovulatory goats in northern México (26°N). Multiparous mix-dairy breed anestrous goats (n = 80) were randomly assigned to one 4 treatment groups: (GT; n = 20) exposed to testosterone-treated bucks (25 mg, 3 d x 3 weeks); (GTH; n = 20) joined to testosterone-treated bucks and expose to estrogenized females x 3-d (pen of bucks were separated of females by a metal mesh); (GH; n = 20) exposed to estrogen-treated females (kept in a pen aside to another pen whit 2 estrogenized females x 2-wk) and (GC; n = 20) exposed to untreated bucks. All goats in this study received an I.M. injection of 25 mg progesterone, 24-h before exposure to males. Response variables considered estrus response during 14-d, ovulatory response and pregnancy rate of goats. Percentages were analyzed through a chi-squared test (SYSTAT 12). Results from the treatment groups (GC; GT; GTH; GH) give important evidence that both treatments: testosterone-treated bucks and (or) exposure of males to estrogenized females were equally effective to promote not only estrus induction (75–90%) but also both an increased ovulatory response (70–90%) as well as pregnacy rates (70–90%; P < 0.05) respectively, in dairy mix-breed anovulatory goats under subtropical conditions.

Key Words: buck, testosterone, reproductive efficiency