Abstract—The aim of this study was to evaluate the effect of a Prolonged Melengestrol Acetate (MGA) treatment in pre-pubertal goats on the induction of ovarian activity, induction and synchronization of estrus and pregnancy rate. 10 pre-pubertal Saanen goats, 9 months of age, body condition of 2.1±0.32 (scale 1-5), a live weight of 30.44±1.93kg and size of 62.1±2.69cm were used. The treatment consisted on the administration of 0.22mg/goat/day of MGA orally, during 46 days. During the treatment, the ovaries were evaluated by rectal ultrasonography using a 7MHz transducer on days 15, 30 and 45 to observe the presence or absence of follicles. Once the treatment was completed, the sire was placed in the pen with the goats and estruses were detected during 10 days post-treatment. The pregnancy diagnosis was performed 45 days after breeding via transabdominal ultrasound using a 3.5 and 5MHz transducer. Since the first evaluation of ovarian activity, the 10 goats showed follicle development; in the right ovary an average of 9.66˂4mm and 9.33≥4mm was observed and in the left ovary 11.33˂4mm and 9.66≥4mm, without the presence of corpus luteum. 100% of the goats presented estrus and the pregnancy rate was 90%; concluding that the use of MGA at a dose of 0.22mg/goat/day in pre-pubertal goats during prolonged treatment induces follicular development, estrus synchronization and a high percentage of fertility by natural mating is obtained.
 

Index Terms—pre-pubertal goats, melengestrol acetate, follicles, estrus, pregnancy, echography

Cite: Guillermo Salas-Razo, Edi Mendoza-Vargas, Ramiro A. Mendoza, and Jesús A. Rojo-Martínez, "Follicular Development, Estrus and Pregnancy Rate in Pre-Pubertal Goats Treated Melengestrol Acetate (MGA) in Rural Areas of Mexico," Journal of Advanced Agricultural Technologies, Vol. 3, No. 3, pp. 217-221, September 2016. Doi: 10.18178/joaat.3.3.217-221