The Effect of GnRH Supplement of FSH and PMSG Treatments for Prepubertal Swamp Buffalo Calves (Bubalus bubalis)

Abstract

The objective of the experiment was to improve the multifollicle stimulation technique and the ovarian response examination in prepubertal swamp buffalo calves. Six animals were stimulated by gonadotropin hormone 7 days after a progesterone ear-implant. The first stimulation was done by giving 24 mg FSH + 100 μg GnRH (FSH+GnRH) and the second, one month after by giving 2, 000 IU PMSG + 100 μg GnRH (PMSG+GnRH). Twenty-four hours after GnRH, the ovarian responses were checked using rectal palpation and real-time B mode ultrasonography. Five out of six animals (83.3%) responsed to both treatments and were selected for oocyte collection. The oocytes were aspirated directly following a caudal midline laparotomy. The results of ovarian responses to FSH+GnRH and PMSG+GnRH averaged 17.6 ± 12.1 (L=9.8 ± 8.7, R=7.8 ± 6.2) and 17.4 ± 5.6 (L=9.4 ± 2.9, R=8.0 ± 3.7), respectively. The average number of recovered oocytes per animal was 9.0 ± 6.4 and 8.4 ± 1.1, respectively which represented a recovery rate of 56.3 (± 9.2)% and 51.9 (± 10.3)%. More than eighty percent of the recovered oocytes were in an immature stage with more than 2-3 layers of compact cumulus mass. The present study showed that the oocytes were collected successfully in prepubetal buffalo calves after the FSH+GnRH or PMSG+GnRH stimulation and most of the recovered oocytes were immature, which made them suitable for in vitro maturation and fertilization.