Effect of EDTA as Chelating Agent in Extender on the Post Thaw Quality of Buffalo Bull Spermatozoa.

BACKGROUND: Spermatozoa are prone to mechanical and biochemical stresses upon freezing. The influx of Ca++ causes early capacitation and production of reactive oxygen species. OBJECTIVE: To evaluate the effect of ethylenediaminetetraacetic acid (EDTA) as a calcium chelator in a semen extender. MATERIALS AND METHODS: The effect of EDTA concentrations (0%, 0.1%, 0.2% and 0.3%) on the post thaw quality of buffalo bull spermatozoa were studied. RESULTS: The extender with 0.2% EDTA improved significantly visual motility, progressive motility and plasma membrane integrity. Sperm kinematics, such as beat cross frequency (BCF), curved line velocity (VCL), straight line velocity (VSL) and average path velocity (VAP), were higher in the extender with 0.2% EDTA. EDTA at 0.2% improves semen parameters (visual motility, supra vital plasma membrane integrity, chromatin integrity and percentage viable spermatozoa with intact acrosome. CONCLUSION: The EDTA supplementation in a semen extender improves the post-thaw quality of Nili-Ravi buffalo bull semen.

Comparative efficacy of G6G and Ovsynch protocols on synchronization and pregnancy rate in Nili-Ravi buffalo.

The aim of this work was to evaluate the efficacy of G6G and Ovsynch protocols on synchronization and pregnancy rate in Nili-Ravi buffalo. For this, a total of fifty buffalo were assigned into two treatment groups: (1) G6G (n=25) and (2) Ovsynch (n=25). The blood samples were collected from all the treated buffalo on day (D) 7 (PGF2α injection of Ovsynch) to measure the progesterone (P4). All the buffalo were fixed time inseminated (FTAI) following last GnRH of Ovsynch. Ultrasonography was performed for follicular, corpus luteum (CL) dynamics and pregnancy diagnosis. The results revealed that synchronization rate and response to final PGF2α were significantly (P<0.05) higher in G6G compared to Ovsynch. The ovulation to first GnRH of Ovsynch was higher (P<0.05) in G6G (84%) than Ovsynch (56%). The mean dominant follicle size following last GnRH of Ovsynch showed significantly larger diameter in G6G (11.7±0.2mm) compared to Ovsynch (10.9±0.2mm). Moreover, the higher (P<0.05) P4 concentration was observed in G6G than Ovsynch. The presence of double CL on D 7 was higher (P<0.05) in G6G (64%) than Ovsynch (24%) group. The pregnancy rate (P=0.08) tended to be greater in G6G compared to Ovsynch. In conclusion, G6G treatment showed better ovulatory and luteolytic response to first GnRH and PGF2α compared to Ovsynch treatment. Moreover, the addition of GnRH and PGF2α prior to Ovsynch is helpful to improve synchronization application of Ovsynch protocol in Nili-Ravi buffalo.