Aim : The study was undertaken to quantify and to analyze the changes in the motion characteristics of bull spermatozoa during various stages of cryopreservation cycle. Materials and Methods: Using computer assisted semen analysis (CASA) technique, 26 ejaculates, collected from two Jersey bulls were analyzed for motility, head behaviour and swimming pattern of spermatozoa on dilution, pre-freeze and post-thaw stages of cryopreservation. French straw technique was employed for deep-freezing of semen using liquid nitrogen.O Results: Equilibration of diluted semen at 5 C has significantly (P< 0.01) reduced sperm motility, progressive motility, path velocity, and progressive velocity. Beat cross frequency was also affected significantly (P<0.05) by equilibration. Freezing and thawing processes drastically affected all the motility, velocity and head behaviour characteristics (P< 0.01). Conclusion: CASA facilitate objective evaluation sperm motion characteristics. Adoption of CASA technique has the potential for improvements in evaluation of semen thereby the quality of frozen semen for fertility can be enhanced.

Aim: This study aims to evaluate genetic and non-genetic factors influencing semen production potential of Gir bulls. Materials and Methods: Data on semen quantity (n=6911) and quality (n=466) available from January 2011 to December 2018 at BAIF's frozen semen station, Jind, Haryana, India, were utilized for the study. Factors, namely, season of collection, age at collection, and bull (random effect) were studied for their effect on quantitative and qualitative semen traits. Least square means for the traits were obtained using a general linear model. The effect of age within bull for repeatable traits was analyzed using a longitudinal model with age as the control variable. Multivariate analysis using mixed repeatability model equation was utilized to estimate bull effect correlation (genetic + permanent environmental correlation), phenotypic correlations, and repeatability. Results: The overall least square means of ejaculate volume, sperm concentration, total sperms, initial and post-thaw motility, hypo-osmotic swelling test, and acrosome integrity of frozen semen were 6.62±0.03 ml, 1.22±0.01 109/ml, 8.09±0.05 109/ml ejaculate, 75.78±0.001%, 55.92±0.0001%, 55.13±0.005%, and 71.08±0.001%, respectively. The season of the collection showed a significant effect on volume, concentration, total sperm, and initial motility. The performance of bulls was superior in summer season, followed by winter and monsoon. Increase in semen attributes during summer season was due to the effect of lower temperature on sensitive stages of spermatogenesis. Age at collection had a significant effect on all semen traits. Volume and total sperm count showed increasing trend while concentration showed a decreasing trend with an increase in age. Motility and quality traits did not show any particular pattern. Individual bulls showed differences in all the semen performance traits with age. The repeatability of the traits ranged from 0.04 (HOST) to 0.58 (acrosome integrity). Bull effect correlation ranged from –0.73 (initial motility and acrosome integrity) to 0.93 (HOST and acrosome integrity). Conclusion: Individual bulls showed variation in traits measured over age. The result of the study could be utilized in suggesting suitable management plans to achieve the desired profit by improving semen quality in Gir bulls.

No abstract

No abstract

No abstract