Studies on the effect of deep freezing and seasons on the leakage of aspartate amino transferase into extracellular medium and sperm morphology of Murrah buffalo bulls

Abstract

Ten young Murrah buffalo bulls between 4 and 5 years of age and weighing 400–600 kg were used in a semen collection programme. The semen was diluted in tris-fructose-citric acid egg yolk-glycerol diluent and was processed for freezing over liquid nitrogen. Observations were made once a fortnight for release of aspartate amino transferase, acrosomal maintenance, live sperm count and normal and abnormal sperm count. These studies were continued through one full calendar year in order to assess the seasonal differences in these parameters. The results showed a highly significant rise in the level of aspartate amino transferase in extracellular medium on freezing. Acrosomal maintenance and live sperm count, as well as normal and abnormal sperm count, also showed significant seasonal differences. Freezing caused a significant decrease in normal acrosomal maintenance, live sperm and normal sperm count and an increase in abnormal sperm count. Autumn (September–November) was found to be the most conducive season, followed by the rainy, summer and winter seasons, for normal buffalo semen production.