Effect of Ambient Temperature on Membrane Integrity of Spermatozoa in Different Breeds of Bulls

Bull’s fertility is highly important as it involves the fertilization of oocyte to produce a good, viable and genetically potential conceptus. Artificial insemination is the most widely used technique followed throughout the world, to increase numbers of genetically potential breeding bulls, offering many advantage over natural service. High quality semen is crucial for successful artificial insemination. Though the technique is being used to increase bull fertility status still the numbers of efficient breeding bulls are reduced day by day. Male related embryonic death owe to reduced semen quality due to heat stress (Setchell et al., 1988; Colas, 1983). Heat stress affects the body growth, the biological functions and the productive and reproductive characteristics of sheep (Sevi et al., 2002). Season is one of the major factors influencing the reproductive performance of breeding bulls and it exerts its effect through macro and micro climatic factors like temperature, humidity, rainfall, photo-period (Mandal et al., 2000). In case of bulls the increased evidence of sperm abnormality and reduced sperm output has been reported during warmer seasons of the year (Igboeli et al., 1971; Parkinson, 1987). In the light of above facts, it is very essential to evaluate the semen quality before artificial insemination. Semen quality study can be best assessed by the funtional integrity of sperm membrane in cattle (Correa et al., 1994). So the present study was undertaken with the objective to find out the status of membrane integrity of fresh and post thaw sperm in bulls during different range of temperature