author(s)
Mridula Sharma

abstract
The present study was undertaken to investigate the effect of temperature humidity index (THI) on seminal attributes in cross bred bulls. Forty one ejaculates from two bulls aged 4 to 6 years, weighing 300 to 450 KGS reared at the Semen Production Centre, Department of Veterinary Gynaecology and Obstetrics, Pantnagar, India, were used for the study. Semen was collected for 6 months. The temperature and relative humidity of respective days was taken from the meteorological department located nearby. THI was calculated. Three groups were prepared on the basis of THI range ie GI (THI <72, n=10), GII (THI 72-78, n=13) and GIII (THI 78-84, n=18). THI variations had no significant effect on ejaculate volume and mass activity but pH and progressive motility affected significantly. With the increase in THI, the pH of the semen decreases significantly and becomes more acidic and progressive motility also gets significantly decreased.