Improving semen quality of heat stressed rams in Egypt

Ossimi rams (25) were maintained under winter and summer (hot climate). The temperature humidity index (THI) was above 84.3, indicating exposure of the animals to severe heat stress during hot season. Exposure to summer hot climate significantly increased rectal and scrotal-skin temperature, and semen quality deteriorated as well as, conception rate and lambing. Therefore ram which have high scrotal-skin temperature (35 degrees C or more) must be useless from mating or artificial insemination. Treatment of the heat-stressed rams in summer with either melatonin or combined vitamins B-1,B-6,B-12 improved significantly rectal and scrotal-skin temperature, libido, semen quality and fertility. While zeranol implantation did not have any improvement in the same parameters.