EFFECT OF METEOROLOGICAL FACTORS AND SEASONS ON LUTEINIZING-HORMONE, TESTOSTERONE AND SEMEN OF ZEBU-TAURUS BULLS

Semen characteristics (volume, mass activity, initial motility, sperm concentration and live sperm per cent), plasma testosterone and luteininzing hormone levels were monitored at weekly intervals for 8 consecutive Weeks during May-June (hot-dry), July-August (hot-humid), October-November (autumn) and December-January (winter) from 4 Jersey x Hariana (J x H) and 3 Holstein-Freisian x Hariana (HF x H) half cross bulls. The semen volume, per cent motile sperms varied significantly (P < 0.01) between both the breed crosses. The seasonal mean values of various seminal attributes were least during summer months than the other 2 seasons. All parameters showed negative correlation with ambient temperature in both the breed crosses. The squares of multi-factor correlation of ambient temperature, relative humidity and sunshine hours with different seminal attributes, testoster one and LH are discuss in the text. Though J x H cross was more susceptible to the ambient temperature effect, the combined effect of the climatic elements was more pronounced on HF x H.