Not AvailableThe present study was conducted on 10 adult mule camels ovar a period of 2 consecutive years to characterize peripheral plasma testosterone profiles in relation to rutting activity. Blood plasma testosterone profiles were monitored during pre-rut, rut and post-rut, stages at weekly intervals by RIA. Testosterone concentration in peripheral plasma is low during the pre-rut period (342.93+-43.90 ng/ml). Onset of rut activity is associated with significant rise in testosterone concentration (4213.94+278 ng/dl), which is maintained for 11-18 weeks followed by decline to basal levels. The onset of rise as well as decline varied individually. It is also not uncommon to observe complete absence of endocrine surge and rut behaviour in come (1/5 in present study) males throughout breeding season. Genetic, nutritional, management. Enviromental or other possible reason for this remains to be explored. It is not uncommon for certain young males to exhibit complete shyness when attempted for semen collection despite high testosterone concentration and other external sexual behaviour symptoms, which apparently may be due to lack of exposure. The libido and production of sernen into AV is maintained for 3-5 months followed by cessation, which also varied individually. Libido subsides in some males in March, in few more in April. Some males continue to have good libido by the end of May. After May majority of the males lose libido and are rendered unable to copulate in AV. Cessation of libido and ability to copulate appears to be associated with decline in testosterone concentration. Cessation of libido appears to be due to erectile importance. The critical level of testosterone required for erectile potency needs to be worked out. This work shows the correlation between hormone profiles and ambient temperature.Not Availabl