Stud bull plays an important role in the development of animal husbandry. Detailed knowledge about maintenance behavior of stud bulls is essential for practicing better management conditions in the farm to support the artificial insemination (AI) industry demand. Therefore, a comparative study was conducted on stud bulls to evaluate the effect of genetic group, season, genetic group × season interaction, temperature, humidity and temperature humidity index (THI) on maintenance behavior. Twenty five stud bulls (five bulls each from five different genetic groups) in two seasons (i.e. winter and summer) maintained at the Frozen Semen Bull Station, Nadia, Haringhata (West Bengal), India were selected for the study. There was a significant effect of genetic group on eating (P<0.05), sitting (P<0.01), lying (P<0.01) and sleeping time (P<0.01), season on rumination (P<0.05) and sitting time (P<0.01), genetic group × season interaction on lying (P<0.01) and sleeping time (P<0.01), air temperature on drinking (P<0.05) and sleeping time (P<0.05), humidity on eating (P<0.01), rumination (P<0.01), sitting (P<0.01) and lying time (P<0.01) and THI on eating (P<0.05) and drinking time (P<0.05). There was no effect of genetic group, season, genetic group × season interaction, temperature, humidity and temperature humidity index on standing time. Different genetic groups responded differently in expression of different subcomponents of maintenance behavior in two seasons. تفاصيل المقالة