Aside nutrition, disease infestations and external factors, seasonal change is another factor that influences the performance of sheep. For a better understanding of the effects of seasonal changes on sheep Six (6) Rams and Six (6) Ewes of  Yankassa breed of sheep were sampled at Landmark University Teaching and Research farms during the rainy season and then the same animals were utilized for the experiment during the dry season. For the rams, findings showed that there was no any significant difference between seasons for the hormones understudied, i.e. no difference between seasons (P > 0.05 ).  In contrary, for yankassa ewes, the values obtained for the follicle-stimulating hormone or FSH (0.823 0.56) during the dry season differed from that of the wet season FSH (0.182  0.08). However, there was no any significant difference between the seasons for testosterone, progesterone, estradiol and leutinizing hormone understudied, that is, p > 0.05.

Keywords: seasonal change, testosterone, wet season, progesterone, Yankassa