There was no significant difference in testosterone concentration between the two groups, only numerical differences; testosterone levels did increase as the months passed and coming closer to the breeding season. Cortisol levels were also not different throughout the study except for August and October. Testicle size was different between the groups with the HS group having severe testicular degeneration at the germ line with no impact on somatic (sertoli and leydig) cells. It was concluded that chronic heat stress during the non-breeding season impacted developing ram lambs negatively, with impairment of the testicular germ line without any effects in testosterone and cortisol concentrations. Mean testicular weights were significantly different with the indoor having an average of 151g and the outdoor group having an average of 90g. At the microscopic level, the testicles from the HS group showed no clear spermatocytes, spermatogonia, or …show more content…
However the differences in breeds involving hair sheep versus wool type sheep and heat stress affecting testicular function has not been intensively studied. The objective of the study is to find differences in developing ram lambs by evaluating testicular structure and endocrine profiles in meat type breeds of sheep, Dorper (hair type) versus Suffolk (wool type) when experiencing chronic heat stress in the non-breeding season (April-Oct) . Dorper ram lambs (hair type sheep) are much better adapted to withstand the negative effects of heat stress on testicular size and structure and spermatogenesis, compared to Suffolk ram lambs (wool type