Spermatozoan numbers and testicular characteristics of male white-tailed deer fawns during the mating season

Testicular spermatozoan numbers, testes weight, testes length, body weight, and kidney fat index (KFI) were obtained for male white-tailed deer Odocoi leus virginianus (Zimmerman, 1780) fawns during the mating season at the Sa vannah River Site (SRS) in South Carolina. Mean values for testicular sperm atozoa, testes weight, and testes length increased significantly over the s tudy period (late October - late December) whereas body weight and KFI did not change with time. Testicular spermatozoa were found in 28% of all fawns examined and the proportion of sexually mature Fawns increased greatly ove r the course of the study and was highest during December. These findings s uggest that male Fawns breed later than adults at a time that coincides wit h the mean conception date in doe fawns. Testes weight, testes length, body weight, and KFI were significantly greater in fawns with testicular sperma tozoa compared to those without testicular spermatozoa. We suggest that tes tes weight is closely associated with the presence of testicular spermatozo a in fawns from SRS.