Semen characteristics and testosterone profiles in ferrets kept in a long-day photoperiod, and the influence of hCG timing and sperm dilution medium on pregnancy rate after laparoscopic insemination

Five domestic ferrets previously maintained for 12 weeks under a 16L:8D photoperiod were electroejaculated weekly for 15-65 weeks while continuing to be exposed to the prolonged light cycle. Two ferrets sustained spermatogenesis for 20 and 26 weeks, while sperm production in the remaining males either was sporadic or decreased, remained depressed and then increased to peak levels observed in other males. Regardless of the temporal spermatogenesis patterns within males, the number of electroejaculated spermatozoa with residual cytoplasmic droplets or abnormal acrosomes increased in all ferrets over time. Diluted ejaculates meeting artificial insemination criteria were deposited intravaginally or by transabdominal laparoscopy into the uterine horns of females treated 0 or 24 h earlier with 90 i.u. hCG. Vaginal insemination was ineffective (0 pregnancies in 10 attempts), but 17/24 ferrets (70.8%) inseminated laparoscopically became pregnant and delivered live young (mean litter size, 5.2 kits). Number of motile spermatozoa deposited in utero (1.6-10.0 x 10⁶ cells), presence of glycerol in the sperm dilution medium (0 versus 4%) and time of hCG administration (0 versus 24 h before insemination) had no effect on pregnancy results or litter size.