EFFECT OF SPERM COUNT ON THE FERTILITY AND PROLIFICITY RATES OF MEAT RABBITS

The effect of sperm count per insemination dose was evaluated on ferti lity and litter size at birth. In the first experiment, 124 receptive multiparous does were inseminated with 16, 4, 2 and 1 million spermato zoa. Does were slaughtered 12 days after insemination and the number o f implanted embryos were recorded. Does inseminated with 16 or 4 milli on sperm showed no differences in pregnancy rate (90%) and number of i mplanted embryos (10.7). Does inseminated with 2 million sperm had a l ower pregnancy rate (66%, P < 0.05) and does inseminated with 1 millio n sperm had lower fertility (23%, P < 0.05) and number of implanted em bryos (4.9, P < 0.05). In the second experiment, 395 receptive does in different reproductive status were inseminated with 16 or 4 million s permatozoa. No differences were found in fertility (74%) and litter si ze at birth (9.0). No interactions between sperm count and reproductiv e status were observed. (C) 1997 Elsevier Science B.V.