Abstract: | Twenty-five mature rabbits were assigned in groups of five to be ejaculated at one of the following frequencies for a period of six weeks: Sexual rest (SR), one ejaculation on Friday (1 × F), four ejaculations on Friday (4 × F), one ejaculation daily Monday through Saturday (1 × M–S), and two ejaculations Monday, Wednesday, and Friday (2 × MWF). Upon slaughter after SR, the average distributions of sperm in the capita-corpora epididymides, caudae epididymides, and ductus deferentia were 184, 1,028, and 86 × 106, respectively. Ejaculation at each frequency significantly reduced the numbers of sperm found in the caudae epididymides, but neither weights of nor sperm numbers in the capitacorpora epididymides were affected by ejaculation frequency. While 79 ± 3% of extragonadal sperm were found in the caudae epididymides after SR, only 27 ± 5% were found there after 4 × F. This depletion of sperm represents 64% of those considered available for ejaculation. The data indicate that the ductus deferentia and ampullae of rabbits contain insufficient sperm to account for those normally found in a single ejaculum, and that the caudae epididymides are the immediate sources of most ejaculated sperm. The average calculated daily sperm production (82 × 106) was not affected by ejaculation frequency (P > 0.10). |