Number of Spermatozoa in the Different Parts of the Reproductive Tract of the Bull

A study was made of the distribution of spermatozoa in the reproductive tract of the bull.The study was subdivided into three separate phases.In the first phase, the sperm nmnbers in the ampulla, duetus deferens, and the cauda epididymis were determined.The average values were as follows: (1) 22 ampullae, 418 million, (2) 10 ducta deferentia, 340 million, (3) 25 cauda epididymides, 8,806 million.The number of spermatozoa in the ampullae and the dueta deferentia of a bull is not sufficient for a normal ejaculate, whereas the cauda contains enough spermatozoa for a number of ejaculates.During the second phase, the distribution of spermatozoa within the epididymides of 46 bulls was determined.The cauda epididymis contained 45.42%, corpus, 18.34%, and the caput, 36.24% of the total spermatozoa counted in the epididymides.The relation of testicular and epididymal weights to the sperm contents in the cauda and caput epididymis was studied in the last phase.The correlation coefficients between the following variables were calculated on a between-bull basis: (1) testicle weight and sperm number in the cauda, 0.16, (2) epididymis weight and sperm in the cauda, 0.32, (3) eauda weight and sperm in the cauda, 0.37, (4) caput weight and sperm in the eauda, 0.36, (5) testicle weight and sperm number in the caput, 0.20, (6) epididymis weight and sperm in the caput, 0.27, (7) caput weight and sperm in the caput, 0.34.None of the correlation coefficients was significant.The average number of spermatozoa contained in an ejaculate of a bull is between four and five billions (1, 9).Ejaculates with numbers of spermatozoa that greatly exceed these values are frequently observed.Individual workers (1,8) have stated that the epididymis serves as the storehouse for spermatozoa.No statements have been found in the literature concerning the immediate source of spermatozoa in an ejaculate.Kirillov in 1937 (6) and Gassner in 1953 (-1) reported a profound diminution in the number of spermatozoa in a bull's ejaculate following vasectomy.Actual counts of the sperm contents o'f the reproductive tract were reported by Polovceva (12).In two castrated rams the epididymides contained on the average 162 × 109 spermatozoa, 76% of which were found in the cauda.Chang (2) found 130 × 109 sperm in the epididymides of the ram, of which 79% were contained in the cauda, and the ampullae contained only 1.4%. of the spermatozoa.Ortavant (11) reports the following values for the eauda epididymis of the bull and ram, respectively: 15 20 × 10:9 and 40-60 × 109 spermatozoa.According to Rao and Hart (13), the concentrations of spermatozoa in the ampullae and the cauda epididymides were 1,240-4,510 × 10a/ram 3 and 2,020-9,310 × 10s/ram 3, respectively.The vo'lnines of fluids obtained were not stated.