Morphology of Spermatozoa from Different Levels of the Reproductive Tract of the Bull1

Abstract

Studies were made on the morphological characteristics of spermatozoa from the reproductive tracts of 21 bulls of different ages. Fertility of only 3 of these bulls was known. Information on the source of morphologically abnormal spermatozoa and the relative proportions of morphologically abnormal spermatozoa, excluding tailless spermatozoa, and spermatozoa with attached protoplasmic droplets was secured. It was found that the various levels of the reproductive tract of the bull did not differ significantly in the proportions of abnormal spermatozoa and that the predominant types of abnormals were those affecting the heads of the spermatozoa. It was, therefore, concluded that the testis is the original source of morphologically abnormal spermatozoa. All bulls studied had three types of spermatozoa as to the location of the protoplasmic droplet. There was no significant statistical difference between bulls as to the proportion of spermatozoa with attached droplets at any given level of the tract. However, the droplet was usually located on the neck of spermatozoa from the head of the epididymis, and was usually absent from ampullar spermatozoa. Copyright © . .