Variations in the spermiograms of bulls with high numbers of sperm cell defects over an extended time period

Five bulls with high levels of sperm-cell defects were evaluated for breeding soundness approx. once a month for several months. Considerable variation with time was observed in the levels of normal and abnormal sperm cells. These variations reflected only minimally on the breeding soundness ratings given the bulls by 2 scoring systems. Variations in semen motility influenced the original scoring system much more than it did the revised system. Some of the sperm-cell defects seen included deformed heads, coiled and bent tails (with the coils or bends frequently enclosed by a single membrane) and disrupted mitochondrial sheaths. Scanning-electron micrographs were used to study these defects..