Levels of Deoxyribonucleic Acid in Bovine Spermatozoa and Their Relationship to Fertility

Abstract

The chemical determination of DNA in 71 ejaculates of 17 bulls indicated that on the average, one billion spermatozoa contain about 2.95[plus or minus]0.17 mg of DNA. Data on 34 ejaculates of 10 bulls revealed an over-all correlationof 0.20 (not significant) between DNA level and fertility. On an among-bull basis, the correlation was -0.35 (not significant) and among ejaculates, within bulls, it was 0.43 (P< 0.05). A study of 10 ejaculates from 2 bulls indicated a nonsignificant decline of 3% of DNA content during storage of raw semen at room temperature. No decline was observed at 5[degree]Ci Data from 20 ejaculates indicated that both high and low levels of DNA were associated with increased percentages of delayed returns to heat after service. Uterine and oviduct luminal fluids of slaughtered cows contained 4-6 mg of DNA per milliliter. This is probably derived from epithelial cell nuclei.