Fertility of Bull Semen with Added Beta-Glucuronidase

Abstract

Motility and fertility of bull sperm were determined following storage in semen extender containing /3-glucuronidase. fl- glucuronidase retarded loss of sperm mo- tility during 7 days storage at 5 C. A prelinfinary trial revealed no harmful in- fluence of fl-glucuronidase on fertility of 279 cows inseminated with frozen semen. Consequently, 120 ejaculates from 14 bulls were used to determine fertility of frozen semen extended in yolk-citrate- glycerol with 0, 10, 30, or )50 units of added fl-glueuronidase, or with 10 or 20 ~g of added a-amylase per milliliter. Each enzyme treatment was replicated three times. The 60- to 90-day nonreturn per- centages and numbers of first services (in parentheses) for 0, 10, 30 and 150 units of fl-glucuronidase were 72.0 (3,401), 72.3 (1,961), 73.2 (1,912) and 77.9 (1,734). Fertility for 150 units was greater than that for 10 and 30 units of fl-glucuronidase (P _~ 0.02). Comparable values for 10 and 20 /~g of a-amylase per milliliter of semen extender were 74.3 (1,504) and 74.2 (2,057).