Fertility of range beef bulls grouped according to presence or absence of heparin-binding proteins in sperm membranes and seminal fluid.
Trials were performed to determine the relationship of heparin-binding proteins (HBP) to fertility of bulls. Red Angus (142), Santa Gertrudis (59), Gelbvieh (59), and Santa Gertrudis x Gelbvieh (40) bulls were identified according to the presence or absence of the greatest affinity HBP (HBP-B5) on sperm membranes and in seminal fluid. Nine to 20 bulls with the same HBP-B5 profiles were assigned to pastures with Santa Gertrudis cows at a ratio of 1 bull:25 cows. Fertility for Group 1 (80 bulls with HBP-B5 in sperm membranes but undetectable HBP-B5 in seminal fluid, in six pastures) was 82% pregnant of 1,692 cows. Group 2 bulls (48 bulls with HBP-B5 detectable in seminal fluid and in sperm membranes, in four pastures) impregnated 67% of 919 cows. Fertility for Group 3 (37 bulls with HBP-B5 in seminal fluid but undetectable HBP-B5 in the sperm membranes, in three pastures) and Group 4 (56 bulls with undetectable HBP-B5 in seminal fluid and sperm, in four pastures) was 63% pregnant of 747 and 1,208 cows, respectively. Group 1 had an average of 17% greater fertility compared with Groups 2, 3, and 4 (P < .05). In conclusion, groups with the greatest affinity HBP-B5 in sperm membranes but not in seminal fluid had greater fertility than did groups with other HBP-B5 profiles.
Bellin
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ME
Department of Animal Sciences, University of Arizona, Tucson 85721.
Hawkins
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HE
Ax
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RL
D000818:Animals; D001947:Breeding; D002352:Carrier Proteins / Q000378:metabolism*; D002417:Cattle / Q000502:physiology*; D005298:Fertility; D006493:Heparin / Q000378:metabolism*; D008297:Male; D012661:Semen / Q000378:metabolism*; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism* / Q000502:physiology
D002352:Carrier Proteins; D006493:Heparin