Natural mating of estrus-synchronized heifers and indicators of bull fertility

K-REx Repository

Show simple item record Pruitt, R.J. Corah, L.R. Simms, D.D. Spire, M.F. 2011-01-27T20:50:18Z 2011-01-27T20:50:18Z 2011-01-27
dc.description.abstract In six trials involving 486 heifers and 23 bulls, we studied factors affecting pregnancy rates of estrus-synchronized heifers mated naturally and evaluated indicators of bull fertility. Heavier heifers and those in fleshier condition had a higher response to estrus synchronization with Lutalyse. Heifers serviced more than once did not have higher pregnancy rates. Pregnancy rates achieved by bulls ejaculating up to 32 times in 2 1/2 days decreased only slightly as the number of ejaculations increased. There was considerable variation in pregnancy rates and the number of ejaculations achieved by individual bulls. Sex drive measured by a 3D-minute serving-capacity test was positively correlated with the number of ejaculations during the mating period and the number of heifers pregnant per bull. None of the variables studied could adequately explain the wide variation in pregnancy rates attributed to individual bulls. en_US
dc.publisher Kansas State University. Agricultural Experiment Station en_US
dc.relation.isPartOf Cattlemen’s Day, 1982 en_US
dc.relation.isPartOf Report of progress (Kansas State University. Agricultural Experiment Station); 413 en_US
dc.subject Beef en_US
dc.subject Heifers en_US
dc.subject Bull fertility en_US
dc.subject Lutalyse en_US
dc.title Natural mating of estrus-synchronized heifers and indicators of bull fertility en_US
dc.type Conference paper en_US 1982 en_US
dc.citation.epage 82 en_US
dc.citation.spage 79 en_US
dc.description.conference Cattlemen's Day, 1982, Kansas State University, Manhattan, KS, March 5, 1982 en_US

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search K-REx

Advanced Search


My Account

Center for the

Advancement of Digital


118 Hale Library

Manhattan KS 66506

(785) 532-7444