Timed artificial insemination in yearling beef heifers: 7-11 Cosynch VS. Cosynch

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dc.contributor.author Thompson, A.W.
dc.contributor.author Holladay, C.D.
dc.contributor.author Eborn, D.R.
dc.contributor.author Grieger, David M.
dc.date.accessioned 2010-08-04T13:49:36Z
dc.date.available 2010-08-04T13:49:36Z
dc.date.issued 2010-08-04T13:49:36Z
dc.identifier.uri http://hdl.handle.net/2097/4445
dc.description.abstract Previous research demonstrated that an estrus-synchronization program using a short period of melengestrol acetate (MGA) feeding in conjunction with a Cosynch protocol was effective in synchronizing estrus in postpartum beef cows. The objective of our study was to test this synchronization protocol (7-11 Cosynch) in yearling beef heifers in comparison to a Cosynch protocol. Fifty-eight commercial beef replacement heifers were assigned randomly to two protocols: Cosynch (n=29) and 7-11 Cosynch (n=29). Beginning on day 1, heifers in the 7-11 Cosynch protocol were fed MGA (0.5 mg/heifer daily) for 7 days. On day 7, the last day of MGA feeding, the heifers on the 7-11 Cosynch protocol received an injection of PGF2α. On day 11 all 58 heifers received an injection of GnRH (100 μg). On day 18, all 58 heifers were injected with PGF2α. On day 20, all of the heifers received a 100 μg dose of GnRH by injection and were artificially inseminated. Ultrasonography was used to determine pregnancy status 29 days after breeding. A greater percentage (P<0.01) of heifers were pregnant after the 7-11 Cosynch treatment (67%) than after the Cosynch treatment (31%). This study demonstrates the potential of achieving acceptable pregnancy rates using timed artificial insemination in yearling beef heifers. en_US
dc.publisher Kansas State University. Agricultural Experiment Station and Cooperative Extension Service en_US
dc.relation.isPartOf Cattlemen's Day, 2003 en_US
dc.relation.isPartOf Kansas Agricultural Experiment Station contribution; no. 03-272-S en_US
dc.relation.isPartOf Report of progress (Kansas State University. Agricultural Experiment Station and Cooperative Extension Service); 908 en_US
dc.subject Beef en_US
dc.subject Timed Timed artificial insemination en_US
dc.subject 7-11 Cosynch VS. Cosynch en_US
dc.subject Yearling heifers en_US
dc.title Timed artificial insemination in yearling beef heifers: 7-11 Cosynch VS. Cosynch en_US
dc.type Conference paper en_US
dc.date.published 2003 en_US
dc.citation.epage 104 en_US
dc.citation.spage 103 en_US
dc.description.conference Cattlemen's Day, 2003, Kansas State University, Manhattan, KS, March 7, 2003 en_US
dc.contributor.authoreid dgrieger en_US

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