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Keywords

Cattlemen's Day, 1987; Kansas Agricultural Experiment Station contribution; no. 87-309-S; Report of progress (Kansas State University. Agricultural Experiment Station and Cooperative Extension Service); 514; Beef; MGA; Prostaglandin; Estrus; Synchronization

Abstract

Four trials were conducted to evaluate the effectiveness of Melegestrol Acetate (MGA ®) and prostaglandin (PGF) in inducing and synchronizing estrus. In trial 1, treated heifers were fed MGA for 7 days and given a PGF injection on either the first or last day of MGA feeding. The 7-day estrus response was higher (P<.01) for treated heifers than untreated controls. In trial 2, treated cows were fed MGA for 7 days and given a PGF Injection on the last day of MGA feeding or 13 days after the last day of MGA feeding. The 7-day estrus response was also higher (P<.01) in treated cows. In trial 3, 59 cows were fed MGA for 7 days followed by a PGF injection, and exposed to bulls for 66 days. The MGA-PGF treatment was ineffective in synchronizing estrus and hastening conception. In trial 4, feeding MGA for 7 days successfully synchronized estrus in. cycling cows, but first service conception rates were reduced by 10% in the Kansas study and by 16% in a four state study.

First page

66

Last page

70

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This work is licensed under a Creative Commons Attribution 4.0 License.

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