Effect of Preinsemination Injection of Gonadotropin-Releasing Hormone on Reproductive Performance of Dairy Cattle

Authors

  • J. A. Pennington Department of Animal Sciences, Purdue University, West Lafayette, IN 47907
  • D. L. Hill Department of Animal Sciences, Purdue University, West Lafayette, IN 47907
  • C. J. Callahan Large Animal Clinic, Purdue University, West Lafayette, IN 47907
  • C. M. Brown Department of Animal Sciences, Purdue University, West Lafayette, IN 47907
  • M. D. Brown CEVA Laboratories, Overland Park, KS 66212

DOI:

https://doi.org/10.21423/bovine-vol1985no20p14-16

Keywords:

Gonadotropins, GnRH, conception rate

Abstract

Holstein-Friesian cows and heifers on 2 farms were injected with 100 μg GnRH or saline as soon as possible after detection of oestrus. Time from detection of oestrus to injection was 2.2 h, and from injection to breeding 6.4 h. The CR of 282 animals injected with GnRH was 51.8% vs. 51.5 for 264 animals injected with saline. The CR did not differ between the 2 groups at 1st, 2nd, 3rd or later services, nor at the following oestrus. There were no significant differences between groups in the interval to next oestrus or in the service period.

Cover image of the 20th Volume of the Bovine Practitioner: A photo of Niagra falls from the opposite side of the falls, a small tour boat in the center right gives scale to the sheer magnitude and power of the falls.

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Published

1985-11-01

Issue

No. 20 (1985 November)

Section

Articles

How to Cite

Effect of Preinsemination Injection of Gonadotropin-Releasing Hormone on Reproductive Performance of Dairy Cattle. (1985). The Bovine Practitioner, 1985(20), 14-16. https://doi.org/10.21423/bovine-vol1985no20p14-16