J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J. Anim Sci. 1972. 35:362-369.
© 1972 American Society of Animal Science
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Brown, J. G.
Right arrow Articles by Foote, W. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Brown, J. G.
Right arrow Articles by Foote, W. D.

Reproductive Response of Beef Cows to Exogenous Progestogen, Estrogen and Gonadotropins at Various Stages Postpartum1

J. G. Brown2, D. W. Peterson3 and W. D. Foote

University of Nevada, Reno 895074

Abstract

The effects of three hormone treatments were studied at five intervals during postpartum anestrus in 97 pluriparous beef cows. The treatments consisted of feeding an orally active progestogen, progestogen treatment followed by an estrogen, and the progestogen treatment followed by gonadotropins. Treatment was started when the postpartum intervals were 5 to 10, 10 to 15, 20 to 25, 30 to 35 and 40 to 45 days. The interval lengths from calving to first estrus, first ovulation and conception were determined.

In most cases the progestogen feeding followed by an estrogen had a greater effect than the other treatments in reducing the interval lengths to first estrus, first ovulation and conception, especially during the early postpartum intervals. Gonadotropin injections following the progestogen treatment did not decrease the interval from calving to estrus, ovulation and conception.

Synchronization of estrus was highest in animals treated with an estrogen following the progestogen treatment, and in animals treated at mid postpartum anestrus (20 to 25 days).

Conception rates at first service were highest in the treated animals which received the progestogen treatment and an estrogen injection on day 2 with no further treatment. When pooled, the treated animals had their highest percent conception at first service in the 30 to 35 day postpartum interval. Conception rates for treated and untreated animals were comparable by the third service.

Footnotes

1 This experiment was supported in part by a grant from E. R. Squibb & Sons, Inc., New Brunswick, New Jersey.

2 Present address: Montana Flour Mills Co., Billings, Montana.

3 Present address: Department of Physiology, University of Alabama Medical Center, Birmingham.

4 Division of Animal Science, Nevada Agricultural Experiment Station. Journal Series No. 118. In cooperation with Regional Research Project W-95.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1972 by the American Society of Animal Science.