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ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #240035
Title: Effects of flunixin meglumine on pregnancy establishment in beef cattle

Author
item Geary, Thomas
item ANSOTEGUI, R - Montana State University
item Macneil, Michael
item Roberts, Andrew
item Waterman, Richard

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/13/2009
Publication Date: 3/1/2010
Citation: Geary, T.W., Ansotegui, R.P., MacNeil, M.D., Roberts, A.J., Waterman, R.C. 2010. Effects of flunixin meglumine on pregnancy establishment in beef cattle. Journal of Animal Science. 88:943-949.

Interpretive Summary: While fertilization occurs 90 to 100 % of the time a cow is bred, only about 70 % of those matings result in successful establishment of pregnancy. Pregnancy failure appears to be the result of the embryo producing insufficient interferon-tau to block uterine prostaglandin (PGF) release and initiate maternal recognition. Earlier work by our laboratory demonstrated that Flunixin Meglumine administration approximately 14 d after AI suppressed systemic PGF concentrations and increased pregnancy establishment in heifers and cows exposed to transportation stress. The objective of this research was to determine effects of a single injection of the prostaglandin synthesis inhibitor Flunixin Meglumine (FM; 1.1 mg/kg BW, i.m.) approximately 13 d after AI on pregnancy establishment. Three experiments were conducted using estrus-synchronized heifers and cows. Technicians and AI sires were equally represented across treatments within locations and experiments. Bulls were introduced on the day of FM treatment. Pregnancy to AI was diagnosed 28 to 50 d after AI using ultrasonography. In Exp. 1, beef heifers (n = 1,221) were divided by age within five locations to receive FM injection or no further treatment (Control). At insemination, heifers were divided into two similar pastures or pens and approximately 13 d later, one group of heifers within each location was worked through an animal handling facility to administer FM treatment. Location had no effect (P = 0.62) on AI pregnancy rates, so data were pooled. Pregnancy rates to AI were reduced (P = 0.02) among heifers receiving FM (66%) compared to control heifers (72%), and this response was consistent across locations. In Exp. 2, suckled beef cows (n = 719) were assigned by calving date within two locations to receive FM injection or no further treatment (Control) approximately 13 d after AI. At insemination, Control and FM cows were divided into separate pastures and only FM cows were handled after AI. There was no location by treatment interaction (P = 0.75) so data were pooled. Pregnancy rates to AI did not differ (P = 0.80) between FM (57%) and Control cows (59%). In Exp 3, beef heifers (n = 247) and suckled beef cows (n = 335) from one location received either no injection (Control) or injection of FM approximately 13 d after AI when all cows and heifers were handled through a working facility. Pregnancy rates to AI were not different (P = 0.43) between FM (45%) and Control (42%) cows or between FM (56%) and Control (55%) heifers. We conclude FM administration at 1.1 mg/kg BW approximately 13 d after AI did not improve pregnancy establishment in beef cows and heifers and that the additional stress of handling heifers at this time may decrease pregnancy establishment.

Technical Abstract: The objective of this research was to determine effects of a single injection of the prostaglandin synthesis inhibitor Flunixin Meglumine (FM; 1.1 mg/kg BW, i.m.) approximately 13 d after AI on pregnancy establishment. Three experiments were conducted using estrus-synchronized heifers and cows. Technicians and AI sires were equally represented across treatments within locations and experiments. Bulls were introduced on the day of FM treatment. Pregnancy to AI was diagnosed 28 to 50 d after AI using ultrasonography. In Exp. 1, beef heifers (n = 1,221) were divided within five locations to receive FM or no further treatment (Control). At insemination, heifers were divided into two similar pastures or pens and approximately 13 d later, one group of heifers within each location was worked through an animal handling facility to administer FM treatment. Location had no effect (P = 0.62) on AI pregnancy rates, so data were pooled. Pregnancy rates to AI were reduced (P = 0.02) among heifers receiving FM (66%) compared to control heifers (72%). In Exp. 2, suckled beef cows (n = 719) were assigned within two locations to receive FM or no further treatment (Control) approximately 13 d after AI. At insemination, Control and FM cows were divided into separate pastures and only FM cows were handled after AI. There was no location by treatment interaction (P = 0.75) so data were pooled. Pregnancy rates to AI did not differ (P = 0.80) between FM (57%) and Control cows (59%). In Exp 3, beef heifers (n = 247) and suckled beef cows (n = 335) from one location received either no injection (Control) or injection of FM approximately 13 d after AI when all cows and heifers were handled through a working facility. Pregnancy rates to AI were not different (P = 0.43) between FM (45%) and Control (42%) cows or between FM (56%) and Control (55%) heifers. We conclude FM administration at 1.1 mg/kg BW approximately 13 d after AI did not improve pregnancy establishment in beef cows and heifers and that the additional stress of handling heifers at this time may decrease pregnancy establishment.