Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/2/2007
Publication Date: 5/15/2007
Citation: Merrill, M.L., Ansotegui, R.P., Burns, P.D., MacNeil, M.D., Geary, T.W. 2007. Effects of flunixin meglumine and transportation on pregnancy in beef cows. Journal of Animal Science 85:1547-1554. Interpretive Summary: Transportation stress applied to cows approximately 14 d after AI increased serum cortisol concentrations and tended to decrease AI pregnancy rates. Treatment of cows with flunixin meglumine, a prostaglandin inhibitor, at the time of transportation reversed the negative effects of transportation stress on AI pregnancy rates. Treatment with flunixin meglumine approximately 14 d after AI increased AI pregnancy rates of both control and transported cows. Both flunixin meglumine treatment and transportation stress suppressed serum prostaglandin metabolite concentrations, suggesting that administration of flunixin meglumine following transportation may result in a more prolonged suppression of prostaglandin. The amount of stress perceived by control cows in this study is difficult to interpret since serum cortisol concentrations did not increase, but body temperature did increase. Whether administration of flunixin meglumine, or other prostaglandin inhibitors, to cows approximately 14 d after AI would improve pregnancy establishment compared to cows that remain on pasture deserves further study.
Technical Abstract: Objectives of these studies were to determine effects of flunixin meglumine (FM) administration on early embryonic mortality and circulating prostaglandin and cortisol concentrations in cows receiving transportation stress or no transportation stress. Cows (n = 483) from three locations were used to evaluate the effects of transportation stress and a single administration of FM approximately 14 d after AI on pregnancy establishment, and serum concentrations of progesterone, prostaglandin F metabolite (PGFM), and cortisol. Treatments were transportation stress (S; n = 129), S + FM (SFM; n = 128), control (CON; n = 130) and CON + FM (CONFM; n = 96). Multiparous cows (n = 224) were used at two locations and nulliparous cows (n = 259) at the third location. The CONFM treatment was used at only two locations. Flunixin meglumine (approximately 1.1mg/kg BW; i.m.) was administered before cows were separated into transportation stress or control groups. Transportation stress included 4 to 6 h of transportation via semi-tractor trailer on unpaved and paved roadways. Control and CONFM cows remained penned with their calves during the same time period as transported cows. Blood samples were collected from all cows before and after treatment and, at two locations, approximately 3 h after onset of treatment. Cows receiving SFM tended to have greater (P = 0.07) AI pregnancy rates (74%) than S (64%) or S and CON cows combined (66%). Cortisol concentration was greater (P < 0.05) for S and SFM cows compared to CON cows. Cows receiving FM treatment had higher (P < 0.05) AI pregnancy rates than non-FM cows (71 and 61%, respectively). Cows receiving transportation stress had lower (P < 0.01) mean PGFM concentrations than non-transported cows (45.4 and 54.6 pg/mL, respectively) and cows receiving FM had lower (P < 0.01) mean PGFM concentrations than non-FM cows (39.4 and 60.6, respectively). We conclude transportation stress applied to cows approximately 14 d after AI increased serum cortisol concentrations and tended to decrease AI pregnancy rates. Treatment of cows with FM at the time of transportation reversed the negative effects of transportation stress on AI pregnancy rates.