Submitted to: Western Section of Animal Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/15/2004
Publication Date: 6/13/2004
Citation: Merrill, M.L., Ansotegui, R.P., Paterson, J., Geary, T.W. 2004. Effect of flunixin meglumine on early embryonic mortality in stressed beef females. Western Section of Animal Science Proceedings 55:304-307. Interpretive Summary: These data indicate that flunixin meglumine reduces early embryonic mortality during early pregnancy (12-14 d). We presume the mechanism is due to decreased uterine PGF secretion that may allow a developing conceptus extra time to secrete sufficient interferon tau to prevent uterine PGF secretion and luteolysis, since serum cortisol concentrations did not differ among females receiving flunixin meglumine. Future trials, containing an additional control group without handling until pregnancy diagnosis may need to be conducted to determine if animal handling for data collection impacts embryonic mortality.
Technical Abstract: The objective of these studies was to determine if a treatment of 1.1 mg/kg BW of flunixin meglumine (FM) would reduce early embryonic mortality in stress (TS) or non-stressed (NTS) beef females. Heifers (n=259) or cows (n=127) were assigned to one of four treatments in a 2x2 factorial design. Treatments were: control (CON), control with FM (CONFM), transportation stressed (S), and transportation stressed with FM (SFM). Treatments were applied to heifers and cows approximately 14d following AI. Rectal temperatures were recorded and blood samples collected from all females before treatment, after ~2.5h of treatment, and at the end of treatment (except final temperature not recorded in cows). Females receiving NTS treatment (CON and CONFM) remained at the ranch while TS treated females (S and SFM) were transported for 5-6 h. After !2.5h of transportation stress, TS females were unloaded from trucks, handled for temperature and blood collection, and loaded onto trucks again. Females were not exposed to clean-up bulls until after treatment. Transrectal ultrasonography was used to determine AIpregnancy status 33-35 d (heifers) or 55-57 d (cows) post-AI. In both heifers and cows, serum cortison concentrations were similar (P>0.1.) at the initial blood sampling, increased (P<0.01)below pretreatment levels in TS compared to NTS females at the final blood sampling. Among pooled data, AI pregnancy rates of TS females (62%) were not different (P>0.10) than NTS females (64%), however, AI pregnancy rates of FM treated females (69%) were higher (P=0.03) than NFM females (59%). Final pregnancy rates did not differ (P>0.10) among treatments. We concluded that FM administration ~14 d post-AI decreased embryonic mortality in beef females, and the magnitude of that decrease was similar in both transportation stressed (10%) and non-stressed (11%) females.