Reports, Powell River Project

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Browsing Reports, Powell River Project by Author "Assay, M."

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    Calm Temperament Improves Reproductive Performances of Beef Cows
    Whittier, William Dee; Kasimanickam, Ramanathan K.; Assay, M.; Schroeder, S.; Kasimanickam, Vanmathy R.; Gay, John M.; Hall, John B. (Virginia Tech. Powell River Project, 2015)
    Profitability of a beef operation is determined by breeding season pregnancy rates and proportion of cows attaining pregnancy early in the breeding season. Many factors including temperament contribute to these reproductive parameters. The objective of this study was to evaluate the effect of temperament on reproductive performances of beef cows. In experiment 1, Angus and Angus cross beef cows (n=1546) from 8 locations received body condition score (BCS; 1-emaciated; 9-obese) and chute-exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). Cows were grouped with bulls (1:25 to 1:30; with satisfactory breeding potential and free of venereal disease) during the entire 85 day breeding season. Pregnancy status and gestation length of cows was determined by per-rectal palpation at 35 days after the end of the breeding season. Controlling for BCS (P<0.01) and handling facility (P<0.0001) and handling facility by temperament score interaction (P<0.001) the breeding season pregnancy rate was different between excited and calm cows [88.6% (798/901) vs. 94.1% (607/645); P<0.001]. Cows with excitable temperament took 24 more days to become pregnant in the 85 day breeding season compared to calm cows (median days to pregnancy: 35 vs. 59 days; P<0.0001). In experiment 2, Angus and Angus cross beef cows (n=1407) from 8 locations received body condition score (BCS; 1-emaciated; 9-obese) and chute-exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). All cows were grouped with bulls (1:25 to 1:30; with satisfactory breeding potential and free of venereal disease) during the entire 85 day breeding season. Pregnancy status was determined by per-rectal palpation at 2 and 6 months from the beginning of the breeding season to determine the pregnancy loss. Controlling for BCS (P<0.05), the pregnancy loss was different between excited and calm cows, 5.5 (36/651) vs 3.2 (20/623), respectively (P<0.05) In conclusion, beef cows with excitable temperament had lower reproductive performance than calmer cows. The modified 2-point chute exit-gait scoring method is repeatable and can be used to identify cattle with excitable temperament.