Authors : A.A Gomez-Danes , C.M.E. Ortega , E.M.T. Sanchez-Torres , H.J. Herrera and M.F. Galindo
Abstract: The objective was to evaluate pregnant bovine dominance in 2 genetic types of cows and its relation to weight and sex of calves, as well as the ovarian function 70 days after postpartum of the cows. Twelve cows were used, Brahman�Simmental (n = 5, Br) and Brown Swiss�Brahman (n = 7, F1) between 550-610 k, 4-5 years old, having experienced parturition 2-3 times and being 6-7 months pregnant. Twelve observations were made every other day, using a displacement and success index, behavior samples and scanning the data every four hours with five minute intervals between each sample. The weight and sex of calves at birth were also recorded. Ten samples were used to determine the progesterone levels in blood serum using the PROC MIXED procedure for sample 3 and 8 (p< 0.01 and 0.05), respectively. In order to determine dominance a Mann Whitney test was used, dominance was measured at U = 38 and U = 33 for F1 and Br, respectively. The Spearman test correlated with the Weight at Birth (WB) with the displacement and success index, at 0.58, 0.26 for F1 and 0.64, 0.57 for Br, respectively, we observed greater correlation between weight at birth and the displacement index for both genetic types. Correlation between progesterone level’s in blood serum and displacement and the success index was 0.84 and 0.07. The only samples that were significant were samples 3 and 8 where correlations of 0.75 and 0.11 were made for F1; 0.28 and 0.61 for Br, respectively which indicates that genetic type F1 had short luteal cycles and genetic type Br had no ovarian activity.
A.A Gomez-Danes , C.M.E. Ortega , E.M.T. Sanchez-Torres , H.J. Herrera and M.F. Galindo , 2007. The Relationship Between Pregnant Cows’ Behavior,Calf Birth Weight and Postpartum Levels of Progesterone . Journal of Animal and Veterinary Advances, 6: 470-476.