Efecto de la alimentación con grasas protegidas en vacas de doble propósito

effect of feeding calcium soaps on double purpose cows. the effect of feeding with protected fats on double purpose cows. the objective of this study was to determine the reduction of post-partum anestrum in cows by supplying protected fats. the study was conducted ad the experimental field la posta, paso del toro, veracruz, méxico. the cows were randomnly assigned to two groups: suplementation with protected fats (gp; t1, n= 20) or tallow (sgp; t2, n=20) at 2.7% of a dry weight-based diet. milk production, physical condition (cc), progesterone and tiroid hormone levels were registered. (t3 and t4). sources of variation were diet, genetic group and number of calf births, and the dependent variables pl were days to the first estrus (dpe), cc and meatabolite levels. correlations among variables were conducted. no effect (p>0,05) of treatments on milk production were observed, but significant effects (p<0,01) for the fist corpus luteum. physical condition 4,5 had the best milk production (p<0,01; 16,68±1,076 l/day) and lower number of days to the first estrum (p<0,05; 31,71±7,5 d). tiroid hormones did not show differences (p>0,05) among treatments: t1= 72,4 and t2 = 72,72 ug/dl. insuline was higher (p<0,05) in t2 (6,87 ui) than in t1 (5,26 ui). it is concluded that the type of fat did not affect milk production but stimulated the resumption of ovarian activity and reduced the concentration of insulin in the serum.