1Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Blvd. Delta s/n, Ejido Nuevo León, Baja California, México, 21705.
2Animal Sciences Department, University of California, Davis, CA 95616, USA.
3Cooperative Extension, University of California, Davis, CA 95616, USA.
In order to determine the effect of a cooling system on prepartum physiological parameters and postpartum productivity, forty multiparous Holstein cows were assigned to one of two treatments 60 days prior to their expected calving date: cooled (soaking for 2 min twice daily) and non-cooled. The highest ambient temperature registered during the study was 49.5C and the average daily temperature humidity index was higher than 72. Cooled cows showed a trend (P=0.08) to reduce their respiration rate, however, rectal temperature, body condition score and body weight were not affected at all (P>0.05). Postpartum milk yield, milk fat and milk energy output did not show significant differences, nor reproduction parameters postpartum (P>0.05). Thus soaking Holstein cows during the prepartum period had no advantage on postpartum productivity under hot and dry conditions.
Dairy cattle, milk production, heat stress, cooling system, reproduction
