Feed handling of lactating crossbred cows maintained in a semi-arid region during the hot season: physiological parameters, ingestive behavior and performance

摘要

The effects of time of feed delivery (14.00hours; 14.00 and 20.00hours; 16.00 and 18.00hours) on the physiological parameters, ingestive behavior, nutrient intake and production of lactating cows maintained in a semi-arid region during the hot season were evaluated. Regardless of treatment, all animals received the first feeding supply at 06.00hours. Eight cows with an average body weight of 600kg, average milk yield of 20kg/day and 80days in milk were utilized. The rectal temperature, respiratory rate and sweating rate were not affected (P>0.05), with average values of 38.5 degrees C, 53.8 movements/min and 104g/m(2)/h respectively. There was no effect (P>0.05) on the eating time (314min/day), ruminating time (564min/day), drinking time (61min/day) and idle time (502min/day). Similarly, the intake of nutrients and performance of lactating cows were not affected (P>0.05), with average dry matter intake of 19.8kg/day, 4% fat-corrected milk of 20.6kg/day and milk fat concentration of 4.03g/100g. Since the behavior and performance have not altered, any times of feed delivery evaluated could be used to crossbred Holstein x Zebu cows maintained on a feedlot in semi-arid regions during the hot season.