Cooling Holstein cows and heifers before calving during the summer: behavioral measures related to animal welfare

The objective of the study was to compare behaviors related to animal welfare and electrolyte levels between multiparous cows and primiparous heifers under an arid environment in a cooling system for 30 d before calving. Cows and heifers were hosted in different pens with shade and a cooling system. The behavior was monitored through visual sweep analysis and included rest and feeding episodes. Blood samples were collected from eleven cows and eleven heifers to determine electrolytes in serum. The frequency of animals in each activity was recorded in percentages, and means were involved in the MIXED procedure of the Statistical Analysis System for comparison. In the mornings, heifers remained standing in the shade foraging, while cows preferred lying down in the breeze and ruminating in the morning (P < 0.05). Cows and heifers similarly maintained their feeding and rumination episodes (P > 0.05). In the afternoon, more heifers than cows resorted to drinking water (P > 0.05). Electrolytes concentrations were similar (P > 0.05). It was concluded that Holstein cows and heifers expressed slight differences in resting and feeding behavior, but blood plasma electrolyte concentrations remained similar and normal.