Effect of water temperature in drinkers and their location on water intake by cows

Abstract

Water temperature in the drinkers and humid environment combined with low or high air barn temperature are equally important factors for cow health, water intake and milk productivity. The study purpose was to determine the water intake by lactating cows from heated drinkers with different location and water temperature and the barn climate in North-West Russia. A group of Holstein dairy cows with loose housing in boxes was selected for the study. Two automatic group drinkers with heating elements were installed in different places in the barn. The experiments had two variants of the drinkers' operation mode. In Variant 1, the heating element in Drinker 1 was switched off, in Drinker 2switched on. In Variant 2, the heating elements were switched off in both drinkers. In Variant 1, the difference in the average daily water temperature between Drinker 1 and Drinker 2 was from 4.8 °С to 6.2 °С, with the average daily air temperature in the barn being from +11.7 °С to +14.8 °С. In this case, the water intake from Drinker 2 with higher, the water temperature was 2.5-5 times bigger than that from Drinker 1. In Variant 2, the difference in water intake between Drinker 1 and Drinker 2 was 35.1-72.3%. At that time, the average daily air temperature in the barn ranged between +10.7 °С and +14.9 °С. The average daily water temperature in the drinkers was from +6.3 С to +8.7 С, with the difference between the drinkers not exceeding 0.8 С. During the study, the milk yield was from 36.3 to 41.4 kg•cow -1•day -1, with the water intake being from 1.96 l•kg -1 to 2.48 l•kg -1 . During the experiments, the cow diets did not change. The graphical models based on the experimental data allowed estimating the effect of water temperature on water intake by cows. The study also showed that drinkers' location influenced the water intake. So, when designing the modern drinking systems, more attention is needed to their optimal placement and provision of free access to freshwater for animals at all times.