Do Calves Drink Water?

Background: Today, it is important to measure livestock water consumption to devise sustainable solutions that consider environmental issues, livestock health requirements and animal welfare. Methods: This longitudinal study measured the water consumption of 66 calves subjected to two feeding diets: a recommended diet as control (CON) and an optimised diet (OPT). Individual measurements were collected daily and summarised on a weekly basis over a 20-week period. The analysis considered the impact of environmental conditions depending on the season of the calf’s birth. Results: Before weaning, calves spontaneously drank significant amounts of water in addition to the water brought by the calf milk replacer (CMR), but there was variability between animals. Water consumption among calves in the OPT group was higher than that among calves in the CON group from week 4 onwards (p = 0.005). At weaning, there was a significant increase in water consumption with a total water intake higher in calves in the OPT group compared to calves in the CON group (118.4 L and 78.9 L; p < 0.001). After weaning, water consumption was correlated with the solid feed intake in our model, which did not include direct fodder other than straw. There were no seasonal effects on water consumption before weaning at 9 weeks, but effects were observed after 13 weeks on the feeding plan (p = 0.008), with higher water consumption among calves born in winter and exposed to warmer temperatures in spring. Over a 20-week period, when calves had reached a weight of 180 kg in the OPT group and 150 kg in the CON group, water consumption had reached 1602 L and 1400 L respectively (p < 0.001). Conclusions: Free access to water should be maintained in calf rearing facilities, as water contributes to concentrated CMR and dry solid feed assimilation and the welfare of calves when the feeding plan remains at a modest level, enabling them to tolerate fluctuating environmental conditions.