It is well documented and accepted that water is a very important nutrient for calves in the pre-weaning phase. Calves ingest water through whole milk or milk replacer, but they also start very early drinking free choice water. As the amount of calf starter increases, the amount of water intake also increases dramatically. Although it is recommended to offer water the first days after birth, a survey done in the United States (USDA’s NAHM, 2014) indicated that producers wait on average 17 days to first offer it to newborn calves.
Benefits of early water intake
A recent study published in the Journal of Dairy Science (Vol. 102 No. 1, 2019) compared the intake of water if offered to calves from birth, with the amount of water consumed when water was offered only after 17 days of age. When offered from birth (W0), newborn calves consumed 0.75 ± 0.05 kg/d water in addition to the water they received from the free choice milk allowance during the first 16 days. Calves offered water at day 17 (W17) drank more water (59%) than calves offered water from birth, during the total pre-weaning period. Starter intake of W0 and W17 calves was similar, but W0 calves consumed 0.285 kg/d more milk and tended to achieve greater body weight and heart girth compared with W17 calves during the pre-weaning period. Despite a similar starter intake, W0 calves had greater hip height, body length, apparent total-tract digestibility of acid detergent fiber and neutral detergent fiber, and feed efficiency than W17 calves post-weaning (50 to 70 days of age). When followed up to 5 months of age, W0 calves had greater body weight than W17 calves. The study concluded that providing drinking water immediately after birth could improve growth and development of calves pre- and post-weaning, potentially by stimulating rumen development and thus increasing nutrient availability.
Not just important in the heat
A document from Arkansas University indicates that water nutrition of young calves in cold weather is at least as important as in hot weather. During cold weather, the relative humidity is typically low so animals lose more moisture from their bodies during breathing. In cold weather, a lack of sufficient drinking water intake will limit starter feed intake.
Keep distance between feed and water buckets
Another aspect regarding providing water to calves that is very seldom mentioned is the positioning of the water bucket relative to the calf starter in individual calf pens. Dr. Beede, from Michigan State University, showed results collected during weeks five to eight of life after early weaning (four weeks) when Holstein calves were offered free-choice drinking water and calf grower in two buckets in very close proximity to each other (side-by-side) or with a partition (divider) physically separating the water and feed buckets. Water and feed were continuously offered and available to calves in buckets in individual pens except when buckets were being cleaned daily. Separation with a divider of the feed and water buckets increased water intake of calves by 33%, grower feed intake by 13% and body weight gain by 18%, compared with that of calves offered feed and water in a side-byside arrangement. Cross-contamination of feed and water when buckets are too close together reduced intake of both. This is a very good improvement for such a simple management practice. Below are some simple examples of setups in calf housing that address this issue.