|Muscha, Jennifer - Boyle|
|MULLINIKS, J - University Of Tennessee|
|Roberts, Andrew - Andy|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2016
Publication Date: 8/1/2016
Citation: Petersen, M.K., Muscha, J.M., Mulliniks, J.T., Roberts, A.J. 2016. Water temperature impacts water consumption by range cattle in winter. Journal of Animal Science. doi:10.2527/jas.2015-0155.
Interpretive Summary: Water is required for all life processes. Multiple factors affect water intake such as physiological condition of the animal, dry matter intake, water availability, quality of water, ambient temperature, and temperature of the water offered. There are numerous field reports/observations suggesting heated water increases water intake by cattle, especially in winter. Our hypothesis was cows provided warm drinking water would have increased forage intake, a more stable temperature in the rumen, drink more water and lose less weight during the winter. Our study demonstrated that as little as a 3°C drop from normal rumen temperature reduced the rate of gas production and extent of neutral detergent fiber disappearance. Cows provided warm water had less variability in ruminal temperature and drank 32% more water than cows provided cold water. Overall, winter water temperature did not have any effects on cow weight or body condition scores. This study suggests that the heat increment associated with digestion and metabolism is a large enough pool of heat to warm ingested snow, cold water and vegetation to body temperature averting body weight and body condition reductions due to partitioning of daily metabolizable energy lost to consumed cold water or forage.
Technical Abstract: Water consumption and DMI have been found to be positively correlated, which may interact with ingestion of cold water or grazed frozen forage due to transitory reductions in temperature of ruminal contents. The hypothesis underpinning the study explores the potential that cows provided warm drinking water would have increased in situ NDF and OM disappearances, a more stable rumen temperature, drink more water and lose less BW during the winter. This hypothesis was investigated in 3 experiments. In Exp. 1, ruminal extrusa (93.1% DM, 90.2% OM, 81.1% NDF (DM), and 4.9% CP (DM)) were randomly allocated to 1 of 3 in vitro incubation temperatures conducted in two separate trials (39, 37, or 35°C (trial 1) and 39, 33, or 31°C (trial 2)). In Exp. 2, four pregnant rumen cannulated cows grazing in January were fitted with Kahne (KB1000) temperature continuous recording boluses for 22 days. Two grazed in a paddock provided cold water (8.2°C) and two in a paddock provided warm water (31.1°C). Two in situ trials were conducted placing 6 in situ bags containing 2 g of winter range ruminal extrusa in each of the 4 ruminally cannulated cows and incubating for 72 h for measurement of NDF disappearance. In Exp. 3, six paddocks (n = 3/water treatment) were grazed by 10-13 head of pregnant crossbred Angus cows from December through February across 3 years from 2009-2012. Water intake per paddock was measured daily and ambient temperature was recorded. Motion activated cameras were used to determine time of day water was consumed and the number of cow appearances at water. In Exp. 1, rate and total gas production (P < 0.05) and NDF disappearance (P < 0.001) at 48 hr was reduced by each incubation temperature below 39°C. In Exp. 2, ruminal temperature for cows supplied with warm water dropped below 38°C for 1.5% of the time while cows provided cold water dropped below 38°C 9.4% of the time (P < 0.01). Drinking water temperature did not alter in situ OM or NDF disappearance. In Exp. 3, cows with access to warm water consumed 30% (P < 0.05) more water and experienced less daily rumen temperature variability than cows provided cold water. In this study there were small energetic costs to range cows consuming colder water in winter. The magnitude of these costs appear to be less than the heat increment due to fermentation, digestion and absorption since no advantage to BW gain, BCS change or calf birth weight were found for cows consuming warmer water.