Environmental effects on water intake and water intake prediction in growing beef cattle

Authors: AHLBERG, CASHLEY - Kansas State University; ALLWARDT, KRISTI - Oklahoma State University; BROOCKS, ASHLEY - Oklahoma State University; BRUNO, KELSEY - Oklahoma State University; MCPHILLIPS, LEVI - Oklahoma State University; TAYLOR, ALEXANDRA - Oklahoma State University; KREHBIEL, CLINT - University Of Nebraska; CALVO-LORENZO, MICHELLE - Elanco Animal Health, Inc; RICHARDS, CHRIS - Oklahoma State University; PLACE, SARA - National Cattlemen'S Beef Association (NCBA); DESILVA, UDAYA - Oklahoma State University; VANOVERBEKE, DEBORAH - Oklahoma State University; MATEESCU, RALUCA - University Of Florida; Kuehn, Larry; WEABER, ROBERT - Kansas State University; BORMANN, JENNIFER - Kansas State University; ROLF, MEGAN - Kansas State University

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/2018
Publication Date: 8/29/2018
Citation: Ahlberg, C.M., Allwardt, K., Broocks, A., Bruno, K., McPhillips, L., Taylor, A.A., Krehbiel, C.R., Calvo-Lorenzo, M.S., Richards, C.J., Place, S.E., Desilva, U., Vanoverbeke, D.L., Mateescu, R.G., Kuehn, L.A., Weaber, R.L., Bormann, J.M., Rolf, M.M. 2018. Environmental effects on water intake and water intake prediction in growing beef cattle. Journal of Animal Science. 96:4368-4384. https://doi.org/10.1093/jas/sky267.
DOI: https://doi.org/10.1093/jas/sky267

Interpretive Summary: Environmental conditions such as humidity, solar radiation, ambient temperature, and wind speed are known to affect consumption and utilization of water in beef cattle. However, these relationships have rarely been quantified and even when examined they generally involved averages of pen water intakes rather than intake for individual animals. In this study, individual water intake was modeled based on these environmental parameters. Individual intake of five groups of cattle was measured for five different management groups. These groups were designed to have seasonal (summer vs. winter) and bunk management (ad libitum vs. restricted feeding differences). Environmental parameters were able to explain much of the differences in water intake; differences after adjustment for these parameters was less than 0.75% of steer body weight or approximately 40% of the observed variation. Resulting environmental models included effects of feed intake, metabolic weight, average temperature, solar radiation, relative humidity, and wind speed averaged over the feeding period. These models will guide decisions related to water availability. However, there is still significant variation due to animal differences that are not explained by these global factors alone.

Technical Abstract: Water is an essential nutrient, but there are few recent studies that evaluate how much water individual beef cattle consume and how environmental factors affect an individual's water intake (WI). Most studies have focused on WI of whole pens rather than WI of individual animals. Thus, the objective of this study was to evaluate the impact of environmental parameters on individual-animal WI across different seasons and develop prediction equations to estimate WI, including within different environments and management protocols. Individual daily feed intake and WI records were collected on 579 crossbred steers for a 70-d period following a 21-d acclimation period for feed and water bunk training. Steers were fed in 5 separate groups over a 3-yr period from May 2014 to March 2017. Individual weights were collected every 14 d and weather data were retrieved from the Oklahoma Mesonet's Stillwater station. Differences in WI as a percent of body weight (WI%) were analyzed accounting for average temperature (TAVG), relative humidity (HAVG), solar radiation (SRAD), and wind speed (WSPD). Seasonal (summer vs. winter) and management differences (ad libitum vs. slick bunk) were examined. Regression analysis was utilized to generate 5 WI prediction equations (overall, summer, winter, slick, and ad libitum). There were significant (P < 0.05) differences in WI between all groups when no environmental parameters were included in the model. Although performance was more similar after accounting for all differences in weather variables, significant (P < 0.05) seasonal and feed management differences were still observed for WI%, but were less than 0.75% of steer body weight. The best linear predictors of daily WI (DWI) were dry mater intake (DMI), metabolic body weights (MWTS), TAVG, SRAD, HAVG, and WSPD. Slight differences in the coefficient of determinations for the various models were observed for the summer (0.34), winter (0.39), ad libitum (0.385), slick bunk (0.41), and overall models (0.40). Based on the moderate R2 values for the WI prediction equations, individual DWI can be predicted with reasonable accuracy based on the environmental conditions that are present, MWTS, and DMI consumed, but substantial variation exists in individual animal WI that is not accounted for by these models.