Water use around feedlot cattle production is an important topic of discussion in sustainability circles. Most of the U.S. feedlot cattle production is in semi-arid climates where water resources are highly dependent on underground aquifers. The level of these aquifers has declined leading to discussion on the sustainability of feedlot cattle production in these regions.
Water intake of cattle accounts for about 3% of total water use for beef production – not just feedlot cattle. Thus, cattle drinking water is not the greatest use of water in these regions, but should be considered when assessing water use.
A few studies have been performed to evaluate the heritability of water intake in beef cattle. Heritability estimates are near 0.40 indicating that genetic improvement could be made through selection. Selecting for reduced water intake of feedlot cattle would result in less water use increasing sustainability. However, whether we should select for cattle with lesser water intake is debatable.
Water intake is related to feed intake where cattle that eat more typically drink more. Selection for reduced water intake could result in lower feed intake and thus lesser growth and performance. The genetic correlation between feed intake and water intake is relatively low near 0.35 indicating that selection for reduced water intake could be accomplished without affecting feed intake.
Cattle drink more water in hot weather as evaporation of water vapor from the lungs is the primary method used to cool themselves. Could selection for decreased water intake result in more heat stress and related deaths in feedlot cattle? Could selection for increased water intake result in fewer heat stress related deaths in feedlot cattle? There has been no data evaluating genetic or phenotypic differences in water intake in association with the animal’s ability to thermoregulate in heat stress environments.
In conclusion, water intake is a moderately heritable trait in cattle, but the use of this trait and the direction of genetic selection that could most benefit the industry is inconclusive.