Impacts of Feed & Water Efficiency in Cattle on Water Conservation & Drought

by Marcy Ward, NMSU-CES Livestock Specialist

Extreme and persistent drought has threatened water security and quality for ranchers in the desert Southwest. Unstable water sources have resulted in accelerated herd culling, to the point of threatening the New Mexico beef industry, the producers, and the communities they support.

As water tables diminish and wells dry, concentrations of total solids and minerals increase, which results in reduced water quality and animal performance. Utilizing the combination of improved genetics in your cattle and adoption of water conservation techniques for your water sources, environmental impacts on this vital resource may be mitigated.

Both feed efficiency and water consumption has been shown to be approximately 35 percent heritable. Efficiency can be improved through genetic selection. Purchasing bulls with known genetics and performance in these traits is a start.

The next step is identifying cows already in your herd that hold their body condition (even in drought years), and breed back on time. Keeping heifers out of these females will also contribute to improved feed and water utilization over all.

Actual performance data can be used when selecting for efficiency in replacement bulls. Feed conversion (FE) offers the clearest picture of how a bull utilizes feed or forage. A low FE demonstrates that a bull can be productive with minimal inputs. Feed intake is also correlated with water consumption.

The less an animal eats, the less they need to drink; in order to maintain good digestion and metabolism. Therefore, an efficient animal likely needs less feed and water to remain productive.

Expected progeny difference (EPDs) values are numeric indicators for breeding pairs that can help determine their offspring’s potential performance on specific traits. When selecting a bull for efficiency, are three different EPDs that indicate efficiency; rADG (Angus exclusively), DMI (Dry Matter Intake), and RFI (Residual Feed Intake).

For example, in the Angus breed, higher rADG values, along with low DMI EPD values are desirable for efficiency. Other breeds have RFI EPDs. For those breeds, you will look for negative RFI EPD values. Combining genetic and actual performance as part of your selection process is the best way to improve forage and water use on your land.

Water is the nutrient of top priority for maintenance, reproduction, growth, and health. Even for efficient animals, if consumption is inhibited for any reason, productivity will be compromised. Previous work has demonstrated inconsistency of water availability and quality affect animals’ watering behavior and influences forage use patterns in pastures (Holechek et al., 2011).

Water consumption will be impacted by total dissolved solids, salinity, pH, and odor. Valuable water sources are all but abandoned because cows refuse to drink from them, rendering them “useless”. Controlling water quality through filtration or aeration systems could help increase overall water access in your pastures.

Reverse osmosis filtration systems have been implemented on some ranches with marked success. This investment has resulted in increased weaning weights and pregnancy rates for those who use the technology. Another alternative is water aeration. These systems add oxygen to the water, improving water chemistry and in some cases palatability. Water conservation techniques can also help control loss to evaporation.

Shade balls (figure 2.) have helped ranchers conserve significant amounts of water in their above ground troughs. In dirt tanks, the balls could also reduce the impact of mineral concentrations increasing due to excessive evaporation. Regardless the techniques used to improve water quality and quantity, water sources that are now rarely visited can be used again as a way to expand pasture utilization. Improving pasture use will help reduce the need for herd reduction in times of drought.

Surprisingly, there is little information available on actual water use and impacts of water quality on ranging beef cattle and wildlife. Most of the work done in this area has been in confinement situations in beef steers. From there, prediction models are applied to all animals. With the help of funding from the Range Improvement Task Force and the USDA Western S.A.R.E program, research has been designed to provide valuable and novel information to aid cattle producers in understanding the impacts both animal genetics and water quality on water use, animal performance, and resource preservation (figure 3). Specifically, the RITF team is conducting research to collect individual water intake from yearling bulls at the Tucumcari Bull Test station in Tucumcari, NM, and at other New Mexico ranch locations.

The trials conducted on ranches are like no other; where water intake data will be collected in ranging beef cattle and wildlife, grazing large pastures. This data in turn will allow producers to make better informed decisions regarding ranch operations and rangeland management. ▫