78 - Young Scholar Award Talk: How Advances in Animal Efficiency and Management Have Affected Beef's Water Intensity Across the United States: 1991 Compared To 2019

Abstract: Updating the static model by Beckett and Oltjen (1993), we determined that from 1992 to 2019, U.S. beef cattle water consumption per kg of beef decreased by 38%. As with the 1993 model, water use included direct water intake by animals, water applied for irrigation of crops that were consumed by the cattle, water applied to irrigated pasture, and water used to process animals at marketing. Numbers of cattle, crop production, and irrigation data were used from USDA census and survey data. On January 1, 2019, a total of 31.7 million beef cows and 5.8 million replacement heifers were in U.S. breeding herds, and 26 million animals were fed annually. In total, the U.S. beef cattle herd (feedlot and cull cows) produced 7.7 billion kg of boneless beef, an increase of 10% since 1992. Beef cattle directly consumed 600 billion L of water per year. Feedlot cattle were fed various grain and roughage sources corresponding to the regions in which they were fed. Feeds produced in a state were preferentially used by cattle in that state with that state's efficiency; any additional feedstuffs required used water at the national efficiency. Irrigation of crop feedstuffs for feedlot cattle required 5,827 billion L of water. Irrigated pasture for beef cattle production required an additional 6,445 billion L of water. Carcass processing required 91 billion L of water. The model estimates 2,271 L of developed water per kilogram of boneless meat for beef cattle production in the United States. As with the previous model, the current model was most sensitive to changes in dressing percentage and percentage of boneless yield in carcasses of feedlot cattle (62.8 and 65, respectively). In conclusion, with more beef, fewer cows, and lower rates of irrigation, beef cattle’s water footprint has decreased at an annual rate of by 1.35% over 28 years.