Characterization of individual beef cattle water intake

Water intake (WI) in beef cattle is influenced by animal class, breed, production system, and environmental conditions, yet current models rely on limited, outdated data. We analyzed 130,000+ daily records of individual WI, dry matter intake (DMI), and body weight (BW) across 10 breeds from grazing and drylot systems over 5 yr. WI varied significantly by class (P < 0.001), with bulls consuming the most water (25.62 ± 0.03 L/d), followed by heifers (23.21 ± 0.07 L/d), and steers (21.83 ± 0.06 L/d), but heifers and steers had higher WI per 100 kg BW (P < 0.001). Breed effects were also significant (P < 0.001), with Red Angus and Limousin exhibiting the highest weight-adjusted WI. Drylot cattle drank more than grazing cattle (24.66 vs. 21.60 L/d; P < 0.001). WI increased with heat load; animals in THI ≥ 90 consumed 8.47 ± 0.03 L/100 kg BW compared to 5.53 ± 0.01 in THI < 72. However, relationships between WI and BW or DMI were weak (R2 = 0.06). These results challenge assumptions embedded in current recommendations (e.g., NASEM) and highlight the need for individualized, context-sensitive models. Our findings support future efforts in water-efficient selection, climate resilience, and sustainable beef production.