FREE-RANGING CATTLE WATER-CONSUMPTION IN SOUTH-CENTRAL NEW-MEXICO

Water-drinking behavior of 67 free-ranging protein supplemented and no nsupplemented beef cattle was examined between May 23 and 16 July 1986 , in southcentral New Mexico. The lactating and nonlactating cows had a mean liveweight of 383 kg and were maintained as a single herd, and separated only during supplementation with an automated sorting and si ngle animal electronic identification system. Mean daily water consump tion was 57 l day-1 (161 (100 kg liveweight)-1) at a rate of 201 min-1 under mean mid-range ambient air temperatures between 14 and 24-degre es-C. Water consumed by cows supplemented at 0.7 kg head-1 day-1 and 1 .4 kg head-1 day-1 fed every 5.9 days and 3.5 days, respectively, was 14 l (100 kg liveweight)-1 and 15 l (100 kg liveweight)-1 (P = 0.7238) , respectively. In contrast, nonsupplemented cows consumed more (P les s-than-or-equal-to 0.0015) water (17 l (100 kg liveweight)-1) than sup plemented cows. Lactating cows consumed more water (P < 0.0001) than n onlactating cows (19 l (100 kg live weight)-1 and 12 l (100 kg livewei ght)-1, respectively). One drinking event every 24 h was sufficient to satisfy cows 94% of the time. Neither supplement level nor lactation affected (P > 0.05 ) daily watering frequency. Water intake was negati vely correlated to predrinking liveweight (r = -0.19; P < 0.01) and th e current day's maximum ambient air temperature if greater than or equ al to 30-degrees-C (r= -0.11; P < 0.02). Water intake was not correlat ed to temperatures greater-than-or-equal-to 30-degrees-C. Water consum ption was positively correlated to relative humidities between 15 and 86% (r = 0.17; P < 0.01 ). Water consumption was not correlated (P > 0 .05) with the mid-range or maximum ambient air temperatures of the cur rent or previous day. Our findings indicate large feedings of protein reduced water consumption, probably as a consequence of lower forage i ntake. Lactation increased water requirements and liveweight was a poo r predictor of water needs. Water consumption is affected by biotic an d abiotic factors other than those we evaluated.