| Abstract | Forty-three Dorper (initial BW = 60 ± 2.6 kg), 45 Katahdin (63 ± 2.4 kg), and 44 St. Croix (45 ± 2.1 kg) ewes (0.9-9.5 yr) from 45 commercial farms in the Midwest, Northwest, Southeast, and central Texas were used to evaluate resilience to water restriction. Sheep were housed individually and fed a 51% concentrate pelleted diet (18% CP) at 160% of their calculated ME requirement for maintenance. In period 1 (2 wk in duration), ad libitum water intake was determined, followed by 25 and 50% decreases in water availability in periods 2 and 3 that were 2 and 5 wk in duration, respectively. Water was offered daily at 0700 h and BW was measured at 1300 h on Monday, Wednesday, and Friday each week. Weekly data in period 3 were analyzed with initial age and average period 1 values serving as covariates, and means were separated by least significant difference. From wk 1-5 of period 3, average water intake was 1,749, 1,745, 1,747, 1,746, and 1,749 g/d (SEM = 4.8). Week affected (P < 0.05) DMI (1,075, 1,016, 1,013, 1,028, and 1,069 g/d; SEM = 17.4), BW (56.4, 56.1, 56.6, 57.0, and 57.8 kg; SEM = 0.17), and the ratio of water intake relative to DMI (1.68, 1.80, 1.81, 1.80, and 1.70 for wk 1, 2, 3, 4, and 5, respectively; SEM = 0.045). Breed did not affect DMI (P = 0.21) or BW (P = 0.51). In conclusion, neither DMI nor BW data indicated breed differences in resilience to restricted drinking water availability. |
