Effects of water restriction on feed Intake and digestion by St. Croix sheep

TitleEffects of water restriction on feed Intake and digestion by St. Croix sheep
Publication TypeJournal Article
Year of Publication2018
AuthorsHussein, AH, Puchala, R, Gipson, TA, Tadesse, D, Wilson, BK, Goetsch, AL
JournalJournal of Animal Science
AbstractEleven St. Croix ewes (49 ± 8.5 kg initial BW) were used in a crossover design to evaluate effects of restricted drinking water availability on feed intake and digestion. Ewes were housed indoors and fed a 51% concentrate pelleted diet containing 18% CP and 33% NDF at 160% of their calculated ME requirement for maintenance of 44.4 g/kg BW0.75 DMI. Periods were 4 wk, with 3 wk for adaptation and 1 wk for total collection of feces. Ad libitum or baseline water intake by individual ewes was determined for 2 wk before the study (3,761 ± 144 g/d). In each period, 5 or 6 ewes were offered water at 75% of baseline intake for 1 wk and subsequently restricted to 50% (RE), while the other ewes were offered the baseline amount (AL). Some water was refused in wk 4, with intake of 2,442 and 1,688 g/d for AL and RE, respectively (SEM = 171.7). Intake of DM was similar (P = 0.582) between treatments (860 and 811 g/d for AL and RE, respectively). Apparent total tract digestibility of DM (67.2 and 62.1%; SEM = 1.30), OM (68.1 and 63.0%; SEM = 1.30), and NDF (44.3 and 34.0%; SEM = 2.46) were greater (P < 0.05) for RE vs. AL, and CP digestibility tended (P = 0.072) to differ (71.1 and 67.2% for RE and AL, respectively; SEM = 1.16). In conclusion, restricted drinking water availability did not influence intake of a 51% concentrate pelleted diet but increased digestibility, presumably by increasing digesta residence time in the gastrointestinal tract.