Spineless cactus as only water source for feedlot lambs

This study evaluated the effects of spineless cactus as the only water source on DM intake and digestibility, ingestive behavior and growth of feedlot lambs. Forty-two male lambs with initial weight of 18.7 ± 2.05 kg were allocated, in a completely randomized design in a 3 × 2 + 1 factorial arrangement with additional treatment of the control type. Factors included three diets with cactus replacing Tifton-85 hay [30, 50, and 70% on dry matter (DM) basis] and two watering regimens (drinking water deprivation or ad libitum access to drinking water). The control treatment contained 0% spineless cactus and had ad libitum access to drinking water. The time spent for drinking was greater (p≤0.05) in lambs with drinking water supply, but time spent urinating was lower. The daily intake of DM and OM quadratically increased while the crude protein, NDF, and EE intakes linearly decreased, and NFC linearly increased due to spineless cactus inclusion in lamb diet (p≤0.05). The inclusion of 30% DM of spineless cactus replacing Tifton grass hay in lamb diet improved DMI, digestibility, metabolic water, weight gain, feeding conversion, and feedlot time compared to control diet (drinking water ad libitum without spineless cactus).