Study on the optimal level of cactus pear (Opuntia ficus-indica) supplementation to sheep and its contribution as source of water

A 90-day experiment using a randomised complete block design with eight sheep per treatment was conducted to determine the optimum cactus pear supplementation level and its contribution as source of water. Cactus pear replaced 0%, 20%, 40%, 60% and 80% of pasture hay (C0, C20, C40, C60 and C80, respectively), on dry matter (DM) basis. Total DM, nutrients and water intake (P < 0.001) and digestibility and sheep performance (P < 0.05) were significantly affected. The highest DM intake (92 g/kg W0.75) was recorded on treatment group C60. Sheep on the control diet drank the highest amount of water (1226 ml/day), while supplemented sheep drunk negligible amount of water. There were no significant (P > 0.05) differences in digestibility among treatments groups, except between C80 and the control group. Only sheep on treatment diet C80 were in a negative N balance. All experimental sheep maintained body weight, and the highest average daily gain (ADG) was recorded on treatment diet C20 (+33.0 g/day). It is concluded that cactus pear could optimally substitute pasture hay up to 60%. Its inclusion has a substantial contribution in satisfying the water requirement of the sheep. The study demonstrated the nutritional potential of cactus pear to mitigate feed and water shortages in drought prone dry areas of the tropics and sub-tropics.