Nutritional Performance and Metabolic Characteristics of Cattle Fed Spineless Cactus

The effect of the inclusion of spineless cactus [0, 14.7, 29.4, 44.1, and 58.8% of Dry Matter (DM)] basis in replacement of Tifton hay on the intake and digestibility of nutrients, feeding behavior, and nitrogen compounds balance were evaluated. Five crossbred steers, rumen fistulated, with average body weight of 380±5.3 kg were assigned to a 5×5 Latin square design. The time spent with rumination activity linearly decreased (P 0.05) with the inclusion of spineless cactus; and the feeding time showed a quadratic effect (P 0.05), with a minimum time of 195 min d^-1 estimated with 35.7% of spineless cactus inclusion. The nutrient intake showed a quadratic effect (P 0.05), with a maximum intake of DM (8.9 kg d^-1), Crude Protein (CP; 1.4 kg d^-1), and Digestible Organic Matter (DOM; 5.8 kg d^-1) estimated with 33.9, 29.9, and 41.8% of spineless cactus inclusion, respectively. Except (P 0.05) to Neutral Detergent Fiber corrected to ash and protein (apNDF), the total digestibility of DM linearly increased (P 0.05) with spineless cactus inclusion replacing Tifton hay. Except for plasma and urinary urea nitrogen, which were not affected (P 0.05), there was a quadratic effect (P 0.05) on nitrogen balance, with a maximum value of 170 g d^-1 estimated with 33.2% of spineless cactus inclusion. It is recommended to include 41.8% spineless cactus in replacement of Tifton hay for crossbred cattle, due to the higher DOM intake without altering the nitrogen efficiency use.