Effect of cactus species in the diets of dairy goats on feed efficiency, milk yield, and milk and cheese composition

This study evaluated the effect of cactus species in dairy goats' diets on feed efficiency, milk yield, and milk and cheese composition. Ten Saanen dairy goats averaging 50.0 & PLUSMN; 10.1 kg of body weight and 3.5 kg/day of milk were randomly assigned to treatments in a replicated 5 x 5 Latin square design, with 14 days for diet adaptation and five days for sample collection. The experi-mental diets included: control (500 g/kg of Tifton-85 hay + 500 g/kg concentrate); NC (150 g/kg of hay + 350 g/kg of Nopalea cochenillifera + 500 g/kg concentrate); NC:OS (150 g/kg of hay + 235 g/kg Nopalea cochenillifera + 115 g/kg Opuntia stricta + 500 g/kg concentrate); OS:NC (150 g/kg hay + 235 g/kg Opuntia stricta + 115 g/kg Nopalea cochenillifera + 500 g/kg concentrate); and OS (150 g/kg hay + 350 g/kg Opuntia stricta + 500 g/kg concentrate). All the treatments contained 500 g/kg of concentrate. Including cactus cladodes increased (P < 0.05) the intake and digestibility of non-fibrous carbohydrates and reduced (P < 0.05) the intake and digestibility of neutral detergent fiber. Furthermore, it increased (P < 0.05) milk yield despite the absence of a difference in dry matter intake. The lowest (P < 0.05) protein and total solids concentrations were observed in the OS treatment milk. The levels of C18:1t10 and CLA in milk were similar (P > 0.05) in the control and NC diets but lower (P < 0.05) for the OS diet. Cactus cladodes increased (P < 0.05) the contents of medium-chain fatty acids (FA) and reduced (P < 0.05) the long-chain and monounsaturated fatty acids in milk. Diets with cactus cladodes increased (P < 0.05) the protein content and pH of the cheese. The cactus cladodes inclusion in the diets of lactating goats, in the proportions studied, increases milk yield and improves the composition and sensory at-tributes of "coalho" cheese