Macromineral balance in lambs fed diets containing spineless cactus speciesABSTRACT
The purpose of the present study was to evaluate the effects of spineless cactus species in diets of feedlot lambs on intake, apparent absorption and retention of macrominerals. Thirty-six uncastrated male Santa Inês lambs presenting an average body weight of 22.0±2.87 kg were distributed in a completely randomized design with three treatments [diet containing Tifton-85 hay as exclusive roughage (control), Miúda cactus cladodes-based diet or Orelha de Elefante Mexicana (OEM) cactus cladodes-based diet] and twelve replicates. The calcium (Ca) and magnesium (Mg) intakes (from feed and total) were higher (P=0.001) for animals fed diets supplemented with Miúda spineless cactus. The spineless cactus, regardless of species, caused a mean decrease of 45.4% in sodium intake (P=0.001). There was a net loss of Ca by lambs fed OEM spineless cactus (P=0.001). The absorption and retention of P was higher in control diet compared to the OEM diet (P<0.05). The amount apparently absorbed, and body retention of Mg were higher for lambs fed Miúda spineless cactus-diet (P=0.001). Therefore, the diet containing Miúda spineless cactus increases the intake and body retention of Ca and Mg in lambs. However, the use of OEM spineless cactus may be unsuitable for a long-term.
Keywords: sheep; apparent absorption; cactus cladodes; mineral elements; semiarid