Diets containing cactus cladodes on serum and liver levels of microminerals in sheep and goats.

Two experiments were performed to evaluate the effects of partial replacement of Tifton hay by Miúda cactus cladodes (Nopalea) or Orelha de Elefante Mexicana (O.E.M.) cactus cladodes (Opuntia) on serum and liver concentrations of iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn) in feedlot small ruminants. The experiment 1 (Exp. 1) lasted 86 days, and thirty-six male Santa Inês lambs (22.0 ± 2.9 kg initial body weight-IBW) were used. In experiment 2 (Exp. 2), lasting 100 days, thirty-six male goats of undefined breed (19.0 ± 2.8 kg IBW) were used. In both studies, the animals were distributed in a completely randomized design, with three treatments (diet control-without cactus; and diets with hay partially replaced by Miúda or O.E.M. cactus cladodes) and twelve replicates. Blood samples were collected to quantify serum micromineral levels, and at the end of the feedlot periods, sheep and goats were slaughtered and liver fragments were collected for micromineral dosage. In Exp. 1, lambs fed Nopalea cactus cladodes diet showed greater hepatic Cu accumulation (441.87 mg/kg DM; P = 0.027). The diets containing cactus cladodes tended to increase serum levels of Cu (P = 0.075) and Zn (P = 0.058). In Exp. 2, goats fed diet containing Opuntia cactus cladodes presented higher serum levels of Fe (P = 0.024) and Cu (P = 0.012). In conclusion, the partial replacement of Tifton hay by cactus cladodes increases hepatic concentrations of Cu in lambs and serum levels of Fe and Cu in goats.

Intake, digestibility, and performance of lambs fed spineless cactus cv. Orelha de Elefante Mexicana.

OBJECTIVE: To evaluate the effects of the carmine cochineal-resistant spineless cactus genotypes cv. Orelha de Elefante Mexicana (Opuntia) and Miúda (Nopalea) on the intake and digestibility of nutrients, ingestive behavior, performance, and ultrasound measurements of growing lambs. METHODS: Thirty-six male (non-castrated) Santa Inês lambs were used, with an average age of 6 months and an initial average weight of 22.0±2.9 kg. They were distributed in a completely randomized design with 3 treatments (Tifton hay, Nopalea and Opuntia) and 12 replications, using initial weight as a covariate. The experimental period was 86 days, with the first 30 days used for the adaptation of the animals to the facilities, diets and management, and the remaining 56 days used for evaluation and data collection. RESULTS: The intake and apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), total carbohydrates (TC), non-fibrous carbohydrates (NFC), and total digestible nutrients (TDN) showed a significant difference (p<0.05) as a function of the diets, with the Nopalea treatment (p<0.05) increasing DM intake (g/kg and % body weight [BW]), CP, TDN, and TC digestibility, whereas the Tifton hay diet led to a high (p<0.001) neutral detergent fiber corrected for ash and protein (NDFap) g/d intake, NDFap (BW %) and digestibility of said nutrient. There was no effect of treatments (p>0.05) on feeding time, however, rumination time and total chewing time were higher (p<0.05) for animals fed Tifton hay. The performance of the animals was similar (p>0.05). For the ultrasound measurements, Nopalea promoted an increase in the final loin eye area, compared to Tifton hay. CONCLUSION: The use of spineless cactus variety Miúda leads to the greater intake and digestibility of nutrients. The evaluated carmine cochineal-resistant spineless cactus genotypes are alternatives for semi-arid regions as they do not negatively affect the performance of growing lambs.