RESUMO
This study aimed to assess the effects of diets containing spineless cactus genotypes resistant to carmine cochineal insect (Dactylopius opuntiae) on the liver condition of sheep. Thirty-six non-castrated Santa Inês male sheep (six months of age and average initial body weight of 22.0 ± 2.9 kg) were assigned to a completely randomized design, with three treatments and 12 replicates. The animals were fed a diet with Tifton hay as exclusive roughage (control) and two more diets in which the hay was partially replaced by 'Miúda' or 'Orelha de Elefante Mexicana' (OEM.) spineless cactus. The animals were randomly slaughtered at 86 days after 16-h solid fast. The use of spineless cactus, regardless of genotype, increased the liver weight and caused inflammatory processes and necrosis on the liver parenchyma. Spineless cactus in diets for sheep confined for 86 days, despite causing liver tissue damage, such as inflammation and death process of hepatocytes, does not compromise weight gain.
Este estudo teve como objetivo avaliar os efeitos de dietas contendo genótipos de palma forrageira resistentes ao inseto cochonilha do carmim (Dactylopius opuntiae) sobre a condição hepática de ovinos. Trinta e seis ovinos machos Santa Inês não castrados (seis meses de idade e peso corporal inicial médio de 22,0 ± 2,9 kg) foram distribuídos em delineamento inteiramente casualizado, com três tratamentos e 12 repetições. Os animais foram alimentados com uma dieta com feno de Tifton como volumoso exclusivo (controle) e mais duas dietas em que o feno foi parcialmente substituído por palma forrageira 'Miúda' ou 'Orelha de Elefante Mexicana' (OEM.). Os animais foram abatidos aleatoriamente aos 86 dias após jejum de sólidos por 16 horas. O uso de palma forrageira, independente do genótipo, aumentou o peso do fígado e causou processos inflamatórios e necrose no parênquima hepático. A palma forrageira em dietas para ovinos confinados por 86 dias, apesar de causar danos ao tecido hepático, como inflamação e processo de morte dos hepatócitos, não compromete o ganho de peso.
Assuntos
Animais , Ovinos , Elaeis guineensis , Fígado/anatomia & histologiaRESUMO
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.