Utilização da palma forrageira orelha de elefante mexicana (Opuntia stricta Haw.) na alimentação de ruminantes

Abstract

This project was divided in two experiments; the first one was to evaluate the inclusion of Orelha de Elefante Mexicana spineless cactus (Opuntia stricta Haw) in the diet of Holstein heifers regarding consumption, digestibility, ingestive behavior and performance. The second one had the objective of evaluating the substitution of sorghum silage by the Orelha de Elefante Mexicana spineless cactus in the diet of crossbred sheep in terms of consumption, digestibility, ingestive behavior and nitrogen balance. Twenty heifers of the Holstein breed with initial mean weight of 249.1 kg ± 34.2 kg were randomly arranged using the initial weight (PI) as co-variable for the experiment with heifers and five male cannulated in the rumen sheep with initial mean weight of 52.9 ± 6.0 kg that were arranged in 5x5 Latin square for the second experiment. Dry matter intake (CMS) was higher than expected, and was not influenced by substitution. Protein (CPB) and non-fibrous carbohydrate (CCNF) intakes increased with inclusion as the consumption of neutral detergent fiber (CFDN) decreased. The ingestive behavior was not influenced by the inclusion of spineless cactus in order of sugarcane, as well as the performance measured by body measurements. This behavior suggests that the fact that sugarcane presents low NDF content (38.5%) made possible a high consumption of DM, and consequently high weight gains. For the replacement of sorghum silage by the OEM palm, the dry matter intake (CMS), organic matter (CMO), non-fibrous carbohydrates (CCNF) and total digestible nutrients (CNDT), MS, and CNF digestibility increased with the replacement of sorghum silage by the OEM palm, as the consumption of neutral detergent fiber (CFND) decreased as expected. The ingestive behavior was influenced by the evaluated substitution, presenting a decrease in feeding and rumination times, and consequently an increase in leisure time. The chewing and rumination efficiencies of DM also increased with substitution. The nitrogen balance was not influenced by the substitution of sorghum silage by the OEM palm, which can be explained by the fact that CPB and DPB did not change. The low retention of nitrogen can be explained by the fact that the animals used have already reached maturity. It is possible to conclude that it is possible to use OEM palm on low-NDF sugarcane diets for Holstein heifers, with the criterion being the cost of the ingredients as well as the substitution of sorghum silage for the Orelha de Elefante Mexicana palm for sheep.