Does macauba cake alter nutrient digestibility and microorganism population in the rumen of sheep?

Abstract

Abstract This study aimed to determine the effects of including macauba cake (MC) in the diets of Santa Ines sheep on nutrients digestibility, and the population of microorganism in the rumen (total bacteria, anaerobic fungi, methanogenic organisms, Ruminococcus flavefaciens, and Fibrobacter succinogenes). Twenty male sheep were distributed in a randomized block design with four MC treatment diets (0, 10, 20, and 30% of total dry matter). MC inclusion did not affect the dry matter, organic matter, or crude protein intake, but increased the ether extract, neutral detergent fiber, and acid detergent fiber intake, mainly because of changes in the concentrations of these components in diets with a higher level of MC. With MC inclusion, a linear decreasing effect was observed for the dry matter and organic matter digestibility, and a quadratic effect with a maximum point of 21.5% was observed for the acid detergent fiber digestibility. MC inclusion reduced anaerobic fungal populations and increased methanogenic populations. The increase in methanogenic organisms can be associated with the higher fiber content in diets containing MC. The inclusion of macauba cake in the diet of lambs reduced the dry matter digestibility, promoted an antifungal effect and increased the methanogenic population.