Chitosan associated with technical cashew nut shell liquid in supplements for grazing beef steers: nitrogen balance and rumen metabolism

Abstract

ABSTRACT The aim of this study was to evaluate the inclusion of the chitosan (CHI) and technical cashew nutshell liquid (CNSLT) on nitrogen metabolism and ruminal fermentation on pasture system. Five steers (5 × 5 Latin square); kept of Marandu grass and supplemented daily by up to 0.4% BW. The experimental diets were: CON (mineral supplement); PRO (protein supplement); CHI supplementation; CNSLT supplementation and CC (CHI + CNSLT supplementation). Animals supplemented with CNSLT showed a reduction of pasture intake. The combination CC increased the intake of supplement. Steers supplemented with the combination of CNSLT, and CHI showed a higher supplement intake. The ruminal pH for the animals that received the combination of CNSLT and CHI, showed the lowest values. CHI decreased rumen acetate concentration, and increased propionate. Animals fed CC had a higher concentration of short-chain fatty acids (SCFA) and a reduced value for purines. CNSLT increased the excretion of total purines, microbial nitrogen synthesis and crude protein. Animals that received CC showed higher urinary excretion of N compared to the other treatments. The CHI + CNSLT proved to be favourable, with a higher total concentration of SCFA and positive effect on nitrogen balance.