Ruminal parameters and nitrogen balance in sheep fed diets containing residue from the extraction of tamarind pulp

Resumo

This study measured the ruminal parameters, feed intake, fecal and urinary N production, and N balance (NB) in sheep fed increasing levels of residue from the extraction of tamarind pulp (RETP) on a 0.0%, 5.0%, 10.0%, and 15.0% dry matter (DM) basis. Four mixed-breed male sheep weighing 40.38 ± 2.10 kg of body weight were distributed in a 4 × 4 Latin square design. The animals were allocated to metabolism cages and fed twice a day. Each experimental period lasted 20 days. The pH and concentration of ammonia nitrogen (NH3-N) in ruminal fluid were measured. Nitrogen intake (NI), fecal N (FN), urinary N (UN), absorbed N (AN), and NB were expressed in g·day-1, percentage of consumed nitrogen (CN), and g·kg-1 of metabolic weight (g·(kg0.75)-1. Statistical analysis of these variables was performed by evaluating the variance and regression at 5% probability. The levels of RETP did not alter (p>0.05) the pH level or NH3-N concentration in the rumen fluid, but a quadratic behavior for the same values after feeding (p<0.05) was observed. The inclusion of RETP in the diet did not change (p>0.05) NI, UN, the AN in g·day-1 and g·(kg0.75)-1, NB in g·day-1 and g·(kg0.75)-1, or the percentage of CN. However, the AN as a percentage of CN showed a linear effect (p<0.05) with the inclusion of RETP in experimental diets. For FN in g·day-1 and g·(kg0.75) -1, no difference was observed (p>0.05) with the inclusion of RETP, but for FN expressed as a percentage of CN, a linear increase (p<0.05) was observed with the inclusion of RETP. Thus, we concluded that diets with up to 15.0% RETP do not alter the pH and NH3-N in ruminal fluid, NI, UN, or NB. In addition, the inclusion of 15.0% RETP has a laxative affect.