Parâmetros da fermentação ruminal e concentração de derivados de purina de vacas em lactação alimentadas com castanha de caju

Abstract

The parameters of rumen fermentation and the concentration of purine derivatives in the urine of dairy cows fed with increasing levels of cashew nut in the diet were evaluated. Eight multiparous holstein cows were used, being four rumen cannulated, with average production of 28±4kg of milk/day. The experimental design adopted was a 4x4 Latin square with split plots for the ruminal parameters and double for the determination of purine derivatives. The treatments consisted of the inclusion of 0; 8; 16 and 24% of cashew nut in the concentrate portion of the diet. The behavior of the ruminal pH was similar between the evaluated diets according to the time after feeding. The average concentration of ammonia nitrogen was 12.70mg/100mL of rumen fluid. The average values of acetate and butyrate showed a linear response, but the acetate:propionate ratio was not altered by the addition of the coproduct. The excretions of purine derivatives in urine did not differ significantly (P>0.05) with the addition of cashew nut. The inclusion of cashew nut did not affect ruminal fermentation parameters neither the concentrations of purine derivatives, so it can be recommended as a potential alternative for feeding dairy cows.