Balanço eletrolítico e redução da proteína bruta da ração sobre parâmetros fisiológicos e sanguíneos de frangos de corte no calor

Abstract

An experiment was carried with the objective of evaluating the effect of diet electrolyte balance (DEB) and crude protein (CP) reduction on respiratory rate, cloacal temperature and concentrations of Na+, K+, Cl- and uric acid of broiler chickens. Eight-hundred male Cobb broiler chickens were randomly allocated in 20 boxes, with four treatments and five replicates of 40 birds per experimental unity. The treatments were: T1 - basal diet; T2 - diet adjustment until DEB = 250 mEq kg-1; T3 - diet with reduction of CP and without adjustment of DEB; T4 - diet with reduction of CP and adjustment of DEB to 250 mEq kg-1. The thermal environment was not favorable during the experimental period. The birds that received diets with correction of electrolyte balance showed low values (p < 0.05) of respiratory rate in the phases studied, as well as of cloacal temperature in the phase between 7 and 21 days. Results of cloacal temperature in the total period were not affected (p > 0.05). Reduction of crude protein decreased (p < 0.05) the concentration of sodium in the serum. The use of electrolyte in the concentration of sodium was influenced (p > 0.05) at 42 days. The supplementation with electrolytes improved homeostasis of the broilers in heat stress conditions.