EFEITO DA IDADE SOBRE AS PERDAS ENDÓGENAS E METABÓLICAS DE FRANGOS DE CORTE INDUSTRIAL E CAIPIRA

Abstract

The objective of this study was to determine the endogenous and metabolic losses in broiler chickens and free range on different age rates. On the experiment 1, 140 broiler chickens distributed in an entirely randomized design with four treatments and five replications have been used. On the second experiment, 120 birds of mixed sex from the Embrapa 041 free range line distributed in tree treatments and five replications distributed in a same design. On both experiments the treatments consisted in the average ages of the birds. To the first experiment the ages were: 5; 15; 25 and 35 days of age and the second experiment the average ages adopted were 15, 45 and 75 days of age. The experimental period was of 72 hours of fasting, being the first 24 hours for digestive tract cleaning and the last 48 hours for total collection of the endogenous and metabolic losses. The contents of dry matter, nitrogen and brute energy from birds` endogenous and metabolic losses have been determined. When relating losses per bird and bird weight, different interpretations were obtained for the same variable. The equations obtained to broiler chicken and free range reveled that those birds had different behaviors during metabolic fecal and endogenous urinary. The losses diminished according to age advance.

Keywords

• Birds on fasting
• endogenous urinary energy
• metabolic fecal energy
• total collection method.