<b>True ileal protein digestibility in broilers fed diets with different crude protein levels</b> - DOI: 10.4025/actascianimsci.v28i3.41

Abstract

Crude protein apparent ileal digestibility (DIA-PB) and true ileal digestibility (DIV-PB) were determined in 39 day old broilers on four corn-soybean meal diets with 19.8 to 23.5% crude protein content (4 replicates of 8 birds/sex/diet). Diets contained 0.25% chromium oxide and were given in four daily meals. Birds were sacrificed between 2 and 4 hours after the start of the last meal. Endogenous protein loss was obtained as the intercept of the linear regression between the feed intake and the protein collected in the ileum. A linear increase in digestibility with dietary protein level increment was observed. Lower coefficients of variation (CV%) and of regression were observed with DIV-PB (1.8*CP + 36.3; r2=0.97; P<0.02; CV%=2.9) than with DIA-PB (3.3*CP + 0.9; r2=0.99; P<0.01; CV%=3.7). Studied methodology was efficient to determine true ileal digestibility in broilers. Apparent ileal digestibility overestimated the effect of dietary crude protein level