Effects of feeding dried broccoli floret residues on performance,ileal and total digestive tract nutrient digestibility,and selected microbial populations in broiler chickens

A study was conducted to determine the effects of feeding dried broccoli floret residues on growth performance, apparent ileal digestibility (AID) and apparent total tract nutrient digestibility (ATTD) coefficients, and intestinal microbial populations in broiler chickens. One thousand two hundred day-old male Ross 508 broilers were randomly allotted to 4 dietary treatments and were grown over a 35-d experimental period. Dietary treatments included 4 levels of dried broccoli floret residues: 0, 3, 6, and 9%. Results showed that inclusion of dried broccoli floret residues increased body weight gain (quadratic effect, P = 0.004) and feed conversion ratio (quadratic effect, P = 0.002) with no effect on feed intake. Apparent ileal crude protein (CP, quadratic effect, P = 0.003) and dry matter (DM, quadratic effect, P = 0.002) digestibility for younger birds (25 d of age) increased as the level of dried broccoli floret residues in the diet increased. However, apparent ileal CP (linear effect, P = 0.022), DM (linear effect, P = <0.001) and gross energy (linear effect, P = 0.001) digestibility for older birds (35 d of age) decreased as a result of dried broccoli residue inclusion. Nitrogen (N) corrected apparent metabolizable energy decreased (linear effect, P < 0.001) as the level of dried broccoli floret residues in the diet increased. However, N retention was not influenced by dried broccoli floret residue inclusion. It was concluded that incorporation of dried broccoli floret residues in broiler diet at moderate levels (i.e., 3 to 6%) may improve the growth of broiler chickens with no detrimental effects on nutrient digestibility and retention. However, at high levels (i.e., 9%), dietary dried broccoli floret residues may compromise ileal and total tract nutrient digestibility.