Effect of a low-energy and enzyme-supplemented diet on broiler chicken growth, carcass traits and meat quality

Abstract

The objective of this study was to evaluate the impact of a low metabolizable energy (low-ME) diet supplemented with a multienzyme blend (KEMZYME^®) on the growth performance, carcass traits and meat quality of chickens. A total of 108 broiler chicks (Ross 308) were randomly allocated to three experimental groups with six replicates per treatment and five birds per replicate; the groups were treated as follows: a control diet with no additive and standard metabolizable energy (ME; 3200 kcal kg ${}^{-1}$ ); a low metabolizable energy (low-ME; 3000 kcal kg ${}^{-1}$ ) diet; and a low-ME diet $+$ 0.5 g kg ${}^{-1}$ diet of enzyme (low-ME-Enz). Live body weight (LBW) at 43 and 47 d and body weight gain (BWG) during the periods from 38 to 43, 43 to 47 and 33 to 47 d decreased with the low-ME and low-ME-Enz diets in comparison with the control-diet ( $p<0.05$ ). The values of the feed conversion ratio (FCR) were significantly increased with low-ME diets with or without enzyme at all growing stages. There were no significant differences among treatments in terms of carcass traits. With the exception of the jejunum weight, dietary treatments did not affect any digestive tract segments. Meat hardness decreased with the low-ME-Enz diet compared with the other diets ( $P=0.039$ ). Meat yellowness of the breast muscle increased ( $P=0.001$ ) with the low-ME-Enz diet in comparison with the other treatments at 24 h post-slaughter. In conclusion, the low-ME diet supplemented with KEMZYME^® did not influence most of performance parameters and carcass traits of chickens; however, adding enzymes to the low-ME diet is an effective strategy to improve the meat quality criteria and small intestine characteristics.