Effect of some natural feed additives on growth performance, health and meat quality characteristics of broiler chickens

Abstract

Two experiments were conducted to assess the effects of some natural feed additives on growth performance, carcass measurements, meat quality characteristics and health parameters of broiler chickens. In the first experiment, three experimental groups with six replicates per treatment and six birds per replicate were allocated. The groups were treated as follows: a control that has a diet with no multienzymes and with standard metabolizable energy (ME; 3200 kcal kg−1); a low metabolizable energy group (low-ME; 3000 kcal kg−1) with no multienzymes; and a low-ME diet with 0.5 g kg−1 multienzymes. The results revealed that; 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 (p<0.05) with the low-ME and low-ME–Enz diets in comparison with the control-diet. The values of the feed conversion ratio (FCR) was 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 significantly (p<0.05) with the low-ME–Enz diet compared with the other diets. Meat yellowness b* 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 the second experiment, there were two trails; the first was six treatments; 0.0 control, 0.1 Maxus, 0.5 CloStat, 0.12 Sangrovit Extra, 0.5 + 0.12 CloStat + Sangrovit Extra and 0.2 g/ Kg-1 of and Gallipro Tech. This trail was conducted from day one to 15 days. While trail two from 15-35 day broiler chicken exposed to Clostridium perfringens challenge, the same treatments plus positive control the chicks were inoculated with Clostridium perfringens except negative control. Chicks were fed a basal diet typical 2 isocaloric and isonitrogenous starter (0-15 d), and trail two finisher diets (15-30 d), diets based on corn-soybean meal (SBM) with, respectively for 35 days. The performance results obtained in trail one (starter period, 0-15 day-old) showed that; the live body weight, feed intake, body gain and feed conversion ratio of all groups received probiotic and basal diet had no significance differences between them. While, the body weight gain (BWG), final body weight (FBW), production efficiency ratio, feed conversion ratio (FCR) and survival rate during finisher phase trail two (15-20; 20-25 and 25-30 days old) and overall period (15-35 day-old) were significantly (P≤0.05) improved in all probiotic treated groups. In trail two (15-35d); carcass traits, meat quality, blood biochemistry, and intestinal health of broiler chicken were evaluated. The results demonstrated that, the inclusion of probiotic and/or phytobiotic compounds had a positive effect on growth performance, blood constituents, liver histopathology, intestinal morphology and histopathology. Furthermore, a notable reduction in both lesion scores was observed when probiotics and phytobiotics alone or in combination were included in the diets. It is concluded that the low-ME diet supplemented with KEMZYME® did not influence most of the performance parameters and carcass traits of chickens tested in this research; however, adding enzymes to the low-ME diet is an effective strategy to improve meat quality criteria and small intestine characteristics. Furthermore, supplementation of probiotics combined with phytobiotic improved the growth, meat quality, carcass characterization and survival rate of NE-infected broiler chickens by modulating gut health conditions and decreasing lesion scores. Moreover, it could be useful as an ameliorated NE disease alternative to antibiotics in C. perfringens confected poultry