The effect of dietary supplementation of prebiotic, probiotic and organic acid, either alone or combined, on broiler performance and carcass characteristics.

A prebiotic, a probiotic and an organic acid were used as performance enhancer feed additives in this study. Two thousand and four hundred, 1-d-old broiler chicken (Ross-308) were weighted and randomly assigned to the six treatment groups, each with eight replicates. The addition of performance enhancer feed additives to the diet significantly increased body weight of broilers in both 21 (P<0.0001) and 42 (P<0.05) days of age. Feed consumption of birds was affected significantly 0 to 3 week (P<0.05) but not at 0 to 6 week period. Dietary treatments had significant effect on feed conversion ratio both at starter and entire experimental period. Supplementation of prebiotic + probiotic combination improved over all feed conversion ratio (P<0.05) when compared to control treatment. Growth promoter feed additives of all had no significant effect on livability, and affected significantly the liver weight and small intestine weight of male birds (P<0.05). The results show that prebiotic, organic acid and probiotic can be used as alternative performance enhancer feed additives, also dietary combination of prebiotic with probiotic revealed additive beneficial effect on feed efficiency through experimental period when compared to supplementation in diet alone. Introduction Feed additive antibiotics have been used more then fifty years in feed industry all over the world as growth promoters. The mode of action of antibiotics was suppressing the detrimental effect of photogenic bacteria in the gut. Since the proposed total ban on sub therapeutic feed antibiotics, prebiotics, organic acid and probiotics are currently receiving considerable attention in animal nutrition because of their association with non-residual and non-resistant properties (Mellor, 2000). Feed organic acids reduce certain species of bacteria, with particular effect against acid-intolerant specie like E. coli, Salmonella spp and Campylobacter ssp. (Dibner, 2004). The improvement effects on protein and energy digestibility and also on immune stimulation of these additives were demonstrated in former studies in detail. Probiotics (Jin et al. 1997) and prebiotics (Shane, 2001) act as growth promoters, feed savers, nutritional bio-regulators, immune stimulators and help in improving performance and health. The objective of this study was to evaluate the ability of principal antibiotic replacer feed additives on the growth performance when used as performance enhancer in broiler diets, either alone or combined. Materials and methods Two thousand and two hundred sexed day-old broiler chicks (Ross 308) were divided into 6 treatment groups of 400 birds each and randomly assigned to the six treatment diets, consist of negative control, prebiotic (mannan oligosaccharide), organic acid, probiotic, prebiotic + organic acid mixture and prebiotic + probiotic mixture. The six dietary treatments were as follows: 1. Basal diet (negative control); 2. Basal diet with prebiotic (0.5 g/kg diet); 3. Basal diet with organic acid (1.0 g/kg diet); 4. Basal diet with probiotic (0.5 g/kg diet); 5. Basal diet with prebiotic + organic acid (0.5 g/kg + 0.5 g/kg diet); 6. Basal diet with prebiotic + probiotic (0.5 g/kg + 0.5 g/kg diet). Each treatment group was further sub-divided in to 8 replicates of 50 birds (25 male and 25 female) per replicate. The ingredients and chemical composition of the diets are presented in Table 1. The diets were isocaloric and isonitrogenous. Experimental diet in pellet form and water were provided ad libitum. The experiment lasted for 42 days. A photoperiod of 24 h/d was maintained. The standard