This study was carried out to investigate the effects of feeding some organic acids mixtures on broilers. Four organic acids (OAs): formic (FA) at 0.50%, acetic (AC) at 0.25%, citric (CA) at 2% and butyric (BA) at 0.2% were used as mixtures. A total number of 210 one day old male Arbor Acres broiler chicks were randomly divided into 7 treatment groups, each in three replicates of 10 chicks per replicate. The first group fed the basal diet without supplementation and served as control (T1). While, the other groups received the basal diet supplemented with the tested organic acids mixtures as follow: T2 (0.5% FA+0.25% AC), T3 (0.5%FA+2%CA), T4 (0.5% FA +0.2% BA), T5 (0.25 %AC+ 2% CA), T6 (0.25% AC+0.2%BA) and T7 (2%CA+0.2%BA). The experiment lasted up to 42 day of age. Performance, pH of feed and some GI-tract segents, cecal bacteria count, blood metabolites, acceptability and nutrients digestibility were measured. Results indicated that:
1) Most of OAs mixtures improved performance of broiler chicks measured as feed conversion ratio, protein utilization efficiency and European Production Efficiency Index (EPEI) compared with the control group.
2) Dietary OAs mixtures improved some nutrients digestibility of the experimental diets compared with the control group.
3) Blood plasma content of calcium, phosphorus, total protein and globulin were significantly increased by feeding OAs mixtures compared with the control group.
4) Relative weights of lymphoid organs (spleen and bursa of fabrics) of chicks fed OAs mixtures were mostly higher than the control.
5) The pH values were significantly reduced in crop and gizzard of the chicks fed OAs mixtures compared to chicks fed the control.
6) Most of OAs mixtures significantly increased lactobacillus count and significantly lowered the population of the anaerobic and E. coli count of ceca.
In conclusion, 0.5%FA, 0.25%AC, 0.2%BA and 2%CA as mixtures may improve performance and health of broiler chickens.