EC Nutrition

This study was conducted to investigate the supplementation of direct-fed microbials (DFM) as an alternative to antibiotic on growth performance, blood parameters, amino acid content, and quality of breast meat of broiler chicken. In total, 800 1-d-old male broiler chicks (Ross×Ross) were randomly distributed into four dietary treatments with four replicate pens per treatment (50 birds/replicate pen). The four dietary treatments fed for 35 d were: a corn-soybean meal basal diet without antibiotic as negative control (NC); NC plus 0.1% virginiamycin as positive control (PC); NC plus 0.1% direct-fed microbials (DFM 1); and NC plus 0.1% mixed direct-fed microbials (DFM 2). Growth performance, blood parameters, and amino acid content, chemical composition, quality attributes and sensory analysis of breast meat of broiler chickens were evaluated. No significant differences were found among the treatments for over all growth performance of broiler chickens at 35 day of age, but the body weight gain was numerically increased when birds were fed PC and DFM supplemented diets. The levels of triglycerides, glucose, total protein and Ca content in blood were not affected by the dietary treatments; however, the total blood cholesterol level was significantly decreased (P < 0.05) in PC and DFM supplemented groups compared with the NC group. In addition, the enzyme aspartate aminotransferase (AST) was significantly lower (P < 0.05) in PC and DFM supplemented groups compared with the NC group, and the enzymes alanine aminotransferase (ALT) was lower in DFM 2 compared with that of other treatments. Dietary supplementation of DFM was significantly increased (P < 0.05) the cystine, valine, isoleucine and proline contents of breast meat of broiler chickens; however, other meat amino acid contents were not affected by the dietary treatments. The shear force values of breast meat of broiler chickens were not significantly affected by the dietary treatments; however, the cooking loss was significantly decreased (P < 0.05) and the water holding capacity was significantly increased in PC and DFM supplemented groups compared with the NC group. The moisture content of breast meat was significantly lower in DFM 2 compared with NC and the lipid content was also significantly lower in PC and DFM supplemented group compared with the NC group. The protein content of meat was not affected by the dietary treatments; however, the ash content of meat was significantly increased in DFM compared with the NC. In addition, the DFM supplementation did not affect the tenderness and flavor of breast meat, but the juiciness was significantly increased in DFM 2 compared with the PC. It is concluded that dietary supplementation has a positive effect on growth performance of broiler chickens to some extent, but it decreases the cholesterol, AST and ALT levels in blood, and increases the meat quality attributes of broiler chickens.

 Keywords: Direct-Fed Microbials; Blood Characteristics; Meat Quality; Sensory Analysis; Broiler Chickens

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