Effect of dietary Korean aged garlic extract by Leukonostoc citreum SK2556 on production, hematological status, meat quality, relative organ weight, targeted Escherichia coli colony and excreta gas emission in broilers

This study was conducted to determine the effects of dietary supplementation of Korean aged garlic extract (AGE) by Leukonostoc citreum SK2556 on growth performance, hematological status, meat quality, cecal microbiota and excreta gas emission in broilers. A total of 765-day old mixed sex ROSS 308 broiler chicks (body weight of 36.65 ± 0.10. g) were randomly allotted to five treatments with nine replications per treatment and 17 chicks per pen. The experiment lasted for 5 weeks and dietary treatments were as follows: (1) NC (negative control, basal diet without antibiotics); (2) PC (positive control, basal diet. +. 5. ppm enramycin); (3) AGE1 (basal diet. +. 0.5. g aged garlic extract/kg basal diet); (4) AGE2 (basal diet. +. 1. g aged garlic extract/kg basal diet); (5) AGE3 (basal diet. +. 2. g aged garlic extract/kg basal diet). Broilers fed with AGE2 treatment showed higher (linear, P=0.02) body weight gain (BWG) compared with NC treatment (910 vs. 842. g) from day 15 to day 28. During this time, feed conversion ratio (FCR) was higher (linear, P<0.01) for the NC (1.95) treatment compared with AGE3 (1.83) and AGE2 (1.81). Overall, BWG was linearly increased (P<0.01) and the FCR value was linearly decreased (P<0.01) in AGE2 and AGE3 diet than the NC diet. Liver weight was lower in AGE3 (28.3. g/kg) and AGE2 (28.3. g/kg) compared with the NC (40.6. g/kg) diet (linear; P=0.04). On analysis of different characteristics of breast meat, the redness (a*) value was reduced in AGE2 compared with NC treatment (12.2 vs. 15.9; P<0.05). Broilers fed the NC diet showed higher E. coli counts (log10. cfu/g) compared with AGE2 (6.70 vs. 6.54; P<0.05) diet. In conclusion, our findings demonstrated that the administration of AGE at a level of 1 and/or 2. g/kg to the basal diet improved body weight gain and reduced FCR, liver weight and cecal E. coli count in broilers.