Growth performance and serum immune responses of the common carp (Cyprinus carpio) using Lactococcus lactis and Weissella cibaria as potential dietary probiotics

The present study aimed to investigate the effect of Lactococcus lactis and Weissella cibaria as potential probiotics on growth performance, some blood and immune parameters, digestive and liver enzyme activity, and intestinal bacterial flora, in common carp (Cyprinus carpio) juvenile. Fish (17.00±1.3 g) were divided into 10 treatments. The experimental diets of treatments 1, 2, and 3 were supplemented with Lactococcus lactis in doses of 1.5×107, 3×107, and 4.5×107 CFU kg-1, the diets of treatments 4, 5, and 6 were supplemented with Weissella cibaria in doses of 1.5×107, 3×107 and 4.5×107 CFU kg-1, these two potential probiotics were equally mixed for preparation the diets of treatments 7,8 and 9 which has been added in doses of 1.5×107, 3×107, and 4.5×107 CFU kg-1. A basal diet (19 mJkg-1 of energy and 38% protein) without probiotic was fed to the fish in the control group. Fish were randomly divided into 30 tanks and reared in the water with an average water temperature of 24.5°C. They were fed two times a day at 3% of body weight for 8 weeks. Results showed a significant increase in body weight (about 4 g), specific growth rate, and average daily growth in the most of the probiotic supplemented treatments (p<0.05) sespecially in treatments 8 and 5. Also, the highest amount of white blood cells, neutrophil, monocytes, Immunoglobulin M, alternative complement pathway activity (ACH50), lysozyme activity, digestive enzymes, and the lowest amount of liver enzymes (Aspartate aminotransferase and Alanine transaminase) were observed in the groups treated with potential probiotics. According to the results, adding 3 to 4.5×107 CFU kg-1 of the potential probiotics mixture, or 3×107 CFU kg-1 W. cibaria, could improve the growth performance and health status in common carp.