Effect of the probiotic Entrococcus faecium on hematological and non-specific immune parameters and disease resistance in zander (Sander lucioperca)

The current study evaluated effects of dietary administration doses of Entrococcus faecium on the hematological factors, and disease resistance of Sander lucioperca against Aeromonas hydrophila infection. Fish were fed with dietary administration containing E. faecium doses including of (۱۰۱۰, ۱۰۸CFU/ g) for diet A۱ and A۲, respectively in a commercial diet as basal diet were used for ۶ weeks. The control group was basal diet with serum. The hematological and immunity parameters were measured and fish were challenged with A.hydrophila (۴.۵×۱۰۸CFU/mL). Fish were monitored daily and the mortality rates were recorded over ۸ days post – challenge. The results indicated that HCT in A۱ treatment (۱۰۱۰CFU/g) had significantly increased in compare to the control and A۲ (۱۰۸ CFU/g) treatments (p<۰.۰۵).  MCV in A۱(۱۰ ۱۰CFU/g) and control groups were significantly higher than A۲ (۱۰۸ CFU/g) Treatment (p<۰.۰۵). However, other parameters e.g. RBC, HB, MCH, MCHC had no significant different. The serum lysozyme, alternative complement activity (ACH۵۰) and IgM levels were significantly enhanced in dietary administration E. faecium(۱۰۸,۱۰۱۰CFU/g) in feeding period. Survival rate of fish by dietary administration E. faecium (۱۰۱۰CFU/g) was significantly higher (p<۰.۰۵) than the other groups (۸۶.۶%).

Keywords:

Entrococcus faecium , Aeromonas hydrophila , Hematology , Immunity