Effect of feeding lactobacilli on serum antibody titer and faecal microflora in chicks

Young broiler chicks were fed skim milk fermented with specific strains of Lactobacillus acidophilus viz., I4, V3, C2 and P for 8 consecutive days at the rate of 1 ml/day/bird. The antibody level in the blood of individual chicks was determined before, during and after feeding by haemagglutination inhibition (HI) test. The HI-antibody titers in sera of pre-vaccinated 3 day old chicks (before feeding) were found to vary in a narrow range of 51.2-76.8. In post-feeding scenario, it was found that the average titer values of all the treated groups were higher (160-233) than that of the control group (148) fed unfermented skim milk. The titers increased up to 3-4 weeks after feeding in all groups and then gradually declined. The HI-antibody level was the highest at all periods in C2 group, followed by P and V3, while in 14 and control group it was significantly (P<0.05) lower. Examination of weekly gain in body weight and feed consumption rate did not show significant changes. Examination of the faecal flora of the chicks indicated no alteration in lactobacilli count. However, the count of coliforms and enterococci decreased during feeding of acidophilus milk. On an average, feeding of Lb. acidophilus I4 and C2 could effectively decrease the coliform count, while I4 and V3 significantly decreased the enterococci count.