Lymphocyte subsets in the small intestine of piglets fed with probiotic and zinc: a qualitative and quantitative micro-anatomical study.

BACKGROUND: Piglet mortality is a real concern to the pig farmers. The major cause is due to the late maturation of the immune system and dietary changes in postweaned piglets. The potential role of probiotic and zinc in the stimulation of the immune system is well established. Hence, the present study was undertaken to evaluate alterations of T and B cells in the small intestine after dietary inclusion of probiotic and zinc in pre and post-weaned piglets. MATERIALS AND METHODS: A total of 18 healthy Large White Yorkshire (LWY) piglets, irrespective of sex obtained from 3 litters at the age-group of 20, 30 and 60 days. They were divided into a control group fed with basal diet and a treatment group fed with probiotic and zinc supplement along with the basal diet, consisting of three animals in each group. The piglets were weaned at 28 days of age. After sacrificing the animals at day 20, 30 and 60 from both the groups, the abdominal cavity was opened and small intestinal tissue samples were collected, processed and stained by indirect immunofluorescence technique. The slides were evaluated under the fluorescent light microscope. The data were statistically analysed. RESULTS: The different T and B cell subsets were recorded in the lining epithelium, core of villus, crypt area of lamina propria and Peyer's patch area. The number of CD4+, CD8+, IgA+ and IgM+ cells was higher in the treated piglets than the control group of animals, irrespective of segments of intestine and age-group. CONCLUSIONS: It can be concluded that the dietary supplementation of probiotic and zinc was found to be good additives as they can stimulate the immune response in piglets, especially during the critical early post-weaning period.