Impact of multistrain probiotics on growth performance, immune response, and gut morphometry in broiler chicken Gallus gallus domesticus

The objective of this investigation was to examine the impact of four lab-isolated probiotics Enterococcus faecium (OR563785.1), Weissella confusa (OR563786.1), Weissella cibaria (OQ543569.1), Lactiplantibacillus plantarum (OQ689085.1) in 1:1:1:1 of CFU dilution as multistrain probiotics (MSP) regarding growth performance, haemato-biochemical indices and immune function in broilers. Ninety uniformly weighed broilers were divided into five groups at random with (n = 18/group). NC: negative control (basal diet); PC: commercial probiotic, G1: MSP supplemented, G2: MSP + vaccinated, G3: (vaccinated). Blood samples were collected at 42 days of age to assess immunological, haemato-biochemical parameters, and intestinal morphometry. Compared to the group of negative control, the broiler chicks' body weight was considerably (p < 0.05) higher in MSP-treated groups (G1, G2). This study found that, as compared to the NC, there was a substantial rise (p < 0.05) in RBC and hemoglobin in the probiotic-supplemented bird group. The results indicated that cholesterol and triglyceride remarkably decreased compared to control in probiotic-treated groups. There was no discernible change in the enzyme activity of ALT, AST, and ALP across the groups (p > 0.05). The findings indicated higher levels of immunoglobulin and interleukins in the MSP group than in the control (NC). The villus's height to crypt depth ratio was higher in the MSP groups (G1, G2) in contrast with the PC group (p < 0.05). The haemagglutination inhibition test (HI) revealed that the probiotic-treated groups had greater New Castle disease virus (NDV) antibodies than the other groups. The humoral response to live NDV vaccinations may be enhanced by multistrain probiotics. These results revealed MSP significantly affected growth performance, haematobiochemical parameters, and immunity through alteration in intestinal morphology which helps in nutrient uptake.