Multi-strain probiotic improved feed conversion ratio and selected health indicators in Japanese quail*

Abstract Use of multi-strain probiotics in poultry nutrition provides advantages, including promoting microbial diversity in the birds’ gut. Less investigated, as compared to broilers, is how application of probiotics affects performance and health of Japanese quails. Up to date effects of either probiotics based on a single microorganism or using a single dose of probiotic were investigated. The aim of the study was to investigate the effect of gradual levels of multi-strain probiotic applied in the Japanese quails’ diet on their performance, carcass, microbiological and immunological parameters. Total of 240 Japanese quail mixed sex chicks were randomly selected into four treatments: 0.15, 0.10, 0.05 g/l of the probiotic and control group not provided with probiotic. Body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), carcass characteristics, selected gut microbiome species and sheep red blood cell (SRBC) immunoglobulin IgT, IgG and IgM antibodies were determined. Repeated measures ANOVA was performed on parameters related to productive performance of the birds, while one-way ANOVA on all other parameters using SAS software v 9.4. FI was the highest in the control group (16.84±2.19) and did not differ significantly between other groups (from 16.53±2.12 to 15.18±1.86). FCR was the highest in the control and the lowest dose group (3.15±0.28 and 3.07±0.27), as compared to two other groups of birds which received multi-strain probiotic (2.8±0.23 and 2.77±0.24, respectively). Birds in the control group and birds which received the lowest dose of the probiotic had lower counts of IgT (5.63±0.26 and 5.75±0.25, respectively) and IgG (4.00±0.38 and 4.13±0.3, respectively), as compared to two other treatment groups which received the multi-strain probiotic. Birds which did not receive the multi-strain probiotic had significantly lower levels of Lactobacillus (6.98±0.01), as compared to other birds, while those in the control group and which received lowest amount of probiotic had significantly higher levels of E.Coli (6.67±0.01). Multi-strain probiotic had overall positive effect on the selected parameters of Japanese quails’ performance and health, while efficacy varied depending on dosage.