The effect of multi-strain probiotics as feed additives on performance, immunity, expression of nutrient transporter genes and gut morphometry in broiler chickens
Avishek Biswas, Kapil Dev, Pramod K. Tyagi, A.B. Mandal
Abstract
Objective: This study was conducted to investigate the effects of dietary multi-strain probiotic (MSP) (Bacillus coagulans Unique IS2 + Bacillus subtillis UBBS14 + Saccharomyces boulardii Unique 28) on performance, gut morphology and expression of nutrient transporter related genes in broiler chickens.Methods: A total of 256 (4×8×8) day-old CARIBRO Vishal commercial broiler chicks of uniform body weight were randomly distributed into four treatments with 8 replicates each and having eight chicks in each replicate. Four dietary treatments were T<sub>1</sub> (negative control-basal diet), T<sub>2</sub> (positive control-antibiotic bacitracin methylene disalicylate at 20 mg/kg diet), T<sub>3</sub> (MSP at 10<sup>7</sup> colony-forming unit [CFU]/g feed), and T<sub>4</sub> (MSP at 10<sup>8</sup> CFU/g feed).Results: During 3 to 6 weeks and 0 to 6 weeks, the body weight gain increased significantly (p<0.05) in T<sub>3</sub> and T<sub>4</sub> groups. The feed intake significantly (p<0.05) reduced from T1 to T<sub>3</sub> during 0 to 3 weeks and the feed conversion ratio also significantly (p<0.05) improved in T<sub>3</sub> and T<sub>4</sub> during 0 to 6 weeks. The humoral and cell mediated immune response and the weight of immune organs were also significantly (p<0.05) improved in T<sub>3</sub> and T<sub>4</sub>. However, significant (p<0.05) dietary effects were observed on intestinal histo-morphometry of ileum in T<sub>3</sub> followed by T<sub>4</sub> and T<sub>2</sub>. At 14 d post hatch, the relative gene expression of glucose transporter (GLUT5), sodium-dependent glucose transporter (SGLT1) and peptide transporter (PepT1) showed a significant (p<0.05) up-regulating pattern in T<sub>2</sub>, T<sub>3</sub>, and T<sub>4</sub>. Whereas, at 21 d post hatch, the gene expression of SGLT1 and PepT1 was significantly (p<0.05) downregulated in MSP supplemented treatments T<sub>3</sub> and T<sub>4</sub>.Conclusion: The supplementation of MSP at 10<sup>7</sup> CFU/g diet showed significant effects with improved performance, immune response, gut morphology and expression of nutrient transporter genes. Thus, the MSP could be a suitable alternative to antibiotic growth promoters in chicken diets.