Effects of Co-Supplementation of β-Galacto-oligosaccharides and Methionine on Production Performance, Blood Metabolites, and Gut Histomorphometry in Broilers

The study was conducted to investigate the role of β-Galacto-oligosaccharides (β-GOS) and methionine on production performance, blood metabolites, and intestinal microarchitecture in broilers. A total of 288, one-day-old, chicks were distributed in a 3×2 factorial arrangement (6 replicates/group) based on three dietary levels of β-GOS (0, 0.2, and 0.5%) and two levels of methionine (0.5 and 1%). Birds were kept under standard husbandry conditions till day 35. In the end, two birds from each replicate were exsanguinated to collect the blood samples, viscera, and portions of each segment of the small intestine for histology. Results of the main effects revealed that FCR was improved (P<0.05) in the β-GOS supplementation groups during the third week. A dose-dependent increase (P<0.05) in globulins levels with an increase in β-GOS concentrations was observed. A high level of methionine (1%), however, increased (P<0.05) the creatinine concentration. The findings of interaction effects between β-GOS and methionine revealed increased (P<0.05) body weights during the third, fourth, and fifth weeks along with higher feed intake during the fifth week only in the birds supplemented with 0.2% β-GOS and 0.5% methionine. Moreover, the birds in 0.5% of β-GOS and 0.5% of methionine showed increased (P<0.05) crypt depth and reduced (P<0.05) VH:CD in the jejunum. In conclusion, 0.2% β-GOS supplementation in the diets containing a basal level of methionine (0.5%) confers some benefits to the broilers. Moreover, the extra topping of methionine did not show any benefits.