Dietary Synbiotic Plus Betaine Modulates Intestinal Microbiota and Organ Development in Broilers Exposed to High Stocking Density Stress

Abstract

Aims: The present study aimed to evaluate dietary supplementation with synbiotic, betaine, and their combination on the gut microbiota balance, internal organ development, and performance of broiler raised under high stocking density. Study Design:  The study was designed to evaluate the impacts of symbiotic plus betaine on broiler chickens subjected to stress from high density, with a focus on gut health, immune organ development, and growth efficiency. Place and Duration of Study: The research was conducted from June to August 2022, at the experimental facility of the Department of Animal Science, Faculty of Animal and Agricultural Sciences, Universitas Diponegoro, Semarang, Indonesia. Methodology: A total of 225 one-day-old broiler chicks (Cobb CP 707 strain, initial weight 49.61 ± 0.59 g) were randomly divided into five treatments and five replicates: (1) CONTR- = normal-density rearing (8 birds/m²) + fed with basal diet; CONTR+ = high-density rearing (15 birds/m²) + fed with basal diet; T1 = high-density rearing + fed basal diet supplemented with 1% synbiotic; T2 = high-density rearing + fed basal diet supplemented with 0.2% betaine; T3 = high-density rearing + fed basal diet supplemented with 1% synbiotic + 0.2% betaine. Results: Results showed that synbiotic + betaine supplementation (T3) significantly increased ileum weight and length (P < .05), enhanced the weights of the bursa fabricius and thymus, and reduced coliform counts while lactic acid bacteria increased. Birds in the T3 group also exhibited higher feed intake and final body weight compared to those raised under high-density without supplementation (P < .05). Conclusion: The combination of synbiotic and betaine (T3) synergistically improved gut health, immune organ development, and overall performance of broiler chickens under crowded conditions.