Effects of lincomycin, sodium butyrate, and probiotic dietary supplementation on growth performance, nutrient digestibility, blood biochemistry, and hepatic expression of growth- and fat metabolism-related genes in broiler chickens

Context. Lincomycin is a natural lincosamide antibiotic that originates from Streptomyces lincolnensis and is usually used against intestinal gram-positive bacterial infections. Sodium butyrate (SB) is a short-chain fatty acid while probiotics are beneficial live microorganisms, which are used in broiler chicken production, as safe alternative to antibiotics, to improve gut health, enhance nutrient utilization, and boost immunity. Aims. This experiment was conducted to explore the effects of lincomycin, sodium butyrate (SB), and probiotic dietary supplementation on broiler growth, nutrient digestibility, blood biochemistry, and selected growth-and fat metabolism-related genes. Methods. A total of 2,640 one-day-old male Ross broiler chicks were randomly distributed into four treatment groups with six replicates each. The 1st group received a corn-soybean basal diet (BD) without supplementation. The second, third, and fourth groups received BD containing 100 g/ton lincomycin, 1,000 g/ton Sodium Butyrate, or 500 g/ton probiotic, respectively. Key results. After 35 days of dietary supplementation, lincomycin and SB significantly improved the growth performance compared to the control and probiotics-treated groups (P < 0.05). Improved growth performance was coupled with increased mRNA copies of growth hormone receptor (GHR) and insulin like growth factor 1 (IGF1). In addition, SB and probiotics resulted in distinct increases in relative carcass weights (%) compared to the lincomycin-treated and control groups (P < 0.05). An increase in the digestibility of crude protein in all supplemented groups compared to the control group was observed, without any changes in the digestibility of crude fibers. Both SB and probiotics increased crude fat digestibility compared to that in the lincomycin-treated and control groups. Interesting reductions in cholesterol and low-density lipoprotein levels linked with noticeable increases in 3-hydroxy-3-methylglutaryl-coenzyme A reductase and fatty acids synthase genes expression were found without alterations in liver and kidney function enzymes or serum metabolites. Conclusions. Based on these findings, sodium butyrate and probiotics improved growth performance and nutrient digestibility in broilers and could therefore be used as effective alternatives to lincomycin in broiler diets.