Effect of Probiotic and Synbiotic Supplementation on Growth Performance, Serum Parameters and Gut Histomorphometry in Broiler Chickens Challenged With Eimeria

This study evaluated the effects of probiotic and synbiotic supplementation on growth performance, serum biochemistry, immune organ development, intestinal length and histomorphometry in broilers challenged with Eimeria. A total of 360 Cobb 500 broilers were assigned to six treatment groups (3 replicates of 20 birds), and from Day 14 to 35, birds received water supplemented with either probiotic, synbiotic or control. On Day 14, challenged groups received a 10× dose of Eimeria from a commercial live vaccine. Data were analyzed using a 2×3 factorial ANOVA. Eimeria challenge significantly reduced average weight gain, final body weight and feed conversion efficiency. Intestinal morphology was adversely affected, as evidenced by decreased villus height (VH) and villus height to crypt depth ratio (VCR) in both the duodenum and jejunum. Eimeria challenge also induced significant alterations in serum biochemical parameters, including alkaline phosphatase, albumin, urea, lipase and triglyceride levels. Probiotic and synbiotic supplementation significantly improved relative spleen weight, intestinal length (jejunum, ileum, cecum) and villus morphology in all intestinal segments. Significant main effects of treatment were observed for growth and serum enzymes. Interaction between coccidiosis infection and treatment was significant for urea, and duodenal VH and VCR. Overall, probiotic and synbiotic supplementation mitigated the adverse effects of coccidiosis, with no significant differences observed between the two interventions.