Effect of natural growth promoters on immunity, and biochemical and haematological parameters of broiler chickens

Purpose: To investigate the efficacy of promising alternatives to antibiotic growth promoters (organic acids, phytobiotics, and their combinations) as feed additives in poultry feed. Methods: Different feed treatments were formulated with organic acids, phytobiotics and their combinations, and their effects on blood profile, serum enzymes and immunity parameters were evaluated in broilers at 21 and 42 days of age. Results: Cholesterol, triglyceride and HDL levels of the 21- and 42-day old broilers were significantly (p < 0.05) affected by the feed additives. The effect of albumin and albumin/globuhn ratios varied significantly (p < 0.05) from that of the control group at 42 days of age. Haematological analysis did not show significant changes (p > 0.05) in parameters except hematocrit, RBC, MCH, MCHC, WBC at age 21 days. However, among the serum enzymes assayed, only gamma-glutamyl transferase activity was altered for the modified feed group. Conclusion: These results suggest that supplementation with organic acids and phytobiotics can be used as alternatives to antibiotic growth promoters without interfering with the overall health and performance of broilers.