Effect of Different Growth Promoters on Lysozyme and Complement Activity of Broiler Chicks

L. K. SOTIROV¹, S. A. DENEV² and V. K. GEORGIEVA³

¹Thracian University, Department of Animal Genetics, BG-6000 Stara Zagora, Bulgaria
²Thracian University, Department of Microbiology and Dairy Science, BG-6000 Stara Zagora, Bulgaria
³Thracian University, Department of Animal Nutrition, BG-6000 Stara Zagora, Bulgaria

Abstract

SOTIROV, L., S. DENEV and V. K. GEORGIEVA, 2000. Effect of different growth promoters on Lysozyme and complement activity of broiler chicks. Bulg. J. Agric. Sci., 6: 75-82

The objective of this study was an evaluation of the effects of different growth promoters: probiotic Lacto-Sacc® (Alltech Inc.), nutritive premix Pharmastim® and nutritive antibiotic Avilamycin® on the Lysozyme and complement levels, in particular, on the humoral factors of natural immunity in broiler chicks.
The experiment was conducted using five feeding groups of one-d-old broiler chicks: Group I: Basal diet without supplement (Untreated control); Group II, III, IV and V: Basal diet supplemented with: Lacto-Sacc®, (1 kg/t); Pharmastim®, (0.3 kg/t); and Avilamycin® (5.0 ppm/kg), and 2.5% Lactose in drinking water, respectively.
Immunity stimulating effect was recorded with probiotic Lacto-Sacc, and to some extent, with Lactose. The nutritive premix Pharmastim and nutritive antibiotic Avilamycin at the doses applied did not have a similar effect.
The results suggested that feed additives based on microorganisms provide an alternative to antimicrobial substances in animal nutrition. The probiotics and especially Lacto-Sacc can reduce or replace antibiotics used for growth promotion in broiler chicks.

Key words: growth promoters, probiotics, nutritive antibiotics, lysozyme and complement activity
Abbreviations: LAB = Lactic Acid Bacteria; BSA = Bovine Serum Albumin; APCA = Alternative Pathway for Complement Activation; DS = Diluted Serum