¹Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, College of Veterinary Medicine,Sichuan Agricultural University, 611130 Chengdu Sichuan, CHINA
²Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, 611130 Chengdu Sichuan, CHINA
³Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), College of Life Science, China West Normal University, 637009 Nanchong Sichuan, CHINA DOI : 10.9775/kvfd.2017.17997 The objective of this study was to investigate effects of COS on cell cycle and relative weights of thymus, bursa of fabricius (BF) and spleen in broilers. Three hundred and sixty 1-day-old healthy Arbor Acres male broilers were randomly divided into control, COS I, COS II and COS III groups, which were respectively fed with diets containing 0, 200, 350 and 500 mg/kg COS for six weeks. The results showed that the relative weights of immune organs were higher in the COS group II than those in the control group at 42 d. When compared with the control group, increased percentages of G2/M phase thymocytes in the COS groups II and III at 21 d, and decreased percentage of G0/G1 phase cells, increased percentage of G2/M phase cells and PI (proliferation index) of thymus were observed at 42 d. The percentage of G0/G1 phase BF cells was lower, and the percentage of S phase cells and PI of BF were higher in the COS group II at 21 d. The increase of G2/M phase splenocytes and PI, decrease of G0/G1 phase splenocytes in the COS group II could be seen at 42 d. Keywords : Chitosan oligosaccharides, Cell cycle phase, Immune organs, Flow cytometer