Effects of chitooligosaccharide supplementation on egg production, egg quality and blood profiles in laying hens

The present study evaluated the effects of dietary supplementation of chitooligosaccharide (COS) on egg production, egg quality and blood profiles in laying hens. A total of 192 Hy-Line Brown laying hens (initial age- 46 weeks) were allocated to one of four treatments with eight replications per treatment and six adjacent cages as replication for eight-weeks study. Dietary treatments consisted of CON, basal diet; COS 1, CON + 0.1% COS; COS2, CON + 0.2% COS and COS3, CON + 0.3% COS. Linear improvement (P<0.05) was observed in egg quality and high-density lipoprotein cholesterol (HDL/C) concentration at subsequent weeks. In week 8, linear (P=0.04) improvement was observed in haugh unit of egg with the increase in the dose of COS. In addition, linear effects (P<0.05) on eggshell thickness at week 3, 5, 6, 7 and 8 were detected as the level for increased COS. In conclusion, the supplementation of COS in laying hens diets linearly improved the egg quality and the HDL/C concentration. Thus, COS has the potential to be used as a substitute to antibiotics in layer hen's diets.