Abstract: This paper was to research the effect of different proportions of fermented cottonseed meal included in diets on the index of blood biochemistry and immune performance in Yellow-feathered chicken. Selected 320 14-day-old healthy broilers, were randomly divided into 4 groups, each group four replicates of 20 chickens. GroupⅠ was the control group fed with the basal diet, group Ⅱ, group Ⅲ and group Ⅳ were added 3%, 6% and 9% fermented cottonseed meal in diets respectively. The aim was to study the effect of different content of fermented cottonseed meal on the early (14 to 28 days), medium (29 to 45 days), and later (46 to 65 days) periods of the index of blood biochemistry and immune performance in broilers. The results showed that compared with group Ⅰ, the levels of total protein of the early, medium and later period in group Ⅲ significantly increased respectively by 41.96%,52.57% and 28.53%(P＜0.05). The levels of albumin of the early, medium and later period in group Ⅲ significantly increased by 21.31%(P＜0.01), 18.10%(P＜0.05) and 19.00%(P＜0.05).The levels of albumin of serum Ca of the medium and later period in group Ⅲ were significantly increased respectively by 18.03%(P＜0.01) and 51.23%(P＜0.05).The levels of albumin of serum P of the early and medium period in group Ⅲ significantly increased respectively by 34.55%(P＜0.05),31.16%(P＜0.05), and 27.65%(P＜0.01). The levels of cholesterol of the later period in group Ⅳ significantly reduced 21.22%(P＜0.05).The levels of immunoglobulin A (IgA) of the later period in group Ⅱ, group Ⅲ and group Ⅳ significantly increased respectively by 11.07%(P＜0.05), 24.41%(P＜0.01) and 13.07% (P＜0.01).The levels of immunoglobulin G (IgG) of the later period in group Ⅱ, group Ⅲ and group Ⅳ significantly increased respectively by 15.27%(P＜0.05), 28.09%(P＜0.01) and 16.63%(P＜0.01). The levels of immunoglobulin M (IgM) of the later period in group Ⅲ, group Ⅱ and group Ⅳ significantly increased respectively by 26.02%(P＜0.01), 11.13%(P＜0.05), 10.26%(P＜0.05).The index of spleen of the early period in group Ⅲ and group Ⅳ significantly increased respectively by 55.86%(P＜0.05) and 75.17%(P＜0.01). The index of spleen of the medium and later period in group Ⅳ were significantly increased respectively by 30.66%, 44.68%(P＜0.05).The index of bursal of the early period in group Ⅱ significantly increased respectively by 28.08% (P＜0.05). The index of bursal of the early and medium period in group Ⅲ and Ⅳ significantly increased respectively by 69.23%, 46.54%, 39.74%, 37.18%(P＜0.01).The index of bursal of the later period in group Ⅲ was significantly increased by 64.71%(P＜0.05).Therefore, adding 6% fermented cottonseed meal in broilers diet could improve the levels of total protein,albumin, Ca, P, IgA, IgG, IgM and the index of bursal were better than 3%, 9% fermented cottonseed meal added to diets, but 9% fermented cottonseed meal in broilers diet, in reducing the levels of cholesterol and increasing the index of spleen were better than 3%, 6% fermented cottonseed meal added to diets.

Key words: fermented cottonseed meal; Yellow-feathered chicken; blood biochemistry index; immune performance