Effects Of Inorganic And Organic Complex Trace Elements At Different Levels On Performance, Egg Quality And Blood Biochemical Parameters Of Laying Hens

This experiment was conducted to study the effects of inorganic and organic trace elements(Mn, Fe, Cu, Zn, Se) at different levels on performance, egg quality, trace elements concentration and antioxidative function of laying hens. Nine hundred and ninety 22-week-old Beijing Red No.1 laying hens were randomly allocated to 11 groups with 6 replicates of 15 birds in each. Group 1 was control group. Groups 2 to 6 and groups 7 to 11 were fed diets supplemented inorganic and organic complex trace elements at 25%, 50%, 75%, 100%, and 125% of requirements NRC(1994) recommended respectively. The experiment lasted 24 weeks. The results: 1. The effect of inorganic and organic complex trace elements at different levels on performance and egg Quality of Laying Hens1) hens fed diets supplemented inorganic trace element at 25% of requirement NRC recommended had the highest egg production during 1 to 24 week, and significantly enhanced the egg shell strength in week 8 and week 22(P<0.01); 2) organic trace element at 25%, 50%, 100%, 125% of requirements NRC recommended significantly increased egg production(P<0.05) and decreased feed/egg during 17 to 24 week(P<0.01), and organic trace element at 50% of requirement NRC recommended significantly increased yolk color in week 8 and albumen height, Haugh unit in week 24(P<0.01); 3) at 25% of requirement NRC recommended, the egg production of organic groups during 9 to 16 weeks, the albumen height and Haugh unit in week 20 were significantly higher than those of inorganic groups(P<0.05); at 50% of requirement NRC recommended, the albumen height of organic groups was significantly higher than those of inorganic groups(P<0.01) and the Haugh unit was significantly higher than those of inorganic groups in week 22(P<0.05), the albumen height and Haugh unit of organic groups were significantly higher than that of inorganic groups in week 24(P<0.05). 2. The effect of inorganic and organic complex trace elements at different levels on trace elements concentration in yolk and excretra of laying hens1) hens fed diets supplemented inorganic trace element at 125% of requirement NRC recommended significantly increased Mn, Cu, Zn concentration in yolk(P<0.05); inorganic trace element at 75%,100%,125% of requirement NRC recommended significantly increased Mn, Cu, Zn, Se concentration in excreta(P<0.01); 2)organic trace element at 50% of requirements NRC recommended significantly increased Cu, Zn, Se concentration in yolk in week 12(P<0.05), organic trace element at 75%, 100%, 125% of requirements NRC recommended significantly increased Mn, Fe, Cu, Zn concentration in excreta(P<0.01); 3)compared with inorganic and organic trace elements, organic trace element significantly increased Mn, Zn, Se concentration in yolk(P<0.05), inorganic trace element significantly increased Fe, Cu concentration in yolk. At 75%,125% of requirement NRC recommended, Mn, Fe, Cu,Zn concentration in excreta of inorganic groups were significantly higher than those of organic groups(P<0.05). 3. The effect of inorganic and organic complex trace elements at different levels on antioxidative function in plasma of laying hens1) hens fed diets supplemented inorganic trace element at 75%, 100%, 125% of requirement NRC recommended significantly increased T-SOD and GSH-Px(P<0.01), significantly decreased MDA(P<0.01), at 125% of requirement NRC recommended significantly increased T-AOC(P<0.01) in week 16; 2) hens fed diets supplemented organic trace element at 25%-125% of requirement NRC recommended significantly increased T-AOC, T-SOD and GSH-Px(P<0.01), at 50%-125% of requirement NRC recommended significantly decreased MDA(P<0.01); 3) At 75% of requirement NRC recommended, T-AOC, T-SOD and GSH-Px of organic groups were significantly higher than those of inorganic groups(P<0.05). At 125% of requirement NRC recommended, T-SOD and GSH-Px of organic groups were significantly higher than those of inorganic groups(P<0.05).It is concluded that the optimal level of inorganic and organic trace element supplemented in diet of laying hens be respectively 25% and 50% of requirements NRC recommended, the level of inorganic and organic trace element supplemented in diet of laying hens be both 25% and 50% of requirements NRC recommended can remain trace elements concentration in yolk while avoid the excess of trace elements in excreta, the level of inorganic and organic trace element supplemented in diet of laying hens be respectively 75% and 25%, 50% of requirements NRC recommended are benifical to increase antioxidative function. Organic trace element in diet of laying hens shows better performance on egg production, albumen height and Haugh unit than inorganic trace element at 25%, 50% of requirement NRC recommended. Organic trace elements can increase Fe, Cu concentration in yolk, and at 75%, 125% of requirement NRC recommended organic groups can decrease trace elements concentration in excreta and organic trace element is better than inorganic on antioxidative function of laying hens.