Effect of Dietary Supplementation of Cu-Methionine Chelate and Cu-Soy Proteinate on the Performance, Small Intestinal Mcroflora and Immune Response in Laying Hens

摘要

This study was conducted to investigate the effect of dietary supplementation of Cu-methionine chelate (Cu-Met) and Cu-soy proteinate (Cu-SP) on the performance, small intestinal microflora and immune response in laying hens. A total of 960 Hy-line Brown laying hens of 39 wks old were assigned to one of the following 6 dietary treatment: control (C), antibiotic (Avilamycine 6 ppm), Cu-Met 50 and Cu-Met 100 (50 and 100 ppm Cu as Cu-methionine chelate), Cu-SP 50 and Cu-SP 100 (50 and lOOppm Cu as Cu-soy proteinate). Each treatment was replicated 4 times with forty birds per replication, housed in 2 birds per cages. Forty birds units were arranged according to randomized block design. Feeding trial lasted 6 wks under 16 hours lighting regimen. Hen-dayand hen-house egg production of groups treated with Antibiotic and Cu supplements tended to be higher than the control with significant difference (P<0.05) shown between Cu-Me 100 and control. Egg weight was significantly (P<0.05) heavier in antibiotic and Cu-SP treatments than Cu-Met treatments but they were not significantly different from the control. Eggshell strength, egg shell thickness, egg yolk color and Haugh unit were not significantly different among treatments. There were no significant differences in leukocytes and erythrocytes in the chicken blood. But mean corpuscular hemoglobin value (MCH) was significantly (P<0.05) higher in Cu-SP 100 than antibiotic treatment. The concentrations of serum IgG and IgA were not significantly different among treatments. Copper concentration in the liver tended to increase as the level of copper supplementation increased, that of Cu-SP 100 being significantly (P<0.05) higher than those of the control and antibiotic treatment. Concentrations of iron and zinc of the liver were not significantly influenced by treatments. Populations of Cl. perfringens and Lactobacilli in the small intestinal content were significantly (P<0.05) influenced by treatments. Population of Cl. perfringens decreased and that of Lactobacilli increased in the copper supplemented groups. The result of this experiment showed that Cu-Met and Cu-SP are comparable to antibiotic in improving egg production in laying hens. Birds fed diets supplemented with Cu-SP produced heavier eggs thanthose fed diets with Cu-Met. There were no significant differences in the performances between 50 ppm and 100 ppm copper supple-mentation as organic forms.