The Research On The Optimum Supplemental Level Of Iron Copper Manganese Zinc Of Commercial Laying Hens Fed On Low Energy Diet

In this study, by measuring the egg production performance、apparentmetabolic rate、egg quality and blood biochemical indexes of Jinghong laying hensunder different iron copper manganese zinc levels, we discuss the appropriate level ofiron copper manganese zinc in low-energy diet to them.Experiment1: Effect of different iron copper manganese zinc levels on laying hens’production performance and amount of excretion in low-energy diets.The experiment took600Hy-line layers which were randomly divided into5treatment groups (5replicates of24hens per treatment). The energy of diet (corn-soya bean meal) was10.89MJ/kg. The iron copper manganese zinc mix proportion in the dietwere according to GB/T5916-2008recommended standard. Experimental group I,II,III andIV added iron copper manganese zinc0%,50%,100%and200%in the basis of GB/T5916-2008respectively. Experimental group V added the protein iron copper manganese zincchelate. Preliminary feeding period last a week formalization phase last8weeks. Theresults show that, for the Egg production performance, there was no markeddifference (P>0.05) among treatment I,II,III and IV. V group was the highest in theegg laying capacity、the average of egg weight and daily egg laying amount；Dailyintake of I group was the highest；The broken egg rate in III group was the highest.With iron copper manganese zinc levels’ increasing, the production performance oflaying hens was up with no obvious differences. In the side of excretion, the intake ofiron copper manganese zinc in treatment I,II,III,IV and V was significantlydifferent(P＜0.05);the excretion of iron copper manganese zinc in treatment I,II,IIIand IV was significantly different(P＜0.05); the intake and excretion IV of iron coppermanganese zinc was highest in treatment IV, treatment III and II second, treatment Ithe lowest.It indicated: adding iron, copper and manganese zinc in low-energy dietscan increase the intake and excretion of copper manganese zinc; With iron coppermanganese zinc levels’ increasing,there were up trend in copper manganese zinc,while there was a down trend in iron.Experiment2: Effect of different iron copper manganese zinc levels on laying hens’egg quality in low-energy diets The purpose of this study was to work out the effects of different iron coppermanganese zinc levels on egg shape index, eggshell strength, high protein, egg yolkcolor and Haugh unit in low-energy diets. The experiment gradient was designed thesame as Experiment1. At the end of the feeding trial, took out six eggs from eachtreatment randomly, then, measured the egg quality and content of iron coppermanganese zinc.The results showed that: in the side of Egg quality: group IV was thehighest in egg shape index, eggshell, eggshell strong velocity ratio and thickness ofeggshell; Group I was the highest in albumen height and Haugh unit;V group is lowerthan other groups in every index. With iron copper manganese zinc levels’ increasing,here was a down trend in albumen height and Haugh unit, while there was an up trendin other conventional egg quality indicators. In the side of content of iron coppermanganese zinc: there were marked differences (P＜0.05) among treatment I,II,III andIV;the content of iron and in group III was the highest; the content of copper in groupIV was the highest; Group V showed lower levels of iron copper manganese zinc thanother groups. With iron copper manganese zinc levels’ increasing, their contents in theeggs were up. The test results showed, the egg quality of the Hy-line hens was notsignificant (P>0.05) under the10.89MJ/kg diet; Organic iron, copper and manganesezinc can improve the quality of eggs; adding iron, copper and manganese zinc inlow-energy diets does not affect the copper manganese zinc content in eggs, but it canreduce iron content.Experiment3: Effect on laying hens’ blood biochemical index in low-energy dietsunder different iron copper manganese zinc levelsThis study aimed to discuss the effects of different iron copper manganese zinclevels on laying hens’ blood biochemical parameters in low-energy diets.4laying hensfrom each repeat were randomly selected after the trial was ended, which had to go ona hunger strike before the wing vein blood sampling by vacuum vessel andcentrifugation. The measured parameters were: AST, ALP, TP, CER, SOD.The resultsshowed that：there were marked differences (P＜0.05) among treatment I,II,III and IVin the serum biochemical indicators; group I had the highest content of AST, thecontent of ALP, TP, CER, SOD in group II was the highest, while The advantage ofserum indexes in V were not obvious; the four groups had a increasing-decreasingtrend as the level increased with. It indicated that: the blood biochemical indexes ofthe Hy-line hens were not significant (P>0.05) under the10.89MJ/kg diet; addingiron, copper and manganese zinc in low-energy diets does not affect the blood biochemical indexes in hens, but it can reduce AST content.