Effect On Layers' Production Performance, Egg Quality And Blood Biochemical Indexes By Additives Of Heat Stress Resisted

The Lohman Brown layers at the age of 51 weeks were divided into 5 groups atrandom, each group is set up 3 repetitions, in which there are 90 layers. Group 1 iscontrol, group 2, 3, 4, 5 were added different additives of heat stress resisted, theeffect on layers' production performance, egg quality and blood biochemicalindexes are compared, the results are as follows:1. The laying percentage of control group is 82.82％, which is the lowest in 5groups. The group2, 4, 5 are significant higher than that of the control group (P＜0.05). No significant egg weight difference was found in every groups (P＞0.05). The percentage of abnormality egg of groupl and 2 are significant higherthan that of group 3 (P＜0.05), and very significant higher than that of group 4, 5(P＜0.01). No significant difference of broken egg rate was found in everygroups(P＞0.05). The control group is the highest in the aspect of feed conversion.2. No significant difference of egg weight, egg homomorphism's index, eggcolour, height of the white of egg, weight of egg yolk, colour of egg yolk wasfound in every groups (P＞0.05). The eggshell strength and eggshell weight ofother group is bigger than that of control group, but is not significant different (P ＞0.05). The eggshell thickness of group 2 is significant higher than that of 1, 4, 5(P＜0.05), but no significant difference was found in other groups.3. The plasma Glu concentration of control group is the highest, but nodifference with other groups. The concentration of plasma TG is biggest in group 1,which is significant higher than that of other group4. No significant difference ofplasma CHO, Ca, P, TP were found among different groups (P＞0.05). The AlbConcentration of control group is the highest, but not significant different (P＞0.05) with other groups.4. The ALT activity of control group is the highest, which is significant higherthan that of group 2, 3, 4, 5.but no significant difference was found in other groups.The AST activity of the control group is significant different with group 2, 3, 4, 5(P＜0.01), but other groups are not significant different (P＞0.05). The AKPactivity of control group is the highest, which is significant with group 5, and verysignificant difference with group 3,but no significant difference was found in othergroups. Both LDH and CK activity of group 2 is lowest, which is higher in group3,4, 5 than that of the control, but no significant different was found (P＞0.05).