Effect And Interaction Of Probiotics And Zn-Met On Production Performance,Egg Quality And Antioxidant Performance Of Layers

This test adopted Hyline brown laying hens as the test object and made use of 4×4(Probiotics×Zn-Met)factorial design to design 4 levels of probiotics(0,250,500,1000mg/kg)and 4 levels of zinc methionine(0,250,500,750mg/kg respectively corresponding to zinc contents of 0,40,80,120 mg/kg).In the test,a total of 1536 healthy Hyline brown laying hens of 44 weeks old were randomly divided into 16 treatment groups,each treatment including 3 replicates(32 layers per replicate).By determining indexes of the laying hens,such as their production performance,egg quality,cholesterol and zinc contents in yolk as well as antioxidant performance,etc.,impacts of such probiotics and zinc methionine on these indexes were explored with an aim to find an optimal level combination.The results of this test showed that:1.Probiotics and Zn-Met only added into the diet could significantly improve both laying rate and the average egg weight(P<0.05).Probiotics and Zn-Met could significantly reduce feed to egg ratio(P<0.05)from fifth week to seventh week.The combination of the two had a remarkable effect on laying rate,the average egg weight and feed to egg ratio(P<0.05).2.Probiotics could significantly increase eggshell strength,egg albumen height,and haugh unit(P<0.05).Probiotics could greatly significant to eggshell thickness(P<0.01).Zn-Met could significantly increase eggshell weight,egg albumen height(P<0.05).Probiotics could greatly significant to eggshell thickness and eggshell strength(P<0.01).Moreover,the combination of them exerted a significant interactive effect on the eggshell thickness,egg shape index,eggshell strength,egg albumen height,and haugh unit(P<0.05).3.Probiotics could greatly significant to reduce egg yolk cholesterol concentration(P<0.01).Probiotics can significantly decrease the contents of egg cholesterol(P<0.05).In addition,the addition of Zn-Met was also able to remarkably improve zinc contents in eggs(P<0.05).In term of egg yolk cholesterol concentration and egg cholesterol contents,there were significantly interaction efifects between probiotics and Zn-Met(P<0.01).The combination of the two had a remarkable effect on zinc contents in eggs(P<0.05).4.Probiotics could significantly decrease the total cholesterol,triglyceride and low-density lipoprotein cholesterol contents,while increase high-density lipoprotein cholesterol contents(P<0.05).By contrast,Zn-Met had not significantly influence on serum lipoprotein(P>0.05).Nevertheless,they had a remarkable interactive effect on triglyceride,the total cholesterol and low-density lipoprotein cholesterol contents(P<0.05).5.Probiotics could significantly increase cupper-zinc superoxide dismutase(P<0.05).Zn-Met had significantly influence on zinc ion,insulin,alkaline phosphatase and cupper-zinc superoxide dismutase(P<0.05).The combination of them had a remarkable interactive effect on zinc ion,insulin,alkaline phosphatase and cupper-zinc superoxide dismutase(P<0.05).6.Probiotics was able to significantly improve the activity of total superoxide dismutase(P<0.05).Probiotics could greatly significant to total antioxidant capacity,lower contents of malonaldehyde(P<0.01).As for Zn-Met,it had capabilities to significantly improve the activity of total superoxide dismutase,glutathione peroxidase and total antioxidant capacity(P<0.05).Zn-Met could very significantly decreased the content of malondialdehyde(P<0.01)The activity of total superoxide dismutase,glutathione peroxidase,total antioxidant capacity and contents of malonaldehyde were subject to an enormous interactive effect between them(P<0.05).7.Probiotics and Zn-Met could significantly improve contents of albumin,the total protein and glucose(P<0.05).Their interactive effects were rather significant as far as the contents of albumin and the total protein were concerned(P<0.05).8.Probiotics and zinc methionine added into the diet,together with their interactive effects,had an insignificant influence on glutamic oxalacetic transaminase,glutamic-pyruvic transaminase,lactate dehydrogenase(P>0.05).The above findings indicate that the two supplements had significant effect on improving the production performance,egg quality,zinc contents in yolk and antioxidant performance,and lower contents of cholesterol in eggs.Furthermore,the complex of probiotics and Zn-Met had significant interaction effects.It was found that 1000mg/kg of probiotics with 750mg/kg of Zn-Met(which zinc content was 120mg/kg)added was the optimal combination.