Effects Of Dietary Gingko Biloba Extracts On Production Performance And Cholesterol Metabolism In Laying Hens

Egg exists as a major dietary source of cholesterol in our diets. To study the effects of gingko biloba extracts on overall performance, plasma, egg quality,egg yolk cholesterol concentrations and cholesterol metabosism in laying hens,192, 22-week-old,Jingfen NO.2 laying hens were assigned completely randomized to one of four groups fed diets supplemented with 0(control), 0.04%, 0.08%, and 0.12% gingko biloba extracts for 60 days. Feed intake and egg weight were recorded daily, feed ratio was calculated,egg quality were mesured and eight layers in each groups were sacrificed for OVR,apoVLDL-II and HMGR gene mRNA expression mesurements by real-time PCR. The results are as follows:(1)The effects of ginkgo biloba extracts to production performance of laying hens: There were no significant differences among diets, egg mass and egg production in all groups(P > 0.05). Compared to the control group, all experiments groups were significantly decreased in soft and broken eggs(p<0.05). Group ? has a significantly increase in egg production ratio compare to control group(P<0.05).(2)The effects of ginkgo biloba extracts to egg quality of laying hens:After 60 days experiments, there were no significantly difference in egg yolk color, egg-shaped index, egg yolk ratio and Hartz unit( P>o.o5). All experiments could increase the proportion of the shell significantly(P<0.05).The group I and ? could increase the The shell thickness significantly(P<0.05), while group II increase but not significantly in statistical.All experiment group could decrease the egg yolk cholesterol significantly at day 30 and day 45(P<0.05). At day 60, only the group I and group ? had significantly increase the egg yolk cholesterol(P<0.05).(3)The effects of ginkgo biloba extracts to layer serum of laying hens: The Group II and group ? had significantly decrease on total cholesterol(p<0.05),while Group I also decrese but had no significantly in statistical. The Group I and Group II derease the plasma triglyceride and LDL cholesterol significantly(p<0.05), group ? had no this effect.All experiment groups could increase HDL cholesterol and increase the VLDL cholesterol significantly(P<0.05).(4)The effects of ginkgo biloba extracts to OVR,apoVLDL-II and HMGR expression of laying hens:After diets ginkgo biloba extracts for 60 days, all diets level group inhibit the expression of apoVLDL- II gene and HMGR gene significantly(P<0.05). This experiment indicate that different ginkgo biloba diets level had no effect on the expression of OVR mRNA.It was concluded that ginkgo biloba extracts in the diets of laying hens could improved egg shell quality, reduced serum and yolk cholesterol concentrations. It was also concluded that dietary ginkgo biloba extracts coulde inhibit the expression of apoVLDL- II gene and HMGR gene.