Effects Of Different Selenium Sources On Production Performance,Egg Quality,and Ovarian Function Of Yellow Feathered Quail

Trace element selenium is essential to animals and plants,and is an important component of selenoprotein.It participates in various physiological processes,including immune function,reproduction and maintenance of antioxidant defense to avoid tissue damage.As a feed additive for egg quails,it can improve their production performance,improve their physical health,and enhance the nutritional value of animal products.In recent years,enhancing the nutritional value of animal products with selenium to increase human selenium intake has been a very positive strategy.This paper investigates the effects of selenium from different sources on the production performance,egg quality,serum sex hormone levels,ovarian tissue morphology,antioxidant indicators,and expression of egg laying related genes in egg quails.This experiment adopts a dual factor experimental design,selecting 660 180 day old yellow feathered egg quails.According to different types and doses of selenium,they are randomly divided into 11 groups for a 6-week experimental feeding period.The aim is to compare the effects of organic and inorganic selenium on egg quails and provide reference for the development and application of selenium products.The main results obtained in this study are as follows:1.When adding different selenium sources to the diet of egg quails,there were significant differences in the average daily feed intake and feed egg ratio during the mid-term of the experiment.The daily average feed intake of the 0.4 mg/kg sodium selenite group was significantly higher than that of the 10 mg/kg sodium selenite group,the 0.4 mg/kg selenomethionine group,and the 10 mg/kg selenomethionine group(P<0.01);In terms of feed to egg ratio,the sodium selenite 5 mg/kg group was significantly higher than the basal diet group and other experimental groups(P<0.01);In the later stage of the experiment,the daily average feed intake of the 10 mg/kg sodium selenite group was significantly lower than that of the basic diet group and other experimental groups;The average egg weight of the sodium selenite 0.2 mg/kg group,selenomethionine 0.2 mg/kg group,and selenomethionine 0.4 mg/kg group was significantly higher than that of other experimental groups(P<0.05);In terms of feed to egg ratio,the selenomethionine 0.2mg/kg group and selenomethionine 0.4 mg/kg group were significantly lower than other experimental groups(P<0.05).2.Different selenium sources were added to the diet to feed egg quails.In terms of fresh egg quality,there was no difference in the egg quality indicators between the basic diet group and all experimental groups during the mid-term of the experiment(P>0.05);At the end of the experiment,the egg yolk weight of the 1 mg/kg sodium selenite group was significantly higher than that of the 10 mg/kg sodium selenite group and the 1 mg/kg selenomethionine group(P<0.01);The eggshell thickness of the 0.2 mg/kg sodium selenite group was significantly higher than that of the basal diet group and other experimental groups(P<0.01);The eggshell strength of the 0.4 mg/kg sodium selenite group was significantly lower than that of the 5 mg/kg selenomethionine group(P<0.05).3.In terms of pathological observation of ovarian tissue,the pathological changes of ovarian tissue after feeding egg quails with different selenium sources were observed under light microscopy.Compared with the basal diet group,significant follicular necrosis was found in local areas in the selenite 1 mg/kg group and selenomethionine 5 mg/kg group,with homogeneous accumulation of eosinophilic substances in the necrotic area;The fibrous connective tissue in the medullary area is tightly arranged.4.In terms of serum sex hormone levels in egg quails,the estradiol(E2)content in the5 mg/kg sodium selenite group was significantly increased(P<0.01);The content of follicle stimulating hormone(FSH)in the 0.2 mg/kg selenomethionine group was significantly increased(P<0.01);The progesterone(P)content in the 1 mg/kg sodium selenite group significantly increased(P<0.05).5.In terms of antioxidant index of ovarian tissue,the superoxide dismutase(SOD)of selenomethionine 0.2 mg/kg group was significantly higher than that of the basal diet group and other test groups(P<0.05);The glutathione peroxidase activity in the selenomethionine 0.2 mg/kg group was significantly higher than that in the basal diet group and other experimental groups(P<0.01);The total antioxidant capacity(T-AOC)of the 0.4 mg/kg sodium selenite group was significantly higher than that of the basal diet group and other experimental groups(P<0.01).6.In terms of the effect of different selenium sources on egg laying related genes in quail ovarian tissue,compared with the basal diet group,the FSHR gene expression levels in the selenomethionine 0.2 mg/kg group and selenomethionine 0.4 mg/kg group were significantly increased(P<0.05);The LHR gene expression levels were significantly increased in the selenomethionine 0.2 mg/kg group and selenomethionine 0.4 mg/kg group(P<0.01).In summary,adding a certain amount of selenium to the diet of egg quails can effectively improve their production performance,improve egg quality,enhance the antioxidant capacity of quail ovarian tissue,and promote the expression of egg laying related genes.