The Effect Of Different Varieties Of Egg Nutrient Content And Storage Time On Egg Quality

This experiment used the standard variety White Leghorn Chicken and commercial variety Hy-Line Brown laying hen as controls to study the differences in nutritional composition of eggs from local Chinese varieties Bashang Long-tailed Chicken,Dongxiang Green-shell laying hen and Beijing Fatty Chicken,as well as the effect of different storage times on their egg quality.In order to provide theoretical basis for further breeding of local laying hens and research on germplasm characteristics.The experiment collected eggs produced by 43 week old chickens and stored them at a room temperature of 17±2℃,a relative humidity of 60±5%,and a well ventilated environment.Starting from the day of egg collection,the eggs were measured every three days until 18 days.The nutritional composition of various types of eggs was determined using fresh eggs laid within 24 hours.The test results are as follows:1.The effect of different storage time on the quality of eggs(1)The protein height,Hastelloy unit and egg weight decreased significantly with the extension storage time(P<0.05).After being stored for 18 days,the protein height of Hy-Line Brown showed the greatest decrease,while Bashang Long-tailed Chicken showed the smallest decrease,accounting for 32.8%and 24.22%,respectively;The decrease in Hastelloy unit of Dongxiang Green-shell laying hen was the largest,while Bashang Long-tailed Chicken was the smallest,with 18.21%and11.59%,respectively;The egg weight variation of Dongxiang Green-shell laying hen was the largest,while Bashang Long-tailed Chicken was the smallest,with 11.61%and 7.38%,respectively.(2)The p H of egg white and the specific gravity of egg yolk significantly increased with the prolongation of storage time(P<0.05).The highest increase in p H was observed in the egg white of Hy-Line Brown,while the lowest was observed in Bashang Long-tailed Chicken,which was 21.22%and 11.88%,respectively;The increase in egg yolk proportion of Bashang Long-tailed Chicken was the largest,while Beijing Fatty Chicken was the smallest,at 14.64%and 8%,respectively.(3)There were no significant changes in eggshell strength,inner shell weight,eggshell thickness,eggshell specific gravity,egg shape index,and eggshell color(P<0.05).2.Differences in egg quality and nutritional content of different varieties of eggs(1)Egg quality1)The egg white height,Hastelloy unit and egg weight of Hy-Line Brown were the highest,but the proportion of egg yolk,egg yellow luster and eggshell color were the lowest,which were 8.11mm,87.42,66.08g,23.71%,5.93 and 31.28 respectively.Bashang Long-tailed Chicken,Beijing Fatty Chicken and Dongxiang Green-shell laying hen eggs were lighter in weight,but have higher egg yolk proportions,which were 30.53%,31.04%and 33.1%respectively.The shell strength,shell thickness,and shell specific gravity of Beijing Fatty Chicken eggs were the highest,which were4.3kgf,0.381mm,and 9.91%respectively.From the perspective of eggshell color,the Bashang Long-tailed Chicken and Beijing Fatty Chicken on the dam are light pink but the Bashang Long-tailed Chicken on the dam is darker,the Dongxiang Green-shell laying hen is light green,the White Leghorn Chicken is uniformly white,and the Hy-Line Brown is uniformly brown.2)There was no significant difference in shell inner membrane weight and egg shape index among different varieties of eggs(P<0.05).(2)Nutritional components1)The fat content of Beijing Fatty Chicken eggs was significantly higher than that of Hy-Line Brown(P<0.05),which was 6.05%higher.The CHO content of the three local varieties was lower than that of the standard variety White Leghorn Chicken and the commercial variety Hy-Line Brown;the order from low to high was:Dongxiang Green-shell laying hen<Bashang Long-tailed Chicken<Beijing Fatty Chicken<White Leghorn Chicken<Hy-Line Brown.2)Except that the calcium content of eggs of Beijing Fatty Chicken was slightly lower than that of Hy-Line Brown,and the content of iron and V_E was slightly lower than that of Bashang Long-tailed Chicken,the contents of calcium,phosphorus,iron and V_E in eggs of the three local varieties were better than that of Bashang Long-tailed Chicken and Hy-Line Brown.3)There were no significant differences in the moisture and protein contents among different varieties of eggs(P<0.05).Therefore,the conclusions of this experiment are as follows:1.The length of storage time had a certain impact on the quality and Hastelloy unit of the egg content of eggs.2.The quality of egg contents such as the proportion of egg yolk,egg yellow luster of different varieties of eggs varies greatly,and the quality of egg contents of eggs of three local varieties had advantages compared with White Leghorn Chicken and Hy-Line Brown,although the value of Hastelloy unit and protein height was relatively low,but it was also within the range of grade A eggs.3.The nutrient content of eggs of different varieties were different,and the nutrient content of eggs of the three local varieties were generally better than that of White Leghorn Chicken and Hy-Line Brown.4.In consideration of egg quality and nutritional content,the nutritional value of local varieties of eggs was better than that of White Leghorn Chicken and Hy-Line Brown.It was recommended that Bashang Long-tailed Chicken and Dongxiang Green-shell laying hen be stored for no more than 18 days,and Beijing Fatty Chicken be stored for no more than 15 days.In the later stage of laying hen breeding in China,it is necessary to strengthen the breeding of local varieties of eggs based on the quality of egg content and nutritional composition,including average egg weight,freshness,shell thickness,and uniformity.In addition,the production performance of local varieties of chickens is poor,and the egg production rate is low,which is also a problem that we urgently need to break through in the breeding of local laying hens in the later stage.