Effect Of Adding Flaxseed Meal To The Diet On The Nutritional Components And Quality Of Eggs

Changing the composition of laying hen diets can regulate the composition and content of yolk fatty acids.However,different sources of dietary additives may have varying effects on the production performance of hens and the quality of eggs.This experiment investigated the effects of adding different proportions of flaxseed meal to the laying hen diets on the composition of yolk fatty acids,production performance of hens,egg quality,and processing characteristics.Based on the determination of the nutritional composition of flaxseed meal,300 laying hens at 27 weeks of age were randomly divided into five treatment groups.The hens’ diets were supplemented with 0%,5%,10%,15%,and 15%+0.02% VE(Vitamin E)of flaxseed meal.The changes in egg production performance,yolk fatty acid composition,component oxidation,and processing characteristics were dynamically monitored during an 8-week feeding period.The study aimed to evaluate the potential of using flaxseed meal as a dietary additive for nutrientenriched eggs and to provide fundamental data for the industrialization of nutrient-enriched eggs in China.The main research findings are as follows:(1)Nutrient analysis of flaxseed meal and its impact on laying hen production performance.The moisture content of flaxseed meal was determined to be 4.20%,ash content was 10.58%,crude fat content was 13.76%,protein content was 31.58%,and nitrogen content was 5.05%.Additionally,16 types of fatty acids were detected,with alpha-linolenic acid representing 45.66% of the total fatty acids,and having the highest concentration.Feeding until the 8th week,with increasing levels of flaxseed meal supplementation,the laying rate and protein content significantly increased in all treatment groups.Feedto-egg ratio and yolk index significantly decreased,while egg weight showed an initial increase followed by a decline trend.There was no significant impact on the Haugh unit of the eggs(p>0.05).Supplementation of vitamin E did not have a significant effect on egg weight or Haugh unit,but significantly increased the laying rate and yolk index,while reducing the feed-to-egg ratio(p<0.05).(2)Effects of dietary supplementation with flaxseed meal on the nutritional composition and component oxidation of eggs.As the level of flaxseed meal supplementation in the diet increased,the content of alpha-linolenic acid(ALA)and docosahexaenoic acid(DHA)in the yolk fatty acids significantly increased.The total content of omega-3 polyunsaturated fatty acids(PUFAs)increased,while the content of omega-6 PUFAs significantly decreased.Among the groups,the highest enrichment rate of omega-3 PUFAs was observed in the 10%flaxseed meal supplementation group,with an omega-6/omega-3 PUFA ratio ranging from 4.58 to 5.97,which is in line with the optimal recommended intake level.The addition of vitamin E significantly enhanced the enrichment effect of ALA and DHA in the yolk(p<0.05).With increasing levels of flaxseed meal supplementation,both yolk diene values and MDA content showed a significant increase,while cholesterol and triglyceride content exhibited a significant decrease.Addition of vitamin E significantly inhibited lipid oxidation in the yolk and simultaneously increased triglyceride content(p<0.05).As the supplementation level of flaxseed meal increased,the content of cysteine in egg yolk and egg white exhibited an overall decreasing trend,while the carbonyl content significantly increased.Addition of vitamin E suppressed the oxidation of egg yolk proteins,leading to a significant increase in cysteine content and a significant decrease in carbonyl content(p<0.05).SDS-PAGE analysis indicated that the protein molecular weight mainly concentrated in the range of 30-45 k Da and 55-70 k Da,corresponding to egg yolk proteins and lipoproteins,with no significant differences observed in band intensity among the groups.(3)The Effect of Adding Flaxseed Meal to the Diet on the Processing Performance of EggsWith increasing supplementation of flaxseed meal,there was a significant improvement in foaming capacity and foam stability of egg white,as well as increased emulsification capacity index(EAI),emulsion stability index(ESI),particle size,absolute value of Zeta potential,and gel water-holding capacity of egg yolk emulsion.However,it decreased the ESI of egg yolk emulsion(p<0.05).Compared to the control group(CG),the addition of flaxseed meal significantly influenced the cohesiveness,elasticity,hardness,chewiness,and adhesiveness of egg yolk,while significantly enhancing viscosity and springiness.The addition of vitamin E significantly increased the hardness,adhesiveness,and chewiness of egg yolk,while decreasing viscosity and springiness.Additionally,it improved the foaming capacity and foam stability of egg white and the ESI of egg yolk,but reduced the emulsion stability index,particle size,and absolute value of Zeta potential of egg yolk emulsion(p<0.05).