Utilization Of Eggshell Powder With Lactic Acid Bacteria Fermentation For Improving Calcium Content In Soybean Meal Feed

With the rapid development of China's economy,the effective disposal and utilization of waste has always been a concern of social environment and economy.In the 21 st century,the aquaculture domestic industry has developed rapidly,and the poultry egg production and consumption are among the highest in the world.However,there is still a certain gap in the comprehensive utilization of by-products between china and the developed countries,such as eggshells and eggshell membranes.The unreasonable discarding of these by-products causes great waste and environmental pollution.Eggshells have a high potential for recycling and the use of them as additives in animal feeds is also becoming more and more widespread.They can supplement the calcium sources animals need during their growth,strengthen their bones,and enhance their immunity.Nowadays,animal feed has been continuously innovated and developed.There are several major categories of formulated feeds including concentrated feeds,additive feeds,and fermented feeds.Among them,fermented feed is increasingly applied and lactic acid bacteria are the most traditional and safe strains of fermented feed.Consumption of lactic acid bacteria fermented feed can improve the intestinal flora of animals,promote the digestion and absorption of nutrients,and can also replace antibiotics in feeds.Soybean meal is a by-product of the processing of soybean products.It contains nutrients such as protein,fat,and carbohydrates.Most of the soybean meal is added to feed for raising poultry and pigs.It is known that soybean meal contains anti-nutritional factors that hinder the digestion and absorption of animals.Using fermentation methods,it can not only effectively remove anti-nutritional factors,but also produce small amino acids and small peptides to supplement the nutritional needs of animals.In this study,eggshell powder was used as a neutralizing agent to ferment soybean meal,and the inorganic calcium in the eggshell was converted into calcium lactate to increase the utilization of the calcium source in the animal body.In the test process,firstly,the collected egg shells were pretreated,and crushed into egg shell powders.The muffle furnace was used to calcine the impurities in the egg shell powder,and the color of the calcined egg shell powder was added and 1 mol/L is added.The amount of bubbles generated by hydrochloric acid was the criterion for the determination and the optimum calcination conditions were optimized.The results are as follows: Calcined temperature 900° C.,time 2 h.Lactobacillus rhamnosus was used as the fermentation strain and the conversion rate of calcium lactate was used as an index to optimize the culture medium of the fermentation strain and,the addition of glucose,corn syrup and other ingredients.The results are as follows: glucose 10%,corn syrup 5%,moisture content 40%,inoculation amount 10%,eggshell and powder 3%.After optimizing the culture medium into Lactobacillus rhamnosus fermentation,the conversion rate of calcium lactate was 56.66%.The optimum fermentation temperature and time for optimizing the fermentation process conditions were 37° C and 36 h,respectively.At this time,the conversion rate was 58.14% and the content of calcium lactate was 4.61%.Lactobacillus fermented soybean meal feed has a certain probiotic effect to prevent death of bacteria induced by extra-high drying temperature were used drying temperature of 30 °C,40 °C,50 °C,respectively,drying at three temperatures 2h,4h,6h,according to the moisture content of soybean meal feed and after drying comprehensive consideration of energy consumption,we decided on 50 °C,4h drying,and 12.55% moisture content and it can be packaged and stored without poilage.The main purpose of this study is to comprehensively utilize eggshell powder and soybean meal.Therefore,the eggshell meal conversion rate is used as an indicator.The lactic acid bacteria fermented soybean meal diet has many advantages,such as reducing the content of antinutritional factors and being a small peptide in soybean mealas well as increasing the content of amino acids and other nutrients.This study mainly focused on the index comparison of soybean meal raw materials and fermented soybean meal.The main test indicators are as follows: Anti-nutritional factors include trypsin inhibitor,urease activity,phytic acid,and poor oligosaccharides;nutrient composition tests include calcium lactate,crude protein,small peptides,amino acids and crude fat.The results showed that the trypsin inhibitor activity and urease activity of fermented soybean meal were lower by 49.28% and 60.74% than that of soybean meal,and the phytic acid content was increased by 10.47%.The results of TLC showed that the content of bad oligosaccharide raffinose and stachyose were significantly reduced.The content of peptide and amino acid in fermented soybean meal was increased by nearly 6.3 and 5.0 times,and crude protein increased by 9.25% and crude fat decreased by 9.29%.In summary,using eggshell powder as a calcium source,fermenting soybean meal with Lactobacillus rhamnosus has significantly increased the soluble calcium content of soybean meal,and significantly increased the nutrient content of the soybean meal,including crude protein,small peptides and amino acids,while effectively reducing Anti-nutritional factors in soybean meal include trypsin inhibitor,urease activity,phytic acid,and poor oligosaccharide content.