Specific application of lutein in laying hens and aquaculture
Lutein belongs to carotenoid, which is a kind of natural pigment. It has bright color, strong tinting power, good anti-oxidation, safe and non-toxic, and has rich nutritional value. It is a natural plant that widely exists in vegetables, flowers, fruits and some algae plants, and is widely used in many fields such as food, health products, cosmetics, medicine, tobacco and animal feed. The U.S. Food and Drug Administration has approved the use of lutein as a food supplement as early as 1995. Due to the wide application of lutein, in the international market, 1g of lutein is equivalent to 1g of gold, so it has the reputation of "plant gold". .
There are two main types of carotenoids: carotene (a general term for carotenoids that do not contain nutrients): lutein (a general term for oxygen-containing carotenoids) including lutein, lutein, a-carotene, Cryptoxanthin, zeaxanthin, light yellow pigment, cryptoxanthin, zeaxanthin, other pigments.
As a carotenoid, lutein is an excellent natural antioxidant and non-toxic natural yellow pigment. It not only has strong coloring power, but also can strengthen the nutritional value of added food. In foreign countries, people generally use it for Margarine, cheese, fruit juice, beverages and many other foods.
As a natural pigment with strong coloring power, lutein has been widely used in chicken feed to color broiler chickens or laying hens. In 1998, my country included natural carotenoids in the national food additive use hygienic standards. Lutein mainly comes from the petals of marigold flowers. At present, marigold is used to commercialize a large amount of lutein extraction products. The content of lutein in marigold is about 1.6%-2.0%. The high content of marigold is planted in my country. , distributed in my country's northeast, northwest, and north China.
Due to the health function of lutein and the high bioavailability of lutein in egg yolk, the development and production of healthy eggs rich in lutein, by adding marigold extract (lutein), design the feed for laying hens, and produce The use of eggs rich in lutein, according to relevant information, produces eggs with 16 times more carotenoids than ordinary eggs. Ordinary eggs contain about 0.12mg of lutein, and the lutein contained in eggs after adding lutein The content is 0.381mg, the change of diet has no effect on egg production, egg weight, feed intake and eggshell quality, but the color of egg yolk changes dramatically within 7 days after adding lutein from 6-7 to 12-13 points, lutein The level of egg is increased to 5-8 times that of ordinary eggs. Serum lutein and macular albin levels are directly related to diet. It is generally believed that as the lutein content in the diet increases, the serum lutein level and MPOD (macular pigment optical density) value also increase accordingly, thereby reducing the chance of suffering from ARMD and other diseases. Lutein Health Eggs are an ideal source of dietary lutein levels. It can be seen that eating lutein healthy eggs not only increases MPOD and reduces the risk of ARMD, but also does not bring about the risk of elevated cholesterol due to eating eggs. In the feed industry, the application of lutein additives has become the most used as a coloring agent to improve the quality of egg yolk, and regulate the lutein in egg yolk through diet, so that lutein can be deposited in egg yolk, There is little research in China to produce more nutritious and healthy eggs.
Lutein plays an important physiological role in eye protection, anti-oxidation, anti-cancer, prevention of cardiovascular diseases, and enhancement of immunity. Some people will recognize it as an antioxidant vitamin. Since lutein has good coloring effect and food activity such as anti-oxidation and vision protection, it is used as a natural feed additive for the coloring of egg yolk, skin and shins, etc. and the production of lutein-enhanced egg boom
Different levels of lutein in the diet have different deposition effects in egg yolk: experiments have shown that the deposition of lutein in egg yolk increases with the increase in the level of lutein in the diet. When the amount of lutein added is greater than 200mg/kg , the difference of lutein content in egg yolk is not obvious, when the lutein addition amount is 300mg/kg, the deposition of lutein in egg yolk is 2.17mg/60gegg. It can be seen that the lutein in egg yolk is not affected by the increase of lutein addition. Experiments show that the most effective amount of lutein to precipitate in the egg yolk is 200mg/kg. After adding lutein, the RCF (Roche yolk grade) is maintained in the range of 10-13 on the 14th day. On the 28th day, the brightness of the egg yolk increases. Higher, red is also higher. Adding different levels of lutein in the diet did not affect the performance of laying hens (p>0.05).
Lutein has many important physiological functions, such as protecting vision, delaying early arteriosclerosis, enhancing immunity, anti-cancer, anti-oxidation and coloring, etc. The main functions of lutein as a coloring agent are:
2.1 Improve the body color of animals Lutein is bright yellow, insoluble in water, soluble in oil and ethanol, and has the characteristics of resistance to light, heat, acid, alkali, and strong coloring ability. As an effective coloring agent, it has been widely used in feed additives. Studies have shown that the lutein accumulated in the subcutaneous fat and egg yolk lipids of broilers is mainly lutein and zeaxanthin, indicating that lutein and zeaxanthin Lutein has coloring activity, so lutein is also called active lutein. When the lutein content in the feed is 20-75mg/kg, poultry can be well colored; when the lutein content in the chicken feed is 18mg/kg, the color of egg yolk and chicken skin can be changed.
2.2 Improve the fertilization rate and egg hatching rate of eggs. Studies have found that eggs with high lutein content have faster development of the circulatory system and blood vessel area of the embryo, and lutein in egg yolk can also promote the accumulation of a large amount of vitamin A and glycogen in the liver of the embryo. Promotes the absorption of lipids in the embryonic liver.
2.3 Enhance immunity, increase reproduction, and survival A large number of studies have shown that lutein can also enhance the reproduction, survival and immunity of livestock, poultry, fish and shrimp, and it can also protect lipids from oxidation and protect meat. The quality and nutritional value of the product during transportation and storage also play a major role.
3 Absorption of lutein by animals
Most animals cannot synthesize lutein themselves and must ingest it from the outside. After lutein is digested, absorbed, transferred and esterified in the animal body, it is finally deposited in different tissues such as the skin, fat, and shin of the animal. The formation process of animal color is divided into two stages, namely the saturation stage and the coloring stage (the former stage is achieved by the accumulation of yellow pigment; the latter stage is achieved by adding red pigment on the basis of yellow).
Application of Natural Pigment Lutein in Broiler Chicken and Aquatic Products Production
With the development of poultry and aquatic products, broiler chicken and aquatic products are becoming more and more abundant, and the seller's market has thus become a buyer's market. Concomitantly, people's living standards have gradually changed from food and clothing to well-off, and the sales demand for various products has changed from quantity to quality. Not only must you eat with confidence, but you must also enjoy the taste, nutrition, and style of eating, so quality has become the focus of common attention of producers and consumers.
Animal meat products are a complex concept. It includes not only meat quality indicators such as taste, tenderness, and juiciness, but also general external light indicators such as appearance and color. Therefore, people are increasingly studying the natural pigment lutein. .
The coloring of meat, poultry and aquatic products is achieved through the deposition of lutein in different tissues such as animal skin, fat, and leg shins. Animals cannot synthesize pigments themselves and must be ingested from feed. Pigments from different sources have different biology. Utilization (deposition efficiency). The absorption process is quite different, and has different affinity for various tissues of the animal body. Generally, only free leaf alternates can be absorbed. It is speculated that the absorption of lutein is similar to the absorption of fat-soluble vitamins. In the body, bile-carotenoid microgroups are formed with bile and enter the hydrostatic layer on the surface of the small intestinal mucosa. A part of lutein may Re-esterified in the small intestinal mucosa, part of it diffuses into the lymph and blood circulation, is transported in the blood through lipoproteins, and most of it is deposited in specific tissues. Animal coloring is divided into two stages: one is the saturation stage, which is deepened by yellow pigment And achieved: the other is the coloring stage, which is to enhance the color by adding red pigment on the basis of yellow. Only when each animal completes these two stages can it achieve its desired color.
There are two main ways for natural lutein to color fish: it can be directly deposited in the scales, skin, fat tissue and eggs, such as yellow catfish, bearded catfish, Chinese soft-shelled turtle, etc.; it can also be converted into astaxanthin and then deposited In the organization, such as Atlantic salmon, goldfish red carp and koi, etc.
Fish can synthesize melanin by themselves, but cannot synthesize carotenoids de novo, so different sources of carotenoids must be obtained from feed. The natural lutein extracted from marigolds is usually yellow powder with bright color and strong coloring ability. Its primary function is to be used as a colorant, which can give aquatic animals and poultry yellow, yellowish brown, and golden yellow body colors. The suitable dosage is 100mg/kg feed (adult fish) or 50mg/kg feed (fish species). Lutein is mainly deposited in the skin, and the skin will be transferred to the muscles after the skin is saturated.
In addition to the coloring effect of marigold natural lutein on fish, it also has the effect of promoting growth, improving the activity of digestive enzymes and reducing fat accumulation to a certain extent. Adding factors in the feed can significantly increase the redness and yellowness of goldfish body color, and increase scales, skin, muscles and tails. The dosage is 150mg/kg