Analysis of factors affecting coloring of Sanhuang Chicken and its existing problems

In recent years, with the development of domestic poultry industry and the continuous improvement of people's living standards, consumers are becoming more and more picky about the consumption of meat, and people in East China have a special preference for Sanhuang chicken. In fact, the yellow deposited on the shank and subcutaneous fat of chicken feet is lutein, which is the general name of a kind of natural pigment. Because the chicken cannot synthesize lutein itself, the lutein that exists in the chicken comes from feed. So, what is the reason for the difference in chicken coloring? Let's analyze them one by one.

1 genetic factors

1.1 there are genetic differences in lutein deposition ability of different breeds and strains of broilers, especially the current Sanhuang chicken breeds and strains are quite confused.

1.2 when fed the same feed, the coloring of hens was better than that of cocks, and that of older chickens was darker than that of young chickens.

2 Dietary factors (raw material composition of feed)

2.1 the feed materials that can provide valuable lutein are mainly corn and corn gluten meal, and the content of lutein in corn and corn gluten meal varies greatly with variety, harvest season, storage time and so on. therefore, the lutein content of each batch of corn and corn gluten meal should be determined if possible.

2.2 the content of rice bran, vitamin A, calcium and antioxidants in feed will affect the absorption of pigment.

2.3 the pollution of mycotoxin in feed and cushion (mycotoxin affects the metabolism and absorption pathway of lutein in chickens), anti-nutritional factors, dietary nutrient concentration, feed processing technology and so on can reduce pigment deposition.

2.4 Fat content in feed lutein deposits in chicken subcutaneous fat can show yellow, so the amount of subcutaneous fat directly affects the coloring effect of chicken skin. The results showed that with the increase of the amount of oil in feed, the content of lutein in chicken serum increased accordingly. For example, adding more fat (especially vegetable oils) to the feed can significantly improve the coloring effect of lutein on the skin.

3Environmental factors

3.1 because light can promote the absorption of pigment, the coloring effect of chickens raised in a conventional transparent chicken house is better than that in a windowless dark chicken house.

3.2 the environment of high temperature and humidity, excessive feeding density and poor ventilation will reduce the utilization of lutein and affect pigment deposition.

4 factors of feeding and management

4.1 Chicken body coloring is a cumulative process, it takes at least 2 to 3 weeks from the beginning of ingestion of lutein to the appearance of yellow on shins and skin (for example, it takes a longer time for high yellowness); at the same time, the deposition of pigment is not evenly distributed in the whole chicken skin, but has a certain selectivity.

4.2 feed intake. The amount of feed intake directly affects the coloring effect. The more you eat, the better the coloring.

4.3 the storage time of feed. The longer the storage time of the feed, the worse the coloring effect of the chicken.

5 Health factors of chickens

The health status of chickens directly affects the deposition of pigments in chickens, especially when intestinal absorption function is impaired. Suffering from coccidiosis, salmonellosis, Newcastle disease, chronic respiratory diseases and other diseases will seriously reduce pigment deposition.

6 coloring product factors

The vitamin An activity, physical shape, utilization and stability of colorants are all related to pigment deposition, and there are some differences in pigment deposition rates of different colorants.

7 relationship between color and taste of skin and shank of chicken

So far, no nutritional effect of lutein has been found in the study of animal nutrition. However, when buying chickens, consumers mainly judge the quality of chickens by more intuitive methods, such as feathers, skin, shin color and so on, in addition to the previous purchase experience and the choice of chickens with brand identity. They generally believe that the yellower the chicken color, the longer the breeding time, then the better the taste after cooking, which actually has a misunderstanding. We know that the important substance that determines the flavor of chicken is inosinic acid, which depends on the type and content of inosinic acid. At present, the fast Sanhuang chickens on the market are generally fed with compound feed containing lutein, and the feeding period is short.

All sectors of society and relevant departments should correctly guide consumers to gradually reduce their requirements for chicken coloring, and feed manufacturers should also strengthen self-regulation, which can reduce the additional feed cost due to excessive addition of pigment. Poultry breeding units should select white chicken breeds that are similar to or even better than "Sanhuang chicken", so as to break the prejudice that yellow chicken must taste better than white chicken.