What are that reason that affect the color and quality of eggshells?

1. Genetic factors affecting eggshell color 1. The ability to synthesize protoporphyrin is determined by genetic factors, and it is limited to chickens with feathers or colored skin. So the color of eggshells is mainly influenced by genetic factors. For a hen, the color depth of the eggshell is relatively fixed. Pigments obtained from natural food or commercial feed cannot be deposited in eggshells, such as riboflavin and β -carotene can only affect the color of egg yolk. 2. The ability to synthesize protoporphyrin is influenced by genetic ability and varies from person to person. Commercial chicken is a hybrid with more than one major genetic strain. Therefore, there are subtle genetic differences among individuals in the synthesis ability of protoporphyrin, even the eggshell color of the same variety has certain differences. In actual production, it is occasionally seen that brown shell laying hens lay white eggs. Second, the age factor The secretion of the membrane on the hen shell does not increase with age. When the hen's egg weight increases with age, the limited membrane on the eggshell will be distributed on the enlarged eggshell, so the color of the eggshell will become lighter. After 40 weeks, the eggshells laid by commercial chickens became thinner and the content of visual pigment was less. In addition, after 40 weeks, the egg weight increased, the eggshell surface area increased, and the pigment distribution area increased, which made the egg color fade. In production practice, the eggs laid by laying hens are obviously different from those laid by old hens. The eggs laid by the old chicken are bigger but darker. Three. Disease and stress factors The upper shell membrane is the outermost layer of the eggshell, and the pigment contained in it is related to the amount of the upper shell membrane, which ultimately determines the color of the eggshell. When environmental stress or disease occurs, the secretion of membrane on the shell will decrease, mainly because hens switch nutrients from unnecessary metabolic activities such as the formation of membrane on the shell to urgently needed metabolic activities under physiological stress. 1. diseases: some infectious diseases cause diseases that induce immune stress, such as infectious bronchitis and atypical pneumonia.

Diseases such as Newcastle disease and egg-laying syndrome will lead to atrophy of eggshell glands and affect eggshell color. Mild infection of Salmonella and Escherichia coli can also affect the secretion of eggshell glands and produce so-called pointed eggs. Many small feed factories also add a small amount of antibiotics to the concentrated feed of laying hens, which is helpful to improve the quality of eggshells. After unexplained eggshell lightening, it is necessary to observe whether chickens have respiratory symptoms, and if necessary, ND ⅳ and H52 can be used to strengthen immunity. 2. Stress: When hens are under stress, especially under heat stress, the pigment secretion of the membrane on the shell will decrease. The stress produced in the last five hours of the formation of the mother egg, especially the physiological or artificial stress factors during the formation of the eggshell, will reduce the quality and lighten the color of the eggshell. Fourth, the nutritional factors affecting the color of eggshells are common. Eggshell whitening occurs in hot summer and rarely occurs in winter. Nutritional factors often lead to the light color of eggshells, not only because of the lack of nutritional components in the formula, but also because of food intake. In the case of low temperature, laying hens can meet their nutritional needs by adjusting their feed intake, but in the summer when the temperature is very high, this adjustment mechanism can't work, and the nutrients that laying hens eat every day can't meet their needs. 1, calcium: calcium deficiency in feed leads to poor eggshell quality. Excessive calcium supplementation will lead to excessive calcium deposition in eggshell and membrane on shell; Too much calcium deposition will make the color of eggshell fade and the color tone become worse. 2. Phosphorus: If there is too much phosphorus in the feed, the broken egg rate will increase. If there is too little phosphorus, the egg production rate will decrease. 3. Manganese: Manganese is related to the formation of mucopolysaccharide. Feed is deficient in manganese, and eggshells become thin and fragile. 4. Insufficient vitamin D3, A and E, and insufficient dietary supply can make eggshells lighter in color. Adding multivitamins to the basic diet in summer can help reduce the occurrence of light-colored eggs. V. Drug Factors A small amount of nicarbazine will affect the color of eggshells and make them worse. The reason may be that it interferes with the synthesis of these pigments, leading to the production of white eggs in normal brown egg varieties. In actual production, because carbazine is often added to feed as an anticoccidial drug, the residue of mechanical equipment will lead to this reason. Sulfonamides also have this effect. Overfeeding high levels of certain drugs can also lead to the deposition of these antibiotics and produce yellow eggshells. Six, electrolyte balance

Electrolyte balance of chicken is the balance of anion and cation in diet, which usually regulates the balance of Na+K-Cl in diet. The balance index is mostly expressed in milliequivalents, and 250 milliequivalents per kilogram of diet is normal. When it deviates too far, it will affect the eggshell quality, overall health and metabolism of chickens.