The quality of eggshell is a very important indicator to measure the performance of breeder and laying hen. It is closely related to the hatching rate, hatching rate, quality of chicks and the production of fresh eggs of commercial laying hens. Related. The quality of the eggshell directly determines the breakage rate of the egg and affects the production efficiency of the laying hen. The nutritional factors affecting the quality of eggshells are mainly the content of calcium and phosphorus in the diet, the proportion of vitamins, trace elements and electrolyte balance. To improve eggshell quality, the following nutritional control measures should be taken:
To ensure the intake of calcium and the retention time of calcium in the body, taking into account the effect of the retention time of calcium on the quality of the eggshell, when the dietary calcium content reaches the theoretical standard, the granularity of the calcium feed must also be guaranteed (8~) 12 items are good), making it suitable for chicken absorption and utilization. The experiment proved that: using a full-thickness diet containing 3.5%~4% of calcium, the calcium retention in the body after cooking is only 50%. Since the eggshells usually begin to deposit at dusk, the chickens do not get enough calcium supplements at night, which is why the eggshell quality is generally poor when feeding the whole powder diet for a long time. It can be overcome by adding 1% to 1.5% of calcium powder in the diet after 3 pm.
Controlling effective phosphorus content and ratio of calcium to phosphorus The effective phosphorus content in the diet of laying hens is maintained at about 0.4%. When the ratio of calcium to phosphorus is 4:1 to 6:1, the eggshell quality is better; while the effective phosphorus content is too high (0.45%). Above), it will cause relative deficiency of calcium, and there will be high phosphorus and low calcium.
Vitamin D3 is a necessary substance for calcium and phosphorus metabolism in laying hens. It can promote the absorption and conversion of calcium and phosphorus in the intestines, and can overcome the improper proportion of calcium and phosphorus to some extent. Generally, the amount added per kg of feed is 2,000 to 2,500 international units. The quality of the eggshell is significantly reduced when the vitamin D3 in the diet is insufficient, ineffective, or other substances that interfere with the metabolism of vitamin D3, such as aflatoxin or other fat-soluble vitamins.
The addition of trace elements manganese and zinc is of particular importance in trace element premixes. At high egg production rates and high stocking densities, at least 70 grams of manganese or an equivalent amount of zinc or slightly higher magnesium is added per ton of feed. In order to ensure the quality of the eggshell, high manganese will inhibit the absorption of zinc.
Under high temperature conditions, vitamin C can increase thyroid activity, promote calcium metabolism, and stabilize eggshell quality. Tests show that when the temperature is 30 ° C, the amount of vitamin C supplement is 50 ~ 100 grams per ton of feed.
Maintaining electrolyte balance chlorine is acidic in chickens, and high levels of chlorine are harmful to eggshells. Because the metabolic acid produced by high chlorine inhibits carbonic anhydrase, hinders the conversion of bicarbonate to carbonate; it also affects calcium and phosphorus metabolism in chickens. Sodium and potassium are alkaline in chickens and can be substituted with each other in a ratio of 1:1 to counteract the effects of excess chlorine on eggshells in diets containing normal amounts of sodium and potassium. Studies have shown that in the diet with normal calcium and phosphorus content, baking soda can be used instead of 0.1%~0.5% salt to effectively regulate the acid-base balance in the body, reduce the eggshell breakage rate, and add 0.3%~1% baking soda. Improve the hardness of the eggshell. ( proudly)
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