In this paper, based on the effect of calcium on laying hens and the more successful examples of calcium addition in laying hens, the recommendations for reasonable calcium supplementation are given in order to effectively improve the performance of laying hens.
Brooding, breeding chicken stage
1 The effect of calcium on brooding and broiler chicken
Chicks and broiler chickens require less calcium, and calcium is mainly used for bone growth in chickens. If the calcium in the feed of chicks and broiler chickens is insufficient, it will not only lead to slow growth of the flocks, but also lead to skeletal dysplasia, but the bones will be brittle and easy to fold, deform and bend, forming cartilage, and then develop into rickets. If the calcium content in the feed is too much and exceeds the body's ability to excrete, it will easily cause calcium salt to deposit in the kidney, which will damage the normal development of the kidney, affect the normal function of the kidney, hinder the discharge of uric acid, and cause gout disease in chickens.
2 brooding calcium addition
In order to give full play to the genetic performance of laying hens, the method of adding calcium during brooding period: 1 using 0.9%-1% calcium in the brooding period, the length of the tibia is 86mm, and the body weight reaches the corresponding age standard as the standard for brooding end (ie, tibia, The weight of the double-standard), because the modern laying hens adopt the double standard of length and weight, so in the early stage of brooding and breeding, the development of bones (that is, the growth of the length of the sputum) is the most important, followed by the increase of body weight; 2 the addition of calcium The time should be extended to 8 weeks for the "bone bone, weight" double standard (about the actual tibia, weight development); 3 in order to promote the chick's grinding, digestion and muscle development, it is recommended from 15 days old Start to set up the tray, add coarse quartz gravel at least 3 times a week, or add 2%-3% coarse quartz gravel directly to the feed. After the tibia and body weight are up to standard, the sand is added and the function is replaced by 0.3%-0.5% medium-sized granular stone powder (the size of the particles is about the size of the northern small yellow rice, and the size should be easy to forage).
3 Adding calcium during the growing period
In the breeding stage, the amount of calcium added in the feed is reduced to 0.6%-0.9%, and the maximum is not more than 1.0%. Because the feed contains too much calcium, it will reduce the ability of the bones of the chicken to deposit calcium, and severely cause calcium poisoning. Calcium specific addition method in the breeding period: 1 feeding the feed with low calcium in the early stage of breeding, feeding the feed with high calcium in the late stage; 2 can not be changed into the egg production in advance (high protein energy, high calcium), otherwise it will cause calcium Excessive intake, exacerbation of renal excretion, while calcium deposits in the ureter and stones, blocking the ureter caused acute death. If the kidney function is disordered for a long time, leading to chronic death; 3 in the tibia and body weight after reaching the standard to 2 weeks before sexual maturity, 0.3%-0.5% larger particles of stone powder may be added (particles are preferably 2-2.5mm, That is, half a soybean grain size).
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