Eggs have high nutritional value and high-quality protein, and are one of the main food sources for people to consume protein. The production of safe and high-quality egg products through efficient and scientific nutritional regulation has become a hot spot in the egg breeding industry. Nutrition regulation of laying hens refers to scientifically and rationally adjusting the feed formula according to the growth and development law of laying hens to achieve the purpose of low cost and high profit. The growth and physiological characteristics of laying hens can be divided into the brooding period, the breeding period and the laying period, and the laying period can be divided into the early laying period, the peak laying period and the late laying period. The nutritional needs of laying hens are different in different periods. Farmers should fully grasp the growth and physiological characteristics of laying hens in each period. By scientifically adjusting the feeding formula of laying hens, they can not only meet the daily nutritional needs of laying hens, but also improve production. Egg rate and egg quality maximize the economic benefits of laying hens. Combined with years of in-depth research on local laying hen farms, the author summarizes the nutritional regulation strategies of laying hens in the three periods of brooding period, growing period and laying period, in order to provide valuable reference and reference for laying hen farmers. .
1 Nutrition regulation during the brooding period
Usually 0 to 6 weeks is the brooding period for laying hens. At this stage, the various tissues and organs of the chick are in the developmental stage, the immune function is not yet perfect, and the resistance to various unfavorable external environments is poor; at the same time, the chick grows very fast, but the volume of the crop and gizzard is small, and the gizzard has The grinding ability is poor, and the digestive enzyme system is not fully developed and the enzyme secretion is insufficient, resulting in weak digestion ability. Therefore, during this period, it is necessary to provide fine pellets with a size between 1.25 and 2.5 mm. Prepare the trough and water tank according to the position of the trough of 2.5 cm/pc and the drinking position of 1.5 cm/pc, and keep the feed in the trough from time to time. , allowing the chicks to eat freely and freely, which is conducive to the uniform growth of the chicks . At the same time, the feed formula in this period needs to meet the requirements of high energy, high protein and low fiber. The feed can be designed with reference to the nutritional structure of egg yolk. First-grade corn, peeled and fermented soybean meal are selected as raw materials to ensure that the protein content reaches 20%. The metabolic energy is maintained at 12.09-12.30 MJ/kg (2 880-2 940 kcal/kg), and high levels of vitamins and minerals are supplemented to meet the needs of rapid growth of muscles and bones. In addition, with the rapid growth and development of chicks, the size of the trough and the water tank should be increased in time, and the weight change of the flock should be observed to determine whether the body weight meets the standard, and the strong and weak chicks should be kept separately in time, and the feed formula should be adjusted appropriately to improve the survival of the brooding. Rate.
2 Nutritional regulation during the breeding period
7-18 weeks of age is the breeding period for laying hens. During this period, the development of various organs of the chickens was relatively complete, the digestive function was gradually improved, the adaptability to the external environment was enhanced, the growth and metabolism were vigorous, and the muscles and bones grew very rapidly, which mainly laid the foundation for the weight and bones of the laying hens before laying. In the early stage of breeding, chickens mainly focus on increasing body weight and promoting bones, and are more sensitive to protein, vitamins and minerals. The egg production rate of adult chickens and the extension of the laying period provide the basis. In the second half of the breeding period, the chicken’s feed intake gradually increases, but the growth rate will relatively slow down, while the chicken’s body fat cell volume begins to increase, the body fat deposition increases, and the reproductive system develops rapidly. Therefore, the energy intake of laying hens should be strictly controlled at this stage to avoid the chickens being too fat and delaying the development of the reproductive system, resulting in a decrease in egg production rate and ultimately affecting production performance. During this period, the restricted feeding method is often used, and the amount of feed intake is limited to 70% to 80% of the free feed; at the same time, on the basis of ensuring the nutritional needs of laying hens for normal growth, it is necessary to reduce the proportion of dietary nutrients. , choose some raw materials with low protein content and relatively high crude fiber content, such as bran, grass powder, etc. Under normal circumstances, the body weight of laying hens in the early stage of laying will increase by 400-500 g, the bone weight of chickens will increase by 15-20 g, and the calcium deposition will be 4-5 g . 25% of the calcium required for eggshell formation comes from the bone marrow, and the rest needs to be provided in the diet, and a large amount of calcium will be deposited in the bone marrow within 2 weeks before the laying hen starts, so it is necessary to increase the calcium content in the feed. Transitional high calcium feed is usually provided from 18 weeks to the start of laying to meet the bone calcium reserve requirements of laying hens. In addition, in order to prevent diarrhea in chickens, 0.5% of micro-ecological preparations can be added, which can effectively improve the intestinal health of chickens, promote the digestion and absorption of feed, and reduce the pollution of manure to the environment.
3 Nutritional regulation during laying period
3.1 Nutritional regulation in early laying period
The pre-laying period is usually 20 to 28 weeks old, and the egg production rate is between 5% and 70%. During this period, the weight of the laying hens increased steadily at an average of 30-40 g per week, and the egg production rate increased at a rate of 20-30% per week; the follicles of the chickens grew rapidly, and the fallopian tubes also increased rapidly. During this period, the nutrient demand will be higher than the peak egg production period. In order to ensure the egg production demand and prevent the overdraft of the laying hens’ physical energy, farmers need to provide high concentrations of nutrients and let them eat freely to meet the nutritional needs and improve the body’s ability. ‘s reserves. In the early stage of laying eggs, the feed formula in the early stage of laying eggs needs to be provided. The formation of eggshells requires sufficient calcium source, so the calcium content should reach 2.25%, and the calcium source should be shell powder or stone powder with larger particles; at the same time, vitamins, methionine and trace elements were appropriately increased. The following feed formula can be used: 61.4% corn, 14% wheat bran, 21% soybean meal, 1.2% calcium hydrogen phosphate, 1.1% stone powder, 0.3% salt, and 1% additive.
3.2 Nutritional regulation during the peak egg production period
When the egg production rate reaches more than 80%, it will enter the peak egg production period, usually 29 to 60 weeks old. During this period, the growth, development and reproductive system of laying hens are mature, with stable feed intake, high metabolic intensity, and high egg production performance, but they are vulnerable to stress. In order to maintain high production and prolong the laying period, it is necessary to provide full-price feed to ensure the balance of energy, protein and amino acids, and to supplement sufficient calcium and phosphorus content. The feed formula cannot be changed at will, and the weight of the chickens should be increased by more than 5.7 g per week. . At the same time, ensure that the chickens drink enough water, add other nutrients such as trace elements, vitamins and linoleic acid to enhance the body’s immunity and reduce various stress reactions.
3.3 Nutritional regulation in the late stage of laying eggs
Under normal circumstances, laying hens enter the late laying stage after 60 weeks of age, the egg production rate continues to drop below 70%, the eggshell quality also decreases significantly, and the egg weight increases. Therefore, the amount of minerals and vitamin D3 in the feed should be appropriately increased to ensure the calcium level of the body and improve the hardness of the eggshell. At the same time, with the aging of chickens, the digestion and absorption capacity of feed is gradually weakened. In addition, the egg production rate of chickens declines, and the demand for energy and protein also gradually declines. Therefore, during this period, the proportion of energy in the feed should be gradually reduced, and the feed intake of the chickens should be controlled at the same time to avoid fat deposition, resulting in obesity in the chickens and reduced egg production performance. In addition, an appropriate amount of probiotics can be added to the feed, such as lactic acid bacteria,clostridium butyricum, enterococcus faecalis, etc., to improve the intestinal health of chickens, regulate gastrointestinal function, improve digestion, and at the same time improve the production of eggs in the late stage. Egg yield and eggshell weight and strength