Commonly used layer feed raw materials

According to the different nutritional content of feed raw materials for laying hens, it can be divided into energy feed, protein feed, rough feed, mineral feed, vitamin feed and additives.　　

1. Energy feed　

Energy is the most important nutrient for chickens. Any feed that contains less than 20% crude protein and less than 18% cellulose in dry matter is classified as energy feed. The commonly used energy feeds mainly include the following.　

(1)Cereals　

mainly includes corn, broken rice, wheat, and wheat flour. Corn is mostly used in northern China. Corn is the most used feed material in layer feed, and it generally accounts for about 65% of layer diets. Corn contains a lot of starch and is easy to digest and absorb, and the content of linoleic acid in fat is high. When storing corn, care should be taken to prevent mold, and the germ of moldy corn is blue-green.

(2) Bran　　

mainly includes wheat bran and rice bran. Rice bran is generally not used in layer feed. Wheat bran contains more fiber (8.5%-12%), has a low energy value, and metabolizable energy is only 7.1 MJ/kg. The crude protein content is relatively large, up to 12% to 17%, and its quality is higher than that of wheat kernels, rich in lysine 0.5% to 0.6%, and methionine only about 0.1%. The phosphorus content of wheat bran reaches 1.13%, which is the highest among plant feeds, but mostly in the form of phytate, which is difficult to digest and utilize. Contain vitamin B1, vitamin E, lack of vitamin B12, vitamin A and vitamin D. Wheat bran has a loose texture, good palatability, and has a laxative effect. Adding wheat bran to the diet of laying hens can accelerate the growth of chickens and promote the growth of feathers, which can account for 5% to 10% in the diet.　

(3) Greases

Including animal fats and vegetable fats. The commonly used animal fats include fish oil, tallow, mutton oil, lard, bone oil, etc., and their metabolizable energy levels are relatively high (more than 2.5 times that of corn). When using it, it is mainly to avoid the use of deteriorated grease. Vegetable oils include corn oil, rapeseed oil, soybean oil, and mixed oils. Generally, it is not necessary to add fat in the feed of laying hens, and only add 1% to 2% of cooked soybean oil in the hot season or when the chicken weight is not up to the standard.　

2. Protein feed　　

Protein is the main component of chicken body cells and eggs. The utilization rate of protein in chickens mainly depends on the content of amino acids in the feed ingredients and the balance of amino acids. Commonly used protein feed materials include plant protein feed and animal protein feed.　　

(1) Plant-based protein feed　

mainly includes soybean cake (meal), puffed soybean, rapeseed cake (meal), cotton kernel meal and peanut cake, sesame cake, flax cake, corn gluten meal, etc. The various amino acids contained in soybean meal (meal) basically meet the nutritional needs of poultry. Soybean meal (meal) also has a relatively high energy level, rich in riboflavin and niacin, but low in selenium. Soybean cake (meal) has good flavor and palatability and is an ideal protein feed. Soybean cake (meal) generally accounts for about 20% of the diet for laying hens. In order to improve protein utilization rate and reduce feed cost, three kinds of miscellaneous cake (meal) can be used at the same time when using soybean meal (meal). The use amount of single miscellaneous cake (meal) is generally 3% to 5%, and a variety of miscellaneous The amount of cake (meal) used should generally not exceed 6%, and the total protein content in the diet should not be lower than the feeding standard.　　

(2) Animal protein feed　

mainly includes fish meal, meat meal, meat and bone meal, blood meal, feather meal, etc. The fish meal used in China (including imported fish meal and domestic fish meal) is pure fish meal made from whole fish without foreign matter. Various types of fishmeal vary greatly in protein content due to different raw materials and processing conditions. The protein content of high-quality fish meal is very high, generally about 64%, the amino acid balance is also very good, and the content of lysine and methionine is high. The content of calcium and phosphorus is relatively high, and all phosphorus is available phosphorus. It also contains vitamin A, vitamin E and vitamin B12, which are not found in all plant feeds, and the content of other B vitamins is also high. It is also worth mentioning that fish meal contains unknown growth-promoting factors. Due to the high price of high-quality fishmeal, it is generally only used in the chicken feed about 3%, and the fishmeal-free diet is generally used during the rearing and laying period.

The crude protein content of meat meal and meat and bone meal is 40%-50%, the content of lysine is higher, but the content of methionine and tryptophan is lower (lower than blood meal), the content of B vitamins is higher, and the content of vitamin A is higher. The content of D, B12 is lower than fish meal.　　 　　

The crude protein content of blood meal is as high as 80%, the lysine content is also as high as 7%-8% (higher than the content of commonly used fish meal), the histidine content is also high, but the arginine content is very low. Matching blood meal with peanut cake (meal) or cotton cake (meal) can achieve better feeding effects. The digestibility of blood meal is very low, the palatability is also poor, the proportion in the diet generally does not exceed 3%.　　

Feather meal is made by high-pressure steaming, drying and crushing of poultry feathers, with a protein content of over 80.3%. When shared with other animal protein feeds, it can supplement the protein in the layer diet. Because of its low digestibility, it is best not to use it.　

3. Mineral feed　　

Mainly includes bone meal, stone powder, shell powder, calcium hydrogen phosphate and salt. Stone powder is the most economical and commonly used calcium supplement. The dosage in the feed for laying hens and adult chickens at the growth stage is 1%-2% and 6%-8%, respectively. The amount of shell powder is generally 1% to 2% for chicks and 5% to 7% for laying hens. The dosage of table salt is generally 0.25% to 0.3%.　　

The functions and deficiency symptoms of several major minerals are as follows:　

①Sodium and chlorine　　

Function: Participate in the formation of digestive juice; regulate body fluid concentration; regulate body fluid pH; participate in nerve and muscle activities.

Symptoms of deficiency: adverse consequences of a lack of sodium in the body: slow growth, loss of appetite, weight loss, lower feed returns; changes in cell function; decreased plasma volume, decreased cardiac output, decreased aortic pressure, and increased red blood cell deposition; The elasticity of the subcutaneous tissue is reduced; the function of the adrenal glands is impaired, leading to increased blood urea or uric acid, shock and even death; sodium deficiency significantly affects protein and energy utilization; sodium deficiency in chickens can also cause pecking.　

Chicklings lack chlorine, have poor growth rate, high mortality, hemoconcentration, dehydration, and reduced chloride levels in the blood. In addition, chlorine-deficient chickens are stimulated by sudden noises or shocks and show typical neurological responses similar to spasms.

②Calcium　　

Function: Participate in bone formation, 99% of calcium in animals is present in bone; regulate nerve and muscle function; maintain acid-base balance.　

Symptoms of deficiency: The symptoms of calcium deficiency in chickens can be summarized as: osteoporosis or low calcium rickets, abnormal posture and footwork; hindered growth and development; reduced feed intake; prone to internal bleeding.　　

③Phosphorus　　

Function: Participating in bone formation is the main component of cell nucleus and membrane; participating in various metabolic processes.　　

Symptoms of deficiency: Phosphorus deficiency is the same as calcium deficiency, resulting in cartilage; early deficiency can be corrected by feeding phosphorus; Phosphorus deficiency usually manifests as poor appetite, low weight gain, low blood phosphorus and poor appearance.　　

4. Feed additives　

The ingredients of feed additives are roughly divided into two categories. The first category is nutritional additives, including vitamins, trace elements, amino acids, etc.; the second category is non-nutritive additives, including growth promoters, insect repellent health care agents, antioxidants, color enhancers, flavoring agents, etc.　　

The functions and symptoms of several major vitamins are as follows:　　

①Vitamin A　

Function: Maintain the integrity of epithelial tissue and normal vision, participate in bone formation, etc.　

Symptoms of deficiency: growth retardation, night blindness, joint stiffness or swelling.　　

②Vitamin D　　

Function: Promote calcium absorption and calcium and phosphorus metabolism.　

Symptoms of deficiency: growth retardation, rickets.　　

③Vitamin E　

Function: biological antioxidants, protect the integrity of cell membranes.　

Symptoms of deficiency: poor growth, muscle atrophy (white muscle disease), liver necrosis.　　

④Vitamin K　

Function: Required to form 4 kinds of coagulation proteins and participate in blood coagulation.　　

Symptoms of deficiency: prolonged clotting time or non-stop bleeding and internal bleeding; usually added when the chicken is broken.　　

⑤Vitamin B family　　

Function: Participate in various metabolisms in the chicken body.

Symptoms of deficiency: indigestion, anorexia, dermatitis, deformity of the feet and legs, growth and development obstruction.　

⑥Vitamin C　

Function: Participate in the composition of intercellular substance; detoxification, anti-oxidation.　

Lack of symptoms: scurvy, easy to fracture, wounds and ulcers are not easy to heal.　　

5. Water　　

Water is the main component of body fluids and plays a particularly important role in the normal metabolism of poultry. Although the chicken's water requirement is uncertain, it is still an essential nutrient. The water requirement of chickens is affected by the following factors: environmental temperature, relative humidity, diet composition and growth. It is generally assumed that the water consumption of chickens is twice the feed intake, but in fact the water consumption varies greatly.