Design principle of feed formula for broilers

The principle of feed formula design for broilers (1) the balance of energy and protein for life activities of broilers must have a certain amount of basic energy. Energy is derived from carbohydrates, fats and proteins in feed. However, protein is not only the basic material of somatic cells, but also the raw material of various functional enzymes and hormones. Therefore, it is a great waste to use protein only as energy. The feed intake of broilers is mainly to meet the necessary energy. Feeding stops when the energy is satisfied. If there is not enough energy in the diet, it is necessary to decompose protein to meet the need for energy, resulting in a waste of protein. However, when the energy is too high, the feed intake of chickens decreases, which will cause protein deficiency and affect the growth. Therefore, the content of essential nutrients such as protein, vitamins and minerals in the feed should be in an appropriate proportion with the energy in the feed in order to achieve the goal of less material consumption, faster weight gain and more eggs. The feed intake of chickens is not only related to the metabolic energy in feed, but also the temperature in the house has a great influence on the energy requirement. The change is the least at the suitable temperature, but the energy needs to increase obviously at the low temperature, which must be paid attention to. (2) the balance of protein and amino acids the main component of animal somatic cells is protein, and chicken body protein is transformed from feed protein. Therefore, the economical and effective use of feed protein is the key to the cost of raising chickens. Protein is a kind of high molecular organic compound, which is hydrolyzed in vivo to form a variety of amino acids. Therefore, amino acids are the basic units that make up proteins. The so-called good quality of feed protein means that the dietary protein contains all kinds of amino acids needed by chickens, and the proportion is appropriate; poor quality indicates that the amino acids contained in protein are not comprehensive or inappropriate. Therefore, the biological value of protein does not depend on the content of protein, but on its utilization. Only the balance of all kinds of essential amino acids can improve the utilization rate of protein. There are many kinds of amino acids, but there are about 20 kinds of proteins, of which half of the chickens can not be synthesized or can not meet the needs, and must be supplied by feed, which is called essential amino acids. If the intake of essential amino acids is insufficient, it will be difficult to give full play to the production capacity of chickens. According to the experiment, the effect of adding methionine to the diet containing 15% crude protein was very significant (P0.05). Many experiments have shown that methionine or methionine plus cystine (synergistic effect in vivo) is the first limiting essential amino acid, followed by lysine and tryptophan. Therefore, the above 3-4 amino acids should be satisfied as far as possible when preparing diets. The nutritional effect of mixed use of more than two kinds of protein is better than that of individual feeding. This is due to the imbalance of various amino acids in natural proteins. The combined use of several kinds of feed can learn from each other to achieve a balance and improve the utilization rate. (3) the requirement and ratio of calcium and phosphorus are the main components of bone. 65% of the total minerals in chicken are compounds of calcium and phosphorus. Calcium in bones accounts for 99% of the body's total, and the remaining 1% is found in blood, lymph and other tissues. Calcium plays an important role in the formation of eggshell, blood coagulation and maintaining the normal function of heart, muscle, nerve and acid-base balance together with sodium and potassium. Phosphorus in bone accounts for 80% of total phosphorus and 0.8% in fat-free chicken body, most of which are organic and related to various metabolism. It is a component of nucleic acid, high-energy phosphate, phosphoprotein, phospholipid, phosphocreatinine and hexose phosphate. There is also some phosphorus in the blood. When preparing diets, we should not only pay attention to meet the needs of calcium and phosphorus, but also pay attention to the appropriate proportion of calcium and phosphorus according to the feeding standard. Because the absorption of phosphorus has a great relationship with the existence of calcium in the feed, if the proportion of calcium and phosphorus in the diet is not appropriate, or in a combined state, it is not easy to dissolve, it will reduce the absorption and lead to deficiency. Excessive calcium content is not only harmful to the growth of chicks, but also affects the absorption of phosphorus, magnesium, manganese, zinc and other elements. In general, the suitable ratio of calcium and phosphorus is 1.1-1.5 for broilers and 5-6:1 for laying hens. The utilization rate of phytate phosphorus in chickens is low, about 30% in chicks and 50% in broilers, while inorganic phosphorus can be used at 100%. Therefore, some inorganic phosphorus must be supplemented in the diet, especially when there is a lack of fishmeal in the diet. (4) Trace elements and vitamins most trace elements are components of hormones and enzymes, and vitamins are also active substances in the process of substance and energy metabolism, which play an irreplaceable role in regulating physical and chemical reactions and osmotic pressure in the body, maintaining body fluid acid-base balance and body metabolism. Compared with domestic animals, chickens have fewer microorganisms in the digestive tract, and most vitamins can not be synthesized in the body; some can be synthesized, but can not meet the needs, and must be ingested from feed. The number of vitamins and trace elements listed in the standard is the requirement, and the safety margin should be increased according to the ecology, environment, feeding conditions and diseases of chickens. The vitamin value listed in the standard can be used as the addition amount, and the content in the feed as the safety margin. For trace elements, it should be determined according to the specific conditions of each region and the source of feed, but the amount of trace elements should not exceed the standard, otherwise it will cause poisoning. (5) the content of crude fiber is limited to chickens with high body temperature, rapid growth and exuberant substance metabolism, so they need higher nutritional level than other animals. In addition, because the chicken has no teeth and relies entirely on the sand and gravel in the muscle stomach to grind the food, and because the intestinal tract is short (the time for the food to pass through is also short), and the cecum has little effect on the digestion of feed, so the chicken's digestibility of crude fiber is low. If there is too much fiber, the nutrition level does not adapt to the physiological characteristics of the chicken, affecting the digestion and absorption of other nutrients, resulting in feed waste. But when the fiber is too little, the intestinal peristalsis is not sufficient, the chicken does not have the sense of satiety, prone to bulimia and so on. The content of crude fiber in chicken diet should be 2.5% Murray 5%. (6) the balance of animal feed and plant feed when preparing poultry diet, attention should be paid to the collocation of animal feed and plant feed in order to improve feed utilization efficiency. The commonly used animal feeds are fish meal, shrimp bran, blood meal, silkworm pupa, etc., and can also be replaced by fresh fish, shrimp, clam meat, earthworms and so on. The main function of animal feed is to balance essential amino acids, change the composition of fatty acids in feed, affect the balance of feed metabolic energy and vitamins, and affect the reproduction of intestinal bacteria, and contains so-called unknown growth factors. When preparing diets, fish meal contains 2%, 5%, no more than 7%, and no more than 10% for other animal feeds. (7) the water of other nutrients in the diet accounts for 60%, 70% of the chicken body, which plays an important role in digestion, absorption, metabolism, body temperature regulation, etc., so it is necessary to provide clean and appropriate amount of drinking water. The amount of drinking water of chickens is affected by air temperature, humidity, body weight, laying rate, feed composition and restricted feeding and other factors. Salt can provide sodium and chloride ions for normal physiological function of chickens. When preparing diets, the salt content of fish meal should be taken into account to prevent excessive salt and poisoning. Source: www.feedsos.com-- good post, I went back to my student days. -- I've learned. It would be better if I had more basic data.-- Animal feed is not easy to use now. The influence of ambient temperature is actually very great-how much more suitable is the egg of a broiler?