Why do your pigs grow slowly? Have you paid attention to feed energy utilization?

Animals need energy in the process of life-sustaining activities and production. The energy needed by animals comes from three organic substances in feed-carbohydrates, fats and proteins. The average emergy of these three main organic substances are 17.35, 39.54 and 23.64kJ/g respectively. Although the emergy of carbohydrate is lower than that of protein and fat, it comes from a wide range of sources. Therefore, the main source of animal energy is carbohydrate, among which starch, monosaccharide and oligosaccharide are the main sources of energy for monogastric animals, in addition, ruminants can obtain most of the energy required by the fermentation of crude fiber by rumen microorganisms. Animals can only use glycogen, fat and protein stored in the body to decompose energy supply in the process of hunger strike, milk production and egg production, but this energy supply is less efficient than direct feed energy supply. In fact, the metabolism of the three organic substances in the feed in the animal body is accompanied by the conversion process of energy metabolism, and it abides by the law of energy conservation. Studies have shown that there are many factors that affect feed energy utilization, and there are many nutritional measures to improve feed energy utilization, which are summarized as follows:

Factors affecting feed energy utilization:

Animal species Different types of animals have different utilization rates of feed energy. In general, the metabolic energy of monogastric animals such as pigs and poultry is more efficient for growth and fattening than that of ruminants.

The utilization rate of feed energy in female animals is higher than that in male animals.

Production purposes When livestock and poultry are used for different production purposes, their feed energy utilization efficiency is different. The order of feed conversion efficiency was maintenance> milk production> growth, fattening> pregnancy and hair production. For example, the feed conversion efficiency for growth and fattening of ruminants is 40% to 60%, and the feed conversion efficiency for pregnancy synthesis is 10% to 30%. When different animals produce different products, the feed energy conversion rate is also very different.

Feeding level within the appropriate feeding level range with the increase of feeding level, the effective energy of feed for body maintenance needs to be relatively reduced, and the net energy for production increases. However, above the appropriate feeding level, with the increase of feed intake, the digestibility decreased, so that the feed energy conversion rate decreased.

Feed ingredients different nutrients body heat different, protein body heat the largest. If the protein content in the feed is too high or the amino acid imbalance will lead to an increase in urine energy loss, and the amino acid carbon frame oxidation release a lot of heat, and increase the loss of body heat, reduce the efficiency of feed energy utilization; if the lack of certain minerals (such as calcium, phosphorus) or vitamins (such as VB1) in the feed will increase body heat and reduce the net energy.

Environmental factors include temperature, humidity, airflow, light, rearing density, stress, etc. Environmental temperature not only affects animal feeding, digestion, metabolism and heat production, but also directly affects animal production. Due to the change of temperature, the distribution of feed nutrients in animals for body maintenance needs and production changes, and the utilization efficiency of animal feed energy also changes. When animals are in an environment with suitable temperature, the feed energy is the least for maintenance, the most for production, and the energy utilization efficiency is also the highest. When animals are in the cold stress zone, feed energy is mainly used to maintain body temperature, and the energy used to produce products must be reduced. When animals are in the heat stress zone, the energy used for production per unit of feed is reduced, because high temperature promotes the excretion of nitrogen from the urine, increasing the loss of urine energy and reducing the net energy value.

The clinical manifestations of disease animal diseases are mostly mental depression, loss of appetite, and metabolic disorders, which in turn cause different other symptoms, such as gastrointestinal infections, parasitic diseases and various nutritional deficiencies, which will inevitably affect animal feed intake, The digestion, absorption and utilization of nutrients also affect the conversion of energy, and ultimately lead to the reduction of feed energy utilization efficiency.

Group efficiency In animal husbandry production, in addition to the individual efficiency of animals, group efficiency should also be considered. Such as less litter, slow weight gain, more male animals and intergroup harassment all reduce the efficiency of feed energy utilization.

Nutritional measures to improve feed energy utilization:

Reduce energy conversion loss through scientific and reasonable feed blending, processing and feeding technology, can reduce energy in the conversion process of fecal energy, urine energy, gastrointestinal methane gas energy, body heat and other energy loss, reduce animal maintenance consumption, in order to increase the production of net energy.

To fully meet the needs of animal nutrition, reasonable selection of feed raw materials, according to feeding standards, scientific preparation of diet, especially the supply of animal amino acid balance of protein nutrition and appropriate crude fiber level. For example, the appropriate ratio of protein to energy must be maintained in the diet, and the level of crude fiber must be controlled to improve the utilization of protein and starch.

Reducing maintenance needs A variety of measures can be taken to reduce maintenance needs in production practices. For example, for fattening animals, on the premise of ensuring health, appropriately restrict activities to reduce unnecessary energy waste; Maintain a suitable enclosure temperature to be warm in winter and cool in summer to avoid shearing sheep in cold seasons; The weight of eggs and breeding animals is controlled to standard weight; Maintain reasonable feeding level and appropriate feeding density, etc. For example, large ring feeding of fat pigs in winter is beneficial to heat preservation, thick and dry bedding and good insulation performance of the ground can also reduce energy consumption. At the same time, animal feeding management should be strengthened to reduce or prevent energy consumption caused by diseases.