The heat treatment of feed is to add a certain pressure of steam to the material or through a mechanical method, so that the material absorbs a certain amount of water and heat in a short time to generate a large temperature rise, so that the material is in the temperature, pressure, humidity. Under the action, its structure changes to obtain the desired properties of a processing technology. In recent years, methods used to thermally process grains or other products (such as oilseeds, pet food, etc.) include steam flattening and steam tabletting, extrusion, pelleting, puffing, microwave heating, and toasting. At some feedlots, the use of autoclaving and popping to process grain has been attempted. However, further use of the device has been hindered by the cost and maintenance issues of the device. Existing research shows that microwave heating method and baking method have not yet been adopted, and the puffing method is gradually being phased out.

1 Steam flattening and steam tabletting of cereals

In the 1940s, the method of steam flattening has been used. This method partially kills weed seeds (early). Steaming is the process of passing steam into a steam conditioner that holds the grain above the roller mill. In the common process, the grain is only subjected to a short (3-5 min) steam treatment before flattening, usually only just enough to soften the kernel, not enough to alter the starch granules to any degree. The results of the study show that steam flattening improves livestock production performance compared to dry rolling, produces larger tablets, produces less powder, and improves the physical properties of the feed compared to dry rolling. structure. This can be an advantage when feeding high levels of grain diets. Grain steam tableting is similar to steam flattening, except that the grain is subjected to steam treatment in a steam conditioner for a longer time (15-30 min), usually enough to raise the moisture content of the grain to 18-20%, and then the grain A flat sheet is formed by pressing between counter rolls whose surfaces are corrugated by wire drawing. Grain steam tableting has been widely used in beef feedlots since the 1960s. It has been shown that steam tableting can increase the feeding value of grain feeds by 12% to 15%. The thinner the grain tablet, the lighter the weight per bushel. Studies have shown that the thinner the grain is, the faster the starch is digested in vitro. Steam tableting is more effective at breaking down grain starch granules, resulting in a more desirable physical texture of the product. In terms of increasing the rate of weight gain, steam-flaked corn, barley and sorghum have very good results. Although the effect of steam tableting on improving feed conversion efficiency of maize and sorghum is very obvious, for barley, the effect of steam tableting on improving feed conversion efficiency compared with steam flattening treatment is not obvious.

2 Granulation

Pelletizing is the process of crushing the feed first, then entering the pelletizer, and through the action of the pressing roller, the material is forced to pass through a thick high-speed rotating ring die with holes. Feeds are usually steam-conditioned to some degree before pelleting, but not always. Pellets are available in different diameters, lengths and hardnesses and have been commercialized for over 50 years. Generally all livestock prefer the physical properties of pelleted feed compared to meal. Most poultry and swine feeds go through the pelleting process. However, for ruminants fed high grain diets, although pelleting improved feed conversion efficiency compared to other methods, the results were not particularly favorable due to reduced feed intake. Since livestock may refuse to eat the powder, pelleting the diet often yields good results. The method of pelleting is also commonly used to store low-quality feed. Pellets mix well with flattened grains to form a full-price or same-texture feed. Supplementary feeds such as protein concentrates are often pelleted together for feeding animals, or in windy areas to reduce feeding losses in other forms of feed.

3 Squeeze

The production of extruded grain or other types of extruded feed is accomplished by passing the feed through a machine with a rotating screw that forces the feed through a conical head. During this process, the feed is pulverized, heated and squeezed to create a ribbon-like product. This process is commonly used to make pet food of all sizes and shapes. For beef cattle fed a high-grain diet, the effects of feeding extruded grain were similar to grains treated with other processing methods. Some extruders are also used to process whole soybeans or other oilseeds that are fed to livestock. Heat treatment can adequately remove anti-nutritional factors from soybean or other legume seeds. Extruders can also be widely used for processing food for humans and pets, as well as for processing oilseed products after fat extraction.

4 Puffing, Microwaving and Baking

The more familiar puffed corn, which is a product made by drying and heating the corn to instantly expand (caused by changing the water from liquid to gas) to destroy the endosperm of the grain. This process increases the availability of starch in the gut and rumen, but reduces the density (weight per volume) of the feed. Therefore, extruded feed is usually flattened before feeding to reduce its volume. Microwave heating is actually similar to puffing, except that the heat is provided in the form of infrared energy. Roasting is to roast the grains on fire, so that the grains are directly heated to produce a certain degree of expansion, so that the materials have good palatability. But this process has not been accepted by most livestock keepers.

The heat treatment of feed is to add a certain pressure of steam to the material or through a mechanical method, so that the material absorbs a certain amount of water and heat in a short time to generate a large temperature rise, so that the material is in the temperature, pressure, humidity. Under the action, its structure changes to obtain the desired properties of a processing technology. In recent years, methods used to thermally process grains or other products (such as oilseeds, pet food, etc.) include steam flattening and steam tabletting, extrusion, pelleting, puffing, microwave heating, and toasting. At some feedlots, the use of autoclaving and popping to process grain has been attempted. However, further use of the device has been hindered by the cost and maintenance issues of the device. Existing research shows that microwave heating method and baking method have not yet been adopted, and the puffing method is gradually being phased out.