Advantages and disadvantages of puffing technology application in animal feed machine

After the feed is processed by extruded technology, it can gelatinize and degrade the starch in the feed, denature protein, reduce anti-nutritional factors, and increase palatability. However, there are also disadvantages such as the production of indigestible substances, the destruction of vitamins, and the increase in cost.

1. Puffing technology

        Puffing technology means that the material containing a certain amount of moisture is fed into the extruder. Under the push of the screw rod and the screw, the material moves forward, and the material and the screw, the material and the barrel, and the mechanical friction inside the material , The material is intensively squeezed, stirred and sheared. The material is further refined and homogenized. The pressure and temperature inside the machine cavity continue to increase and rise. The material is under the action of high temperature, high pressure and high shearing force. , So that the material components have undergone complex physical and chemical changes. Finally, the paste-like material is sprayed out from the die hole, an instant pressure difference is generated, and the material is puffed, thereby forming a loose, porous and crisp puffed product.

2. Advantages of puffing technology

        After the feed material is extruded, it has a unique fragrance and fluffy feeling, good palatability, high gelatinization, and has a good food attractant effect. At the same time, the long-chain structure of some proteins and organic substances such as aunts becomes a short-chain structure, making it easier for animals to digest and absorb.

2.1 .Starch gelatinization and degradation

        The first is starch gelatinization. During the puffing process, the dense crystal structure of the starch molecules is broken up, the crystal structure is absorbed, the hydrogen bond is broken, and the puffed starch granules are broken and become one kind. Viscous melt. Due to the instantaneous pressure drop at the exit of the extruder, a large amount of steam is lost instantaneously. A large number of extruded starch granules collapse and the starch gelatinizes to form many microporous extruded feeds. The average molecular weight is obviously deviated, and oligosaccharides with small molecular structures such as maltodextrin can be produced through cleavage. Gelatinized starch has strong water absorption and stronger bonding function than ordinary starch. It can reduce the starch in production and at the same time gelatinized starch can tightly combine the protein with the starch mixture to form a reverse animal rumen The non-degradable protein body, the rumen bypass protein, improves the utilization of protein by animals in reverse.

2.2 protein denaturation

        The tertiary and quaternary structure of the protein is destroyed, the molecular structure of the protein is decomposed and regenerated, the surface tends to be homogenized, and the intermolecular hydrogen bond, disulfide bond and other parts are broken, resulting in the final decomposition of the protein. The degree of protein deterioration is closely related to the parameters in the extrusion process. The puffing process also reduces many anti-nutritional factors, such as urease, anti-protease and hemagglutinin in soybeans, myrosinase in rapeseed flour and polyphenolic compounds such as mustard compounds produced by decomposing glucosinolates, and in cottonseed Gossypol etc.

        Feather is a high-quality protein feed material with a protein content of about 75% to 90%, making it a popular material among feed materials. However, the protein of feather meal is mostly a cord-like structure formed by several tandem chains arranged in parallel spirals along the fibers. The chains contain a large number of cross-linked bonds, disulfide bonds, and hydrogen bonds have a strong and stable structure. The strong hydrophobic force makes it difficult to be digested and utilized by animals. The value of feather meal feed for processing is very low, with a digestibility rate of only about 7%. After puffing, the keratin protein in the feathers is denatured, splitting the spatial structure of the keratin protein, and becomes a digestible state, and the digestibility can be increased to more than 70%.

2.3 Transgender of aunt

        Extrusion process destroys the cell wall structure of oilseeds and releases the oil in it. This processing method can improve the utilization rate of oil. Puffing or combining starch and protein to form a composite product (lipoprotein) or (lipopolysaccharide)), which reduces the content of free fatty acids, and at the same time reduces the esterase, inhibits the degradation of oil, and reduces the oil during product storage and transportation. The rancidity is conducive to the alternative preservation of feed.

2.4 Increase palatability and digestibility

        The expanded feed becomes a loose and disordered structure. This change provides a larger contact area for enzymes, which is conducive to the contact of starch chains, peptide chains and digestive enzymes, and is conducive to the digestion and absorption of feed, thereby improving the digestion of feed rate.

2.5 Improve fiber solubility

        Through the extrusion technology, due to the high temperature and high pressure to the instantaneous expansion of the outlet during extrusion, the intercellular substance and the lignin in the cell wall are melted, part of the hydrogen bonds are broken, and the high molecular substances are decomposed into low molecular substances, and the original compact structure It becomes fluffy, but also releases some digestible substances, thereby improving the utilization rate of feed.

2.6 Conducive to feed storage and extend the shelf life of feed

        Under the action of high temperature, high pressure and expansion, the material kills the content of mold, bacteria and debris in the raw material, thereby improving the sanitary quality of the feed, and effectively reducing the occurrence of animal diarrhea, digestive inflammation and diarrhea.

3. Disadvantages of puffing technology

        During the extrusion process, Maillard reaction occurs between reducing sugars and free amino acids in the feed, which reduces the content of reducing sugars and free amino acids in the feed, resulting in weakening of the effectiveness of amino acids and friction of materials at high temperature and high pressure And the evaporation of water will cause the loss of vitamins, especially the vitamin loss rate of diabetes is up to 50%, so some extra vitamins should be added in the process of feeding animals to compensate for the loss caused by puffing.

4.Application of puffing technology in animal production

4.1 Raising pigs

        Due to the small stomach cavity, suckling pigs have weak digestion and absorption capacity in the body, so they are prone to nutritional diarrhea during the process of changing from breast milk to feed. It is believed that gelatinized feed, sterilization is not ideal, it is easy to cause piglets to digest and expand the feed, which will greatly reduce the incidence of diarrhea when feeding weaned piglets, thereby reducing waste costs, shortening fattening time, and improving economic benefits.

4.2 Raising poultry

        The extruded feed is granular, which is conducive to the eating of chickens and ducks, increases the wear rate of the feed in the crop, accelerates the digestion and absorption of the feed, and improves the utilization rate of the feed. The pathogenic bacteria, thereby reducing diseases such as diarrhea of poultry.

4.3 Raising ruminants

        Due to the degradation of fiber in the feed, the soluble fiber increases, and the long stick improves the digestion and absorption of the feed by the animal. Puffing technology can improve the utilization rate of non-protein nitrogen by animals in the reverse phase, increase the amount of rumen protein, and reduce the cost of food. Extruded feed can also increase the milk fat rate of dairy cows, and has a very obvious effect on fattening beef cattle.