The impact of pellet on vitamins: as the vitamins with bad thermal stability would be easily lost during pelleting process, it is vulnerable to increase conditioning time and raise temperature. Vitamins like VA,VE,VC, thiamine hydrochloride will be killed rapidly as the temperature and conditioning time is raised. As a result, it is necessary to choose formulation with sound thermal stability. Good pellet conditioner (pellet mills), correct air admission and mixing methods are also the vital factors for pelleting process.

The first control point of pellet quality is the conditioning time, temperature, added water and pasting degree of starchy. The second control point is the percentage of powdered pellet, cooling temperature, moisture, evenness and water durability of the pellet. To achieve better control of the above items, it is necessary to apply proper steam supply system, conditioning, cooling and screening equipment and adjust the control data according to the features of the equipment. The critical condition for conditioning of feed with vitamins is as follows: temperature℃,moisturetimes.

As for the quality of expanded or extruded pellet, the first control point is the conditioning time, temperature, added water and pasting degree of starchy. The second control point is the percentage of powdered pellet, cooling temperature, moisture, evenness and water durability of the pellet. To achieve better control of the above items, it is necessary to apply proper steam supply system, conditioning, expanding, extrusion, cooling and screening equipment and adjust the control data according to the features of the equipment.

Pellet process also affects feed enzyme and other microbial. Enzyme and microbial are biological products, the activity of which are usually damaged under the comprehensive function of high temperature, humid and pressure. It is reported the activity of phytase would drop by 87.5% at the temperature of over 80℃. So the utilization rate of N.P will be affected. The microbe additives in the feed is especially reactive to high temperature so that its activity will lost completely if the pellet temperature exceeds 85℃. It is better to coat enzyme after pelleting or enzyme with better thermal stability should be added.
Quality control of added liquid. With the constant development of feed process technology, many additives would be added into powder, pellets and expanded feed in form of liquid so as to maximum the activity of the additives and lower the feed costs. The quantity of the liquids should be accurately controlled. Make sure the liquids are evenly sprayed or coated on the feed. The stability and effective duration of the additives after coated on pellet should also be guaranteed. It is necessary to choose liquid coating equipment with high performance, vacuum coating device and control technology.

Pellet process also affects anti-nutrition factors which will cause disease of animal s and slow down their growing speed. As a result, it is very important to get rid of the anti-nutrition in the raw material. Only the technology and equipment of professional company can ensure the quality and nutrition of the feed. Sometimes during the conditioning of pellet, part of anti-nutrition factors and harmful substance will be killed. Anoxia sterilization before pelleting can kill various bacterials effectively so as to improve the quality of feed.

Reduce cross contamination of feed. Cross contamination usually takes place during the storage, transportation. Moreover, residue in bins and buffer hoppers can also cause cross contamination. It is necessary to equip residue-free conveyor and bins, apply scientific technology of cleaning and sequencing.

Quality control also includes cleaning of feed which covers control of cross contamination and heat treatment of feed like cooking under high temperature, extrusion, high pressure, ultraviolet irradiation, etc. All these technologies can be combined with the common process technology and be used separately.

Dingli company is a technical issue of professional company to determine the size of grain for different animals. Protein denaturation has little impact on the amino acid while the digest rate of amino acid will be improved greatly. So does the utilization rate of the protein.

Post condition can affect the feed vitamins. After conditioning, the paste degree and water durability of the pellet would be improved, however, some thermal alert vitamins would be killed. As a result, to preserve nutrition of feed as much as possible, it is better to use formulations with sound thermal stability or apply the improved coating technology which is mostly used in the production of aquatics feed or special aquatics feed like shrimp.