The Application of Unconventional Raw Materials
We should pay attention to three points in the application of unconventional raw materials:
? Accurate nutritional indicators
? Reliable nutrition standards
? Appropriate processing technology
The price of corn has remained high, reaching 3,400 yuan the day before yesterday! In recent years, as Australian sorghum barley and American sorghum have entered the Chinese market one after another, the application of sorghum barley in feed has been increasingly accepted by the market. Sorghum barley as a raw material that can replace corn feed has been well used in more and more feed companies. The research on production technology cannot be ignored as well.
1. The difference of crushing process
There are big differences in the understanding of the crushing particle size of sorghum barley in China and abroad. According to Australian feed mills and farms` self-proportioning data, the difference in sorghum and barley crushing process is likely to cause low production efficiency for pigs. In vitro starch digestion experiments have shown that the larger the crushed particle size, the lower the digestibility. The crushed size of sorghum or barley cannot be more than 1 mm.
Other studies have concluded that the ideal crushing particle size for hard sorghum and soft sorghum is 300 to 500 microns, respectively. But as pigs and chickens get bigger and bigger, the ideal particle size also increases.
The editor believes that the crushing particle size of sorghum barley should be based on the principle that it is more suitable for quenching and granulating. When the particle size is small, the unit weight of the feed has a large contact surface, and the conditioning will be more adequate. Therefore, the crushing particle size of sorghum barley feed should not be too large (sieving is recommended that the hole should not exceed 1.2mm). It is generally believed that the hammer mill is more capable of reducing the crushing particle size than the roller mill.
2. Material moisture control during mixing
The moisture content in the powder before conditioning is a very important parameter, which has a greater impact on the quality of the finished feed product, the efficiency of feed processing, the loss of equipment, the absorption of feed nutrients by the animal, and the performance of animal production.
Sorghum and barley require higher temperature and low humidity steam due to conditioning. Therefore, in order to have better temper and granulate, the moisture after mixing is particularly important. The editor thinks that the moisture after mixing should be controlled at about 12-12.5%%, because the best granulating moisture is 15%-16.5%, every increase of 1% moisture, the material temperature will rise by 11 degrees, so if the moisture is too low after mixing, the material temperature will not reach the optimal temperature. When the moisture is too low after mixing, it is recommended to add a liquid antifungal agent aqueous solution in the mixer for adjustment.
3. Higher steam requirements during tempering
Conditioning is an important part of feed production. Steam quality plays a decisive role in quenching and tempering quality. Conditioning is a process in which steam transfers moisture and heat energy to the feed. Only dry saturated steam can quickly transfer heat energy to the feed. The heat transfer of saturated steam is instantaneous.
Due to the low heat capacity and poor heat transfer performance of superheated steam, superheated steam requires a self-cooling process of 2-3 minutes, and the conditioning process is less than 3 minutes, so the conditioning cannot be completed well. The heat capacity of wet steam is also very low, and the secondary evaporation will further reduce the heat energy, and its water content will also hinder the heat exchange between steam and feed, causing local moisture to be higher, easy to cause pelleting slip, and after the spot moisture gets higher, it will be hard to be taken out during cooling, and it is easy to cause spot mildew.
Since sorghum and barley are rich in starch and fiber, it will be more prone to slipping if wet steam is used during conditioning; while if superheated steam is used, the starch will be poorly gelatinized due to insufficient conditioning and granulation will be more difficult. , So the steam requirements are higher than corn feed.
How to get dry saturated steam? The following measures must be taken:
1. The pressure of steam coming out of the boiler must be guaranteed. Generally speaking, the steam coming out of the boiler must be guaranteed to have a pressure above 0.6MPa;
2. The transmission pipeline must achieve minimum loss: use pipelines with appropriate diameters and minimize the pipeline length. When the length of the pipeline cannot be reduced, the slope of the pipeline (100:1 inclined to the direction of steam delivery) should be done, and a trap should be added to the bottom of the pipeline every 50 meters for effective drainage;
3. Before entering the conditioner, it is necessary to effectively reduce the pressure and adjust the steam pressure to a suitable pressure (different conditioners, different materials, and different conditioning pressures). Generally, the conditioning pressure cannot exceed 0.4MPa;
4. The steam pipeline after decompression is about 1.5 times larger than the conveying pipeline, and it must be effectively drained. Generally, there should be a riser before entering the conditioner, with steam at the bottom, the upper end into the conditioner, and the bottom for draining , Strictly prevent the condensed water from entering the conditioner;
5. After decompression, pay close attention to the temperature and pressure, check the temperature according to the pressure, and ensure that the steam is saturated steam (for example, the pressure after decompression is 0.2MPa, which corresponds to 2.04 kg/cm2, and the temperature should be 120.24 degrees by query. If the temperature is too high, the steam is superheated steam. When the temperature is too low, it is wet steam). Generally, the pipeline after decompression should not be insulated, which is more conducive to the temperature of the steam falling to the corresponding temperature after decompression.
4. The difference of pelletizing ring die
Because sorghum and barley have a lot of starch and fiber, more squeeze is needed to ensure smooth granulation during granulation. Therefore, the opening rate of the ring die is not easy to be high, otherwise the area of the bell mouth will decrease. The amount of feed squeezed makes pelleting difficult and reduces pelleting productivity. The editor believes that the ring die with the same compression ratio has a slightly lower ring die opening rate than the feed using sorghum barley and corn feed.
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