At present, there are three kinds of feed types for sows: powder feed, liquid feed and pellet feed. Powder materials can be divided into two types: coarse powder (simple mixture) and commercial fine powder. With the sharp rise of corn price in recent years, some customers realized that the demand for pellet material increased sharply when the cost of self mixing was almost the same as that of the mixture. Therefore, feed factory was developed to cope with market changes. However, the use of granular feed has been controversial. This paper analyzes the problems in sow nutrition physiology and production practice
The feed intake of the sows was higher than that of the pellet feed
The main reason behind this fact is that sows have developed teeth, flexible tongue and large mouth. The stimulation of taste and smell by powdery materials makes the secretion of digestive juice in the first stage more than that of granular materials. The effect of salivary amylase on powder was more rapid than that of granular material. Therefore, sows have a stronger appetite for powdery materials. Therefore, it is not suitable for the wide range of sows and sows in the state of small and solid grain. In addition, pigs have the habit of grabbing food, and the consequences of eating a large amount of granular materials at a time are very serious: the grains that are not fully chewed remain in the digestive tract for a long time, and the insufficient secretion of digestive juice in the first stage also leads to the slowing down of gastrointestinal peristalsis. Especially in the perinatal period, the loss of appetite and constipation of sows become inevitable.
2. Powder is more "fresh" than particles
As we all know, powdery materials are not easy to be preserved. In the north, the storage time in summer can not exceed 15 days, because the contact area between powder materials and oxygen in the air is larger after unpacking, and it is easier to be oxidized; but the granular materials are different. After extrusion, the contact area with air is reduced, so it can be stored for a longer time. In terms of field application effect, the powder produced within 3 days is more advantageous (the less intermediate links, the better for sows).
(1) In summer, can the cooling fan rapidly cool the newly produced materials?
(2) Can granulation process achieve effective sterilization? In terms of microorganism, the effect of dry heat sterilization is better than that of wet heat sterilization, but can granulation process be achieved? Moreover, the materials after granulation have been transported to the finished product warehouse in a semi open way. Is there any possibility of secondary pollution?
(3) For some heat sensitive substances, such as phytase, microecological agents and vitamins, how much should the safety threshold be raised? In terms of common sense, as long as the enzyme protein has a survival rate of less than 10% at high temperature, what is the meaning of excessive addition?
3. The adaptability of powder material is stronger than that of granular material
For fattening pigs, the finer the material powder is, the higher the digestibility is. On the premise of no peptic ulcer, 2.0-3.0 mm particles are most popular. Sows are different, especially for sows within three fetuses. Since their feed can ensure the growth rate of lean meat and exercise their gastrointestinal function, the genetic advantage of high litter rate can be brought into play.
On the premise of meeting the nutrient requirements, the grinding particle size of feed is closely related to the function of upper digestive tract, while the fiber content of feed is related to hindgut fermentation. Most studies have shown that the comminution size of about 4.0 mm is more beneficial to the health of sows, and the content of 5% ~ 8% crude fiber is beneficial to improve the moderate growth of microorganisms in the hindgut segment of sows. These two indicators are very unfavorable for the production of granular feed, and the most important point is that it has a great impact on the service life of the ring mold.
In order to maintain sow performance, I think sow feed should include three parts
One is the comprehensive nutrition powder, in order to ensure the digestibility of protein and other nutrients, the crude fiber level is not more than 5%.
The other is green feed or tuber feed, which can be washed and chopped to feed, supplement part of fiber and vitamin, and play a role in gastrointestinal health care.
Third, soil or peat feed, the role is to protect sow hoof health. The main reasons for the high population regeneration frequency, poor bone development and weak hoof quality of modern high-strength breeding sows are that they have not reached the fifth and sixth production, because of joint problems or hoof problems.