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

1 母猪对粉状料的采食量比颗粒料的采食量大

The feed intake of the sows was higher than that of the pellet feed

这个事实背后的原因主要是母猪有着发达的牙齿、灵活的舌头和硕大的口腔，粉状料对其味觉、嗅觉的刺激使得头期消化液的分泌较颗粒料量大。唾液淀粉酶对粉料的作用也较颗粒料更为迅速。因此母猪对粉状料的食欲更强。在野生状态下，母猪的食物范围相当广泛，包括块根块茎类、青绿饲料、谷物籽实、小动物等，成熟的谷物籽实很硬，所以颗粒状的食物并不是母猪。并且，猪有抢食的习惯，一次大量进食颗粒料的后果很严重：未经充分咀嚼的颗料在消化道存留的时间很长，头期消化液分泌不足也导致消化道蠕动减缓。特别是在围产期，母猪食欲下降和便秘的出现就成了必然。

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 粉状料较颗粒更“新鲜”

2. Powder is more "fresh" than particles

众所周知，粉状料不易保存，在北方，夏季库存时间也不能超过15天，因其开包后与空气中的氧气接触面积更大，更易被氧化;而颗粒料则不同，经过挤压之后与空气接触面积减小，因而可放置更长时间。就现场应用效果来说，3天以内生产的粉状料更有优势(中间环节越少，对母猪来说越好)。

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)在夏季，冷却风机对新生产的物料可否做到迅速冷却?

(1) In summer, can the cooling fan rapidly cool the newly produced materials?

(2)制粒过程能起到有效吗?从微生物方面来讲，干热的效果要好于湿热，但制粒工艺能达到吗?况且制粒后的物料也一直是半开放式的被输送到成品仓，有没有二次污染的可能?

(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)一些热敏物质如植酸酶、微生态制剂和维生素等，阈量提高水平多少为宜?就常识而言，只要是酶蛋白，高温下存活的几率不超过10%，那么超量添加意味着什么?

(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 粉状料较颗粒料适应性更强

3. The adaptability of powder material is stronger than that of granular material

对于育肥猪，物料粉得越细，消化率越高，在保证其不得消化道溃疡的前提下，2.0-3.0mm的微粒。母猪则不同，尤其是3胎以内的母猪，其饲料既然保证其一定的瘦肉生长速度，还要锻炼其胃肠功能，使得其高产仔率的遗传优势得以发挥。

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.

在其养分需求得到满足的前提下，饲料的粉碎粒度与其上消化道的功能发挥密切相关，而饲料中的纤维含量则与后肠发酵有关。多数研究已经表明，粉碎粒度4.0mm左右对母猪的健康更有利，而5%~8%的粗纤维含量则有利于改善母猪后肠段微生物的适度生长，这两个指标对于颗粒料的生产是十分不利的，更关键的一点是，对环模的使用寿命影响很大。

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.

那么理想的母猪料是什么形式的呢?为保持母猪的种用性能，我认为母猪料应包括三部分：

In order to maintain sow performance, I think sow feed should include three parts

一是营养的粉状料，为保证其中蛋白质等养分的消化率，其粗纤维水平不超过5%。

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%.

二是青绿饲料或块根块茎类饲料，可洗净后切碎饲喂，补充部分纤维和维生素，同时可起到胃肠保健的作用。

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.

三是泥土或泥炭饲料，作用是保护母猪的蹄质健康。现代高强度选育的母猪品系之所以群体更新频率高，骨骼发育较差，蹄质较弱是主要原因，往往还未达到5产、6产，就因为关节问题或蹄质问题淘汰掉了。

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.