The reasons why mother pork can't be eaten are as follows:

1. Because mother pork is generally used for breeding, mother pork is not only low in nutrition, but also has a particularly bad taste and fragrance. Moreover, mother pork also contains an immunoglobulin, which will affect health. Eating mother pork can easily lead to anemia, jaundice and other diseases.

2. The skin tissue structure of old mother pork is slack, with thick and white hair, thick and hard skin, and the skin of neck and lower abdomen shrinks. If the slaughter time is long, the skin will dry up more obviously and lose elasticity. The combination of skin and subcutaneous fat is not tight, and there is a thin layer of fat between them, which is called "red line", and the outer membrane of fat is yellow and white.

3. Because the subcutaneous fat is thin, it looks thin and often brick red. The nipple is large, long and oily, and it is conical. There are mammary glands on both sides of the breast. When cut, it can be seen that the gray breast penetrates into the fat layer, which is similar to honeycomb, and the pores around the breast are thick and sparse. The ribs are generally flat and wide, and the periosteum is yellowish. The ribs of old sows are prominent, and the ribs of normal pigs are blue-red.

Extended information:

Cooking skills of pork:

1. Pork should not be soaked in water for a long time;

2. The pork should be cut obliquely. The meat quality of the pork is fine and the tendons are few. By cutting obliquely, it will not be broken, and it will not be stuffed when eaten.

3. Generally, pork is washed with cold water, but not with hot water. Hot water will pyrolyze myoglobin in pork, which will affect the taste.

4. Sometimes there are parasites in pork. When eaten raw or inadequately conditioned, there may be hookworms in the liver or brain. Pork should be cooked at will.

5. It is not advisable to drink a lot of tea after eating pork. The tannic acid of tea will synthesize protein with astringency with protein, which will slow down intestinal peristalsis and affect digestion.

Reference: Baidu Encyclopedia-Pork.