In pig production, piglets weaned to 70 days old are generally called weaned piglets. Weaning is the second great change in the living conditions of piglets, and the resulting pressure is also great. Stress mainly comes from three aspects: first, the change of food. Eating warm liquid breast milk instead of solid raw dry feed not only affects palatability, but also increases the burden of digestive tract. The second is the change of living environment. From relying on sows to living independently, from delivery room, accompanied by regrouping. The third is the change of digestive ability and immunity in the body. At this time, the activity of digestive enzymes, which is already insufficient, is reduced, and there is less hydrochloric acid, and the immune system is not perfect. At this time, the antibody in breast milk is lost and the immunity is reduced.

The above factors affect the growth and development of piglets, and even cause illness and death. Therefore, weaning time and weaning method should be selected in production to reduce and eliminate the invasion of diseases and promote the healthy development of piglets.

First, the choice of weaning time for piglets

The weaning time of piglets can not be the same, according to the physiological characteristics of sows and piglets and the feeding and management conditions of each pig farm. From the perspective of improving the utilization efficiency of sows, the earlier the weaning time of piglets, the higher the utilization efficiency of sows. However, it takes about 20 days for sows to recover their uterus after delivery, and they mate when their uterus is not fully recovered, which leads to low conception rate, blocked embryo development and increased death. Considering the physiological characteristics of piglets, when the weight of piglets is above 8 kg or 4 weeks old, piglets have used most of the sow's milk, and their immune ability is gradually enhanced, and they have the ability to obtain nutrition through feed. From the point of view of feeding management, the earlier the weaning time of piglets, the higher the requirements for feeding management conditions, and the later the weaning time, the stronger the resistance to weaning stress. At the age of weeks, piglets basically have the ability to resist weaning stress. Therefore, in the current production, piglets are weaned at 4 weeks old.

Second, the feeding and management of weaned piglets

1. feed and feed system transformation

(1) feed transition. Piglets kept the original feed unchanged for 2 weeks after weaning, still fed with lactation feed, and gradually switched to weaning piglet feed after 2 weeks, so that piglets had an adaptation process. The feed composition of weaned piglets should be basically the same as that of lactation, but the nutritional level of feed should be adjusted to avoid sudden change of feed to reduce the appetite of piglets and cause gastrointestinal discomfort and digestive dysfunction.

(2) the change of feeding methods. After weaning, piglets change from eating feed and breast milk to eating feed completely. Gastrointestinal tract often does not adapt, easy to indigestion, diarrhea. 3 ~ 5 days after weaning, it is necessary to properly control the feed intake of piglets, and generally let them eat 80% full. After 5 days, gradually increase the feeding amount and gradually transition to free feeding. If you feed too much and too fast, piglets will often have diarrhea due to overeating, so pay special attention to it during production.

2. Environmental changes

Piglets are very restless in the first few days after weaning and often yell at sows. In order to reduce the stress after weaning, it is required to drive away the sow at weaning, keep the piglets in the original pen for a period of time, and then transfer them to the weaning pigsty after the piglets adapt to the stimulation of weaning, that is, drive away the mother piglets and leave the piglets. At the same time, the piglets in the original litter are not grouped, but directly transferred to the weaned piglet house as a group, but if there are too many or too few piglets in a litter, they need to be regrouped.

3. Piglet training

Train piglets to develop the habit of defecation at fixed points and changing groups after weaning. Piglet defecation mostly occurs in the period of waking up in the morning, before and after feeding, and before going to bed. Therefore, in these several periods, piglets should be driven to the defecation area in the pen to defecate, and observed artificially for a period of time, and then released after defecation. At the same time, leave some feces in the defecation area, so that piglets can confirm the defecation area according to the smell of feces and urine, so as to quickly develop the habit of defecation at fixed points. Pigs defecating in designated places can not only keep the pens clean and reduce pollution, but also benefit the health of piglets and reduce the labor intensity of breeders.

4. Prevent pigs from biting their tails

Tail biting often occurs after weaning, which not only affects the rest of pigs, but also may cause serious casualties of pigs.

(1) The reason why pigs bite their tails.

①? Improper management measures. Feeding density is too high, contact is too frequent, and lying down will hurt the tail; Factors such as high humidity, poor ventilation, dirty air, too high ammonia, hydrogen sulfide, carbon dioxide and carbon monoxide in the air, too strong light, group stress, short sleep and feeding time, long activity time and monotonous environment are all easy to induce piglets to bite their tails.

②? The feed is not balanced in nutrition. Unbalanced nutrient elements in feed or poor quality of raw materials in feed are also important reasons for tail biting. For example, the lack of one or more nutrients such as protein, amino acids, vitamins and minerals in feed, especially the lack of salt, can easily lead to heterotopia of piglets, and they like to bite salty things such as feces. Piglets often have feces and urine on their tails, which are salty and easy to induce pigs to bite their tails.

③? Infected with parasites. When the piglet is infected with parasites (especially scabies), it will cause the tail to itch, so the piglet will keep rubbing and cause the tail to bleed. Blood is salty and fishy, and pigs like to bite their tails.

(2) Preventive measures for piglet tail biting.

①? Improve feeding management conditions. Clean and disinfect the pigsty regularly, keep the proper temperature in the pigsty, strengthen ventilation to reduce harmful gases, control the time and intensity of light, reduce stress and make the piglets live comfortably; Feed a balanced and complete feed, pay special attention to the sufficiency of trace elements, vitamins and salt, and ensure the feed quality.

②? Reasonable grouping. According to the variety, age and weight, it is best to adopt a nest-and-circle feeding method to prevent fighting after grouping. If pigs from different sources are transferred to the same pen, the fighting will be fierce, and the whole pen can be sprayed with odor such as Sur to slow down the fighting.

③? Regularly expelling internal and external parasites can not only prevent tail biting, but also promote the growth of piglets.

④? Set the toys. Hanging chains or putting stones in the pig house can satisfy the fun habits of pigs.

⑤? Early tail cutting is an important way to solve the problem of tail biting in piglets. Tail cutting should be done within 1 ~ 3 days after piglets are born, and only 1/3 of the tail can be kept.

⑥? If tail biting is found, it should be handled in time. According to the principle of diminishing inflammation, relieving pain and controlling secondary infection, the bitten pigs were isolated, and 800,000 IU of penicillin, 5mL of antongding and 2mL of hemostatic were injected intramuscularly, and 2% tincture of iodine or erythromycin ointment was used externally.