Detailed Explanation of Key Technical Points for Feeding and Management of Lactating Sows
Besides maintaining their own body consumption, lactating sows produce 5 kg to 8 kg of milk per day. If feeding and management are improper and nutrient supply is insufficient, it will directly affect the sow's milk yield, piglet survival rate, piglet weaning weight, as well as the sow's normal estrus and mating after weaning. Therefore, strengthening the feeding and management of lactating sows is an important part of improving the economic benefits of pig farming.
Nutritional Requirements
1. Daily feed intake
For sows weighing 180 kg to 200 kg, when no green feed is available, each sow should be fed no less than 5.5 kg to 6 kg of complete compound feed per day during peak lactation. The digestible energy in the diet should not be lower than 12.55 MJ.
2. Crude protein
The crude protein in the daily ration should not be lower than 15%, and it is best to include a small amount of animal-based feed, such as fish meal.
3. Minerals and vitamins
A sow excretes 12 g to 16 g of calcium and 9 g to 10 g of phosphorus daily through her milk. In addition to the calcium and phosphorus needed for the sow's own normal metabolism, the feed for lactating sows should contain 0.9% to 1% calcium and 0.7% to 0.8% phosphorus per kg. Feed containing vitamins is very beneficial for promoting sow lactation and piglet development. Almost all the various vitamins needed for piglet growth and development are obtained from breast milk. If a sow lacks vitamin A, it will cause a decrease in milk yield and milk quality. A deficiency of vitamin D will cause postpartum paralysis in sows.
4. Ensure adequate drinking water.
Milk Yield of Lactating Sows and Influencing Factors
1. Milk yield
Milk yield of sows over 60 days: for small local breeds, 300 kg to 400 kg; for large breeds and introduced lean-type breeds such as Large Yorkshire and Landrace, approximately 600 kg.
2. Milk ejection frequency and interval
The milk ejection time of sows is relatively short, with relatively long intervals, better in the early stage than the late stage, and better during the day than at night. On the day of farrowing, the milk ejection time is the longest, reaching 46.75 seconds; on the 3rd day it is 22 seconds, and then gradually shortens, to only 11.1 seconds on the day before weaning (60 days). The milk ejection interval gradually lengthens as the lactation period extends: before 40 days it is generally 45 minutes to 60 minutes, and during the 40-day to 60-day stage it is 60 minutes to 80 minutes.
3. Influencing factors
Milk yield has a relatively large relationship with pig body weight. Large sows have high milk yield, while small sows or fat-type breeds with few piglets have low milk yield. Crossbred sows can show strong heterosis in milk yield. Adjusting the number of piglets nursed by the sow after farrowing so that all functional teats are occupied can fully tap the sow's lactation potential and increase milk yield. Sows suffering from mastitis show a significant decline in milk production, or even no milk at all. Causes of mastitis: First, feed reduction before farrowing is not timely, especially green and succulent feed, and feeding is increased too rapidly after farrowing, especially high-protein and high-moisture feed. Second, too many piglets are born and teeth are not clipped, so when competing for teats they bite and injure the teats, causing the sow pain and refusing to let piglets nurse, which then causes udder inflammation. Third, environment and disease.
Key Points of Feeding and Management
1. Control the amount of feed
Sows should not be given too much feed immediately after farrowing. Gradually increase the feed amount over 3 to 5 days. By 1 week after farrowing, when the sow's appetite and digestion are normal, feeding can be opened up. Under the condition of weaning at 35 days, the daily feeding amount from 10 days to 20 days after farrowing should be 4.5 kg to 5 kg; during the peak lactation period from 20 days to 30 days it should be 5.5 kg to 6 kg; from 30 days to 35 days it should gradually decrease to about 5 kg. After weaning, feed should be reduced as appropriate according to body condition. If weaning is at 50 days, then emphasis should be placed on feeding before 40 days after farrowing, and the feed amount should be reduced after 40 days.
2. Feeding frequency
During lactation, it is best to always have feed and water available so that the sow can eat and drink to satisfaction freely. If meal feeding is adopted, then it should be fed 4 times a day, with intervals as even as possible, and the last feeding at night should be no earlier than 22:00.
3. Drinking water and providing green feed
If feeding dry feed, the drinker should ensure water output and flow rate. For lactating sows, it is best to feed wet feed (feed:water = 1:0.5 to 0.7). In addition to complete compound feed, some green feed such as sugar beet, carrots, pumpkin, Chinese cabbage, and legume forage can be given, which is very effective for increasing milk yield and improving milk quality.
4. Feed structure
The feed for lactating sows during lactation should ensure relatively high energy and protein levels, and the feed should be varied in combination, palatable, and easy to digest. In addition to plant-based protein feed, it is best to have some animal-based protein feed, such as fish meal. In addition, the feed structure for lactating sows should be relatively stable during lactation; do not frequently change or suddenly change feed varieties, and do not feed moldy or deteriorated feed, so as to avoid changes in sow milk quality that cause piglet diarrhea.
5. Pig house environment
Maintaining a clean, dry, quiet, comfortable environment with good air circulation and sufficient sunlight is conducive to improving the sow's lactation capacity. In winter, keep warm and prevent cold drafts. Prevent the pig house from becoming excessively damp. Every 2 to 3 days, use a disinfectant with no toxic side effects to spray-disinfect the pig pens and walkways.
6. Exercise
Let the sow lead the piglets to move around in the exercise yard. This can increase the sow's milk yield, improve milk quality, and promote piglet development.
7. Protect the udder and teats
For first-litter sows, ensure that all teats are used evenly; otherwise, the udder will develop unevenly in size, and milk yield will vary. If there are too few piglets, cross-fostering can be adopted. If there are no conditions for cross-fostering, one piglet can be allowed to suck several teats, especially the rear teats of the sow, and piglets should be allowed to suckle them to prevent atrophy. At the same time, keep the udder clean to prevent contamination.
Handling of Sows with Insufficient Milk
Analyze the causes of insufficient milk and treat each case differently. For sows that have insufficient milk due to improper feeding during gestation, poor body condition, and being thin, feed with high energy and protein content should be used to strengthen feeding, and high-quality protein feed such as fish meal should be added to the feed composition. For sows in good body condition but without milk, the feed amount should be appropriately controlled, and more green feed should be given. At the same time, combine with some milk-promoting drugs, such as lactation tablets and Yimusheng.