How to formulate lactating sow feed scientifically
Sows bear very heavy responsibilities. Lactating sows in particular must not only supply the nutrients they need themselves, but also supply the breast milk on which newborn piglets depend for survival, growth and development. Moreover, lactating sows in the high-temperature season face an even more unfavorable living and production environment, and heat stress is a severe challenge for farrowing sows. Therefore, how to scientifically formulate the summer diet of lactating sows and strengthen feeding management should be a problem that @#@227@#@ producers must actively consider and focus on solving.
Optimizing the formulation
To raise the energy level, the digestible energy of the diet should be ensured at above 14 MJ/kg and the metabolizable energy at above 13 MJ/kg. The main approach is to select high-quality corn, whose moisture must be controlled within 14%, with other indicators reaching Grade 2 or above of the national standard. Raw materials with high crude fiber content should be avoided in the diet. In addition, an appropriate amount of fat (3%-5%) or high-quality soybean phospholipids (4%-6%) can be added to raise the energy level.
Increasing the crude protein content The crude protein content of the summer diet for lactating sows can be formulated to 18%. High-quality protein raw materials must be selected; it is recommended not to use miscellaneous meals, but to use high-quality soybean meal (crude protein content >= 44%), extruded soybeans, imported fish meal and other protein raw materials.
Balancing amino acids The lysine content should be about 1%, the methionine content about 0.23%, the cysteine content about 0.46%, and the threonine content about 0.5%. A relatively high lysine level and ideal protein are beneficial to the normal performance of lactating sows.
Appropriate calcium-to-phosphorus ratio The calcium content should be 0.8%-1%, phosphorus 0.7%-0.8%, and available phosphorus 0.45%. To improve the absorption and utilization of phytate phosphorus, phytase can be added to the diet. Too low a calcium or phosphorus content or an imbalanced ratio can cause hind-limb paralysis in lactating sows, so attention should be paid to selecting high-quality calcium and phosphorus additives when choosing raw materials. Adding necessary vitamins Adding a certain amount of vitamin C (150-200 mg/kg) to the summer sow diet can alleviate heat stress symptoms; beta-carotene can improve lactation capacity and shorten the interval from weaning to first estrus; vitamin E can enhance the body's immunity and antioxidant function and reduce the occurrence of sow mastitis and metritis; when deficient, it can reduce the number of weaned piglets and cause piglet diarrhea. Biotin is widely involved in the metabolism of carbohydrates, fats and proteins, and biotin deficiency can lead to animal dermatitis or hoof cracks. A high-temperature environment can reduce the synthesis of biotin by intestinal bacteria in animals, so more biotin should be supplemented in the feed. Vitamin D can regulate calcium and phosphorus metabolism in the body. Other essential vitamins such as B vitamins, folic acid, pantothenic acid, choline, etc. should also be added in appropriate amounts and must not be neglected. Recommended formula: corn 58.0%, wheat bran 6.0%, soybean meal 15.0%, imported fish meal 5.0%, soybean phospholipids 6.0%, corn germ meal 6.0%, premix 4.0%.
Feeding strategy
The feeding goals for lactating sows are, first, to increase the number of weaned piglets and the weaning litter weight; second, to maintain normal breeding body condition during lactation, that is, a weight loss of no more than 12 kg at 28 days weaning. Excessive weight loss will prolong the estrus period after weaning and can also cause a reduction in the number of piglets born in the next litter, and the consequences are serious. Therefore, feeding strategies must be adopted around the above goals.
Reasonably increasing feed intake To maximize sow feed intake, the following measures can be taken respectively: the first is to implement ad libitum feeding, with no limit on the amount fed. That is, starting 3 days after farrowing, gradually increase the feed intake, and achieve ad libitum feeding after 7 days; the second is to feed small amounts frequently, implementing a multi-meal system, feeding 4-8 times a day; the third is to implement time-period feeding, using the cool periods in the early morning and evening to feed, fully stimulating the sow's appetite and increasing its feed intake. Regardless of the feeding method, care must be taken to ensure the feed is fresh and hygienic, and absolutely avoid moldy or spoiled (rancid) feed. To increase palatability, the method of feeding wet mixed feed can be adopted.
Supplying sufficient clean water The drinking water demand of lactating sows in summer is very high. Therefore, the sow's drinking water should be guaranteed to be supplied freely. If it is a trough-type drinking system, it should always be filled with clean water; if it is an automatic drinker, it should be observed and checked frequently to ensure it is unobstructed, and the water flow rate and flow volume are required to reach a certain level. The drinking water should be clean and meet hygiene standards. Insufficient or unclean drinking water can affect the sow's feed intake and digestive and lactating functions.
Strengthening temperature regulation Heat stress can be prevented and reduced by installing rain curtains, exhaust fans, shade cloth, feeding watermelon rind, and using heat-clearing Chinese herbal medicines, among other methods.