Sows generally store calcium during pregnancy to meet lactation needs. If the mineral reserves are insufficient during pregnancy, the physiological requirements of lactation will use calcium and phosphorus in the body's bones to meet the needs of lactation, which will lead to the sow's syndrome. , often occurs in the late lactation or weaning period. From the production point of view, the nutrient requirements of calcium and phosphorus can be floated by 30% without affecting the animal's production performance, and the normal development of pigs can be guaranteed.
At present, most feed enterprises in China are often low when considering the calcium and phosphorus requirements of pigs. Although the calcium source is very cheap, the dosage is not appropriate, which will also affect the performance of pigs. The phosphorus source is relatively expensive. Most of the diets are insufficiently added. In the calculation of total phosphorus, the phosphorus content in the grain feed is mainly considered, and the effective phosphorus is not noticed, which leads to the deficiency of phosphorus and limits the weight gain rate of the pig. The amount of vitamin D required for growing pigs at different stages is different, and the current feed is also generally insufficiently added, thereby reducing the utilization rate of calcium. Calcium, phosphorus and vitamin D are important nutrients for the growth and maintenance of soft and hard tissues. They should not be considered alone because there is a strong interaction between them, recognizing that this interrelationship is necessary to better understand the nutritional needs of pigs.
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