As the saying goes: "A boar is a good wave, a sow is a good litter". Sow is the production of piglet factory, the current domestic sow common problem is that the number of sows to provide weaned piglets is low (an average of about 16, more than 25 abroad), and the sow does not estrus, prolonged affection, stillbirth, litter number is small, piglet survival rate is low and other phenomena are widespread, which is also one of the main reasons for the normal recovery of pig inventory in recent years and the fluctuation of pig prices. By strengthening the nutritional management of sows, scientifically combining the nutritional needs of each stage, regulating the dietary nutrition of sows, and carrying out scientific feeding management, we can increase the reproductive rate of sows, increase the number of weaned piglets, reduce ineffective sows, and improve the economic benefits of pig farms.
One. The importance of nutritional management in sows
The influence of sows not only affects their own health, but also affects the birth weight, survival rate, weaning weight and later growth performance of piglets, as well as the slaughter time and the production efficiency of fattening. Therefore, the key to the management level of a pig farm is to look at the nutrition and production level of the sows.
The nutritional status of sows is measured by the body condition of sows, which directly affects the reproductive performance of sows. The sow's nutrient supply should be set according to body weight and physiological needs at each stage. Over-fattening or over-thinning will affect the production performance of sows, and there is room for supplemental feeding to increase the newborn weight in the later stage, so that there is a better appetite during lactation and milk production.
At present, many pig farms do not understand the science and importance of sow feed and feeding, and often measure the performance of sows by the number of litters born in a single parity. Problems such as non-estrus, non-pregnancy, repeated infertility, miscarriage, and stillbirth are blamed on diseases. The survival rate and poor growth and development of piglets are blamed on the trough feed. However, they ignore the impact of sow nutrition, and would rather suffer from low sow production levels for a long time, rather than invest in improving sow nutrition, which is the fundamental reason for the low production level of some pig farms.
Two. Stages of sow nutrition management
According to the needs of the production status of sows at each stage, the sow feeding management is divided into 6 stages: pre-pregnancy (30 days after breeding), mid-pregnancy (30 days and 85 days after gestation), late pregnancy (85 days and 110 days after gestation), perinatal period (5 days before farrowing and 5 days after farrowing), lactation period, and empty waiting for mating period (weaning and re-breeding). The key points of feeding management at each stage are as follows:
Pre-pregnancy: The goal of sow rearing is to reduce the death of embryos. The main cause of embryonic mortality is that the concentration of nutrients ingested by sows is too high, which will reduce the secretion of progesterone, so controlling the feed intake of sows in the early stages of pregnancy and ensuring sufficient vitamins and minerals can improve the fertility rate and embryo survival rate.
Second trimester: (30-85 days of gestation) The goal of sow feeding is to ensure the needs of fetal development and the needs of the sow's own metabolism. Under normal circumstances, the feeding amount at this stage should be controlled at 22~2.5 kg, and the amount of feed should be adjusted appropriately according to the fat condition, as overfeeding at this stage can lead to a decrease in feed intake during lactation. After 75 days of gestation, which is a critical period for breast development, excessive energy intake can increase the deposition of fat in the mammary glands, thereby reducing the number of secretory cells in the mammary glands, resulting in a decrease in milk production.
The feeding of sows in the late stages of pregnancy (85 110 days) is extremely critical for the growth and development of the fetus, during which the growth and development of the fetus is extremely rapid, and 60% and 70% of the piglet's birth weight comes from the rapid growth in the first month of the first month. This stage is also the period of full development of the mammary glands, in order to ensure the needs of the fetus and the sow's mammary gland development, it is recommended that the daily feeding amount be increased to 28~3.5kg.
The perinatal period (5 days before farrowing and 5 days after farrowing) is to achieve smooth farrowing, reduce the occurrence of constipation, and ensure the recovery of appetite after farrowing. At this stage, lactating sow feed is used, and the feed is gradually reduced by 05~1kg。In general, sows do not eat on the day of farrowing, and if sows are fed, they should be fed 15~2.0kg of feed, increase the feeding amount of sows per day after giving birth by 05~1.0 kg until 5 days postpartum ad libitum.
Lactation: The goal of sow feeding is to maximize the sow's milk production while controlling the sow's weight loss, ensuring that the sow remains in suitable condition after weaning and smoothly enters the next reproductive cycle. The importance of lactation to piglets is self-evident, and the birth weight and weaning weight of piglets directly affect the fattening effect.
Now sows need to be fed high-energy protein diets due to their body weight, large litter size and high lactation, and ensure the balance of energy and protein, and also increase the feed intake of sows by using wet mixtures to increase the number of feedings and other measures to ensure that sows are in early estrus and normal breeding and pregnancy. At this time, if the nutrition is unbalanced, the sow will use the amino acids and fats in its own tissues to synthesize milk, resulting in fatty diarrhea in piglets, and the sow's hormonal imbalance will cause too long estrus interval and reduced litter size.
The goal of the feeding is to ensure that the sow is in heat 5 days and 7 days after weaning. The daily feeding amount is 30 4kg or ad libitum feeding, which is conducive to the recovery of the sow's body condition, is conducive to promoting the development of follicles, and helps estrogen, promotes the secretion of follicle hormone, and ultimately facilitates the estrus, ovulation and conception of the sow.