The key points of fetal protection technology of pregnant sows, these details should be paid attention to.

Introduction: the feeding of pregnant sows is the main link in the production process of modern pig farms. The advantages and disadvantages of feeding and management of pregnant sows not only test the success or failure of sow breeding, but also prepare for sow delivery and lactation. This production stage plays a key role in realizing the sustainable development of economic benefits of pig farms. Therefore, pig enterprises should attach great importance to the implementation of safe and effective fetal protection technology to improve the fecundity of pregnant sows.

The growth and development of fetus and the physical condition of sows are closely related to the fetal protection techniques of pregnant sows. The implementation of fetal protection technology is to ensure the normal development of fertilized eggs, embryos and fetuses in sows according to the law of fetal growth and development and the changes of the state of sows, to ensure the normal development of fertilized eggs, embryos and fetuses in sows, and to reduce embryo death and abortion in sows; at the same time, it is necessary to ensure that sows have a good body condition and smoothly enter the lactation period.

The synthetic metabolism of sows was significantly improved after pregnancy, the body weight of pregnant sows could be increased by 25~35kg, and the utilization rate of feed nutrition of pregnant sows was 9.2% and 18.1% higher than that of empty sows.

Studies have shown that the weight gain of a sow in the first 40 days of pregnancy is only 1% of its birth weight; on the 41st to 80th day of pregnancy, the fetal weight gain is 20% of its birth weight; and on the 81st to 114th day after pregnancy, the fetal weight gain is more than 60% to 70% of its birth weight.

It can be seen that the weight gain of uterine contents of sows in late pregnancy is higher than that in early pregnancy, but the increase of body weight in sows is higher in early pregnancy than in late pregnancy.

In order to protect the fetus and obtain a large birth weight, it is necessary to focus on the feed quality management of sows in the early stage of pregnancy, especially to meet the needs of sows for digestible amino acids, vitamins and trace elements.

Essential amino acids such as lysine, methionine, tryptophan and threonine in feed should be supplied; at the same time, conditional essential amino acids such as arginine and histidine should not be lacking in pregnant sows, which can improve the reproductive efficiency of sows and promote fetal growth and development.

Vitamin A, E, B2, B6, B11, biotin and trace elements zinc, manganese, selenium and iodine can maintain the normal reproductive function of pregnant sows and ensure the growth and development of the fetus.

If there is a long-term lack of feed, it will cause reproductive dysfunction of pregnant sows, resulting in stillbirth, weak litter or abortion.

Because the absorption rate of vitamin D in pigs is only 20% to 30%, sows have a high demand for vitamin D.

Lack of vitamin D in feed can also lead to decreased fecundity and miscarriage.

And because the tolerance of black pigs to feed deficiency of vitamin D is only 25% of that of white pigs, pregnant sows of black pig breeds in China should increase the supply of vitamin D, requiring that the content of dietary vitamin D during pregnancy should not be lower than that of 200IU/kg.

After pregnancy, sows should be protected by different feeding modes according to their age and physical condition.

The feeding level of parturient sows was improved with the increase of gestational age, and reached the peak one month before parturition, so that the sows themselves and the fetus could get good growth and development.

According to the physical condition, the parturient sows can be divided into two types: good physical condition and poor physical condition. the fat deposition and plumpness of the tail root, buttocks, spine and ribs of the sows can be identified more accurately by observing the fat deposition and plumpness of the sows.

For the parturient sows in good condition, the nutritional needs of the mother and fetus can be met by feeding high quality green roughage and formula feed with low energy and protein content in the early stage of pregnancy.

The feed quality should be improved in the later period of pregnancy to ensure the rapid growth and development of fetus.

For sows in poor health, good feed should be provided in the early stage of pregnancy, especially adequate supply of vitamins and trace elements, which can not only ensure the growth and development of the fetus, but also restore physical strength and increase body fat as soon as possible. to ensure the health of sows to better maintain pregnancy; in the middle stage, due to the improvement of sows, the fetus does not need much nutrients, so you can feed more green roughage at this time. The growth and development of the fetus in the late pregnancy is accelerated, so it is necessary to increase the fine feed, not to feed the feed that is too large and difficult to digest, so as to prevent the digestive organs of the sows from squeezing the uterus and causing abortion.

Overweight pregnant sows will affect the fetal survival and reproductive performance of subsequent parity, so under the condition of nutritional balance, nutrient intake can be controlled by shortening feeding time, limiting feeding quantity, reducing feed quality and so on.

The average daily feed intake of pregnant sows should be 2.0~2.5kg/, which should be adjusted according to the type and environment of enclosure, feeding mode, health degree, production performance level and management standard, in addition to the body condition and parity of pregnant sows, so that the difficulty of delivery can be reduced and the embryo survival rate can be increased after restricted feeding, so as to achieve the purpose of effective fetal preservation.

The feed of pregnant sows should be kept clean and fresh, and it is forbidden to feed moldy, spoiled, rotten, frozen and strongly irritating feed, so as to prevent metamorphosis, weak fetus, stillbirth and miscarriage.

In order to protect the fetus, the feed should not be changed frequently during pregnancy, and when it is really necessary to change, the feed should be gradually transferred within 1 week, so that the sows can fully adapt.

The most suitable environmental temperature for pregnant sows is 15: 21 ℃, and the humidity is 45% to 65%. Attention should be paid to preventing cold and heat; good ventilation equipment should be provided to ensure fresh air inside the piggery; the floor of the enclosure should be flat, dry, clean and keep warm in winter and cool in summer; feces should be cleaned in time, the manure pit should be shallow, and the slope of the upper and lower pit should not be too steep; the enclosure should be quiet.

Breeders should have a gentle and patient attitude towards pregnant sows, observe their feeding, drinking, lying, faeces and mental state every day, often brush the pig body to keep its skin clean, and often touch the abdomen to help protect the fetus; sows should be avoided from crowding, skidding and falling, and shock, beating and scolding are strictly prohibited to prevent mechanical abortion.

Sows should exercise properly in the middle and later stages of pregnancy in order to strengthen their physique and ensure the growth and development of the fetus, and the exercise should be stopped one week before delivery.

1. Prevention of infectious diseases

Infectious diseases have the characteristics of complex etiology, changeable clinical symptoms, difficult diagnosis and serious harm. Viral infectious diseases are the main causes of reproductive disorders in pregnant sows, especially classical swine fever virus, pseudorabies virus, parvovirus, Japanese encephalitis virus, circovirus and porcine highly pathogenic blue ear disease virus discovered in recent years. Single or mixed infection can lead to reproductive disorders in pregnant sows, such as premature delivery, recessive abortion, stillbirth, mummified fetus, weak baby, fetal malformation and so on.

Some bacterial infectious diseases, such as brucellosis, salmonellosis, leptospirosis, listeriosis, chlamydia trachomatis, porcine haemophilic mycoplasma disease and so on, can also cause similar symptoms. these infectious diseases cause great harm to pregnant sows and are the main prevention and control objects in pig production.

two。 Prevention of parasitic diseases

Toxoplasma gondii and Schistosoma japonicum (Schistosoma japonicum) are typical multi-host parasites, which are one of the most serious parasites in pregnant sows, which can cause abortion, weak fetus and stillbirth in pregnant sows, especially toxoplasmosis, with rapid epidemic, acute morbidity and high mortality. the clinical symptoms are similar to classical swine fever and directly affect human health.

Pig scabies mites, pig lice and other skin surface parasites, feed on pig tissue and lymph or suck blood, infected with these parasites make pregnant sows show depression, itching, friction, loss of appetite, often emaciated and weak due to malnutrition, and easily lead to sow miscarriage.

3. Prevent common diseases

Once the pregnancy of sows is determined, strict preventive measures should be taken to ensure the safety of pregnancy for common diseases, such as common diseases and frequently-occurring diseases. In addition to ovarian inflammation, vaginitis and other reproductive system diseases can cause abortion, colds, feed poisoning, stress and other can also cause abortion

In particular, it is necessary to avoid poisoning caused by improper feeding or excessive feeding in order to prevent sows from being overfed during pregnancy, such as distiller's grains, cottonseed cake, rapeseed cake and so on, which will cause miscarriage or even death of sows.

Green feed is best fed fresh, if boiled and fed, a small amount of vinegar should be added, which can not only sterilize, but also decompose nitrite, which can avoid premature delivery, weak fetus or stillbirth of pregnant sows caused by nitrite poisoning.

4. Correct use of drugs

During pregnancy, sows should be highly cautious in the use of drugs, and the following drugs should be strictly prohibited:

First, drugs that can directly stimulate uterine smooth muscle, such as ergot preparation, Pituitrin, oxytocin, quinine, etc. (except for induction of labor and postpartum hemostasis)

Second, drugs that can indirectly stimulate uterine smooth muscle (strong laxatives), such as magnesium sulfate, sodium sulfate, castor oil, etc., can stimulate the digestive tract mechanically or chemically and induce abortion by reflexively stimulating the uterus.

Third, drugs that can affect fetal growth or fetal malformations, such as salicylic acid, nicotinamide, pilocarpine, lentil, etc., in addition, drugs with adverse consequences such as cortisone, sex hormones and long-acting sulfonamides should be avoided in the early stage of pregnancy.

Fourth, Chinese herbal medicine with blood stasis and regulating qi, such as peach kernel, safflower, Sangleng, zedoary, motherwort, Guanzhong, Euphorbia officinalis, Guansui, Phytolacca, Erchou, rhubarb, soap horn, Fructus Aurantii, Yuanhu, Wulingzhi, musk, water frog, and proprietary Chinese medicine Huoluodan, Dieda pills, etc., will cause serious harm to sow fetus protection, and even lead to sow abortion.

The key to disease prevention of pregnant sows is to give priority to prevention, and the following comprehensive prevention and control measures can be taken:

The first is to establish a scientific technical system for epidemic disease diagnosis and detection. Strengthen the surveillance of epidemic diseases, formulate and implement reasonable immunization procedures, and timely cull and purify pigs with infectious diseases that are harmful, incurable or expensive to treat.

The second is to carry out self-breeding and strictly guard against external sources of disease. When breeding pigs must be introduced, they must be proved to be disease-free by isolation and quarantine before they can be raised in mixed groups.

The third is to strengthen daily feeding management, improve environmental conditions and improve disease resistance of sows.

Fourth, the mode of production should be all-in and all-out, and thoroughly do a good job in the hygiene and disinfection of the site. There should be no weeds within 5m around the pregnancy enclosure, and mosquitoes, flies and rats should be often killed, and aborted fetuses, placentas, stillbirths and pollutants should be treated innocuously at the fixed point.

Fifth, pigs should not be mixed with cattle, sheep, chickens and ducks, let alone pets such as dogs and cats. Pregnant sows should be regularly dewormed, and sows should be treated in time to prevent the expansion of the disease and secondary infection.