1. Select excellent breeding pigs
To raise a batch of high-quality sows, we should start with the selection of high-quality breeding pigs, from the selection of high-quality breeding pigs to artificial fertilization to management, and the methods of each link should be scientific. For the majority of farmers, the selection of good quality sows is directly related to the number of breeding benefits. In order to strengthen the overall performance of sows and improve the reproductive rate, the selection of sow varieties has also become a key control point in breeding production.
At present, the foreign excellent pig breeds in China mainly include Landrace, Yorkshire, Duroc and Pitland, and the local excellent pig breeds in Hunan Province mainly include Shaziling, Dawei, Ningxiang and Taoyuan pigs. The first generation produced by hybridization between different varieties or strains has higher vitality and growth intensity than their parents, which is heterosis. Landrace pigs with high lean meat rate and fast growth rate can be selected to cross with Yorkshire sows to produce "Landrace× Yorkshire" binary hybrid sows. The sows have good maternity, strong reproductive ability, litter size of about 12, good lactation performance and lean meat rate of 65%. Boars can choose Duroc, thus producing a pure external ternary guess (Du X is long and X is big). At the same time, local pig breeds can also be selected as female parents to cross with Landrace and Yorkshire pigs to obtain Landrace× Ben binary sows, and then Duroc pigs can be used as male parents to produce ternary hybrid commercial pigs (Landrace× Ben, Duroc× Landrace× Ben and Duroc× Ben). This hybrid pig has strong adaptability and high feed reward, reaching 2.8-3.0: 65438.
2. Timely breeding
Primiparous sows should be bred for the first time at the age of 7-8 months and weigh about 1 10 kg. Grasping timely breeding is the key to improve economic benefits. Because of the late sexual maturity of boars, boars should be two months older than sows for supporting use. Before the weight is less than 50 kg, the male sow can breed. Before reaching 60 kg, eat freely, exercise fully and get enough light. When it is about 60 kg, it should be strictly selected according to the seed retention standard.
1, estrus identification. When the sow is in heat. It is not the best time to breed because of restless behavior, climbing or being climbed by other sows, frequent urination, redness and swelling of vulva, etc. When the swelling of sow's vulva subsides, mucus is extracted, the back-pressing reflex is obvious, or there is ear motor reflex or tail root vibration, and the limbs are stretched out to mate, this is the best time for breeding.
2. Reasonably arrange sow breeding season, preferably in April-May, then in September-10, and so on, so that sows can breed in spring and autumn to avoid the hot environment in Leng Xia in winter. It is very important to master the time and times of breeding to improve the reproductive efficiency of sows. The ovulation time of adult sows in estrus is 24-36 hours after the start of estrus, the peak is about 3 1 hour, and the ovulation duration is 8 8- 10/hour. The fertilization ability of an egg in vivo can be maintained for 8- 12 hours, and the fertilization ability of sperm entering a sow can generally be maintained for 10- 15 hours. After insemination, the sperm advances at a speed of about 2-3 hours to reach the tubal fertilization site. Therefore, we began to mate for the first time 24 hours after estrus, and the interval was 10- 12 hours.
3. The timely breeding method should be "old early mating, small late mating, middle neither old nor small mating". Under normal circumstances, when the swelling of the sow's vulva just begins to subside and there is filamentous mucus flowing out after estrus 19 -30 hours, it is necessary to breed at the right time when pressing the sow's hindquarters to make it still. When artificial insemination is used, it is necessary to adopt secondary mating (that is, the first mating is carried out when there is a waiting response, and the second mating is carried out at an interval of 12 hours), which can obviously improve the conception rate and litter size. It is necessary to select healthy and improved semen of male sows, with more than 40 million semen per milliliter and sperm motility of more than 0.6, and strictly disinfect the equipment. First, wash the sow vulva with 0.0 1% KmnO4 solution, then slowly insert the vas deferens into the cervix for 20 cm -30 cm, then connect the insemination syringe, and slowly inject 20 ml of semen every 10 time.
3. Strengthen the management of sow feeding.
Strengthening sow feeding management is an important measure to improve sow reproduction rate. It is necessary to make sows have enough nutrients to promote the growth and development of embryos during pregnancy, and to ensure that sows have good nutritional reserves, reduce weight loss during lactation, and maintain good physical condition during breeding period. Therefore, there are specific feeding and management requirements for sows at different stages:
Sows are fed roughage during empty pregnancy, middle pregnancy and late lactation, and green feed is appropriately fed; In the early and late pregnancy, protein, concentrate rich in minerals and vitamins, and green and juicy feed should be fully supplied in the early lactation. At the same time, it is necessary to provide a relatively stable living environment for sows and minimize external stimuli such as changing herds, driving and fighting.
1. Do a good job in the protection and management of sow fetuses.
Because the fertilized egg has just formed in the early pregnancy, the embryo does not need high-level nutrition, and the feeding level should be maintained below 0.5 times the required level of 65438+ in order to maintain normal reproductive needs. Low-level feeding in early pregnancy can improve the survival rate of embryos. Sows are prone to miscarriage 9 days after mating-13 days, and 2 1 day before delivery. Therefore, special measures should be taken to protect the fetus, and protein, minerals, vitamins and other rich concentrate and green and juicy feed should be supplied as much as possible to avoid frozen and moldy feed. Pregnant sows try to avoid mechanical stimulation, such as squeezing, biting, slipping, whipping and scaring. The breeding of pig farms should be recorded in detail to avoid inbreeding. Pig farms should do a good job in the prevention and control of epidemic diseases, especially Japanese encephalitis, epidemic fever, brucellosis and other diseases, and treat diseases in time when they are found. Those with threatened abortion should be injected with progesterone 15 mg -25 mg immediately, and the fetus should be induced by oral sedative.
The nutritional level of sows in the second trimester of pregnancy is very important for the fiber growth of newborn piglets and the growth and development after birth. The amount of muscle fiber is an important factor to determine the growth rate and feed conversion rate of piglets after birth. The proliferation of muscle fibers is completed around the 90th day of pregnancy. The feeding management of pregnant sows can appropriately improve the crude fiber level, increase the satiety of sows, prevent constipation, and reduce the occurrence of stillbirth and miscarriage.
Feeding sows in the third trimester of pregnancy is the key to improve the birth weight of piglets, because 60-70% of the birth weight of piglets comes from the rapid growth and development before delivery 1 month. Therefore, it is of great significance to give sows high nutritional feed before delivery 1 month and do well the feeding management of sows in the third trimester of pregnancy, which will improve the newborn weight of piglets, postpartum lactation of sows and reproductive performance of sows.
2. Do a good job in sow delivery and farrowing management.
Five days before delivery-10, clean the sow's delivery ring, spray 10%-20% fresh lime water for disinfection, and disinfect the sow's abdomen, breasts and vulva with 2%-5% Lysol before delivery. After the sow gives birth, clear the mucus and fetal membrane in the pig's nose in time. For suspended piglets, methods such as beating chest, hanging hind legs upside down and pungent alcohol can be used for first aid. For dystocia sows, it is necessary to do a good job of midwifery so that sows can give birth smoothly. In addition, for newborn piglets, heat preservation is particularly important. When piglets are born, the temperature in the delivery room must be kept at 26℃-32℃, and it is 26℃-28℃ for one week after weaning.
3. Do a good job in feeding and managing lactating sows.
To strengthen the feeding management of lactating sows, we must maximize the feed intake of farrowing sows, because lactating sows need to spend 75% of their energy on lactation every day, and whether they can provide effective nutrition for lactating sows will directly affect the growth and development of piglets. If the intake of feed nutrition can not meet its lactation needs, it will cause a large amount of fat consumption in the body, leading to fat loss, weight loss and lactation loss in sows. Excessive fat loss not only directly affects the estrus mating of the next fetus. For sows with high yield and poor appetite, 4% fat should be added to the diet, which can improve the milk yield and milk fat level in colostrum and regular milk, thus improving the survival rate and weaning weight of piglets.
4. Strengthen the feeding management of weaned sows.
Weaned sows and reserve sows should be given high-nutrition diet two weeks before mating to enhance their physique, so as to promote estrus, ovulation and increase litter size. Under normal circumstances, the estrus mating rate of weaned sows should reach 80-90% within one week. Our piglets are weaned in 35 -40 days, and the sows are fed aphrodisiacs in 3 -5 days after weaning. After the sow is in estrus, it is necessary to breed immediately during lactation, which can also increase the annual fetal yield.