Technical measures to increase the annual parity of sows

Pig breeding is an important part of pig production. The reproduction rate is closely related to the number of fetuses per year, the number of births and the survival rate of piglets. The number of tires per year is the key link. In theory, it is entirely possible for the sow to produce 2.5 tires per year. The sow’s gestation period is approximately 114 days. If sows are estrus in the 32 days after farrowing, one sow has a production cycle of 146 days, and one year is 365/146=2.5 production cycles, ie 2.5 births a year, and two births 5 fetal. To achieve sow post-natal breeding for 32 days, the piglets need to be weaned at 25 days of age, and sows usually take 5 to 10 days from weaning to estrus, with an average of 7 days. Therefore, the key technology to increase the number of births per year is early weaning at the right time and promoting early estrus in sows.

1 Piglets early weaning

1.1 Appropriate age at early weaning According to statistics, foreign piglets are mostly weaned at 19 to 32 days of age, accounting for about 92%; according to the situation of most pig farms in China, piglets are 21 to 28 days old with an average of 24.5 days. Age weaning is appropriate. Because at this age segment, the digestive tract of piglets develops the fastest and the absorption capacity gradually increases; the secretion and activity of enzymes such as amylase, maltase, pepsin and trypsin, and chymotrypsin in the digestive tract of piglets increase significantly; gastric juice The acidity (pH) increased significantly and the piglets' own immune system began to develop antibodies around the age of 3 weeks. And at this stage, the uterus of suckling sows has basically recovered, which is beneficial to estrus and breeding, and improves the conception rate. Specific to rural pigs, piglets are recommended to be weaned at 28 days of age or later. This is due to the fact that the supporting facilities and feeding and management of the pig farms of the vast majority of farmers are still not complete, and the weaning age should be appropriately extended to the specific circumstances.

1.2 Prepare pre-weaning preparations Firstly, sow feed intake should be gradually reduced a few days before weaning. In particular, feeds that promote lactation should be reduced to gradually reduce milk production and prevent mastitis. The second is to carry out early feeding training for piglets. After 5 to 7 days after the birth of the piglet, the piglet can be trained to eat, and young green feed and roasted soybean powder can be used to attract food. Sprinkle less material each time to avoid wastage. One of the reasons for eating and feeding is to exercise the function of digestive organs of piglets, promote the development of gastrointestinal tract, in order to reduce the feed conversion stress after weaning, and secondly, to increase the nutrition needed for piglets as they age, especially after 2-3 weeks of age. Breast milk can not fully meet the needs of growth and nutrition of piglets, and it is particularly important to feed materials in advance.

1.3 Master the correct method of weaning

1.3.1 Gradually weaning In the 4 to 6 days before weaning of piglets, gradually reduce the number of breastfeeding and increase the amount of feed. On the first day, the piglets were suckled 4 to 5 times, and the second day was reduced to 3 to 4 times. The third to fifth days were cut off. This provides good adaptation conditions for the early weaning of piglets.

1.3.2 Weaning in batches should be treated differently based on individual differences in body weight, feeding conditions, and physical strength of the piglets, and they should be weaned in batches. For piglets with strong physique, large size, strong appetite, or intended for fattening, weaned first; for individuals with small individuals, weak physique, poor appetite, sick piglets or piglets intended for breeding, appropriate prolonged lactation to facilitate the growth of piglets development.

1.3.3 Separation of milk from piglets After entering the weaning period, the number of feedings is determined according to the duration of the weaning. During the day, the sows are regularly driven out of the pens, and the pigs are regularly returned to the pens for lactation. Feeding piglets for feeding at regular intervals during lactation, and letting the mother in the same column at night. Piglets are not likely to cause adverse reactions such as stress in this more stable environment, and are very easy to achieve for weaning purposes.

2 Promoting estrus breeding after sow weaning

2.1 Increased Initial Birth Weight of First-Planted Sow The phenomenon of ecstasy after multiple production of newly born sows is mainly due to premature and light weight. Initial ageing generally requires local pigs to be 8 to 9 months old and weigh 60 to 70 kg; imported or hybrid pigs to be 9 to 10 months old and weigh about 100 kg. According to this standard, the initial allocation, the high number of litters, and the lack of grief after weaning.

2.2 Changing the rearing environment After weaning, the sows are concentrated in a single column, transferred from the original environment, or the sow is driven out of the house to increase the light, which can effectively promote the early estrus of the sow.

2.3 Physical Induction In the breeding house, place the sow pens opposite to the male pens or arrange them adjacently; or sows the sows in the pens to consciously let the boar chase, climb over the sows, or move the boars. Sow to the sow sports field, 15 to 20 minutes each time, once a day, after 3 to 4 days of continuous sows can be estrus.

2.4 semen induced by healthy boar semen 1 ~ 2ml, diluted with 3 ~ 4 times cold boiled water, a small amount of injection into the nose of the sow with a syringe; or use a small sprayer spray to the sow nostril, usually 4 to 6 hours to heat, 12 hours That is, reaching estrus. According to the test, this way aphrodisiac breeding, the fertility rate of the sows was 96%, 87% of the sows.

2.5 Recording Inducing recording of courtship voices when the sow heats up, broadcast to sows that are not in heat, several times a day, and broadcast for several days, can promote faster heat in sows.

2.6 estrus and communicative sow herd In a non-estrus sow herd, a sow that is estrus and seeking mating is placed. This sow will forget about the urge to mate, chase and crawl across the sow in the posture of a boar and make boars to mate. Sows can enter estrus after being induced by false boars.

2.7 Exogenous Hormone Induction The boar glands, submandibular gland secretions, and urine of adult boars all contain boar pheromones. Use gauze to extract these secretions or urine and put them on the corners of the sow housing to let them smell and promote estrus. For example, the sow expressed intimacy with gauze that had these secretions, and frequent urination and defecation actions proved that the sow was at the best time for mating.

2.8 Injection of aphrodisiac drug Injection of 2000 IU maternal serum gonadotropin (PMSC), two artificial inseminations 4 to 5 days after injection, pregnancy rate of lactating sows up to 70%; injection of PMSG 300-600IU, or intramuscular injection on the day of weaning Prosenol 1 to 2 ml, injection every other day 300 to 600 IU PMSG, usually about 80% of sows in heat within 7 to 8 days; each injection of triad hormone 3 ~ 4ml, more than 97% of sows in 3 days of estrus, The conception rate is more than 80%. You can also try to promote the situation and receive good results.