How many times a year do pigs reproduce during the pig breeding cycle?

Pigs generally reach sexual maturity at the age of 4-5 months and can be mated for the first time at the age of 6-8 months. The pregnancy period is short, only 114 days. Pigs are prolific animals that are in estrus all the year round. The sow can give birth for the first time at the age of 1 or earlier, and the sow can give birth to 2 births a year. If the lactation period of the piglet is shortened, the sow can be treated with hormone, up to 5 births in 2 years or 3 births in 1 year.

Generally speaking, one of the common characteristics of Chinese pig breeds is strong fecundity. 3-month-old boars begin to produce sperm and sows begin to ovulate in estrus, 3 months earlier than western breeds. For example, the proestrus of Meishan sows is usually 75-85 days old. under normal feeding conditions, Meishan sows can be mated for the first time at the age of 6-8 months and give birth for the first time at the age of 1 year. It is reported that Taihu pigs gave birth at the age of 7 months.

In terms of reproductive performance, Taihu pig has the highest litter size among known pig breeds in the world. According to statistics, the average first litter size of sows is 12.14, 2 births 14.88, 3 births and more than 3 births 15.83. On February 17, 1982, the first Erhualian sow and Meishan boar in Yuecheng commune, Jiangyin City, Zhejiang Province, gave birth to the eighth birth, 42 litters, 40 live births and 29.6 kg litter weight, setting a record for the largest number of babies born at one birth. The average litter size of sows is about 10 per litter, which is higher than that of other livestock.

There are 110000 oogonia in the ovaries of sows, but only about 400 ovulations are ovulated in the lifetime of reproduction and utilization. Sows can ovulate 12-20 eggs in one estrus, while the litter size is usually only 8-10. The ejaculation volume of boars was 200,400ml at a time, including 20 billion ~ 80 billion sperm. Thus it can be seen that the reproduction rate of pigs is not high, but the reproductive potential is great. The experimental results show that through hormone treatment, sows can ovulate 3040 eggs in a period of estrus, and some sows have as many as 80 eggs. Therefore, as long as appropriate measures are taken to improve nutrition, proper feeding and management and advanced breeding methods, it is possible to improve the reproductive efficiency of sows.

Because the sexual maturity of pigs is early and the periods of pregnancy and lactation are short, the generation interval is also short, with an average of 1.5 to 2.0 years. If appropriate measures are taken to select good individuals from first-born piglets for breeding, the generation interval can be shortened to one year, that is, one generation a year, which is the most favorable condition for rapidly increasing the number of pigs, speeding up the breeding process and providing meat products. At the same time, due to the strong fecundity of pigs, a large number of offspring can be proliferated in a short period of time, one sow can give birth to two births a year, and the piglets in spring can breed in the same year, and more than 70 offspring can be multiplied within a year, reaching three generations in the same house.

Meat pigs also have the characteristics of high yield and short generation interval, but the sexual and physical maturity are later, and the ability to deposit body fat is later than other pigs.