Modern pig production generally adopts the production technology of feeding in stages and all-in and all-out, which makes production management convenient and systematic and improves production efficiency. The scale and technical level of pig farms are different, the physiological requirements of different pig herds are different, and the feeding stages adopted are also different. Commonly used production technologies mainly include the following:

(1) three-stage feeding process

Empty pregnancy → lactation → fattening period. Three-stage feeding and two-stage herd transfer is a relatively simple production process, which is suitable for small-scale pig farms. Its characteristics are simple, few times of assembly and rotation, few types of pig houses, saving maintenance costs and focusing on measures. For example, during childbirth and lactation, good environmental control measures can be taken to meet the growth conditions of piglets, improve the survival rate and improve the production level.

(2) Four-stage feeding process

That is, empty pregnancy → lactation → piglet conservation period → fattening period. In the process of three-stage feeding, the separation of piglet care stage is the process of four-stage feeding and three-stage group transfer. The conservation period is generally 5 weeks, and the pig weighs 20 kilograms and is transferred to the growth and fattening house. Weaned piglets have higher requirements for environmental conditions than growing and finishing pigs, so it is convenient to take measures to improve the survival rate. Feeding in the growing and fattening house for 15 ~ 16 weeks, and slaughtering when the weight reaches 90 ~ 1 10 kg.

(3) Five-stage feeding process

That is, empty breeding period → pregnancy → lactation period → piglet conservation period → fattening period. Compared with the four-level feeding process, the five-level feeding and four-level transfer is to separate empty sows and pregnant sows, which is beneficial to breeding and improving reproductive rate. Empty-pregnant sows were observed for 2 1 day after mating, and then transferred to the pregnancy house for feeding until 7 days before delivery. The advantages of this technology are that weaned sows gain weight quickly, and estrus is concentrated, which is convenient for estrus identification and easy to master timely breeding.

(4) Six-stage feeding process

Empty pregnancy → pregnancy → lactation → conservation period → breeding period → fattening period. Compared with the five-stage feeding process, the fattening period is divided into growth period and fattening period, and each feeding period is 7-8 weeks. Piglets go through four stages from birth to slaughter: lactation, seed conservation, breeding and fattening. Its advantage is that it can meet the feeding needs of its growth and development and the different needs of environmental management to the maximum extent, give full play to its growth potential and improve production efficiency.

(5) All in and all out

The above-mentioned staged feeding process requires all pigs to go in and out. The most favorable measure for epidemic prevention is to design a pigsty according to the pigs in each feeding stage. All pigs enter and leave in one unit, or some pigs enter and leave in one unit, but this is only applicable to pig farms with a scale of 30,000 to 50,000. In small and medium-sized pig farms, pig farms can be transferred to some fields in pig houses, and then cleaned and disinfected. However, due to the air and sewage in the pig house, it is difficult to cut off the source of infection and strictly prevent epidemic. Therefore, some pig farms divide the pigsty into several units according to the number of transferred groups, which is beneficial to epidemic prevention, but it is difficult to ventilate and prevent heatstroke in summer and needs to be further improved.