How exactly is the staged fattening method for feeder pigs carried out?

Feeder pigs are managed with the staged fattening method: before piglets reach 60 kg, use a high-energy, high-protein diet, with crude protein at 16 to 18% in the mixed feed and digestible energy at 3.2 Mcal, feeding 2 to 3 times a day, with free access to feed until satiety, to give play to the advantage of fast early growth in young pigs, with daily weight gain reaching 1 to 1.2 kg or more. At the 60 to 100 kg stage, use medium energy and medium protein, with crude protein at 13 to 14% in the feed and digestible energy at 3 Mcal, feeding twice a day with restricted feeding, taking in only 80% of the nutritional amount each day, to reduce fat deposition, with a required daily weight gain of 1.2 to 1.4 jin. To keep the pigs from going hungry, the proportion of roughage can be increased.