Before the eighties of the last century, due to the lack of grain, backward feed technology, lack of excellent pig breeds, backward pig facilities, pigs generally need to be raised for more than a year before they can be slaughtered, and domestic meat food is relatively scarce, and it is supplied by ticket. Since the eighties of the last century, a large number of foreign raw material pig breeds, domestic feeding technology and feed technology have made great progress, especially the grain harvest every year, pig feeding methods from the past hanging frame fattening to compound feed feeding, breeding varieties from local varieties to foreign lean breeds, now 5-6 months to reach about 250 pounds of slaughter weight.
In the past, the breeds raised were meat and fat varieties, providing more fat, generally 55-60% of fat, 40-45% of lean meat, and 5-7 cm thick. Piglets are weaned at an average age of 60 days, fattening pigs gain an average of 0.19 kg per day, and a slaughter rate of 65%. In the past, it was raised by the method of hanging shelves, and the pigs were fed with a large amount of green feed before 100 catties, and rarely added grain, and the weight reached 100 catties after adding grain for fertilization. Due to the high fat content of local pig breeds, the meat is full of oil when touched by hand, and a large number of fat particles are distributed in the muscle fibers of local pork, especially lean meat, which is relatively tender, smooth and fragrant after cooking. At present, the vast majority of domestic pig breeds are foreign breeds, and foreign pig breeds are lean meat type, generally lean meat accounts for 50%, and the fat thickness is 3.5-4.5 cm. The growth rate of foreign pigs is very fast, such as the current breeding of foreign ternary hybrid pigs can reach the slaughter weight after 5-6 months. Lean pork lacks fat and is cooked with additional oil, so this type of pork is more chai and has a worse taste.
In terms of feed, in the past, due to the lack of food, pig breeding is mainly to take hanging frame fattening, in the past, the weight of fat pigs purchased by food companies is very small, the general weight of 100 pounds can be slaughtered, and now the slaughter weight must be more than 250 pounds. In the past, due to the lack of food, it was very difficult for each family to raise pigs, so in the past, clinker was basically used to feed pigs, except for feeding fresh green feed is raw feed, the rest of the feed is fed cooked feed. In our village, at that time, every household had to use a large pot of pig feed every day, and a special stove was used to cook pig food.
Because at that time the grain is relatively scarce, raising pigs are generally to take hanging rack fattening, that is, in 100 catties before the basic use of green feed to feed pigs, after the start of fattening to reduce the proportion of green feed, add grain feeding, to the slaughter of the week before the basic feeding of grain, most of the rural small potatoes, sweet potatoes and pumpkin fertilizer, these green roughage volume is relatively large, through cooking can reduce the volume, soften the crude fiber, can improve the digestibility of these green feed, promote the growth of pigs. After the feed is cooked, it can kill the pathogens and parasite eggs in the feed, especially the swill master the feed to feed pigs to achieve the purpose of disinfection. Moreover, the fat pork fed with cooked feed tastes better than that fed with raw feed, and the oil and gas that consumers say is heavier. Most of the green feed is made of Chinese herbs, which can prevent and cure diseases and improve the quality of pork, so the meat of local pigs is more delicious.
Now due to the progress of feed science and technology, the feed conversion rate has been greatly improved, now with compound feed to feed pigs, generally about 3.2 pounds of feed can grow a pound of meat, in the past need 4.5 pounds of pure grain to produce a pound of pork.