Twenty years ago, every family in the countryside used swill to feed pigs. Why can't swill pigs eat now?

Swill refers to the waste and sewage produced in family life, including vegetable leaves, vegetable roots, leftovers, feces and so on. In the past, the feeding methods of rural families were primitive, and it was a common method to feed pigs with swill. But the main reasons why swill pigs can't eat now are as follows: 1. Environmental pollution is serious. Nowadays, with the development of urbanization and the improvement of people's living standards, pollutants such as chemical substances and drug residues produced in family life have increased, and the pollution degree of swill is higher than in the past. 2. Swill feeding does not conform to the concept of circular economy. Swill itself has good resource value and can be used to produce organic fertilizer and biogas after reasonable treatment. Feeding pigs with swill not only wastes resources, but also has adverse effects on the environment. 3. swill feeding will affect the health of pigs. There are some pathogens in swill that are not easily infected by human beings, but they will have pathogenic effects on pigs and affect their health. In addition, the high content of inorganic salts in swill will affect the digestion and absorption of pigs, and may also cause problems such as poor rumen fermentation. To sum up, swill pigs can't be eaten now because the environmental pollution is serious, which doesn't conform to the concept of circular economy, and it will also affect the health of pigs, so it is no longer suitable for pig feed.