Detailed Explanation of Ecological and Healthy Pig Farming Models

In accordance with the principles of "reduction, harmlessness, resource utilization, and ecologicalization," implement emission reduction, biogas fermentation, organic fertilizer processing, and the integration of forestry with livestock and agriculture with crop farming to achieve compliant discharge.

Slatted floor - no flushing - emission reduction farming model: This model is an environmentally friendly farming model that has developed rapidly in recent years. The main production process is: when building pig pens, lay a layer of cast iron or cement slatted manure floor, equipped with dedicated ditches and pipes. After pigs excrete manure and urine, as much manual dry manure collection as possible is used, and the remaining manure is trampled by the pigs' hooves through the slatted floor into the underground ditch beneath the slats, without flushing the pig pens with water. When a certain amount of manure and urine accumulates in the underground ditch beneath the slatted floor, the valve is opened, and the pig manure and urine flow through pipes into a large-capacity covered manure storage tank. The concentrated manure and urine either naturally ferment, or undergo solid-liquid separation and enter a biogas fermentation system. The fermented manure and urine still need to be transformed and utilized through the integration of planting and farming. This model does not require water flushing of the pig houses, which can reduce the wastewater discharge of the pig farm by more than 70%, greatly alleviating environmental pressure. It is suitable for newly built or renovated large and medium-sized pig farms.

Pig - biogas - fruit (grass, forest, vegetables, tea, etc.) ecological farming model: This model is an ecological pig farming model that integrates planting and farming. The main production process is: after dry manure collection and solid-liquid separation of pig farm manure and sewage, the solid manure residue is piled and fermented to make organic fertilizer, which is centrally transported to orchards, grasslands, bamboo forests, woodlands, etc. for use as base fertilizer and top dressing; the sewage enters a biogas digester for anaerobic fermentation, and the biogas slurry is transported through dedicated pipes or vehicles to orchards, grasslands, bamboo forests, woodlands, etc. for use as base fertilizer and top dressing. This model fully absorbs and utilizes pig farm manure as organic fertilizer by the planted crops, causing no pollution to the environment or water sources, and has low construction costs and operating expenses. It is suitable for medium and small pig farms in mountainous areas with an annual slaughter volume of under 10,000 head.

Compliant discharge environmentally friendly farming model: This model belongs to the traditional environmentally friendly farming model. The main production process is: after dry manure collection and solid-liquid separation of pig farm manure and sewage, the concentrated solid manure residue is piled and fermented to make organic fertilizer, while the sewage enters a biogas digester for anaerobic fermentation. The biogas slurry undergoes sedimentation in a dedicated sedimentation tank, treatment in an aeration tank, and absorption and degradation in an aquatic plant biological oxidation pond. After meeting the water quality standards of the "Discharge Standard of Pollutants for Livestock and Poultry Breeding Industry of the People's Republic of China (GB-18596-2001)," it is discharged. This model is suitable for areas with relatively small areas of agricultural and forestry land.

Microbial fermentation bed zero-discharge ecological farming model: This model is an emerging environmentally friendly farming model. The main production process is: the pig farm uses wood chips, rice husks, rice bran, etc. mixed in proportion and added with beneficial microbial flora for fermentation as pig pen bedding. The microorganisms contained in the bedding can absorb, utilize, and transform the manure and urine excreted by the pigs as nutrients for their own activities. Daily routine management of the pig pen bedding is all that is needed, with no flushing, no cleaning, and zero discharge; after 1 to 2 years of microbial transformation and utilization, the biological bedding can be used as organic fertilizer for returning to fields, fertilizing fruit trees, growing vegetables, etc. This model has certain requirements for the building structure of pig houses, and there are still problems such as summer heat stress, tight supply of bedding material, and elevated ammonia nitrogen concentration in the micro-environment.

For newly built large-scale pig farms, the microbial fermentation bed zero-discharge ecological farming model should be comprehensively promoted. Sun Ruiluan