Enviropig™

Enviropig™ > Environmental Benefits


Environmental Benefits

Approximately 50 to 75% of the phosphorus present in cereal grains including corn, soybeans, barley and wheat is present in an indigestible compound called phytate that passes through the digestive tract and is enriched in the manure approx. 4-fold because the protein and carbohydrates in cereals are digested and absorbed. The manure is an excellent phosphorus fertilizer, but in areas of intense swine production there is a build up of phosphorus in the soil. During spring thaws or heavy rainfall the phosphate may be leached into tile drains, ponds, streams, rivers and lakes. High phosphorus content in water is a major factor allowing extensive algal growth (and in some cases algal toxin production) in fresh water systems, which eventually leads to a reduction in oxygen content (anoxia), fish kills, and water that is no longer suitable for drinking. The presence of blue green algae (Cyanobacteria) often leads to production of toxins.

There are serious pollution problems with the spreading of manure in many countries where there is intensive pig production. For example, in the United States there are many areas in which there has been an excess of manure spread on land (http://www.nrcs.usda.gov/technical/NRI/pubs/manntr.html). It has been reported that only 20 to 50 percent of all large hog farms have sufficient land to meet land application standards, depending on whether a nitrogen or phosphorus standard is to be met. Phosphorus-based standards are more costly than nitrogen-base standards and this reflects the higher concentration of phosphorus in the manure (http://ageconsearch.umn.edu/handle/33911). Manure management regulations are set by the state and overlaying these regulations are the confined animal feeding operation (CAFO) rules that applies to livestock operations, for example hog operations with more than 2,500 animals weighing more than 55 pounds or more than 10,00 swine weighing 55 pounds or less (http://cfpub.epa.gov/npdes/afo/cafofinalrule.cfm).

Another example, is China where there is serious manure pollution from pigs and other livestock as reviewed by Gu et al. (2008) and Gerber et al. (2005). There, livestock accounts for 39% of agricultural phosphorus pollution and swine account for a large part of it (Gerber et a., 2005).

The Enviropig excretes from 30 to 70.7% less phosphorus in manure depending upon the age and diet. Therefore, by raising Enviropigs instead of ordinary pigs a more expensive manure phosphorus application limit could be avoided, and would contribute to an overall phosphorus pollution reduction in addition to reducing the feed cost by eliminating the need to supplement the diet with either phosphate or phytase.

Relevant Environmental Publications
  1. Burkholder,J., Libra, B., Weyer, P. Heathcote, s. Kopin, D. and Thorne, P.S. 2007. Impacts of waste from concentrated animal feeding operations. Environmental Health Perspectives 115: 308-312.
  2. FAO. 2007.LIVESTOCK'S LONG SHADOW environmental issues and options. http://www.fao.org/docrep/010/a0701e/a0701e00.HTM.
  3. Gerber, P., Chilonda, P., Franceschini, G., and Menzi, H. 2005. Geographical determinants and environmental implications of livestock production intensification in Asia. Bioresourse Technology 96 (2):263-276. http://www.ncbi.nlm.nih.gov/pubmed/15381225?dopt=Citation
  4. Gu, P., Shen, R.F., and Chen Y.D. 2008. Diffusion pollution from livestock and poultry rearing in the Yangtze Delta, China. Environmental Science and Pollution Research International 50 (3):273-277. http://www.ncbi.nlm.nih.gov/pubmed/18504847?dopt=Citation.
  5. Koneswaran, G. and Nierenberg, D.. 2008. Global farm animal production and global warming: impacting and mitigating climate change. Environmental Health Perspectives 116:578-582.
  6. LaSalle, T. 2008. The organic green revolution. http://www.rodaleinstitute.org/files/GreenRevUP.pdf.
University of Guelph
50 Stone Road East
Guelph, Ontario, N1G 2W1
Canada
519-824-4120