Reducing the environmental impact of livestock farms is an important consideration for all members of the livestock industry as it not only affects production, but affects the rest of society as well. The main environmental concerns are pathogens and disease- such as Salmonella and Avian Influenza, air quality-such as methane and ammonia levels, and nutrient concentrations in the soil and water. Over the past 90 years agricultural practices have become much more specialized and efficient, resulting in an increased production in the same land constraints. This increased efficiency has allowed for tremendous increases in standards of living, but has also been associated with growing environmental concerns.
One of these environmental concerns is a nutrient imbalance in the soil, as crops are shipped in to livestock, which excrete excess nutrients in a location where they are not required. In doing such, the portion of the land where crops were grown has a nutrient deficit, and the area where livestock are produced experiences a nutrient excess in the soil. The main nutrients of concern are nitrogen and phosphorous, as these are excreted in much higher quantities than plants need, and then become part of the water cycle as rain allows the excess nutrients to run-off the soil with the surface water, or the nutrients seep down to contaminate the ground water stores. Nitrogen and phosphorous can be contributed to the environment through livestock, detergents, human sewage, fertilizers, urban storm water, and atmospheric deposition.
This increasing imbalance in nitrogen and phosphorous is of concern for a number of reasons. Nitrates in the ground water can contaminate available drinking water and cause a potentially lethal condition , one of the Blue Baby Syndromes where the oxygen in blood is replaced by nitrate, depriving infants who consume contaminated water of oxygen. Also of major concern is that the increase in nitrogen and phosphorous in water allows for increased algae growth. Eventually, as the algae dies it sucks all of the oxygen from the water which kills all of the fish in the area. The algae bloom also prevents light from penetrating the surface of the water, which inhibits the growth of important aquatic plants. The Gulf of Mexico contains an algae bloom the size of Rhode Island that results in massive fish and plant die-offs every summer.
Although there are methods used to filtrate and cleanse water, waste-water treatment plants are designed to reduce the levels of nitrogen and pathogens in the water, not remove phosphorous. The treatment plants are also designed to allow storm water to overflow and bypass the treatment stage so that the facilities do not flood or back up. This however, means that large amounts of run-off carried by storm waters are bypassing filtration, and the levels of phosphorous contaminating the environment is much greater than nitrogen. The cost of altering water treatment plants to handle phosphorous and filter through storm water would cost billions per state, making the updates unfeasible without an increase in taxes.
There are proactive measures taken by livestock producers to minimize environmental contamination. Producers can compost manure to kill pathogens, or use an anaerobic digester to break down organic matter and capture the methane produced to generate electricity. Proper fencing is also very important. Livestock should be fenced out of streams, and if possible a strip of land referred to as a buffer strip should be in between the pasture and water source. This buffer should maintain any feasible difference between the fence line and water-such as five to fifteen feet, though a thirty-five foot buffer is optimal. The purpose of the buffer is to create as much distance as possible for the nutrients to be absorbed or utilized before ending up as part of the water system.
It is important not only for livestock producers but for all members of society to do their part to reduce environmental pollution, as well as to clean up areas which have already been effected by high levels of pollutants, in order to maintain the standards of living to which we have become accustomed.
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