Livestock represent only 3.6 percent of greenhouse gas emissions, and specifically, cattle represent only 20 percent of the methane production in the U.S. Methane production by cattle results in a loss of 2 to 12 percent of the gross energy consumed by the animal.

Therefore, improving efficiency will not only reduce energy loss for the producer but also decrease methane production and result in a decreased carbon footprint for agriculture.

Dr. Jude Capper reported that as technology has been developed, and management, nutrition and genetic selection have improved, it has allowed beef producers to produce more beef per carcass and decreased the time it takes to produce a finished carcass.

As a result, the carbon footprint for producing beef was reduced by 18 percent from 1977 to 2007.

As the beef industry strives to be more efficient and sustainable, it is likely the next 30 years will see an additional reduction in the beef production carbon footprint.

In a recent University of Nebraska survey, beef cattle producers indicated they were not very confident in their knowledge of methane production in cattle. It has been estimated that the methane produced by cattle will likely contribute less than 2 percent to any global warming that will occur in the next 50 to 100 years.

However, there are special-interest groups who believe cattle have a negative impact on the environment, and there are consumers who may believe misinformation about the beef industry.

Therefore, it is our responsibility as the beef industry to educate ourselves and the public about beef production impacts on the environment.

There are production practices already in place that have improved beef production efficiency and environmental sustainability. Producers need to understand these before they can confront misinformation.

Additionally, as an industry we can always improve. The improvements we’ve made over the past 30 years are impressive, and we can continue to improve our efficiency and reduce our environmental footprint, and we can educate the consumer on the improvements we have made – but only if we understand them ourselves.

Grains vs. forages

It is well-documented that diets high in grains (example: finishing diets) result in the most gain per pound of feed consumed and also result in lower methane emissions than most forage-based diets.

This is because fiber-digesting microbes produce more methane than other microbes. However, throughout the production cycle of a calf’s life, about 85 percent of its dry matter intake will be from forages.

Fossil fuel use is very limited in the production of grazing cattle, but improvements in forage utilization will still improve animal efficiency, possibly reduce enteric methane production and benefit the producer and the environment.

Forage digestibility

Producers are generally aware that higher forage quality results in higher digestibility, and that translates to greater production in the animal. Research has also indicated that increased quality and digestibility in forages also results in reduced methane production.

Therefore, grazing systems which include rotational grazing will have a tendency to reduce forage maturity and therefore methane production.

Research has also indicated that methane production is less for cattle consuming cool-season grasses relative to warm-season grasses. Again, this is logically a function of the fiber content of the forage. Additionally, legume mixes have been shown to have reduced methane production compared to grass-only forages.

Corn silages have been shown to produce less methane than grass silages. This is possibly due to the concentrate (grain) in corn silage and related fiber content. There are many things producers do when managing forages to improve digestibility. When digestibility is improved, methane production is often reduced.

Supplementation

Today, many cattle are fed corn distillers grains either as a supplement in the growing diet or as a component of the finishing diet. Research in both dairy and beef finishing diets has indicated that corn distillers grains reduces methane emissions in cattle.

This is partially due to the fat content of the corn distillers grains. Fat has been shown to be toxic to methane-producing bacteria in the rumen. Additionally, no methane is produced from ruminally undegradable protein, and in distillers grains, about 60 percent of the crude protein is ruminally undegradable.

Limit-feeding

Limit-feeding a highly digestible diet can be a way to reduce the total amount of dry matter fed while maintaining the desired performance if the nutrient needs of the animal are met. This reduced intake may increase the digestibility of the diet and has been shown to decrease methane production.

The reduced methane production is likely a function of increased concentrate or nutrient-dense byproducts in the diet and a decreased proportion of lower-quality roughages. Concentrates and fats have been shown to decrease methane production.

During the widespread drought in 2011-2013, many producers chose to limit-feed cows in confinement to remove them from pastures struggling from drought conditions. This is another example of how beef producers have improved efficiency while caring for the environment.

Ionophores

The use of low-quality forages is necessary, at least for part of the production cycle, in most cattle operations. Therefore, measures to improve the utilization of these forages are economically as well as environmentally important.

Many studies have documented that including ionophores (examples: Rumensin, Bovatec) in low-quality forage-based diets improves digestibility, intake and performance.

Research recently conducted at the University of Nebraska has also shown ionophores to mitigate methane production on a low-quality forage diet. In that study, methane production was reduced by 16 percent when monensin was included in a low-quality forage diet, but methane production was unaffected when monensin was included in a high-quality diet.

Cattle producers: Stewards of the environment

Cattle producers have worked for generations to provide an efficient and economical product for consumers while preserving forage resources for generations to come. Many of the production practices commonly employed by cattle producers have methane mitigation capabilities.

As cattlemen understand these concepts, it will allow them to better explain to consumers and environmentalists the role cattle producers undertake every day to reduce the carbon footprint of beef production.

Additionally, understanding mitigation strategies will allow producers to continue to become more efficient and continue to decrease the carbon footprint of beef production.  

• Karla H. Jenkins

• University of Nebraska – Lincoln
• Panhandle Research and Extension/li>
• Email Karla H. Jenkins