Kris Johnson – Research
The focus of my research program is the use of nutrients by the beef animal. This research is important for several reasons.Understanding and enhancing the use of dietary energy by beef cattle will ultimately lead to more sustainable production of beef.Governmental agencies are examining the impact of livestock on the environment and imposing regulations by which farmers and ranchers must abide. For sustainable production of food we must develop sound mitigation practices.
Beef production efficiency can also be improved though effective use of by-product feed resources by reducing feed input costs. With mandated reductions in field burning, bluegrass straw is a product available to beef producers in the Northwest. We investigated methods by which bluegrass straw could become a valuable commodity for both grass seed growers and livestock producers and determined the feeding value of grass seed straw pellets for growing beef and dairy heifers, examined ammoniation of straw, and addition of fibrolytic enzymes at feeding to enhance its value. All strategies appear to increase the feeding value of the straw but will require additional financial input by either the seed grower or producer. Recently, we completed an undergraduate research project that determined that feed costs for growing heifers could be lowered with the replacement of alfalfa with liquid feed supplements. Heifer performance was unchanged.Another method by which beef production efficiency can be enhanced is through our understanding of cellular and subcellular processes that occur in the mitochondria. Recently we examined the impact of body weight loss, fat mobilization, in beef cows on the genes associated with protecting the mitochondria (Brennan et al., 2009 a,b). This work identified several places that the animal changes gene expression to handle the potential for damage due to fat metabolism in the mitochondria. These data not only provide basic information regarding ruminant physiology, but also provides us the opportunity to examine specific places to potentially select for efficiency.Future goals. We intend to continue to work on animal energy metabolism to examine the whole animal energy requirements of cattle so appropriate feeding strategies can be developed to meet their needs. Future work is planned to examine animal-to-animal variation in energy metabolism on a mitochondrial level. We plan to examine the animal by mitochondria by genome interactions. Future progress in animal nutrition and selection will be a result of genetic selection for efficient individuals.
Environmental sustainability. While it is certain that ruminant produce gases that impact the atmosphere, there is considerable uncertainty as to the extent of this contribution. Prior to the implementation of public policy decisions, actual ruminant contributions must be determined and valid techniques must be developed to measure these emissions. To develop these techniques, we work with the atmospheric scientists from the College of Engineering. We developed and validated a method using an inert gas tracer that allows sampling and quantification of methane emissions from free ranging ruminants and used the tracer technique to determine the actual contribution of the major classes of ruminant livestock to the United States ruminant methane budget. This project, funded by the Western Regional Center of the National Institute for Global Environmental Change and the US Department of Energy, resulted in the only methane inventory of cattle in the United States that is derived from actual animal measurements (Westberg et al., 2001; Kebreab et al., 2008). Funding from EPA was continued and we investigated several management options for emission reductions (Awadeh et al., 1998; Johnson et al., 2002). The results of these mitigation studies have been mixed. In all cases, methane reductions could be achieved by enhanced animal productivity (methane produced/unit of product), but not all strategies achieved actual reduction in methane production per day.Our methane emissions research has lead to collaborations across the US and the world. We work or have worked with researchers in Canada, Mexico, Brazil, Uruguay, Japan, China, India, Ukraine, France, Ireland, New Zealand, Australia, Switzerland and Germany. One of these collaborations with Ireland had as its foundation an evaluation of the potential to select pasture plants with high organic acid content to reduce methane emissions by grazing ruminants (Cobb et al., 2009).We also expanded our work to include the development of a differential optical absorption spectroscopy instrument to measure ammonia emissions from dairies (Mount et al., 2002) and are using it to measure emissions from the WSU dairy. This collaboration has led to the development of a whole dairy examination of ammonia emissions (Rumburg et al., 2004; 2006a; 2006b; 2008a; 2008b).Increased attention to the environmental impacts of cattle and CAFO’s on the environment have lead us to work to provide not only real emissions estimates to cattlemen but also to work to provide mitigation strategies that promote real savings in GHG emissions. We have worked with feedlots in the west and in the midwest using state-of-the-art technology to generate emissions and mitigation data.Future goals. Future work will address immediate and future challenges for the livestock industries. For livestock enterprises to exist they must have effective management options to lessen their environmental impact. Additionally, beef cattle CAFO’s need information regarding the extent of emissions and mitigation opportunities and we will work to assist them in gaining this information.