Lime-treated corn stover as a livestock feed input: Economic and environmental implications
There is wide availability of corn stover in many corn growing regions of the United States. As a livestock feed input, corn stover has the potential to be a valuable component in the rations of both dairy and beef cattle. This research assesses the economic viability of lime-treated corn stover as a replacement feedstock primarily for a portion of corn silage in the diets of mid- and late lactating dairy cows and as a replacement feedstock primarily for corn grain in beef cattle. This research also assesses best farmer management practices to mitigate environmental impacts of stover removal. Hypothetical dairy operations and beef feedlots are assumed in Elkhart County, Indiana and Washington County, Indiana, respectively. Data from four dairy feeding trials and three beef feedlot feeding trials are used to determine lime-treated corn stover’s economic viability as a livestock feed input. Data from the Landscape Environmental Assessment Framework is used to quantify the environmental impacts resulting from the ration substitutions in the feeding trials. For both dairy and beef operations, feed rations including lime-treated corn stover were always cost-effective compared to the control rations. Only dairy feeding trial one produced a negative income over feed cost (IOFC) calculation, where a decrease in milkfat production compromises the profitability of the feed substitution. The average annual increase in returns per lactating cow on a dairy farm when lime-treated corn stover was included in feed rations was $119.42/cow. The average annual increase in returns per beef feedlot animal was $40.82/head when fed lime-treated corn stover. This research did not consider potential benefits from feeding lime-treated corn stover to other segments of the dairy herd, such as replacement heifers. Environmental impacts considered were soil erosion, changes in soil organic carbon, and rate of nitrate leaching. Values were assigned to these environmental categories, and impacts from specific crop rotation changes were integrated into the economic analysis. Crop rotations involving corn silage were the most environmentally degrading, and corn silage could only be grown sustainably when managed with a winter cover crop. The incorporation of environmental values to the economic values of the feed substitutions can impact the social outcome of the feed substitution. In general, as the rate of corn stover harvest increases to supply stover for the feed substitutions, the more likely the social impact of the feed substitution will become negative. However, this outcome is dependent upon the value of soil erosion used in the analysis, which is a topic for future research.
Tyner, Purdue University.
Environmental economics|Agricultural economics
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