|Nienaber, John - Jack|
Submitted to: Climatic Change
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2009
Publication Date: 12/1/2009
Citation: Mader, T.L., Frank, K.L., Harrington, J.A., Hahn, G.L., Nienaber, J.A. 2009. Potential Climate Change Effects on Warm-Season Livestock Production in the Great Plains. Climatic Change. 97:529-541. Interpretive Summary: This report presents comparisons of the impact of potential climate change on swine and cattle performance in the United States. Changes in climate are predicted by two different climate models based on carbon dioxide levels of the air. The results of these increases are projected to cause temepratures to rise. While the two models vary in how much temperatures are expected to rise as the carbon dioxide levels increase, each model shows some effect of the predicted temperature rise during the five month period from June through October. The most adverse effect shows a 74% increase in the time needed to grow swine to market weight in the eastern part of the U.S. Some locations show no impact of the predicted changes. However, the predictions show that the southern region will generally be most affected for all three categories of livestock. The predictions should give producers some warning of the possible adverse consequences of the potential environmental changes, along with the most vulnerable locations. Results can benefit livestock managers in adapting their production systems to reduce those impacts on their animals and minimize economic losses.
Technical Abstract: Climate changes suggested by some global circulation models (GCM) will impact livestock production systems in the Great Plains region of the United States. Production/response models for growing swine and beef cattle, and milk-producing dairy cattle, were developed based on summary information contained in the most recent Natonal Research Council publications outlining the nutrient requirements of the respective animals. This study employs the output of two GCM, the Canadian Global Coupled Model, Version I (CGCMI), and the United Kingdom Meteorological Office/Hadley Center for Climate Prediction and Research (Hadley) model, for input to the livestock production/response models. Production output data are presented for five points along each of the three transects in the central U.S. Weight gain of beef cattle and swine were calculated daily beginning June 1 and the number of days for the animal to grow to the target weight were determined for each year (climate scenario). For dairy cattle, daily values of fat corrected milk (FCM) produced (kg) were summed to yield the total production for the season June 1 to October 31. Annual values are averaged for three climate scenarios: baseline, CO2 doubling, and CO2 tripling. For swine, producers face increases in time to slaughter weight as large as 74.1% in eastern parts of the region under the CGCMI CO2 tripling scenario. The Hadley scenarios do not predict the magnitude of production change that the CGCMI model does. A slight northwest to southeast gradient is evident with the southern-most points impacted the greatest. Transect 1 (west side) shows no losses under the Hadley CO2 doubling scenario and minimal losses under the CO2 tripling scenario. Transect 3 (east side) displays losses of up to 40.5% under the Hadley CO2 tripling scenario. For beef, under the CGCMI scenarios when CO2 levels were increased, positive benefits were observed in Transects 1 and 2, although the northwest to southeast gradient which was observed for swine is somewhat evident. Production declines were less than 5% using Hadley scenarios. For dairy, the % change in milk production based on the CGCMI model was slightly greater than the Hadley model. As opposed to the beef and swine projections, no benefits in milk production were found to increasing CO2 levels. On the average, the Hadley scenarios project slightly lower production declines (1.3 to 4.8%) than the CGCMI model (-1.0 to -7.2%). However, differences between the models were less than those observed for beef and swine. Exploration of the effects of climate changes on livestock should allow producers to adjust management strategies to reduce the potential economic losses due to environmental changes.