|Powell, J Mark|
Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/5/2006
Publication Date: 4/15/2006
Citation: Powell, J.M., Jackson-Smith, D.B., McCrory, D.F., Saam, H., Mariola, M. 2006. Validation of feed and manure data collected on Wisconsin dairy farms. Journal of Dairy Science. 89:2268-2278. Interpretive Summary: Feed and manure management data were collected by farmers and a research team on fifty-four representative Wisconsin dairy farms. This data was used to calculate feed nitrogen (N) and phosphorus (P) use efficiencies, and manure N and P excreted, collected and land-spread. The close correspondence between the study's data and literature values indicated that the study provided an accurate snap-shot of Wisconsin dairy industry practices. It also provided good information on the range of feed and manure management practices on individual farms. Improvements to data collection methods would require increased skill and training of both farmers and those responsible for assisting farmers in on-farm data collection. This study showed that farmers are able to provide accurate information on feed and manure nutrient use, which can be used to improve Comprehensive Nutrient Management Plans.
Technical Abstract: An on-farm study of fifty-four representative Wisconsin dairy farms was conducted to evaluate the influence of biophysical and socioeconomic factors on overall feed, fertilizer, and manure nutrient use. This report validates (1) how well data on cow diets, feed analyses and milk production reflected established feed-milk-manure relationships; and (2) how well farmer-recorded data on manure spreading reflected literature values of manure nitrogen (N) and phosphorus (P) excretion, collection and loss. Calculated feed N and P use efficiencies (18-33% and 18-35%, respectively) fell within ranges expected for dairy farms. This suggested that our on-farm methods of data collection provided reliable information on relationships between N and P intake, secretions in milk, and excretion in manure. On stanchion farms, there were no differences (P<0.05) between farmer estimates (kg farm-1) of manure P collected (1140) and spread (1210), or what would be calculated from the literature (1340). On free-stall farms, there were no differences in amounts of manure P collected (2889), spread (2350), or literature estimates (2675). Manure P applications (kg/ha) to tilled cropland would be similar (P<0.05) using either farmer estimates of manure collected and spread, or literature estimates. The data provided an accurate snap-shot of Wisconsin industry practices, as well as accurate information on the range of feed and manure management practices on individual dairy farms. Improvements to data collection methods would require increased skill and training of both farmers and those responsible for assisting farmers in on-farm data collection and analyses.