Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: Six subprojects, most of which are multiyear, were conducted this year. A pasture renovation project was conducted on 5 grazing farms in Wisconsin with the purpose of maximizing productivity of grazing livestock. For each farm, two acre areas of relatively uniform aspect, slope, and productivity were delineated, with each split in half for random assignment of renovation treatments. Renovation treatments involving herbicide, fertilization, and reseeding treatments began in fall 2005 and continued through subsequent years. In spring 2006, some plots were disked and sowed with a mix of two improved grass varieties, Pizza orchardgrass and Bartura meadow fescue. Livestock were excluded from the renovated pastures until July 2006. Plant species composition was quantified by researchers in August 2006 and 2007 with a line-point method. Forage production was measured by farmers, who were supplied with rising plate meters and datasheets and asked to measure standing biomass immediately before and following each grazing or haying event throughout the growing season. Productivity data were analyzed separately for each year with linear mixed-effects models assigning farm as a random effect and renovation status and pasture management as fixed effects. A total of 21 different binary combinations or monocultures of seven pasture grasses and two legumes were evaluated for sward density, seasonal distribution of yield, growth rate after defoliation in the field. A second project surveyed farms throughout the driftless region of the Midwest for presence of meadow fescue. On a small number of farms within this region, we surveyed meadow fescue plants for presence or absence of the endophytic fungus that infects this species. A third project looked at the nitrogen balance of grazing dairy ewes and does. Four sheep and three goat farms were visited and sampled for feed (hay, pasture and grain) neutral detergent fiber, crude protein, indigestible neutral detergent fiber, milk production, fat, protein, urea nitrogen, feces crude protein, indigestible neutral detergent fiber, and urine urea, creatinine, and uric acid. Other projects evaluated fescues and grass and legume mixtures for improving yield and sward density in pastures. A total of 21 different binary combinations or monocultures of seven pasture grasses and two legumes were evaluated for sward density, seasonal distribution of yield, growth rate after defoliation in the field. Forage from 28 days of regrowth from six growth cycles was sampled for determination of species composition and nutritive value. Laboratory analyses of nutritive value and data summary are in progress and the effort will be repeated in the coming season. The aim of the project is to systematically test standard and new alternative species for performance characteristics that have been identified as desirable for maximizing productivity of grazing livestock. A final project reviewed finding of past work on the environmental impact of grazing systems. PARTICIPANTS: USDA-ARS, US Dairy Forage Research Center, Grassworks, WI University of Wisconsin Arlington Experimental Farm. Wisconsin Department of Agriculture and Consumer Protection; More than thirty farmers in the Midwest; Dr. M. Casler, USDA Dairy Forage Research Center; Dr. K. Albrecht, UW Madison Agronomy Department; Dr. J. Lehmkuhler, UW Madison Animal Sciences Department; Dr. D. Combs, UW Madison Dairy Sciences Department; J. Taylor, UW Madison CIAS; S. Neary, UW Madison CIAS; Dr. R. Jackson, UW Madison Agronomy Department; Dr. D. Thomas, UW Madison Animal Sciences Department; Dr. C. Gratton, UW Madison Department of Entomology; Dr. R. Cates, UW Madison CIAS TARGET AUDIENCES: Since pasture-based farming keeps a high percentage of the cropped land in permanent cover, environmental benefits gained from a wider adoption of this practice are apparent. However, recent studies have indicated that there may be considerable economic and social benefits as well. In Wisconsin, the stability and profitability from milk production using grass-based cow feeding systems is greater that conventional confinement herds and that graziers generally express a higher level of satisfaction with their work and life styles. If added benefits such as improved nutritional and flavor characteristics of products derived from pasture-based production and regionalized identities of distinct production areas become effective marketing tools, then such value-added traits may make Wisconsin pasture-based products more competitive in national and international markets. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Renovation of pastures by interplanting with improved grass varieties increased production in the second year, but only with high inputs of fertilizer and herbicide. Overall composition and cover of the pastures was unaffected by renovation techniques, but the increased bare ground but the increased bare ground during the establishment year where weed suppression occurred was undesirable. Replacing existing grasses with improved varieties is effective in boosting productivity but only when managed very carefully. In addition, the economics of such renovations should be considered. Meadow fescue was found on over 300 farms within the driftless region. The highest concentration of meadow fescue coincides with the historical Military Ridge Road. Over 98% of meadow fescue plants we tested were found to contain grass endophytes. For sheep and goats, over the grazing season, daily milk production for ewes averaged 1.98 lb/dl (0.9 kg), 6.8% milk fat, 5.3% milk protein and 29 mg/dl milk urea nitrogen. For does, daily milk production averaged 4.6 lb/d (2.1 kg), 3.1% fat, 2.7 % protein and 31 mg/dl milk urea nitrogen. Dairy ewes consumed pasture as the primary forage source, which averaged 20.3% crude protein (CP). Supplemental grain averaged 10.9% CP. Protein is provided primarily by pasture for dairy ewes. Dairy does consumed both pasture, which averaged 15.3% CP, and hay, which averaged 11.8% CP. Supplemental grain averaged 17.2% CP. Protein is provided primarily from grain in dairy does. Although complete nitrogen balance of the ewes and does has not been calculated, based on initial MUN values, dairy ewes in this trial are excreting excess N in the form of MUN (recommended MUN values range from 14-21 mg/dl). Studying the environmental benefits of managed grazing is challenging and expensive due to the high number of variables and overall complexity of farms, watersheds, and habitats. Some researchers have shown improvements over current agricultural practices by modeling land use scenarios which increased the use of managed grazing and other grasslands. In addition, many farmers and others who observe the agricultural landscape have seen that managed grazing has positive effects on land and livestock; however, the research cited in this report shows mixed results. Overall, research indicates that careful managed grazing practices benefit the environment. Still, questions remain, particularly about carbon sequestration and resource conservation. As these issues grow in importance to society and funding becomes more widely available, it will be increasingly valuable to research and document whether managed grazing can assist in these conservation goals. In so doing, however, there are large differences in management, soil types and slopes, livestock species, stocking density and watershed characteristics that make it hard to generalize about the environmental benefits of managed grazing in Wisconsin and elsewhere.
Publications
- Taylor, J. and Neary, S. 2008. How does managed grazing affect Wisconsin environment Research Report, Center for integrated Agricultural Systems, University of Wisconsin, Madison, WI, 4 pp.
- Casler, M., Albrecht, A., Lehmkuhler, J., Brink, G., and Combs, D. 2008. Forage fescues in the northern USA. Research Report, Center for integrated Agricultural Systems, University of Wisconsin, Madison, WI, 21 pp.
- Lehmkuhler, J. and Cox, T. 2008. Forage-based beef production in the bio-energy era. Forage Focus. Forage First, Midwest Forage Assoc., pg.10-11
- Lehmkuhler, J. 2008. Value of maintaining legumes in stands increasing. Forage Focus. Forage First, Midwest Forage Assoc., pg. 4-5.
- Ramos, M., Lehmkuhler, J. and Albrecht, K. 2008. Tall fescue and clovers for stocker systems in southwest Wisconsin. Proceedings: Grazing Pays, 2008 Grassworks Conference.
- Brink G. E. and Jackson, R.D. 2008. Renovation and management effects on pasture productivity under rotational grazing. Forage Focus, Forage First, Midwest Forage Assoc p. 4-5
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