2013 Annual Report
Objective 1: Produce a 12-month supply of pasture-based beef by expanding the harvest window with retention of acceptable meat quality. Subobjective 1.1: Evaluate the use of variation in frame scores of sire and dams and different creep grazing systems to expand the harvest window of grass-fed beef. Subobjective 1.2: Develop soil, plant species and plant/animal managements for heifer replacement and pasture finishing of cattle. 1.2.1 Heifer wintering systems. 1.2.2 A predictive model for sustained pasture production. 1.2.3 Alternative forage species and nitrogen sources. Subobjective 1.3: Quantify the costs, revenues, and profitability associated with a 12-month production system. Objective 2: Develop criteria for pasture raised beef that define “the window of acceptability”. Subobjective 2.1: Quantify performance efficiency of cattle in pasture-based forage systems. 2.1.1 Estimate residual feed intake (RFI) of forage-fed cattle. 2.1.2 Quantify actual intake of grazing cattle during finishing. 2.1.3 Evaluate utilization of nutrients from forage and their transformation into end products. 2.1.5 Identify life cycle risk factors relevant to meat quality. 2.1.6 Assess economic and market implications of end product production of differing grades. Subobjective 2.2: Define “window of acceptability” by relating animal production systems, meat quality and consumer parameters. Objective 4: Develop tools for pasture-based beef producers to assess and manage risk. Subobjective 4.2: Compare economics and risk potential of different soil, plant and animal systems supporting winter stock gain of at least 1 lb. per day. Subobjective 4.3: Develop risk-profitability decision tools for producers.
Grazing management: Grazing grassland most susceptible to quality deterioration (permanent grassland) before tall fescue (less susceptible to winter damage) improved liveweight gain of steers. Winter grazing and feeding haylage on pasture increased quality and quantity of subsequent forage in Spring and Summer. Care must be taken to avoid bare spots in Spring due to uneaten or poorly distributed haylage. Stockpiled forage lasted until early January when conserved forage was fed until April. Tall fescue produced most herbage and herbage mass declined more quickly on orchardgrass and pastureland. Orchardgrass had the highest and pastureland the lowest crude protein concentration, but differences were small. No differences were found in animal performance, however, with early and persistent snow cover some supplementation with pelleted soybean hulls was required to maintain animal gains. Furthermore, wintering stockering system had no effect on metabolic efficiency of animals when tested immediately prior to spring turn out. The pastureland system was the one requiring most supplementation, the only one requiring no supplementation was orchardgrass with haylage. Over the last three years of the project the areas were grazed in sequence from November to January. Animals initiated grazing on pastureland, continued on orchardgrass and ended on tall fescue. No differences were found between grazing treatments in final weight of steers. Feeding hay on grassland from January to March increased the proportion of forbs in the vegetation. Including sheep with cattle that graze grassland on which hay was fed from January to March, reduced the presence of forbs and improved the botanical composition of the grassland. Multispecies grazing in spring also improved ground cover the following winter.
Pasture Growth Responses and Nutritive Value: Date of initiation of spring grazing has more impact on subsequent seasonal herbage production than does previous fall grazing severity. Early spring grazing appears to penalize total-season forage utilization. Implementation of improved pasture and grazing management practices from this research could improve economic returns from, and productivity and soil organic matter improvement of, forage-livestock systems.
Soil Fertility: We quantified the effects of dolomitic lime and water availability on sudangrass and red clover forage quality, the effect of landscape position on humic acid-meditated P solubilization and the effects of water availability and soil pH on N and P response in bluegrass and white clover. We also developed soil order specific lime calibration curves.
Soil Quality/Landscape Attributes/Time: Biomass production in hayfields under winter grazing at lower landscape positions was more susceptible to extreme weather conditions (excess rain or drought) than higher and middle elevation areas. Temporal stability in herbage mass was found to be related to elevation. Medium elevation position of the field showed the highest stability measured with Spearman rank correlation index, followed by the higher and the lower landscape positions. Hayfields can be used to extend the grazing season and increase profitability. Hayfields can be used to extend the grazing season due to winter grazing, and increase profitability. There is evidence that single species grazing management, when compared to the mixed, is detrimental to soil structural properties, increasing soil erodibility and compaction. On the other hand, data suggest that the mixed species grazing system affects soil surface properties and soil cover, and as a consequence more runoff is produced in this system than the single species grazing system. The data indicate that, over time, land management practices can affect the sustainability of the grassland based on soil and grassland hydrologic properties. More research is needed to reinforce these findings.
Heifer reproductive performance: We demonstrated that mixed cool-season naturalized pastures can be utilized for stockpiling and grazed intensively without detrimental effects to subsequent stockpiling periods. Also, fall pasture allowance did not affect percentage of heifers reaching puberty by the time of AI. Pregnancy rates for AI tended to be higher for heifers with a higher fall pasture allowance than for heifers with low fall pasture allowance. Fall average daily gain across treatment groups affected the probability of a heifer becoming pregnant by AI. Overall, these studies demonstrate that mixed cool-season naturalized pastures can be effectively stockpiled for fall and winter grazing and delaying the majority of heifer BW gain until 35-44 days prior to breeding have the potential to result in adequate overall pregnancy rates. Also, heifers raised on pasture based systems that are not pregnant and therefore not kept as replacements could be sold as “Pasture Raised Beef”. Although it may be impractical to totally remove stored feeds from winter feeding system, utilizing stockpiled forages to increase the number of days that grazing can replace stored feed has the potential to reduce costs of production while still achieving acceptable heifer performance.
Rumen microbiology: Animal manure deposition affects fertility and sanitary quality of pasture soils. Composition and metabolic capacity of soil microbial populations vary with patterns of fertility and manure deposition on summer pastures. Populations and persistence of antibiotic resistant E. coli vary with patterns of manure deposition on winter pastures. Sites of feeding of supplemental forage in winter pastures should be varied to avoid concentrated areas of manure and uneaten hay. Rumen microbial populations vary as a function of grass-fed diets. Future work should correlate this information with animal carcass quality.
Economic and Market Assessment: Since PBB has the potential to enhance producer income, consumer health and societal wellbeing, we investigated how PBB systems can fit into achieving societal goals of improved environmental quality and energy independence alongside the goal of food production that could be more profitable for producers, more healthy for consumers, and more sustainable for communities. Specifically, we identified the conditions under which a given PBB farm can be structured (i.e., optimal product mix of calves, finished cattle, forage and manure) to contribute simultaneously to meeting both farm-level goals (e.g., enhanced profitability and reduced risk) and to community or societal goals (e.g., on-farm energy production from animal waste and carbon offsets). We also conducted a comprehensive market assessment including retail taste tests from within-project meat cuts, to ascertain how consumers react to and value PBB products relative to grain-finished meats. This information can ultimately be used to set marketing claim standards so that products labeled "Appalachian Pasture Raised Beef" can be sold at the retail level and consumers can be assured of product quality and consistency. Likewise, information from the risk assessment can help producers make better management decisions.
Risk Assessment and Management: We developed simple to use Excel computer models that enable farmers to evaluate economic risk for forage species and mixtures used on farms in the region. Weather data bases for all states in the region were developed as well as generalized rainfall probabilities for use in these models. These models are being implemented in the Pasture Land Management System (PLMS) software to enable them to make stochastic estimates of production and economics in pasture based livestock systems. The PLMS team, composed of VT and WVU faculty, has completed the addition of the risk component to the PLMS model. We also developed Excel worksheets using Excel stochastic functions to model variability in cool-season and warm-season pasture systems using historical NOAA weather data. The weather data is summarized by county for all states east of the 100th meridian. Finally, as documented in previous progress reports, we developed a set of user-friendly on-line decision support tools to assist producers better manage risk.