Managing organic dairy herd health: Current roles and possible future roles for veterinarians with organic dairy clientele.

This study aimed to understand the veterinary-client relationship and perspectives in organic dairy production systems. Twenty-three organic dairy producers and 12 veterinarians were interviewed using semi-structured, one-on-one interviews. Consultation with local veterinarians was typically infrequent, as there was greater reliance on other producers and organic industry professionals for advice on dairy herd health management, perhaps due to a shared focus on organic farming principles. Organic producers generally consulted local veterinarians most frequently to develop vaccine protocols, address animal health emergencies, and gain reproductive services. Common reasons organic producers cited for not regularly consulting a local veterinarian included the cost of veterinary services and a perception that local veterinarians have limited experience with organic systems and products. Some producers also expressed the idea that infrequent veterinarian usage is indicative of a healthy herd. Meanwhile, local veterinarians reported that organic dairy producers often delayed consulting them about individual cases until animal health problems were severe. Local veterinarians also identified challenges in servicing organic herds, such as the lack of standardized regulations between different organic certifiers and limited safety and efficacy data for many herd health products used by organic producers. In addition, their formal training generally did not include organic herd health strategies. Organic dairy clients were typically a small fraction of the overall workload for local veterinarians, which precluded their ability to accumulate experience. In contrast, a handful of specialized veterinarians in the organic milk processing industry work more frequently with organic producers and have published most of the available resource materials on organic dairy herd health. Veterinary-client partnerships could be improved through more open communication and discussion of the challenges identified in this study and through participatory research and outreach engagement that includes local veterinarians, organic certifiers, organic industry veterinarians, and producers.

Organic dairy producer experiences and decisions related to disease prevention and treatment.

Organic dairy producers have distinct perspectives, approaches, challenges, and experiences when managing herd health, but little research has been conducted to develop a deeper understanding of producer decision-making related to disease-prevention and treatment strategies. We used 23 semi-structured interviews with organic dairy producers to better understand their perceived herd health challenges and overall disease-prevention strategies; decision-making and attitudes related to vaccination; and approaches to the treatment of infectious diseases using alternative or conventional antimicrobial therapies. Organic dairy producers reported improvements in overall animal health after they transitioned from a conventional to an organic system. Outdoor access, a balanced forage-based diet, and animal and environmental cleanliness were reported as the predominant disease-prevention measures. Over half of producers vaccinated their animals, and almost all preferred to use vaccines sparingly. Among producers who did not use vaccines, reasons cited were low perceived risk for infectious disease and minor vaccine safety concerns, yet many were not opposed to using vaccines in the future. Non-antimicrobial therapies were viewed as alternative effective treatment strategies for most common infectious diseases. Producers used antimicrobials very rarely and generally reserved them for severe cases when alternative treatments failed. Because US organic standards prohibit selling milk from cows that have ever been treated with antimicrobials, producers described the decision to use antimicrobials as extremely challenging and involved balancing considerations of economics, convenience, and animal welfare. This research fosters a better understanding of organic dairy producers' disease-prevention and treatment strategies and could be used by veterinarians and other animal health specialists to facilitate services for organic clients.

Validation of feed and manure data collected on Wisconsin dairy farms.

An on-farm study of 54 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 land application reflected literature values of manure N and P excretion, collection, and loss. Calculated feed N and P use efficiencies (18 to 33% and 18 to 35%, respectively) fell within ranges expected for dairy farms. This suggested that our on-farm methods of data collection provided reliable information on relationships among feed N and P intake, secretions in milk, and excretion in manure. On stanchion farms, there were no differences between farmer estimates (kg/farm) of manure P collected (1,140) and land-applied (1,210) and what would be calculated from the literature (1,340). On freestall farms, there were no differences in amounts (kg/farm) of manure P collected (2,889), land-applied (2,350), or literature estimates (2,675). Manure P applications (kg/ha) to tilled cropland would be similar using either farmer estimates of manure collected and land-applied, or literature estimates. The data provided a snapshot of Wisconsin industry practices, as well as 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.

Manure collection and distribution on Wisconsin dairy farms.

Manure management plans require knowing the amount of manure produced, collected, and available for land-spreading. Whereas much information is available to calculate manure production, little is known about the types and amounts of manure actually collected on typical dairy farms. This study of 54 representative Wisconsin dairy farms showed significant regional, housing, and herd size differences in collection of manure from lactating cows (Bos taurus), dry cows, and heifers. Significantly (P < 0.05) less manure is collected in the hilly southwest (56% of total annual herd production) than in the undulating south central (72%) or the flat northeast (68%) regions. Collection of lactating cow manure is significantly (P < 0.05) lower from stanchion (66% of total annual production) than free-stall (89%) housing, and significant (P < 0.05) positive relationships were found between the number of lactating cows a farm keeps and the percentage manure collected. Average annual manure N (range of 116-846 kg N ha(-1)) and P (range of 24-158 kg P ha(-1)) loading rates in areas where manure goes uncollected was highest in unvegetated barnyards followed by vegetated and partially vegetated outside areas. Once uncollected manure was accounted for, average annual loading rates on cereal cropland ranged from 128 to 337 kg ha(-1) of manure N, and from 45 to 139 kg ha(-1) of manure P. Compared with adjacent cropland, the accumulation of uncollected manure has vastly increased soil test P, K, and organic matter levels in outside areas. Manure management on Wisconsin dairy farms with small to medium herds might require assistance in managing manure in outside confinement areas to reduce the risk of impairing surface and ground water quality.

A survey of selected heavy metal concentrations in Wisconsin dairy feeds.

Heavy metals such as zinc (Zn), copper (Cu), chromium (Cr), arsenic (As), cadmium (Cd), and lead (Pb) are potential bioaccumulative toxins of the dairy production system. The heavy metal content of dairy feeds, however, remains poorly documented, particularly in the United States. This survey determined the heavy metal content of 203 typical dairy ration components sampled from 54 dairy farms in Wisconsin. Lowest heavy metal concentrations were found in homegrown alfalfa (Medicago sativa L.) hay and haylage, and corn (Zea mays L.) grain and silage. Highest metal concentrations were found in purchased feeds, particularly mineral supplements, and to a lesser extent corn- or soybean-based concentrates. Zinc and Cu were found at the highest concentration in complete dairy (total mixed and aggregated component) rations and reflected the deliberate addition of these metals to meet animal nutrient requirements although more than half the farms fed Cu and Zn above US recommended levels. Concentrations of Cr, As, Cd, and Pb were present in much lower concentrations and decreased in the order Cr > As > Pb > Cd. No complete Wisconsin dairy ration contained heavy metal concentrations above US maximum acceptable concentrations and would be unlikely to induce any toxic effects in dairy cattle. Concentrations of Cd in complete dairy rations were closest to US maximum acceptable concentrations, suggesting the greatest potential long-term risk to exceed US maximum acceptable concentrations if whole farm levels of Cd were to increase in the future. With the exception of Pb, the main sources of Zn, Cu, Cr, As, and Cd in the complete dairy feed ration originated from imported feed. The continued importation of heavy metals in dairy feed is likely to be associated with accumulation of these metals in soils where manure is applied. Although the cycling of many heavy metals through the dairy food chain will be limited by factors such as a soil's cation exchange capacity, pH, salinity, and phytotoxicity of the metal, these may be less limiting for Cd. It is important that sources of Cd in the dairy system are identified and minimized to prevent problems associated with Cd accumulation in the dairy soil system arising over the long-term.

Producer satisfaction, efficiency, and investment cost factors of different milking systems.

A modernization survey was used to determine producer satisfaction, efficiency, and investment cost measures of different milking systems. The 301 producers included in this study expanded herd size by at least 50% for smaller herds (60 to 100 cows), or 40% for larger herds, (>100 cows) between 1994 and 1998. The milking systems analyzed and compared were stall barn with pipeline, flat barn parlor walk through and back-out, and herringbone or parallel parlor in old barn or new building. Investment costs per cow were higher for pit parlor in new building, $979. Parallel parlors had a higher cost per milking unit, $13,201, and cost per cow, $860, than herringbone, $8944 and $582, respectively. Herringbone parlors were used more hours per day, 10.75, than parallel parlors, 8.84, of similar size. Pit parlors in new buildings were more labor efficient, as measured by cows per worker hour, than stall barns with pipeline or flat parlor or pit parlors in old barns. Herringbone and parallel parlor in new building were similar for cows per hour (82 and 83) and cows per worker hour (41 and 43). Parallel or herringbone parlors in old barns had fewer cows per hour (63 and 58) than parallel or herringbone parlors in new buildings. Survey respondents showed greater satisfaction for time spent milking, physical comfort of milker, and milk quality for parlor types over stall barn with pipeline. Safety of operator satisfaction was higher for pit parlors than flat parlors or stall barn. No difference in satisfaction was observed between parallel and herringbone parlors.

Modeling milk production and labor efficiency in modernized Wisconsin dairy herds.

The 1999 Wisconsin Dairy Modernization Project was conducted to examine variation in milk production and labor efficiency among herds that had recently expanded. Data were obtained from a sample of Wisconsin herds that expanded between 1994 and 1998. Using rolling herd average milk production in 1998 as the dependent variable in the milk production model, milking frequency, bovine somatotropin use, sprinkler use, average linear somatic cell score, average age at first calving, average days dry, and rolling herd average milk production in 1994 predicted 69% of the variation in milk production. Milking three times daily, using bovine somatotropin, using sprinklers to cool cows, and decreasing linear somatic cell score, age at first calving, and days dry were associated with increased milk production. Each of these variables supports previous research from designed experiments with on-farm results. Variation in milk production is determined primarily by differences in management ability and management practices employed by the dairy producer. Using cows per full-time equivalent as the dependent variable in the labor efficiency model, acres per cow, number of people involved in the milking operation, milking system type, herd size, and interactions between milking system types and herd size predicted approximately 43% of the variation in labor efficiency. As expected, labor efficiency increased with larger herd sizes, fewer acres per cow, and fewer people involved in the milking process. Parallel milking parlors were associated with the highest cows per full-time equivalent followed by herringbone parlors, flat barns, and stall barns.

An overview of experiences of Wisconsin dairy farmers who modernized their operations.

Wisconsin dairy producers who modernized their operations between 1994 and 1998 had positive feelings about their expansion experiences, accompanied by increased production and improved profitability and quality of life. The average herd in this survey experienced increased production during the 5-yr period studied. Nearly all producers were satisfied with their expansion experience. The negative effect on milk production normally associated with expansion was minimal for most years and did not exist if all herds were summarized together. Managing labor appeared to be the most daunting challenge facing producers following expansion. Respondents who built all new facilities observed higher production, greater labor efficiency, and satisfaction with measures of profitability and quality of life than respondents who modified facilities or added no new facilities. As herd size increased, milk production, labor efficiency, and satisfaction with herd performance, profitability, and quality of life increased. Producers who built all new facilities spent less time on farm work, more time managing employees, and had less difficulty finding, training, supervising, and keeping farm employees than producers who modified facilities or added new facilities to existing operations. Larger herds were associated with an increased reliance on nonfamily labor. Managing labor appears to be an easier task for managers of larger herds. The most difficult challenges for producers who modernized their operations were with labor management, financing, and loan procurement, construction and cost overruns, and feet and leg health. Difficulties with expansion differed little between expansion types (same type, some new, or all new facilities) or herd sizes.

A comparison of free-stall barns used by modernized Wisconsin dairies.

A primary objective of the Wisconsin Dairy Modernization Survey was to compare features of free-stall barns available to dairy producers. This study used data from a large random sample of expanding dairy farms to determine whether the theoretical benefits of particular free-stall configurations bear out under on-farm conditions. Comparisons were made among herds using free-stall barns as their primary housing for new versus remodeled facilities, barn design, bedding used, feed-delivery design, manure removal strategies, animal restraint, maternity areas, overcrowding, and cooling methods. Producers who made the transition from tie-stall housing to free-stall housing were satisfied with this decision. New free-stall barns provided a more desirable environment for the herds than remodeled free-stall barns, although initial investments were higher. When new free-stall barns were compared, herds with four-row barns had higher production, lower somatic cell count, and higher stocking rates than herds with six-row barns. Respondents were more satisfied with four- and six-row barns than with two- and three-row barns. Respondents felt sand provided some advantages for cow comfort, while satisfaction with bedding cost and manure handling was higher with mattresses. Dairy Herd Improvement data showed no difference in milk production or somatic cell count for producers who chose sand or mattress-based free stalls. Respondents were more satisfied with the use of drive-through feeding than other feed-delivery designs. Most producers chose to use tractor scrapers to remove manure; however, producers who used automated systems were more satisfied with manure management. Few differences were observed when comparing self-locking head gates to palpation rails. Overcrowding did not have any adverse affect on production or user satisfaction with feed intake or cow comfort. Using supplemental cooling appeared to facilitate higher production.