Quantification of antimicrobial usage in adult cows and preweaned calves on 40 large Wisconsin dairy farms using dose-based and mass-based metrics.

Use of antimicrobials in animal agriculture is under increasing scrutiny, but the quantity of antimicrobials used on large US dairy farms has not been evaluated using data from large farms and different metrics. This study investigated total antimicrobial usage (AMU) in adult dairy cows and preweaned calves (PWC) and contrasted 2 metrics used for measurement of AMU. Wisconsin dairy farms were eligible if they had >250 lactating cows, maintained computerized animal health records, and were willing to allow researchers access to treatment records. Animal health data for a 1-yr period was retrospectively collected from computerized records, and a farm visit was performed to verify case definitions and recording accuracy. Both dose-based (animal daily doses; ADD) and mass-based (total mg of antimicrobials per kg of body weight; BW) metrics were calculated at the herd, cow, and PWC levels. Descriptive statistics for AMU were examined for both age groups. Mean AMU was compared among active ingredients and route of usage using ANOVA models that included farm as a random variable. At enrollment, farms (n = 40) contained approximately 52,639 cows (mean: 1,316 ± 169; 95% CI: 975, 1657) and 6,281 PWC (mean: 180 ± 33; 95% CI: 112, 247). When estimated using ADD, total herd AMU was 17.2 ADD per 1,000 animal-days (95% CI: 14.9, 19.5), with 83% of total herd-level AMU in adult cows. When estimated using the mass-based metric, total herd AMU was 13.6 mg of antimicrobial per kilogram of animal BW (95% CI: 10.3, 17.0), with 86% of total AMU used in adult cows. For cows, 78% of total ADD (15.8 ADD per 1,000 cow-d) was administered as intramammary (IMM) preparations. In contrast, when AMU was estimated using a mass-based metric, IMM preparations represented only 24% of total AMU (12.1 mg of antimicrobial/kg of cow BW). For cows, ceftiofur was the primary antimicrobial used and accounted for 53% of total ADD, with 80% attributed to IMM and 20% attributed to injectable treatments. When estimated using a mass-based metric, ampicillin was the predominant antimicrobial used in cows and accounted for 33% of total antimicrobial mass per kilogram of BW. When AMU was estimated for PWC using ADD, injectable antimicrobials represented 79% of total usage (28.3 ADD per 1,000 PWC-d). In contrast, when AMU was estimated for PWC using a mass-based metric, injectable products represented 42% of total AMU, even though more farms administered antimicrobials using this route. When AMU in PWC was summarized using ADD, penicillin represented 32% of AMU, and there were no significant differences in ADD among ampicillin, oxytetracycline or enrofloxacin. When a mass-based metric was used to estimate AMU in PWC, oral products (sulfadimethoxine and trimethoprim-sulfa) represented more than half of the total AMU given to this group. Overall, these results showed that choice of metric and inclusion of different age groups can substantially influence interpretation of AMU on dairy farms.

Use of the North American guidelines for children's agricultural tasks with Hmong farm families.

This literature review synthesizes available studies on Hmong agricultural practices, patterns of childhood growth and development of Hmong children in the context of injury prevention, and potential application or adaptation of the North American Guidelines for Children's Agricultural Tasks (Lee and Marlenga, 1999) for Hmong children working in the U.S. Data from qualitative interviews, focus groups, case studies, and surveys were collected, categories were determined, and themes were identified. Field tools and practices, gender roles, and reasons for farming were examined, as well as physical and cognitive development of Hmong children and Hmong parenting techniques to describe factors related to farm task assignment of children. Current agricultural practices of Hmong in the U.S. can be described as generally small-scale operations that use mainly hand tools, manual labor, and local direct-marketing techniques. Specific practices include thinning, weeding, and hoeing; carrying tools, buckets, or baskets; setting plant supports; and watering. Hmong children appear to be given greater amounts of responsibility at earlier ages than North American children. Hmong parenting practices, as would be used in task assignment, are somewhat more authoritarian-based and lead to psychosocial skills that are more group-oriented than individual-oriented. Hmong children were found to be shorter than children in the U.S. of the same ages. This review suggests that the NAGCAT cannot be literally translated and disseminated to Hmong farming families as an injury prevention intervention. Further information is needed about what farm tasks Hmong children do and how Hmong parents assign those tasks to children.

The impact of biotechnology on agricultural worker safety and health.

Biotechnology applications such as the use and production of genetically modified organisms (GMOs) have been widely promoted, adopted, and employed by agricultural producers throughout the world. Yet, little research exists that examines the implications of agricultural biotechnology on the health and safety of workers involved in agricultural production and processing. Regulatory frameworks do exist to examine key issues related to food safety and environmental protection in GMO applications. However, based on the lack of research and regulatory oversight, it would appear that the potential impact on the safety and health of workers is of limited interest. This article examines some of the known worker health and safety implications related to the use and production of GMOs using the host, agent, and environment framework. The characteristics of employers, workers, inputs, production practices, and socio-economic environments in which future agricultural workers perform various tasks is likely to change based on the research summarized here.

Injuries among children and youth in farm households: Regional Rural Injury Study-I.

OBJECTIVES: The purpose of this effort was to identify the incidence and consequences of both farming and non-farming related injuries and the potential risk factors for farming related injuries among children and youth, aged 0-19 years, who lived in farm households in a large region of the United States. METHODS: Data were collected from randomly selected farm households during 1990. Rates and rate ratios with 95% confidence intervals were calculated for sociodemographic and exposure variables. Multivariate analyses were conducted, using a priori and backward stepwise logistic regression models. RESULTS: Within the population of 3,939 farm households and 13,144 persons, children and youth accounted for 33%. Injury rates for farming and non-farming sources, respectively, were 1,683 and 6,980 per 100,000 persons. Animals (40%) were the primary sources of the farming operation related injuries; sports/recreation sources (61%) were associated primarily with non-farming related injuries. Of the farming and non-farming operation related injury cases, 83% and 90%, respectively, required some type of health care; moreover, 17% and 24%, respectively, were restricted from regular activities for one month or more. Through multivariate analyses, important increased rate ratios were observed for operating a tractor, working with dairy cattle, and being male. Increased rate ratios for working with beef cattle, operating a harvester, and living on a farm where there were all terrain vehicles in use, and a decreased rate ratio for living on a farm where there were sheep, appeared suggestive. CONCLUSIONS: Based on the relevant rates, injury consequences, and potential risk factors identified, injuries to children and youth on farms represent a significant problem. Future analytic studies are essential to identify more specific risk factors that can serve as a basis for development of appropriate intervention efforts. Given the population at risk, and the opportunity for intervention in this unique occupational setting, many of these injuries may be readily amenable to prevention efforts.

Evaluation of a microwave and infrared human-presence sensing system for agricultural equipment.

The potential use of electronic safety sensors to protect operators from agricultural equipment with rotating hazards has been identified and discussed as a possible means to prevent traumatic entanglement injury. A multi-sensor human-presence sensing system to protect persons approaching a rotating PTO shaft powering a stationary implement was developed using commercially available, passive infrared and microwave sensors. A control and data acquisition system was designed and constructed to evaluate sensor performance and response. The sensor system performed well during 822 warm weather test passes in which a person approached the potentially hazardous area near the drawbar and PTO/IID located between an IH 986 test tractor and a self-unloading forage wagon. During the 822 test passes, there were no false alarms and no misses. Operators approached the hazard space walking from 92 to 227 cm/second. During tests, the sensing system yielded warning times generally between 0.5 and 1.0 seconds, providing an estimate of the time available to accomplish machine shutdown or operator warnings. Additional cold weather tests caused the control and data acquisition hardware to function erratically. This work suggests that multi-sensor human detection systems have the potential to reduce false alarms through redundancy when more than one sensor is required to detect a person before the system signals a "detect" condition. However, the use of multiple, redundant sensors also increases the potential for a "miss." Further work is needed to determine whether these types of sensor can yield timely enough information to prevent injury via mechanical shutdown or operator warnings.

Machinery-related injuries: regional rural injury study--I (RRIS--I).

Although it is known that farm machinery is a source of serious and catastrophic farm work-related injuries, little is known about the magnitude of, and potential risk factors for, this problem. The study population is from the five-state Regional Rural Injury Study--I (RRIS--I) that included 3,939 farm households and 13,144 persons who were interviewed about their injury experience and farming operation-related exposures during 1990. Rates were calculated for sociodemographic variables and various exposures pertinent to large farm machinery (excluding tractors). Multivariate analyses were conducted using logistic regression, based on a model developed a priori and further confirmed using backward stepwise logistic regression. Among the total farming-related injury events (n = 764), 151 (20%) were related to large machinery use (1,127 injured persons per 100,000 persons per year). Through multivariate analyses, several variables were associated with elevated rate ratios that were important in both models: hours worked per week on the farm (40-59, 60-79, 80+); operation of an auger; field crops as the enterprise requiring the most time; and male gender. In addition, in the backward stepwise model, certain marital status categories (married; separated/widowed/divorced) were also associated with elevated rate ratios that were important. The majority of injury events occurred while persons were lifting, pushing, or pulling (21%), adjusting a machine (20%), or repairing a machine (17%). While only 5% of the cases were hospitalized, 79% required some type of health care. Among all injured persons, 34% were restricted from regular activities for 1 week or more and 19% were restricted for 1 month or more; 25% continued to have persistent problems. In summary, the RRIS-I permitted one of the most comprehensive studies of agricultural machinery-related injuries, to date. The findings indicate that these injuries represent a significant problem, based on the relevant rates, potential risk factors, and consequences from trauma.

A population-based study of tractor-related injuries: Regional Rural Injury Study-I (RRIS-I).

Although tractors account for the majority of fatal farming-related injuries, little is known about the magnitude of this problem. The study population in this article was obtained from the five state Regional Rural Injury Study-I (RRIS-I) database that included 3939 farm households and 13,144 persons interviewed during 1990. Rates were calculated for sociodemographic variables and various exposures; logistic regression was used to calculate the relative risks and respective confidence intervals. Among the total farming-related injury events (n = 764), 65 (8.4%) were related to regular tractor (> or = 20 horsepower) use (495 injured persons per 100,000 persons per year). The rates increased incrementally for those persons working between 20 to 39 and 60 to 79 hours per week (range, 529 to 1430 per 100,000 persons). Among the 12 rollover events, there were only three injuries. The majority of injury events occurred while persons were mounting or dismounting the tractor (42%). Although only 7% of the cases were hospitalized, 83% required some type of health care. Among all injured persons, 43% were restricted from regular activities for 1 week or more and 20% were restricted for 1 month or more; 28% continued to have persistent problems. The finding of the large proportion of events associated with activities of mounting and dismounting suggests a need to investigate specific design characteristics of the tractors associated with these events and, in general, the tractors to which the population is exposed.