Two-Dose Ceftiofur Treatment Increases Cephamycinase Gene Quantities and Fecal Microbiome Diversity in Dairy Cows Diagnosed with Metritis.

Antimicrobial resistance is a significant concern worldwide; meanwhile, the impact of 3rd generation cephalosporin (3GC) antibiotics on the microbial communities of cattle and resistance within these communities is largely unknown. The objectives of this study were to determine the effects of two-dose ceftiofur crystalline-free acid (2-CCFA) treatment on the fecal microbiota and on the quantities of second-and third-generation cephalosporin, fluoroquinolone, and macrolide resistance genes in Holstein-Friesian dairy cows in the southwestern United States. Across three dairy farms, 124 matched pairs of cows were enrolled in a longitudinal study. Following the product label regimen, CCFA was administered on days 0 and 3 to cows diagnosed with postpartum metritis. Healthy cows were pair-matched based on lactation number and calving date. Fecal samples were collected on days 0, 6, and 16 and pooled in groups of 4 (n = 192) by farm, day, and treatment group for community DNA extraction. The characterization of community DNA included real-time PCR (qPCR) to quantify the following antibiotic resistance genes: blaCMY-2, blaCTX-M, mphA, qnrB19, and the highly conserved 16S rRNA back-calculated to gene copies per gram of feces. Additionally, 16S rRNA amplicon sequencing and metagenomics analyses were used to determine differences in bacterial community composition by treatment, day, and farm. Overall, blaCMY-2 gene copies per gram of feces increased significantly (p ≤ 0.05) in the treated group compared to the untreated group on day 6 and remained elevated on day 16. However, blaCTX-M, mphA, and qnrB19 gene quantities did not differ significantly (p ≥ 0.05) between treatment groups, days, or farms, suggesting a cephamycinase-specific enhancement in cows on these farms. Perhaps unexpectedly, 16S rRNA amplicon metagenomic analyses showed that the fecal bacterial communities from treated animals on day 6 had significantly greater (p ≤ 0.05) alpha and beta diversity than the untreated group. Two-dose ceftiofur treatment in dairy cows with metritis elevates cephamycinase gene quantities among all fecal bacteria while paradoxically increasing microbial diversity.

Emissions of hydrogen sulfide from a western open-lot dairy.

Hydrogen sulfide (H2 S) emissions are considered hazardous to the environment. Animal agriculture operations must therefore report emissions exceeding a threshold to the National Response Center. Estimating the emissions from operations is needed because monitoring at all operations is not possible. However, little is known about H2 S emissions from open-lot dairy operations commonly found in dry regions. Daily mean H2 S emissions from a Texas open-lot dairy were relatively uniform over the year. Emissions were greatest during the fall when air temperatures were relatively high and vapor pressure deficits were low. Higher air temperatures and wind speeds and lower surface wetness corresponded with higher mean hourly emissions in winter, spring, and summer. Hourly mean emissions in the fall differed substantially from those of the other seasons. These high fall emissions appear to have been associated with unreported producer activity of hauling manure from the manure windrow storage onto the surrounding fields. Mean annual live animal basis emissions were 3.6 g d-1 hd-1 . Annual mean emissions for the entire 3,400 head dairy were 12 kg d-1 . The maximum measured daily emissions for this 3,492-cow dairy were 33.1 kg d-1 .

Challenges and opportunities for manureshed management across U.S. dairy systems: Case studies from four regions.

The manureshed represents cropland needed to safely assimilate manure nutrients from an animal feeding operation. Dairy manuresheds can be contained on-farm but may need to involve additional farms that can assimilate excess nutrients. We present case studies reviewing challenges and opportunities to manureshed management in four major dairy-producing states using available information on local manuresheds. Additionally, geographic information system software was used with data from regulated Minnesota dairies to assess cropland assimilative capacities and transport needs surrounding large dairies. Manureshed requirements vary across regions, but increased import of feed and soil phosphorus accumulation constrain on-farm manure utilization across the United States. In Minnesota, a growing proportion of Jersey cattle and differences in continuous corn (Zea mays L.) vs. corn-alfafa (Medicago sativa L.) rotations contribute to the amount of land needed to absorb dairy manure nutrients. Farm-gate budgets reveal that N-based manuresheds can be contained within Idaho dairies, but P-based manuresheds extend beyond the farm. In New Mexico, relocation of surplus manure nutrients off the farm is common via informal networks, but incentives to strengthen these networks could ensure sustainable manureshed management. Evaluation of manureshed requirements in Pennsylvania is often complicated by the need for additional nutrient management planning and greater understanding of nutrient balances on the preponderance of small dairies. Nutrient imbalances with highly concentrated dairy production often lead to the need for manure transport off-farm. However, advances in herd and cropland management offer opportunities to improve on-farm nutrient efficiencies, and emerging networks and technologies promise to facilitate manure export when needed.

A Scoping Review of Safety and Health Interventions in the High-Risk Dairy Industry: Gaps in Evidence Point to Future Directions in Research.

The occupational injury rate of the dairy industry (6.6 per 100 full-time workers) is twice that of the national average across all industries (3.3 per 100 full-time workers). While dairy farms are becoming larger in size and fewer in number, this rate has not changed. A scoping review was conducted to identify published reports of occupational safety interventions in the dairy industry. An additional criterion was that the study included an evaluation of the intervention. Out of 22 articles that met the first criterion (discussion of interventions specific to the dairy industry), 19 met the second of having an evaluative component. These 19 articles corresponded to 16 unique studies, because 4 articles corresponded to the same study. Of the 16 unique studies, only 3 had a comparison of treatment vs. control effects, and none measured the impact of the intervention on injuries and fatalities. Of the 16 interventions, 6 were focused on training or informational campaigns in which the evaluations primarily measured knowledge acquisition. Additionally, none of these studies had a sufficient sample size to compare injury rates as an outcome. Our study demonstrates that the literature lacks any rigorous evaluation of whether dairy safety interventions are making an impact on injury prevention. Given this, it is not possible to determine how work-related injuries and deaths can be prevented in the dairy industry. Recommendations for future research include incorporating rigorous evaluation into research designs and attempting to develop low-cost, unobtrusive methods for collecting data on intermediate and final outcomes.

Using mobile technology to increase safety awareness among dairy workers in the United States.

BACKGROUND: Modern U.S. dairy farm operations present multiple safety hazards which may result in worker injuries, illnesses and fatalities. The U.S. industry trend towards large-herd milking operations, especially in the Western U.S., necessitates an increased number of workers on each farm. The U.S. dairy workforce is comprised of an increasing percentage of immigrant workers with limited English proficiency which presents a safety training challenge. Our objective was to develop, deliver and evaluate safety awareness training to U.S. dairy farm workers using mobile tablets as a personal learning environment. METHODS: A non-random sample of 1,436 dairy workers received safety awareness training on a mobile device platform. Kirkpatrick Levels 1, 2 and 3 training effectiveness evaluations were performed. RESULTS: Approximately 58.7% of training participants received a middle school education, and 22.7% were from Guatemala who reported K'iche' as their native language. A statistically significant large effect size suggests safety knowledge was gained among training participants when comparing post-test scores to pre-test scores (Level-2). Training participants rated their training experience favorably (Level-1), and applied knowledge gained in their daily work activities three months after training (Level-3). CONCLUSION: Our findings suggest the utilization of mobile learning techniques is an effective means to deliver safety awareness training content to dairy workers. Dairy worker safety training should be culturally, linguistically, and literacy appropriate and comprehensive in nature to include all applicable dairy safety hazards. Our observations support the use of mobile devices as just one component of a more comprehensive health and safety management program on farms.

Effect of waste milk pasteurization on fecal shedding of Salmonella in preweaned calves.

The objective of the current research was to determine if pasteurization of nonsaleable waste milk influences fecal Salmonella concentrations and prevalence, or antimicrobial susceptibility and serotype of the cultured isolates. Holstein dairy calves (n = 211) were housed on a single commercial dairy in the southwestern United States and randomly allotted to be fed either pasteurized (PWM; n = 128 calves) or nonpasteurized waste milk (NPWM; n = 83 calves). Fecal samples were collected via rectal palpation or from freshly voided, undisturbed fecal pats, weekly during the first 4 wk of the animal's life and then again at weaning. Eight total collections were made and 1,117 fecal samples cultured for Salmonella. One isolate from each culture-positive fecal sample was preserved for antimicrobial susceptibility screening and serotyping. Sixty-nine percent of the fecal samples were culture positive for Salmonella with no difference due to treatment (67.7 and 69% Salmonella positive for PWM and NPWM treatments, respectively). Few fecal samples (178/1,117; 15.9%) contained Salmonella concentrations above the limit of detection (∼1 cfu/g of feces) with concentrations ranging from 1.0 to 6.46 cfu (log10)/g of feces. Concentration was not affected by treatment. Seventeen different serotypes were identified, the majority of which were Montevideo and Anatum. A greater percentage of Typhimurium (87 vs. 13%), Muenchen (88 vs. 12%), and Derby (91 vs. 9%) were recovered from calves fed PWM compared with NPWM-fed calves. Conversely, Newport (12.5 vs. 86%), Bredeney (22.2 vs. 77.8%), and Muenster (12.5 vs. 87.5%) were lower in PWM compared with NPWM treatments. The majority (66.7%) of isolates were susceptible to all of the antibiotics examined. Results from this one commercial dairy suggest that milkborne Salmonella is not an important vector of transmission in dairy neonates, nor does pasteurization of waste milk influence fecal shedding of this pathogen. Caution should be used, however, when extrapolating results to other farms as Salmonella contamination of milk on farm is well documented. The potential benefits of pasteurization in disease prevention outweigh the potential risks of feeding a nonpasteurized product and warrants incorporation into any calf-rearing program using nonsaleable waste milk for feeding young dairy neonates.

The dairy industry: a brief description of production practices, trends, and farm characteristics around the world.

The global dairy industry is composed of a multitude of countries with unique production practices and consumer markets. The global average number of cows per farm is about 1-2 cows; however, as a farm business model transitions from sustenance to market production, the average herd size, and subsequent labor force increases. Dairy production is unique as an agricultural commodity because milk is produced daily, for 365 days per year. With the introduction of new technology such as the milking parlor, the global industry trend is one of increasing farm sizes. The farm sizes are the largest in the United States; however, the European Union produces the most milk compared with other global producers. Dairy production is essential for economic development and sustainable communities in rural areas. However, the required capital investment and availability of local markets and labor are continued challenges. Due to farm expansion, international producers are faced with new challenges related to assuring food safety and a safe working environment for their workforce. These challenges exist in addition to the cultural and language barriers related to an increasing dependence on immigrant labor in many regions of the world. Continued success of the global dairy industry is vital. Therefore, research should continue to address the identification of occupational risk factors associated with injuries and illnesses, as well as develop cost-effective interventions and practices that lead to the minimization or elimination of these injuries and illnesses on a global scale, among our valuable population of dairy producers and workers.

Work-related injuries and fatalities on dairy farm operations-a global perspective.

Agriculture is among the most hazardous sectors for workers globally, and dairy farming has been associated with a high risk of injury among workers in several countries. The purpose of this paper is to provide an update on what is known about modern dairy farms and related injuries and fatalities in different regions of the world. As in other sectors of agriculture, fatalities appear to be associated with heavy equipment usage, whereas injuries occur at higher rates with animal production, specifically cattle and milk production. Dairy farming is associated with higher rates of injury as compared with other industrial sectors, but a lack of work-related injury reporting continues to be an issue in several countries. Worker fatality associated with heavy equipment use is not a new observation (e.g., tractors); however, manure-handling systems, livestock handling, and quad bike operation continue to be associated with worker injuries and fatalities on modern farms. Opportunities exist for improvement of safety-related equipment to reduce injury and fatality risk during worker interactions with large animals and farm equipment.

A review of health and safety leadership and managerial practices on modern dairy farms.

As modern dairy operations around the world expand, farmers are increasingly reliant on greater automation and larger numbers of hired labor to milk cows and perform other essential farm tasks. Dairy farming is among the most dangerous occupations, with high rates of injury, illness, and employee turnover. Lower education levels, illiteracy, and limited language proficiency increase the possibility of injury or death associated with higher risk occupations such as dairy. Sustaining a healthy, productive workforce is a critical component of risk management; however, many owners and managers have not received formal training in employee management or occupational health and safety. Optimal dairy farming management should address milk production that is sustainable and responsible from the animal welfare, social, economic, and environmental perspectives. Each of these aspects is interdependent with each other and with a sustainable, healthy, productive workforce. Very few studies address the effectiveness of risk management in the dairy industry. Studies suggest that labor management practices are a potential competitive advantage for dairy farms, but the connection with efficiency, productivity, and profitability has not been clearly demonstrated. Transformational leadership has been associated with improved safety climate and reduced incidence of injury, whereas passive leadership styles have opposite effects. There is a need to develop and evaluate the effectiveness of safety-specific transformational leadership among dairy owners and managers. A systematic approach to risk management should address worker health and safety as an integral component of production, food safety, and animal welfare. A successful program must address the cultural and linguistic barriers associated with immigrant workers.

Occupational health and safety aspects of animal handling in dairy production.

Livestock handling in dairy production is associated with a number of health and safety issues. A large number of fatal and nonfatal injuries still occur when handling livestock. The many animal handling tasks on a dairy farm include moving cattle between different locations, vaccination, administration of medication, hoof care, artificial insemination, ear tagging, milking, and loading onto trucks. There are particular problems with bulls, which continue to cause considerable numbers of injuries and fatalities in dairy production. In order to reduce the number of injuries during animal handling on dairy farms, it is important to understand the key factors in human-animal interactions. These include handler attitudes and behavior, animal behavior, and fear in cows. Care when in close proximity to the animal is the key for safe handling, including knowledge of the flight zone, and use of the right types of tools and suitable restraint equipment. Thus, in order to create safe working conditions during livestock handling, it is important to provide handlers with adequate training and to establish sound safety management procedures on the farm.

Influence of weaning on fecal shedding of pathogenic bacteria in dairy calves.

The objectives of the current research were to determine the effect of weaning on fecal shedding of Salmonella and Escherichia coli O157:H7 in dairy calves and to examine cultured isolates (to include Enterococcus) for antimicrobial susceptibility. This research was conducted on one large commercial dairy (>3000 head) in the southwestern United States. Two collections were made, during the winter (January 2009) and summer (July 2009) seasons. For the winter collection, two groups of calves were sampled (group 1: n = 18 pens, 69 head, ∼12 weeks of age; group 2: n = 19 pens, 75 head, ∼10 weeks of age). Fecal samples were collected from all calves via rectal palpation 2 days pre- and again 2 days postweaning. For the summer collection, one group of calves housed in 40 pens were utilized and 79 and 76 calves sampled 7 days pre- and 5 days postweaning, respectively. Fecal samples were collected into sterile palpation sleeves, placed on ice, and shipped to our laboratory for bacterial culture of E. coli O157:H7, Salmonella, and Enterococcus. Antimicrobial susceptibility was determined on select isolates. No differences (p > 0.10) in prevalence of Salmonella or E. coli O157:H7 were observed due to weaning in the winter collection. In the summer collection, more (p < 0.01) fecal samples were Salmonella positive preweaning (15.2%) as compared to postweaning (2.6%). No differences were observed for antimicrobial susceptibility in isolates collected pre- as compared to postweaning in either winter or summer collections, with the exception that multidrug-resistant Enterococcus faecium isolates preweaning were resistant to six antibiotics compared to seven or eight antibiotics postweaning (summer collection). Results of the current research indicate that the weaning of dairy calves does not increase the prevalence of pathogenic bacteria or substantially modify antimicrobial susceptibility profiles of these bacteria.