Timely Euthanasia in the United States Dairy Industry-Challenges and a Path Forward.

Euthanasia is a valuable management tool utilized on dairies to end the suffering of sick or debilitated cows. Euthanasia should be implemented if an animal's pain cannot be adequately alleviated and if there is a limited chance of recovery. To be humane, euthanasia should be quick, painless, and administered by a trained individual. Despite its importance in ensuring cow well-being, the timeliness with which euthanasia decisions are made for dairy cattle is often overlooked or neglected. The timeliness of euthanasia is as important as the efficient, rapid administration of euthanasia itself. Timely euthanasia is a critical component of many on-farm animal care and verification programs yet opportunities exist within the industry to improve how effectively the industry is executing this critical component of cow management. There are challenges associated with performing euthanasia in a timely manner, such as inconsistencies in treatment protocols, inadequate employee training, difficulties assessing a cow's quality of life, and impacts of the human-animal bond on decision-making. The objective of this paper is to explain the importance of timely euthanasia to dairy cattle welfare, identify the challenges that can prevent the timeliness of euthanasia, and provide solutions and practical suggestions for improving the management of timely euthanasia on dairies.

Staphylococcus aureus shedding pattern throughout lactation in dairy cows with naturally occurring intramammary infection.

OBJECTIVE: To evaluate shedding patterns of Staphylococcus aureus, specifically the association between clonal relatedness and shedding patterns of S aureus for cows with naturally occurring S aureus intramammary infection. DESIGN: Longitudinal field study. SAMPLE: Milk samples from 22 lactating cows (29 mammary glands) of varied numbers of lactations on 2 dairies. Procedures-Foremilk samples were collected weekly for 26 to 44 weeks during lactation from individual mammary glands. Milk samples were cultured bacteriologically with a 0.01-mL inoculum. Samples were considered culture positive for S aureus if ≥ 1 colony-forming units were obtained. Milk samples from known S aureus-positive mammary glands that were culture negative for S aureus or culture positive with a single colony of S aureus were cultured bacteriologically a second time with a 0.1-mL inoculum. Longitudinal shedding patterns of S aureus and the effect of strain type on ln(colony forming unit count) were examined. RESULTS: With the 0.01-mL inoculum, 914 of 1,070 (85%) samples were culture positive. After reculturing of negative samples with a 0.1-mL inoculum, 1,011 (95%) of the samples were culture positive. There was no significant difference in the detection of S aureus between genotypic clusters when either the 0.01- or 0.1-mL inoculum was used. There was no significant difference in the amount of shedding between mammary glands infected with isolates in genotypic cluster 1 or 2. No consistent shedding patterns were identified among or within cows. There was a significant difference in mammary gland linear score and test day (composite) linear score between mammary glands infected with isolates in genotypic clusters 1 and 2. CONCLUSIONS AND CLINICAL RELEVANCE: S aureus was shed consistently in cows with naturally occurring intramammary infection in cows, and regardless of the pulsotype, variations in the amount of S aureus shedding had no significant effect on the ability to detect S aureus with a 0.1-mL inoculum.

Variation in daily shedding patterns of Staphylococcus aureus in naturally occurring intramammary infections.

The goal of the current prospective field study was to examine the shedding patterns of naturally occurring Staphylococcus aureus intramammary infections and the association of pulsed field gel electrophoresis pulsotype with shedding. Milk samples from 5 multiparous and 2 primiparous cows identified with S. aureus intramammary infections were collected for 21 consecutive days, 3 times throughout the lactation (63 days total). Cyclicity of each quarter was evaluated using a locally weighted regression. Pulsed field gel electrophoresis was used for genotypic cluster comparisons to evaluate the association of strain type and shedding patterns. Although the amount of shedding varied greatly, 97.5% of the samples were culture positive. There were notable differences in S. aureus shedding patterns among cows as well as within cows; however, no consistent cyclic pattern was identified. Quarters infected with S. aureus isolates grouped in genotypic cluster 1 appeared to shed at consistently higher levels with a median cfu/0.01 ml of 154 (ln[cfu] = 5.0). In comparing ln(cfu)/0.01 ml between genotypic clusters over the first 21-day sample period, accounting for the effect of sample day, samples collected from quarters infected with S. aureus in genotypic cluster 1 had a 1.5 times greater ln(cfu) than those collected from quarters infected with strains in genotypic cluster 2. The ability to detect S. aureus from day to day was very consistent. The current study examining naturally occurring intramammary infections would support the conclusions of other studies suggesting that a single quarter sample would be adequate in determining S. aureus intramammary infections status.

The effect of inoculum volume on the microbiologic detection of naturally occurring Staphylococcus aureus intramammary infections.

Currently no standard definitions for the diagnosis of Staphylococcus aureus intramammary infection (IMI) exist. As a result, criteria applied in research to diagnose S. aureus IMIs have varied making comparisons between published works difficult. The goal of the current study was to define the optimal inoculum volume used in the diagnosis of naturally occurring S. aureus IMIs. Microbiologic results from 2 field studies examining S. aureus IMIs were used to examine the effects of inoculum volume on the microbiologic detection of S. aureus. A total of 1,583 milk samples were included in the analysis, and the results of using a 0.01-ml and a 0.1-ml inoculum are presented. Using a 0.01-ml inoculum resulted in a sensitivity of 91% (95% confidence interval [CI]: 88.6-93%) and a specificity of 99.4% (95% CI: 98.6-99.8%). Using the larger 0.1-ml inoculum resulted in a sensitivity of 96.8% (95% CI: 95.2-97.9%) and a specificity of 99.3% (95% CI: 98.4-99.7%). All false-positive samples were from S. aureus-negative quarters in S. aureus-positive cows. There were no false-positive cultures from S. aureus-negative cows. Of the false-negative samples, the majority (77%) were from 6 of the 34 S. aureus-positive quarters. Results from the current study of naturally occurring S. aureus IMIs support the hypothesis that, when using quarter level milk samples, a S. aureus IMI is most accurately diagnosed using a 0.1-ml inoculum. Regardless of inoculum volume, a single quarter sample culture that is positive with S. aureus (>or=1 colony-forming unit) is sufficient to diagnose a S. aureus IMI.

A comparison of veterinary students enrolled and not enrolled in an animal-welfare course.

An online survey was conducted to compare 46 veterinary students who previously enrolled in a discussion-based animal-welfare elective with 45 veterinary students who did not take the course. Students were asked a series of questions about their attitudes toward animal welfare and were presented with animal-use scenarios that had not previously been discussed in the elective course: greyhound racing, veal calf production, and the use of genetically engineered mice in research. For each scenario, students' actual knowledge was scored on the basis of open-ended factual questions. Students were also asked how comfortable they were with educating themselves about each topic and to describe factors they would use to evaluate the welfare of animals in each scenario. Factors were classified as being associated with (a) biological functioning, (b) ability to exist in a natural state, or (c) measures of affective state or feelings. There was no significant difference in actual knowledge of the three scenarios between students who took the course and those who did not. Students who took the course were significantly more likely to be comfortable about educating themselves on each of the three animal-use scenarios and scored significantly higher in identifying welfare-affecting factors than students who did not take the course. The results suggest that this approach to instruction is an effective way to teach veterinary students about how to educate themselves about animal-welfare issues and to increase their confidence in appropriately evaluating novel animal-welfare topics.

An outbreak of late-term abortions, premature births, and congenital deformities associated with a bovine viral diarrhea virus 1 subtype b that induces thrombocytopenia.

Bovine viral diarrhea virus 1 (BVDV-1) subtype b was isolated from premature Holstein calves from a dairy herd that experienced an outbreak of premature births, late-term abortions, brachygnathism, growth retardation, malformations of the brain and cranium, and rare extracranial skeletal malformations in calves born to first-calf heifers. Experimental inoculation of 3 colostrum-deprived calves aged 2-4 months old with this BVDV isolate resulted in thrombocytopenia, lymphopenia, and leukopenia. Outbreaks of brachygnathism are rarely associated with BVDV, and thrombocytopenia is rarely associated with BVDV-1 strains.

An approach to teaching animal welfare issues at The Ohio State University.

Despite the growing importance of animal welfare and the critical role of the veterinary profession, animal welfare is not formally taught in many veterinary curricula. In addition, veterinary students are often not exposed to current contentious animal welfare issues, which are subject to much debate and often proposed regulation. To address this deficiency in our curriculum at The Ohio State University College of Veterinary Medicine, we have developed a course titled "Contemporary Issues in Animal Welfare." Our specific objectives for the course are: 1) to provide students with the opportunity to objectively evaluate and discuss current issues in the welfare of animals as companions, and in the industries of agriculture, science, education, conservation, and entertainment; 2) to increase students' awareness of current important animal welfare issues; and 3) to develop students' skills in the critical evaluation of written and visual material used in the scientific literature and lay press. We hope that, over time, this teaching model will be considered a means to educate veterinary students about animal welfare issues in other veterinary curricula.