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Background: To improve bovine transrectal palpation (TRP) and pregnancy diagnosis (PD) training, the effect of a high-intensity one-week training programme for veterinary elective students (N=59) with an interest in production animal practice was evaluated., Methods: Training consisted of exposure to rectal examination simulators, abattoir organs, theory materials and live cow PDs supervised by experienced large animal practitioners. Palpation skills were assessed before and after training using a validated TRP Objective Structured Clinical Examination (OSCE) in non-pregnant cows. Each student then performed PDs (n=12) on cows of known pregnancy status. Students' PD accuracy was measured as sensitivity and specificity, being respectively defined as the proportion of pregnant and non-pregnant cows correctly identified., Results: Students' scores improved from the first to the second OSCE (P=0.03), mostly as a result of improved ability to identify uterine symmetry/asymmetry and the presence/absence of a corpus luteum on the right ovary (P<0.01 and P=0.03, respectively). Overall student sensitivity and specificity of PD were 89.1 per cent (95 per cent CI 78.1-92.2 per cent) and 67.7 per cent (95 per cent CI 60.1-74.5 per cent), respectively., Conclusion: This prospective cohort study describes a strategy to improve students' TRP skills with the potential to reduce training time and animal use at teaching institutions by outsourcing student training to private practitioners., Competing Interests: Competing interests: None declared., (© British Veterinary Association 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

It remains a challenge for the role of the dairy veterinarian to move beyond that traditionally held. In larger herds with a high reproductive workload, we are at great risk of becoming specialist technicians. Instead we seek greater involvement, to deliver comprehensive services and to be recognised for them, personally and financially. Given the frequency of our visits, knowledge and analytical skills we are in a unique position to provide inputs that complement advice given by other consultants. Failure to do so has economic consequences for both veterinarian and dairyman. The opportunity for and value of inputs will differ for every client, and we need to remain cognizant of their motivation. This review article shares perspectives, opportunities and tools that might enable moving beyond the traditional role. It starts with a review of available research describing the dynamic between dairyman and veterinarian and how this might impact an animal health production management programme. A description of the experiences of others follows, interspersed by the personal experiences of the author, working with large total mixed ration-fed herds in the United States of America. The following attributes and roles can be associated with a significant economic impact: gatekeeper; conduit; executor; verifier; monitor; facilitator and mediator; trainer, motivator and coach; applied nutritionist; technologist; champion of animal welfare, food safety and judicious antibiotic use; and confidant. Each is elucidated and described in context, revealing a need for continuing education. The nature of the relationship between veterinarian and client will determine the opportunity for and value of each. The veterinarian is in a unique position to become an integral part of the management team and to be fairly compensated as such. The onus rests on the veterinarian to broaden his/her knowledge and skills and to demonstrate their value.

Pigs were vaccinated by scarification or intramuscular injection with a swinepox virus-Aujeszky's disease (pseudorabies) recombinant (rSPV-AD) constructed by inserting the linked Aujeszky's disease virus genes coding for glycoproteins gp50 and gp63, attached to a vaccinia virus p7.5 promoter, into the thymidine kinase gene of swinepox virus. By 21 days after vaccination, 90 and 100 per cent of the animals vaccinated by scarification or intramuscular injection, respectively, had developed serum neutralising antibodies to Aujeszky's disease virus. Upon challenge with virulent virus, significantly fewer vaccinated pigs developed clinical Aujeszky's disease, nasal shedding of challenge virus was markedly reduced, and the vaccinated groups of pigs maintained or gained weight during the week after challenge whereas the unvaccinated control group lost weight. No transmission of rSPV-AD to in-contact controls was detected during the three weeks before challenge. In a second experiment, serum neutralising antibodies to Aujeszky's disease virus persisted for 150 days after the pigs were vaccinated with rSPV-AD by scarification or intramuscular injection and all the pigs showed an anamnestic response when they were revaccinated.

Serum samples collected from feral swine (Sus scrofa) throughout Florida (USA) from 1980 to 1989 were tested for antibodies to pseudorabies virus (PRV) by the serum neutralization test, the latex agglutination test, or by the enzyme-linked immunosorbent assay. Seropositive swine were detected at 11 of 13 sites with a composite seroprevalence of 34.8% (579 of 1,662 samples; range = 5.9% to 58.2%) for sites with seropositive swine. Data on age and sex of the swine were available from three sites. Seroprevalence in males and females did not differ significantly (P = 0.62 for the combined data). Seroprevalence in adult (> or = 8 mo) and juvenile swine (< 8 mo) was significantly different at all sites (P < 0.05 for the combined data). From these data, PRV infections appear to occur widely in populations of Florida feral swine and may seriously undermine efforts to eradicate this virus from the domestic swine population of the USA.

Serum samples collected from feral swine (Sus scrofa) throughout Florida (USA) from 1974 to 1989 were tested for antibodies to Brucella sp. by the card test, the standard tube test, the rivanol test or the complement fixation test. Seropositive swine were detected at six of 18 sites with a composite prevalence of 23.4% (238 of 1,015 samples; range = 5.5% to 33.3%) for sites with seropositive swine. At one site for which age and sex data were available there was no significant difference (P = 0.50) in seroprevalence between males and females. Antibody prevalence in adult (> or = 8 mo) and juvenile swine (< 8 mo), however, was significantly different (P < 0.05). Based on these data, Brucella sp. infections are limited only to certain populations of feral swine. To avoid the spread of Brucella sp. organisms, however, relocation of feral swine is not recommended.

After confirming that long-term serum storage (frozen at -20 C for greater than 3 mo) causes optical density to drift upward, several modifications of an enzyme-linked immunosorbent assay (ELISA) protocol were evaluated to identify a protocol that would reduce background in porcine sera tested for trichinellosis. Modifications evaluated included blocking the antigen-coated ELISA plate with sample diluent containing 10% bovine serum albumin (BSA) or 10% nonfat milk powder (bovine lacto transfer optimizer or BLOTTO), diluting sera in sample diluent containing 10% BSA or 10% BLOTTO, and preincubating samples in sample diluent containing 10% BSA or 10% BLOTTO. Overnight preincubation (approximately 12 hr at 2 C) of fresh sera diluted (1:10) in sample diluent containing 10% BLOTTO significantly reduced background and improved the detection of experimentally infected pigs by enhancing positive-negative discrimination. When testing stored sera, the modified protocol effectively reduced the effect of storage and the kit revealed specificity of 98.4%; there was no loss in sensitivity. The effect of long-term storage at -20 C must therefore be considered when testing swine sera for trichinellosis by ELISA and possibly also when conducting other immunoglobulin assays. The modification described here may prove useful if there is no alternative to using serum stored for greater than 3 mo at -20 C.

Experimental and field trials were conducted to evaluate an ELISA for its ability to detect Trichinella-infected domestic swine and to compare ELISA results with muscle-digestion test results. The ELISA used was a commercial double-antibody kit, containing an excretory-secretory antigen, and was evaluated principally for epidemiologic use. Experimentally induced infection in swine (4 groups of 3 pigs each; inoculated with 0, 50, 500 or 5,000 larvae) was detected as early as postinoculation week 4, with seroconversion of all inoculated swine by postinoculation week 8. The rate of seroconversion appeared to be affected by initial larval dose, time after inoculation, and immunocompetence of the individual host. Determination of antibody kinetics generally revealed rapidly increasing antibody titer, followed by its steady decrease in most pigs. Once seropositive, however, all pigs remained seropositive for the duration of the 10-week study. Presence of muscle larvae was confirmed in all infected pigs at termination of the study. We recognize that the experimental conditions may not be truly representative of those under which natural infection develops in pigs; however, the ELISA detected an infected pig with muscle larval density of 0.87 larvae/g of tissue. Results of a field trial (n = 310) indicated no muscle digestion test-positive pigs (35 g of diaphragm muscle digested/pig), but 3 samples tested positive by ELISA for specificity of 99.0%.

Following the use of diflubenzuron controlled-release insecticide boluses in a dairy herd, there was a concern that post-calving cows were testing positive on a milk antibiotic residue test for more milkings than they had prior to the use of diflubenzuron. A field trial was conducted to examine for possible effects of diflubenzuron milk residues on the milk antibiotic residue test, Delvotest-P. Data of 24 cows in the treatment group and 29 cows in the control group were analyzed. There was no significant difference in the number of milkings after calving in which the milk tested positive on the milk antibiotic residue test between the treatment (2.75 +/- .94) and control (2.97 +/- 1.05) groups when cows in all lactations were analyzed or when analyzed by lactation (1, 2, and greater than or equal to 3). It was concluded that the use of diflubenzuron boluses had no effect on the milk antibiotic residue test.