A comparison of vitamin B12 levels in the liver and serum of sheep receiving treatments used to correct cobalt deficiency

The efficacies of four methods, used for the prophylaxis of cobalt deficiency in sheep as measured by the elevation of liver and serum vitamin B12 levels, were compared in marginally deficient sheep over 14 weeks. The methods used were weekly drenches of either cobalt sulphate or cobalt chelate (EDTA) three-weekly injections of hydroxocobalamin, and ruminal cobalt pellets. On the basis of elevated liver and serum vitamin B12 levels, chelated cobalt was shown to be available to rumen microflora for the synthesis of vitamin B12. However, at no stage were liver and serum vitamin B12 levels of sheep receiving the chelate significantly different from those receiving the same amount of cobalt as the sulphate. After five, three-weekly injections of hydroxocabalamin liver vitamin B12 levels were significantly higher (p<0.01) than for the other treatments, with the exception of cobalt sulphate. Cobalt pellets led to an initial rapid and significant rise in serum vitamin B12 when compared with the other treatments. However, at four weeks there was no significant difference between treatment groups for serum vitamin B12. Fourteen weeks after the administration of cobalt pellets, serum and liver.vitamin B12 levels in this group were not significantly different from those of untreated sheep. At this time, three out of 12 sheep had lost their pellets.     

Molecular Diversity of Campylobacter coli and C. jejuni Isolated from Pigs at Slaughter by flaA‐RFLP Analysis and Ribotyping

A population of porcine isolates of Camplobacter jejuni (n=11) and C. coli (n=17) were examined for genotypic relatedness employing ribotyping, as well as polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analysis of the flagellin (fla)A gene locus. PCR was employed to amplify a 533 bp fragment from the flaA gene, including the previously described short variable region (SVR), employing the novel primers, A2 and A1 and successfully generated this amplicon for all wild‐type strains examined (n=28) of both C. jejuni and C. coli, as well as with both type strains, i.e. C. jejuni NCTC 11351 and C. coli NCTC 11366. Individual genotypes were assigned to each isolate typed employing the four typing methods (flaA‐RFLP_{Hae III}, flaA‐RFLP_{Pst I} ribotyping_{Hae III} and ribotyping_{Pst I},) and were assigned an arbitrary genotype code in ascending alphabetical order in comparison with a database of established genotypes for each of the methods employed. This study showed that several flaA‐RFLP and ribopatterns existed within C. jejuni and C. coli, and demonstrated a heterogeneous diversity of strains occurring in the pigs examined. Ribotyping of strains with 16S and 23S rRNA with Pst I and Hae III digested chromosomal DNA allowed subdivision of strains into nine and eight groups, respectively. RFLP analyses with Pst I and Hae III digests probed with the flaA gene probe allowed subdivision of strains into eight and eleven subtypes, respectively. Employment of RFLP with the flaA nucleic acid probe and Hae III digests produced the greatest amount of variation of any genotyping scheme employed. Although there was a high degree of variability demonstrated by both typing methods, most isolates (>60%) clustered into four main genotypes, i.e. genotypes A–D. FlaA‐PCR–RFLP typing demonstrated that the majority of isolates, 67.9 and 60.7%, were included in these four main genotypes for Pst I and Hae III restriction digests, respectively, although there was a high prevalence (7/11; 63.6%) of fla_{Hae III} genotype A occurring within the C. jejuni isolates. Likewise, ribotyping studies demonstrated that most isolates were clustered into these four main genotypes, accounting for 81.5 and 60.7% of isolates for Pst I and Hae III restriction digests, respectively. This may indicate that the clonal population of campylobacters within this pig population is largely composed of persistent and dominant types, with a smaller number of hypervariable subtypes. Such data may useful in determining epidemiological routes of transmission of campylobacters from animal to animal, as well as helping to identify virulence determinants in persistent subtype populations.     

Use of a multifenestrated indwelling lavage system for treatment of septic digital teno-synovitis in cattle

Septic tenosynovitis was diagnosed in seven cattle on the basis of history, physical examination, radiographs, cytological examination of tendon sheath fluids, and microbial culture. A commercially available indwelling multifenestrated silicone rubber drain was used to perform frequent lavage of the flexor tendon sheaths. The sepsis resolved in all cattle. Five of six cattle for which long-term (> 1 year) follow-up information was available were clinically sound on the affected limb and had remained productive members of the herd.     

Relationships between N2O emissions and water-soluble C and N contents of agroforestry residues after their addition to soil

Nitrous oxide emissions are usually increased following incorporation of N-rich plant residues, but the effects of residue soluble C and N contents on emissions have still to be determined. Here we report a controlled environment experiment in which emissions of N₂O were measured following addition of ¹⁵N-labelled (2.5-4.2 atom % excess ¹⁵N) agroforestry residues (Sesbania sesban, Macroptilium atropurpureum and Crotalaria grahamiana) to an Oxisol. Exposure of these trees to different irradiance during growth resulted in differences in water-soluble C and N contents. The highest emissions were generally measured from the lower water-soluble C and N (LS) residues with 7 mg N₂O-N m⁻² emitted over 29 d after addition of Crotalaria LS residues (4.9% soluble C, 0.7% soluble N). Emissions were negatively correlated with the residue soluble C-to-N ratio (r=−0.68 to −0.89; P<0.05) at the time of main flux activity during the first 8 d after residue addition, indicating that under controlled environmental conditions substrates with a high soluble C-to-N ratio may result in low N₂O emissions during the early stages of residue decomposition. This relationship has still to be verified under field conditions.     

The Ethics and Role of AI with Fresh and Frozen Semen in Dogs

The use of artificial insemination (AI) with fresh semen has resulted in many benefits for the management of dog breeding, but there are disadvantages that can sometimes be overlooked. Furthermore, poorer quality semen arising as a result of cryopreservation necessitates uterine insemination, which raises the potential for surgical insemination. A number of significant ethical concerns have been raised by key stakeholders (such as The Kennel Club and the Royal College of Veterinary Surgeons) about AI per se , but particularly about the use of surgical insemination. This paper discusses the technological development of AI and explores a number of the ethical issues raised by its application to dog breeding. An Ethical Matrix method is used to map the potential ethical issues for key interest groups, namely dogs, breeders, owners, veterinarians and wider society. There are national variations in the way in which institutions have evaluated potential ethical impacts, and this is reflected in the different regulatory frameworks governing the use of AI in dogs. In order to facilitate decision-making and reduce some of the ethical risks associated with this technology, the veterinary research community could take several proactive steps including: (i) clarifying clinical decision-making processes, (ii) enhancing informed choice among clients and (iii) increasing the knowledge-base of potential impacts of AI.     

Identification of management risk factors for VTEC O157 in young-stock in England and Wales

We conducted a cross-sectional study on 255 cattle farms in England and Wales to identify risk factors for verocytotoxin-producing E. coli O157 (VTEC). Exposure variables were collected at the levels of the farm and of the group of young-stock within the farms. On each farm a group of young-stock (6-18 months of age) was sampled to establish VTEC status. In our multiple logistic regression, farm VTEC status was associated with access to springs (OR: 0.31, CI95%: 0.12, 0.78) and assessing the wetness of the bedding material less frequently than daily (OR: 3.89 CI95%: 1.5, 10.2). At group-level we found no associated risk factors for animals housed outdoors in fields. Significant for groups housed in pens were wet bedding (wet OR: 3.43, CI95%: 1.3, 9.4; very wet OR: 4.24, CI95%: 1.2, 14.6), number of animals in the group (10-15 OR: 2.72, CI95%: 0.75, 9.9, 16-24, OR: 3.78, CI95%: 1.2, 12.3; >25 OR: 3.78, CI95%: 1.1, 12.7) and feeding straw (OR: 2.29, CI95%: 1.2, 5.5).