The ASI Annual Convention was held in Phoenix, AZ, January 24-28, 2012. The Association has a number of committees as well as a list of policies and directives many of which are pertinent to animal health. http://www.sheepusa.org/ASI_Positions
The Animal Health Committee met from 3-5 pm on Thursday, January 26. Dr. Diane Sutton of USDA/APHIS reviewed the current highlights from the National Scrapie Eradication Program. The numbers of scrapie cases in sheep have been steadily declining as a result of selective breeding programs and slaughter trace back efforts. She also discussed proposed changes in the Scrapie Flock Certification Program that will be announced this spring. In the last ten years, 25 cases of scrapie in goats have been diagnosed with an increase in the annual numbers in the past 3-5 years. (check out the “monthly report” link on the right at http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/ ) It is likely that the increased numbers are related to increased surveillance. New sampling minimums for slaughtered goats will be coming soon.
Dr. Katherine Marshall provided a preliminary report on findings from the 2011 NAHMS Sheep Study which will reflect about 70% of US sheep operations and 85% of the national ewe inventory. Interestingly, results from the on-farm sampling portion of the study indicated that 47% of sheep operations were positive for exposure to toxoplasmosis; 52% of operations were positive for campylobacter, a cause of abortions and human foodborne illness; and 47% of operations were positive for salmonella bacteria. Samples were also taken for Q fever. Of 563 participating operations, samples from 16% tested positive by ELISA. These samples will be further tested by the more specific immunofluorescence assay (IFA). A series of reports will soon be available at their website: http://www.aphis.usda.gov/animal_health/nahms/sheep/ .
Dr. Margaret Highland of the Animal Disease Research Unit at Pullman, WA, gave an overview of what is currently known about severe pneumonia outbreaks in bighorn sheep and their possible association with contact between bighorns and domestic sheep on public range land. ASI estimates that ~23% of domestic sheep production in the USA utilizes at least some public land grazing. Suggestions for further research were presented. This topic has created considerable controversy and will remain a very important issue for the US sheep industry. Some recent references related to this issue are below.1-3 You can see the abstracts at the National Library of Medicine online search engine http://www.ncbi.nlm.nih.gov/sites/entrez .
Dr. Don Knowles, Research Leader for the Animal Disease Research Unit at Pullman, WA, provided an update on research into a possible genetic marker for susceptibility to ovine progressive pneumonia virus (OPP). A candidate marker, TMEM154, has been identified which appears to be present more frequently in infected animals.4 Further work needs to be done to validate the findings, but this work suggests that it may be possible to select sheep that are less susceptible to OPP and gradually reduce the prevalence of this disease.
During the meeting of the Production Education and Research Council on Friday, Dr. Keith Inskeep of West Virginia University presented an informative review of appropriate uses of CIDR devices, and Dr. Dan Morrical of Iowa State University demonstrated the use of some new ration balancing software for sheep, Sheep BRaNDS, that appears to be user friendly and that utilizes the 2007 NRC Nutrient Requirements of Small Ruminants data. Dr. Morrical would be a contact for inquiries about this software.
For those of you who do not know, ASI publishes the Sheep Production Handbook which would be an excellent source of information for some of your clients. http://www.sheepusa.org/Order_Materials ASI also publishes the Sheep and Goat Research Journal, and the articles, including those in back issues, are available online at http://www.sheepusa.org/Sheep_and_Goat_Research_Journal .
Respectfully submitted, William Shulaw, ASI Animal Health Committee Member, AASRP Board Member Region 1
1. Dassanayake RP, Shanthalingam S, Herndon CN, et al. Mannheimia haemolytica serotype A1 exhibits differential pathogenicity in two related species, Ovis canadensis and Ovis aries. Vet Microbiol 2009;133:366-371.
2. Dassanayake RP, Shanthalingam S, Herndon CN, et al. Mycoplasma ovipneumoniae can predispose bighorn sheep to fatal Mannheimia haemolytica pneumonia. Vet Microbiol 2010;145:354-359.
3. Lawrence PK, Shanthalingam S, Dassanayake RP, et al. Transmission of Mannheimia haemolytica from domestic sheep (Ovis aries) to bighorn sheep (Ovis canadensis): unequivocal demonstration with green fluorescent protein-tagged organisms. J Wildl Dis 2010;46:706-717.
4. Heaton MP, Clawson ML, Chitko-McKown CG, et al. Reduced Lentivirus Susceptibility in Sheep with TMEM154 Mutations. PLoS Genet 2012;8:e1002467.