Study of Frequency of Scrapie Resistant Genotypes in Țurcană Breed
Keywords:
small ruminants, spongiform encephalopathyAbstract
Transmissible spongiform encephalopathies are caused by prions, which are pathological isoforms of normal proteins encoded by host organisms. The tests were performed on Țurcană breed sheep from a private farm in Sibiu County. Blood samples were taken from adult sheep and lambs born in 2021, and the next batch of samples was collected from 3-4-month-old lambs born in 2022. Blood samples were collected from the jugular vein, on EDTA, in a quantity of 6 ml/animal, and refrigerated at 4°C for transport to the laboratory. The analysis was performed in the molecular genetics laboratory of DSVSA Sibiu and at the National Reference Laboratory for Animal Health and Diagnosis in Bucharest. Sheep are classified into five classes of scrapie resistance: highly resistant, resistant, low resistance, susceptible, and highly susceptible. In 2021, resistant lambs accounted for half of the tested population. Among adults, 57.07% were resistant to the disease, 32.59% were in the low resistance group, and 10.34% were susceptible and highly susceptible. In 2022, 50.77% of lambs tested for scrapie were included into the resistant groups and 49.23% into the low resistance, susceptible, and highly susceptible groups. For breeding, only resistant sheep from the first two groups should be used and only in exceptional cases, sheep with low resistance from the third group. We recommend testing for scrapie resistance at the first sign of the disease, selecting sheep according to genotype, and purchasing rams that have been tested and found to be highly resistant for breeding purposes.
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