Bovine Spongiform Encephalopathy :: Biology Cattle Disease Essays

Bovine spongiform encephalopathy ( mad cow disease) is a relatively raw disease plungeprimarily in cattle. This disease of the bovine breed was prototypal seen in theUnited Kingdom in November 1986 by histopathological examination of affectedbrains (Kimberlin, 1993) . From the first discovery in 1986 to 1990 thisdisease developed into a large-scale epiphytotic in more or less of the United Kingdom,with very serious economic consequences (Moore, 1996).BSE primarily occurs in adult cattle of both male and female genders.The most common age at which cows may be affected is between the ages of fourand five (Blowey, 1991). Due to the fact that BSE is a neurological disease, itis characterized by many distinct symptoms changes in mental state mad-cow,abnormalities of posture, movement, and sensation (Hunter, 1993). The durationof the clinical disease varies with each case, but most commonly lasts forseveral(prenominal) weeks. BSE continues to progress and is usually considered fatal(B lowey, 1991).After extensive research, the pathology of BSE was finally determined.Microscopic lesions in the central nervous system that consist of a bilaterallysymmetrical, non-inflammatory vacuolation of neuronal perikarya and grey-matterneuropil was the scientists overall conclusion (Stadthalle, 1993). Theselesions are consistent with the diseases of the more common scrapie family.Without further investigation, the conclusion was made that BSE was a new memberof the scrapie family (Westgarth, 1994).Transmission of BSE is rather common throughout the cattle industry.After the incubation period of one to two years, experimental transmission wasfound possible by the injection of brain homogenates from clinical cases(Swanson, 1990). This only confirmed that BSE is caused by a scrapie-likeinfectious agent.How does the transmission become so quickly available among the entireUnited Kingdom feedlot population? Studies showed that the mode of infectionwas meat and bone meal that had be en incorporated into concentrated feedstuffsas a protein-rich accessary (Glausiusz, 1996). It is thought that the outbreakwas started by a scrapie infection of cattle, but the subsequent course of theepidemic was driven by the recycling of infected cattle stuff within thecattle population (Lyall, 1996). Although the average rate of infection is verylow, the reason why this led to such a large number of BSE cases is that much ofthe United Kingdom dairy cattle population was exposed for many, continuousyears (Kimberlin, 1993).To help control the outbreak, the British government in 1988 introduceda ban on the feeding of ruminant protein to other ruminant animals (Lacey, 1995).Such knowledge for the pathogenesis of the BSE disease shows precisely theactions that must be taken in order to control and minimize the risk of