Epidemiologic Aspects of a Foot- and-Mouth Disease Epidemic in Cattle in Ecuador
A case-control study was conducted to identify herd-level risk factors associated with foot-and-mouth disease (FMD) in Ecuador. Case herds were those with presence of cattle with clinical signs of FMD and that tested positive for FMD virus during the epidemic of 2002 (n = 39). Control farms (n = 78) were selected randomly from a list of farms without a history of FMD. All study farms were visited, and managers were interviewed to complete an epidemiologic questionnaire. Feedlot operations, purchase of livestock at markets, and close proximity to markets or slaughter facilities were identified as risk factors for FMD (P ≤ 0.01). In addition to systematic vaccination of the national herd, we recommend allocation of funds for ring-vaccination of cattle herds in close proximity to markets or slaughter facilities, and to enforce movement of vaccinated-cattle only to help control and prevent new epidemics of FMD.
Lessons from the foot and mouth disease outbreak in The Netherlands in 2001.
The Netherlands had recently developed a new strategy for the eradication of foot and mouth disease (FMD). When FMD was confirmed in Great Britain and France, recent imports of susceptible animals from these countries were traced and preventive measures were taken. On 21 March 2001, FMD was confirmed in The Netherlands. The disease was introduced by calves which became infected at a staging post in Mayenne, France, where infected sheep from Great Britain were present. A total of 26 farms were infected. Emergency vaccination of all susceptible animals was applied. Suppressive vaccination was chosen, implying that all vaccinated animals had to be slaughtered. Ring vaccination of all susceptible animals within 2 km of an infected herd was the standard procedure. However, in the 'Noord Veluwe', vaccination had to be applied to a larger area. The last affected farm was confirmed on 22 April 2001. Emergency vaccination contained the FMD infection rapidly. The last vaccinated animal was slaughtered on 25 May 2001. Many farmers were not convinced that the killing of their healthy, vaccinated animals was justified and tried to prevent the culling, but without success. Politicians and the public at large are now strongly opposed to the large-scale slaughter of vaccinated animals should a future outbreak of FMD occur. The Office International des Epizooties (OIE: World organisation for animal health) should incorporate control of vaccinated animals with non-structural protein (NSP) tests in the chapter on FMD in the International Animal Health Code.
Genetics of the phenotypic evolution in sheep: a molecular look at diversity-driving genes
Background After domestication, the evolution of phenotypically-varied sheep breeds has generated rich biodiversity. This wide phenotypic variation arises as a result of hidden genomic changes that range from a single nucleotide to several thousands of nucleotides. Thus, it is of interest and significance to reveal and understand the genomic changes underlying the phenotypic variation of sheep breeds in order to drive selection towards economically important traits. Review Various traits contribute to the emergence of variation in sheep phenotypic characteristics, including coat color, horns, tail, wool, ears, udder, vertebrae, among others. The genes that determine most of these phenotypic traits have been investigated, which has generated knowledge regarding the genetic determinism of several agriculturally-relevant traits in sheep. In this review, we discuss the genomic knowledge that has emerged in the past few decades regarding the phenotypic traits in sheep, and our ultimate aim is to encourage its practical application in sheep breeding. In addition, in order to expand the current understanding of the sheep genome, we shed light on research gaps that require further investigation. Conclusions Although significant research efforts have been conducted in the past few decades, several aspects of the sheep genome remain unexplored. For the full utilization of the current knowledge of the sheep genome, a wide practical application is still required in order to boost sheep productive performance and contribute to the generation of improved sheep breeds. The accumulated knowledge on the sheep genome will help advance and strengthen sheep breeding programs to face future challenges in the sector, such as climate change, global human population growth, and the increasing demand for products of animal origin.