Survival and dispersal of a defined cohort of Irish cattle

The movement of animals is often implicated in the spread of disease; for example, foot-and-mouth disease [1,5], scrapie [10] in Great Britain and Johne's disease in the Netherlands [22]. Logically, effective disease prevention, control and prediction depend in part on a sound understanding of movements in relevant animal populations. For a range of diseases, studies have been conducted to define the importance of animal movement and the potential of movement in disease transmission [19,18,9,16,21,20]. Modelling studies have also been conducted to quantify the role of animal movement in disease spread [19,14,12,13,3,6,10,11] Such is the importance of disease transmission due to animal movements, new methodologies have been adapted from other areas of science, such as network analysis, in a further attempt to describe and predict disease spread [21,4,7].To-date, no studies have been conducted to quantify the dispersal, movement and survival of Irish cattle. As a result, there is no knowledge on the potential for disease transmission as a result of these movements. The objectives of this study were to describe the movement of cattle born in Co. Kerry in 2000 in terms of dispersal, distance travelled and frequency of moves, as well as the survival of this cohort over a four-year period.There are approximately seven million cattle in the Republic of Ireland, including 2.2 million Friesian cows. The latter animals are used in the production of dairy products, the remainder are beef breeds producing beef for export and local consumption. The dairy herd produces five billion litres of milk per year. Counties Cork, Tipperary, Limerick and Kerry hold the largest numbers of dairy cattle, whereas counties Cork, Galway, Tipperary and Mayo have the largest numbers of beef cattle. Approximately 150,000 live cattle are exported from Ireland each year, the majority of which are beef animals. Each year, 1.6 million beef carcases are exported and 106,000 are slaughtered for domestic