THE EFFECT OF THE STRATEGIC ADDITION OF CHLORTETRACYCLINE IN THE LACTATION DIET ON SOW MORTALITY

摘要

Sow mortality appears to be increasing in the US swine industry (1,2). The cause of this increase has not been defined and appears to be multifactorial. A number of studies have been performed to study the pathology of sows that have died, and these have shown a range of causes including heart failure, cystitis and gastroesophageal ulcers (3,4). There can be a number of risk factors and these appear to differ by farm (or system), genotype and sow age. Very few reports exist on interventions to reducesow mortality. It appears that there is more than one factor that leads to higher mortality in herds, and these factors may be herd specific. However, some guidance can be gained by looking at the epidemiology of the problem. The farrowing-lactation period is a high risk time frame, as 50% of deaths occurred within 21 days after farrowing (1). Factors that place sows in a weakened condition such as retained placenta or retained pigs, and physical injury, can predispose sows to reproductive failure, impaired immunological response, and perhaps inadequate lactational feed intake that leads to extremely poor body condition.