Introduction - the nature of pre-weaning mortality

• The pig has multiple births and in the natural environment high levels of piglet mortality are expected. Much of the focus of intensive swine production has been in reducing mortality levels in newborn piglets by improving management and the piglet environment..
• 1990s, a summary of the PigCHAMP database and the USDA National Animal Health Monitoring System survey indicated that 14-15% pre-weaning mortality was average. In North Carolina we aim to do better than average and 10-12% pre-weaning mortality seems to be fairly common. We also hear reports from Latin America that some intensive farms achieve 6-8% pre-weaning mortality with high labor inputs in the farrowing houses. Most of the progress in reducing preweaning mortality is a function of improving environment, management and husbandry.
• On most farms the majority of piglet deaths result from multiple factors rather than a single disease problem. Some studies indicate that an infectious disease is the primary cause of only about 5% of piglet deaths.
• Low birth weight remains the single most important factor influencing the risk of piglet mortality, and somewhere around 2/3 of all deaths occur in the first 3 days after birth.
• In most cases attention to overall farrowing house management is far more important than individual diseases.
• Outbreaks, or 'epidemics', will occur from time to time. Good biosecurity is the best protection. Accurate diagnosis is essential in these cases, and will usually require veterinary and laboratory investigations.

Risk factors for pre-weaning mortality

• People
• Low viability: low birth weight or weak born piglets
• Sow health, nutrition and lactation performance
• Temperature
• Litter size
• Variation in weight within litters (greater in older sows)
• Housing
• Birth order

Scouring in suckling piglets

• Intestinal infections are common in neonates of all-species. The immunologically naive young are abruptly transferred from a protected clean environment into a world full of microbial challenges. Obviously, farrowing room hygiene is a key factor in minimizing the degree of this challenge.
• The main agents causing scouring in piglets are shown in Table 1, but some studies suggest none of these agents can be found in about 1/4 of scouring newborn piglets. Failure of adequate colostral intake, starvation and chilling all contribute to the risk and severity of scouring in neonatal piglets.
• Some differentiation between these agents can be made based on age, severity and other factors, but laboratory testing is needed for a definite diagnosis.
• Several of these agents exist on almost all herds, and the appearance of disease is usually linked to management problems rather than the introduction of a 'new' bug. Hygiene is probably the single most important factor.