Postweaning mortality in Manitoba swine

Area of Science:

• Veterinary Pathology
• Swine Health Management
• Epidemiology

Background:

• Postweaning multisystemic wasting syndrome (PMWS) and Porcine circovirus type 2 (PCV-2) are significant concerns in piglet mortality.
• Understanding the multifactorial causes of nursery piglet deaths is crucial for improving swine production.
• PCV-2 is a widespread pathogen in swine populations, necessitating investigation into its role in mortality.

Purpose of the Study:

• To investigate the association between PCV-2 infection and piglet mortality in Manitoba nurseries.
• To identify other contributing factors, including infectious agents and management practices, to high nursery mortality rates.
• To explore the relationship between the clinical syndrome PMWS and PCV-2 infection in affected piglets.

Main Methods:

• A case-control study design was employed.
• Data collection involved assessing PCV-2 infection status and other potential risk factors in nursery pigs.
• Analysis focused on identifying significant associations between various factors and piglet mortality rates.

Main Results:

• A significant positive association was found between PCV-2 infection and increased mortality in nursery pigs.
• Mycoplasma hyopneumonia infection, porcine reproductive and respiratory syndrome (PRRS), and E. coli K88 diarrhea were more strongly linked to mortality than herd-level PCV-2 infection.
• Management factors such as herd proximity, sow numbers, age/weight variation, piglet movement, and diet composition were associated with higher mortality.

Conclusions:

• While PCV-2 infection contributes to piglet mortality, it is not the sole or strongest factor.
• Effective nursery piglet management requires addressing a complex interplay of infectious agents and environmental/managemental influences.
• The findings emphasize the host-agent-environment triad in understanding and mitigating high nursery mortality.