ABSTRACT A limited ability to cope with environmental stressors (cold, disease, limited nutrition), particularly over the first 2 to 3 d of life, predisposes the piglet to relatively high rates of neonatal morbidity and mortality. Due to the serious economic impact, numerous surveys of preweaning losses have been conducted over the last century. Although losses are still significant, the existing literature indicates a significant improvement in piglet survival over time, as determined by reports of 35% preweaning mortality in 1924 and 13 to 15% in 2000. Major sources of mortality have been categorized as overlying by the sow, insufficient energy intake, and disease. Causes of mortality may be more closely linked with one another than previously believed. Interactions exist between disease, thermoregulation, and nutrition. Piglets with disease and nutritional problems experience hypothermia and express altered behaviors that increase the likelihood of their being laid on by the sow. High probabilities of neonatal losses are associated with low birth weights, cold ambient temperatures, and scouring. An understanding of the interactions between environmental stressors and the biology of the piglet forms the basis for strategies and recommendations for improving preweaning survival.
Implications
It is apparent that neonatal, preweaning mortality in many cases is an unnecessary production loss and an animal well-being concern. Most losses due to stillbirths, crushing, chilling, and starvation should be preventable given good management, genetics, facilities, and health. However, our understanding of the underlying mechanisms that allow these losses to occur needs further development in order to be implemented in a production situation. Currently, we do not understand the implications that gestation housing, farrowing environment, and sow stress has on neonatal piglet mortality. We work to control factors known to be detrimental to piglet survival, such as disease, unequal competition between littermates, thermal stress to the piglet, and inadequate nutrition.
Key Words: Mortality, Piglets, Preweaning Period, Survival
© American Society of Animal Science. All rights reserved.
J. Anim. Sci. 80(E. Suppl. 1):E74-E86
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