| Abstrakt: |
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. |
