Environmental components of pig health

Abstract

One of the limiting factors in pig production is the ill health of the animals. Besides the effect of overt disease, subclinical disease and more subtle disturbances in health may be a continual problem affecting all production parameters. These disturbances range from reproductive problems such as infertility, neonatal health problems, gastrointestinal and respiratory problems during the growing-finishing period, and injuries at all production stages.The causes of many of these disturbances and losses are multifactorial, resulting froman interaction between different environmental factors (stressors) and the animals. Many health problems are not initially due to infections but infections may appear as a secondary factor. Where bacteria, viruses and parasites are involved, the pig's immune status and ability for immune defence is often the determinant for disease. Unfavourable environmental factors do not result in a specific disease if the agent is missing.When animals are housed, their life form is altered. Housing creates limits in their choices, freedom of movement, activities, and feeding. While pigs generally have a talent for adapting to the environment, modern production methods have made it difficult for some animals to cope with their situation. They become stressed, and especially if this stress is prolonged, negative effects appear, generally reflected in their state of health.