Pigs to Pork
Cooperative Extension Service PURDUE UNIVERSITY Lafayette, Indiana
Environmental Influences on Swine Production
C.J. Heidenreich, Animal Sciences Department
-Principles
AS-325 January, 1965
This publication is designed as a teaching aid for the intensive swine schools conducted by the Cooperative Extension Service. It is also included in the Pork Production Handbook for County Extension Agents.
It is intended to offer a more thorough understanding of the environmental influences on swine production.
Summary
The animal is a complex organism with considerable "built-in" capacity to adjust to a dynamic environment. The environment, in like manner, is complex and continually changing, thereby imposing situations demanding constant adjustment. The precise balance or relation existing between the animal and his natural environment is evidenced by his continued survival.
An understanding of the physiological mechanisms involved in the animal and the inherent complexities of the environment is prerequisite to successful swine husbandry.
Any decision concerning the degree of management to be imposed, in anticipation of increased economic returns, must be based on a fundamental knowledge of the animal as well as the environment.
The Environment
Swine productivity is affected by both genetic and environmental factors. It has been said that genetics determines what an animal's potential is, whereas environment determines the extent to which he expresses his potential. In a sense, environment can be expanded to include all those factors which are external to the animal himself. These factors then can be classified into two categories with several subclasses in each.
I	Biotic
Nutritional
Disease
Social
II	Physical
Heat (7, 900-500, 000 Angstrom units (A), includes infra-red)
Light (3,900 to 7,700 A)
Radiation (for example, ultra violet, less than 3, 900 A)
Atmospheric pressure Water vapor and other gases Air movement
Biotic factors are those originating with living organisms such as nutritional