Dairy producers are often concerned with placing emphasis on different production traits in their breeding program. Selecting on only economically important traits should be the objective of every producer. A cow's record is a measure of her genetic potential, which is modified by the environment in which she is kept. Environmental factors that directly influence a cow's record include types of housing, milking equipment, feeds and feeding, veterinary care, mastitis treatment, and climatic conditions. Only through control of these factors can the true genetic ability of a cow be expressed.
All environmental factors are in a constant state of change.
Therefore, most changes made in the environment that influence production traits are not permanent. These factors must be monitored and adjustments made daily to maintain optimal production. Unlike environmental changes, genetic changes are permanent. You need only to breed to a top production A.I. sire to make genetic gain that is permanent throughout a cow's lifetime. The investment is made only once when breeding your herd.