Selection within each breed for critical production traits, in order that only superior animals are used for breeding. These criteria, together with a breeding system geared to increase productivity within a workable management climate, produce optimum results. This makes the system efficient and productive. The availability of management resources Cow size and growth Cow size is an important consideration in breed selection.
Size affects growth, weight gain, milk production and the cost of feeding.
Studies in general indicate that cow size becomes critical when feed becomes limited. The maintenance requirements for large cows are higher than requirements for small cows and this becomes critical in Alberta due to the long winters. A Charolais or Simmental cross needs 10 to 30 percent more energy for maintenance than does an Angus X Hereford cross. In areas where moisture limits pasture growth and feed availability, a smaller sized cow is preferred. However, where nutrition is not liiting, cows that are slightly above average prove to be the most economical and productive.