G. E. Dickerson

The Choice of Selection Objectives in Meat Producing Animals

In the breeding of animals used for meat production, the choice of biological objectives presumably should be guided primarily by their expected contributions to efficiency (E) in terms of lower total production cost per unit of animal product, C/U. Cost per unit seems more realistic than profit per breeding female per year, (U•V-C)/YI, because selling prices (V) for products tend toward a fluctuating margin above production costs, so that lower costs benefit consumers more than producers. The cost and the profit definitions of efficiency lead to the same performance rankings when product price (V) is constant, but selection programs deal with future reductions in relative cost per unit product when price per unit may decline correspondingly. Also note that discounting the value of future gains in efficiency for cumulative interest charges on capital used in breeding programs is justified only for the excess of interest rates over (steady) rates of currency inflation, since rates of inflation affect scales of both the interest and the future cost savings from improved efficiency.

Sampling, evaluation and utilization of animal genetic resources

No program exists in the U.S. to sample, evaluate, and use optimally the genetic diversity present in animals important as food and fiber worldwide. Yet animal products provide U.S. consumers with substantial amounts of essential nutrients. Animals and animal products constitute about 50% of total farm sales in the U.S. Furthermore, all domesticated food and fiber animals now in the U.S. originated in, or were introduced from, other parts of the world. Because the U.S. has a limited sample of animals important as food and fiber worldwide, there is a need to develop a comprehensive program of systematically sampling, evaluating/characterizing, and developing breeding systems to use these resources in an optimal manner. Such an effort could provide the foundation for an organized program of acquiring and maintaining the genetic variation needed in our populations of food and fiber animals to achieve and maintain optimum adaptation to continuing changes in our diverse production-marketing ecosystems. An organized program of animal genetic resources management is needed to provide the framework for a comprehensive program of animal breeding research and development. The development of procedures for movement of animal genetic resources with minimal risk to animal health should receive high priority. The level of genetic diversity needed is greatest and perhaps easiest to maintain for the extensively managed food and fiber animal species (e.g., beef cattle, sheep, goats) because of their variable, dynamic production environments and marketing situations. Continuing optimum adaptation of global genetic stocks to varied production-marketing ecosystems is required for most effective use of U.S. animal production resources and to insure an adequate supply of reasonably priced animal products to meet the nutritive requirements of the U.S. population in the 21st century and beyond.