Agriculture Reference
In-Depth Information
Birth of identical twins in farm animals (and in humans) is an example of clon-
ing of animals in nature. Nevertheless, cloning technology is of concern to the gen-
eral public. However, meat from cloned animals has U.S. Department of Agriculture
approval as safe for human consumption. Nutritional value of meat from cloned
animals may be improved by the presence of superior genetic traits in the cloned
animal for lean growth, efficiency of growth, and disease resistance. The high costs
of cloning animals will limit this technology for the production of food animals for
the foreseeable future.
Embryo Transfer
Nonsurgical embryo collection and transfer are now widely used in dairy and beef
cattle for genetic improvement (Hasler, 2005). Embryos (usually more than one
resulting from superovulation) from a genetically superior donor cow are transferred
at a few days of age to a recipient cow whose genetic background may be of little
concern but whose high milk supply is important to the foster calf. This technology
has had an important positive impact on the livestock industry.
Transgenic Animals
All organisms (microbes, plants, animals) continually undergo genetic alteration
by mutation and natural selection or by intentional genetic selection for phenotypic
traits. The development of recombinant DNA technology has made it possible to
isolate single genes, modify their nucleotide structures, make copies of these isolated
genes, and insert copies of the genes into the genome of animals and plants (Pursel
and Wall, 2005). Gene transfer has been accomplished in mice, pigs, sheep, and
rabbits. Theoretically practical applications of transgenic technology in food animal
production include improvements in milk production and composition, growth rate,
disease resistance, carcass composition, reproductive performance, and prolificacy.
conclusIons And study toPIcs
1. Humans have evolved as omnivores.
2. Large increases are projected in global demand for meat, milk, and eggs,
particularly in the developing countries. Global meat production is pro-
jected to more than double over the next two decades.
3. The challenge of producing enough food from plant and animal sources to
meet the needs of all is perhaps the largest challenge facing society in the
coming decades.
4. Food animal production on a crowded planet must be based on practices
conducive to sustainable agroecology. Actions needed in food animal pro-
duction to ensure sustainable animal agriculture include
a. Develop improved livestock grazing measures in vulnerable locations
to prevent land degradation
b.
Continue to improve biologic and economic efficiency in food animal
production
c. Continue to develop technologies in manure management and use in
crop production and in biogas plant initiatives to recycle manure
