individual dairy cows is now widely used, nationally
and internationally. Crossbreeding of beef cattle brings
together desirable characteristics from more than one
breed. The public will resist and a crisis is likely to
occur soon in the use of feed additives, antibiotics,
pesticides and herbicides for livestock and poultry. A
permanent solution must be sought through genetic
resistance to disease.
 With greater reproductive efficiency, high-quality
breeding animals will be better used. Marvelous oppor-
tunities exist for rapid genetic improvement through
chemical induction of super-ovulation and control of
the reproductive cycle, non-surgical embryo removal
and implantation, coupled with embryo storage,
embryo sexing and eventually, sexing of sperm and
cloning of embryos. Other possibilities for future
livestock improvement involve selecting and culti-
vating supermicroorganisms (bacteria) and inoculating
the rumen. Young animals will be screened or
monitored for hormone levels as predictors of future
productivity.
 Livestock are genetically vulnerable to harsh
environments. In developing countries, where many
production factors are limiting, conditions for ex-
ploiting high genetic capabilities are lacking. Feed
shortages, diseases or adverse environments reduce the
productivity of otherwise genetically superior animals.
U.S. livestock producers are in "position to create
favorable environments for such animals.
 One means of overcoming genetic vulnerability of
livestock in agriculturally developing countries is
through genetic manipulation within the native
breeds. An example is the Criollo of Central America,
which has been crossed with the Zebu. The resultant F,
generation of cattle shows excellent performance,
though rapid degradation occurs in subsequent genera-
tions. One remarkable achievement has been with
Jamaica-Hope, a cross of the Jersey and Sahiwal. This
new, high-performing breed is adapted to tropical
environments.
 Genetic material may also be introduced through
game animals such as the eland, an antelope adapted
to very arid areas, which could be a meat animal of
some potential. The problem is that game animals are,
or have the potential to be, propagators and carriers of
disease. Thus, veterinary officials tend to refuse con-
sideration of anything other than cattle, sheep, goats
and pigs. Nevertheless, game or wild species, with their
great genetic diversity, should be considered in the
decades ahead as alternative meat animals. Another
objective would be to breed toward more effective
utilization of given feedstuffs, including by-products
and wastes. This will be particularly true with short-
generation species such as swine and chickens.


 Improved Feeding In the future, livestock may be
fed less corn as producers increase their use of legumes
(primarily alfalfa) and move toward the use of more
forages in livestock-producing systems. Whether this
occurs will depend on prices of energy used in corn pro-
duction and green chopping of alfalfa. Increasing labor
costs and land scarcity will also be important. (See the
later sections on land- and labor-conserving animal
husbandry.) Legumes fix their own nitrogen. Soil ero-
sion on rough land is decreased if grazing is carefully
managed or eliminated by green chopping. Problems
with alfalfa and other forages include the need for
harvesting and transporting to animals, harvest and
curing losses estimated at 30 to 50 percent, and erosion
associated with grazing. Challenges in technology for
the future will be to minimize harvesting and handling
costs and losses, improve storage facilities and hasten
field drying by the use of chemicals (Na2COs, K2CO3).
 Computers will assist in day-to-day and weekly
management decisions for feeding. Other ways to im-
prove livestock feeding will be through the use of
anabolic steroids (steroid hormones) for increased feed
utilization.
 The manipulation of basic biological processes is as
promising for livestock as for crops. The first area for
beef cattle involves the composition of gain in weight
with the objective of more lean meat. Feeding,
management and. genetics all hold possibilities to en-
courage more lean and less deposition of fat. Up to
now, the only feasible way to produce lean beef has
been to kill larger steers at a young age. Now there are
two other options. The first involves interventions with
several hormones or anabolic steroids now commer-
cially available. They consist of combinations of pro-
gesterone, estrogen, testosterone and zearolone (of
plant origin from corn) as feed additives. A second
possibility is with growth hormones for cattle, hogs and
poultry. By the year 2000 or 2030, these will be
available to regulate the growth and productivity of
food animals.
 An additional possibility in manipulating a basic
biological process is control of rumen nutrition with
ionophores, which are antibiotics produced by strep-
tomyces. They are effective for ruminants and also pro-
tect chickens from coccidiosis. The best results with
ionophores are obtained with beef cattle. In dairy
cattle, their use reduces butterfat in the milk. Carbox-
ylic polyether ionophores increase production when
given to growing ruminants. Animals on a high-
roughage ration that includes ionophores have in-
creased rates of gain for the same feed intake. Two
ionophores have been introduced and widely accepted.
"Monensin" obtained a 90 percent market penetration
in less than one year. Monensin and "Lasalocid,"
another ionophore, have received U.S. Food and Drug