xt7tb27ps927 https://exploreuk.uky.edu/dips/xt7tb27ps927/data/mets.xml Kentucky Agricultural Experiment Station Kentucky Agricultural Experiment Station 1998 journals English College of Agriculture, University of Kentucky, Lexington, Kentucky Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station The Kentucky Agricultural Experiment Station 111th Annual Report 1998, June 30, 1999 text 2009ua018 The Kentucky Agricultural Experiment Station 111th Annual Report 1998, June 30, 1999 1998 1998 2022 true xt7tb27ps927 section xt7tb27ps927 The Kemmcﬁcy ’
Agricuiéwzzl Expéi‘imem Siaffan

111.1

Annual Report
1998

4 Ceiiage cf Agricultugé"

' ~ Univsrsity Of Kannada “ Lexingmn; Kentucky £0346

The Kentucky
Agricultural Experiment Station

111m

Annual Report
1998

College of Agriculture
University of Kentucky - Lexington, Kentucky 40546

To His Excellency,
The Honorable Paul Patton
Governor of Kentucky

1 herewith submit the one hundred and eleventh annual report of the Kentucky Agricul—
tural Experiment Station for the period ending December 31, 1998. This is done in accordance
with an act of Congress, approved March 2, 1887, entitled, “An act to establish Agricultural
Experiment Stations, in connection with the Agricultural Colleges established in the several
states under the provisions of an act approved July 2, 1862, and under the acts supplemen—
tary thereto,” and also the act of Kentucky State Legislature, approved February 20, 1888,
accepting the provisions of the act of Congress.

Very respectfully,

ﬂay/m

C. Oran Little, Director
Lexington, Kentucky
June 30, 1999

Contents

Purpose .................................................................................................................... 7
Agricultural Economics .......................................................................................... 9
Agronomy .............................................................................................................. 1 1
Animal Sciences .................................................................................................... l3
Biosystems and Agricultural Engineering ............................................................ 15
Entomology ........................................................................................................... l7
Forestry .................................................................................................................. l9
Horticulture and Landscape Architecture ............................................................. 21
Nutrition and Food Science ................................................................................... 23
Plant Pathology ..................................................................................................... 25
Regulatory Services .............................................................................................. 27
Rural Sociology ..................................................................................................... 30
Veterinary Science ................................................................................................. 32
Robinson Station ................................................................................................... 34
Publications ........................................................................................................... 36
Financial Statement ............................................................................................... 51
Staff ....................................................................................................................... 52

AS
wealt
searc]
struct
Grant

Th
viding
than ]
cultur
technl
and i1
perf01
have:
ers, ir
devel‘

Re
ment
sand,
1998

Ef
studi(
ers at
facili
of the

C:
all re

C4
Beef
ages

U:
farm
ment
farm

A1
catio
tion ]
swim

A‘
is th<

Purpose of the Kentucky Agricultural
Experiment Station

Ha Land Grant institution, the University of Kentucky
is responsible for serving the people of the Common-
wealth of Kentucky. The College of Agriculture, with its re-
search, teaching, and extension activities, has developed a
structure and organization to provide the mandated Land
Grant services in agriculture and related areas.

The Kentucky Agricultural Experiment Station has been pro—
viding research results to farmers and rural residents for more
than 100 years. The continued advancement of Kentucky agri-
culture attests to the beneﬁts of applying new knowledge and
technology. Much of the research leading to increased quantity
and improved quality of Kentucky’s agricultural output was
performed by the Experiment Station. College researchers also
have successfully addressed problems of agribusiness, consum-
ers, international trade, food processing, nutrition, community
development, soil and water resources, and the environment.

Although much Experiment Station research has imme-
diate application to agricultural and natural resource-related
problems, scientists are also involved in basic research, gen—
erating new information to help solve present and potential
problems. The ability of Kentucky producers to be competi-
tive in domestic and world markets requires an expanded
base of knowledge in emerging areas of research applicable
to agriculture, food, and natural resources.

This Annual Report summarizes Experiment Station re—
search highlights for 1998. Lists of the faculty, research
projects, and publications completed during the year are also
provided.

The research programs of the Kentucky Agricultural Ex-
periment Station have benefited Kentucky’s agriculture over
the past century, and the results of present and future research
will continue to serve Kentucky’s primary industry.

Statewide Research

Research activities of the Kentucky Agricultural Experi-
ment Station were conducted at Lexington, Princeton, Quick—
sand, and Owenton and in counties throughout the state in
1998.

Efforts are constantly made to ensure that the research
studies have application to the problems of all Kentucky farm—
ers and other clientele groups. Locations of the experimental
facilities provide conditions representative of most sections
of the state.

Campus — Laboratories and specialized equipment for
all research program areas.

Coldstream — Maine Chance — Spindletop Farms —
Beef and dairy cattle, poultry, horses, sheep and swine, for—
ages and grain crops, tobacco and turf.

South Farm — Fruits and vegetables, ornamentals.

UK Animal Research Center (Woodford County ) — This
farm was purchased in late 1991 as a location for develop-
ment of state-of-the-art food animal research programs. The
farm is in Phase I of development as a research facility.

At Princeton (Caldwell County) the Research and Edu-
cation Center facilities and the West Kentucky Substa-
tion Farm are devoted to research on grain crops, beef cattle,
swine, fruits and vegetables, forages, and tobacco.

At Quicksand (Brent/rift County) the Robinson Station
is the location of research on fruits and vegetables, orna-

1 University of Kentucky, Lexington

2 Research and Education Center and West Kentucky
Substation Farm, Princeton

3 Robinson Station and Forest, Quicksand

4 Eden Shale Farm, Owenton

mentals, forages, grain crops, tobacco, and wood utilization.
Quicksand is also the headquarters of Robinson Forest,
which spreads over parts of Breathitt, Perry, and Knott coun-
ties and is the site of forestry and watershed management
research.

The Eden Shale Farm, located in Owen County near
Owenton, is where experimental and demonstration studies
are conducted on forage crops, tobacco, fruits and vegetables,
and beef management.

Re
jects i
comp;
financ
ogy, 1i

Polic

Risk

P0
form.
used 1
dies f:
cause
risk n
plant:
also 1
be wi

Envil

A
could
tional
has bi
marki
gases
contn
21 mai
carb(
(BMl
ing tl

Dair}
E)
comp
lie in‘
is tha
ity. T
perce
data
Each
volat
ence
cally

Agricultural Economics

Research in Agricultural Economics involves diverse sub-
jects including crop insurance, environmental policy, dairy
compacts, farm profitability, farm safety, input management,
financial analysis, telecommunications, information technol-
ogy, labor constraints, and credit issues.

Policy Research

Risk

Policy makers are once again debating crop insurance re-
form. Research conducted at the University of Kentucky was
used to inform that debate. It showed crop insurance subsi—
dies favor high-risk regions and high-risk farmers, which has
caused crop production to shift from the low—risk to the high-
risk regions. In addition, there are up to three percent more
planted acres due to risk management subsidies. Prices are
also likely to be two to three percent lower than they would
be without the risk subsidies.

Environment

A new area of research examined the role U.S. farmers
could play in reducing greenhouse gases, a major interna—
tional objective. Using the market to trade sulfur emissions
has been a large success in the US. Likewise, a worldwide
market for carbon emissions could help reduce greenhouse
gases in a more cost-effective fashion than command and
control systems. U.S. farmers could be big winners from such
a market as they are uniquely positioned to sequester more
carbon by adopting more Best Management Practices
(BMPs). Adopting more BMPs has the dual effect of clean-
ing the global and the local environment.

Dairy Compacts

Existing policy allows the formation of interstate dairy
compacts only if they are deemed to serve a compelling pub—
lic interest. One argument used in support of dairy compacts
is that consumers will benefit from greater retail price stabil—
ity. This study estimated demand systems for whole, two
percent, one percent, and skim milk using weekly scanner
data at the national level from March 1996 to June 1998.
Each system includes one of four measures of retail price
volatility. The results suggest that price volatility can influ—
ence fluid milk demand but does not necessarily systemati-
cally depress demand.

Enhancing Farm Profitability and
Management Efficiency

Farm Safety

Farm owner-operators and workers tend to make safety
decisions from a subjective cost/beneﬁt perspective. Research
indicates that farm workers do not recognize the direct and
indirect costs associated with work-related injury and thus
are not making safety decisions on an accurate basis. Injury
prevention interventions requiring farm worker participation
relate safe work practices and safety improvements to the
economic viability of the farm.

Nonuniform Inputs

An econometric model was developed to improve opti—
mal farm decision-making when inputs are nonuniformly
applied to a field such as irrigation water from a sprinkler
system, pesticides from an airplane, or manure from a
spreader. There are important implications for input-cost
minimization and precision agriculture in Kentucky.

Financial Analyses

Two mistakes in a top—tier econometrics methodology jour—
nal were corrected. The newly developed econometric meth—
odology permits the economist to analyze time series and
cross—sectional data in a simultaneous-equations system.
These methods can easily be used to properly analyze the
relative financial economic performance of farms in our
Kentucky Farm Business Management database or the rela-
tive competitiveness of counties in the databases maintained
by the TVA Rural Studies Center.

Economic Development

Telecommunications

The ability to use advanced telecommunications technol—
ogy is critical to the well—being of rural areas. TVA Rural
Studies contracted two research projects to this end. The first
looked at the availability and quality of central office
switches. It found that while most rural areas are served by
digital switches, the capacity in terms of advanced services
those switches provide tended to be less than in urban areas.
Furthermore, any telecommunications user farther than ap—
proximately three miles from the switch was unable to re—
ceive and use digital (including data processing) services
without purchasing expensive “dedicated lines.” Thus, many
rural areas are not able to enjoy the full benefits of advanc—
ing technology.

The second report provided an overview of other barriers
that keep rural areas from gaining access and using advanced
telecommunications. These barriers include market—based
constraints, regulatory constraints, and end—user constraints.
Various ways that rural communities can surmount these
obstacles were discussed.

Information Technology

A study was conducted to shed light on the extent to which
information technologies such as computers, the World Wide
Web, telephones, ATM cards, etc., can be used to enhance
the delivery of public services into rural communities. The
study found that rural residents, the poor, and the elderly
were significantly less likely to use such technologies in
Kentucky, raising questions about the feasibility of basing
the delivery of government services on these technologies in
the future.

Rural Southern Labor

There is great concern that areas in the rural South will be
unable to compete in the new economy. Advancing technol-
ogy, globalization, and changes in government policy such
as welfare reform all present the rural South with a new set
of challenges. Unfortunately, the region does not appear
wholly prepared to respond. Poverty, racial discrimination,
and poor education all hamper the performance and poten-
tial of many workers in the region. These findings and oth-
ers were presented at a research conference co—sponsored by
TVA Rural Studies.

Rural Credit
In most rural places, the bank system provides adequate
access to debt capital. However, the availability of equity

capital continues to be a problem. This study found there is
no single model for a rural equity institution. Key model
determinants included the institution’s goals, what weight to
put on rate of return versus economic development, target—
ing decisions, choice of instruments, and exit strategies.

Further, the study found that utility cooperatives—elec-
tric and telephone—are viable providers of equity invest—
ments in rural America. This research identified several ad-
vantages cooperators can offer including access to capital
and long-term development interest. Thus, utility coopera—
tives may be an underutilized resource for rural communi-
ties and could provide important start-up capital for economic
development projects.

Research Projects

Agricultural Industrialization and Globalization: Implications for Ru-
ral Economies — S. Goetz, D. Debertin, R. Fleming, A. Pagoulatas

An Evaluation of International Markets for Southern Commodities —
M.A. Marchant, M.R. Reed

Analyzing Impacts of Structure of US. Agriculture on Structure of
Nonfarm Rural Communities — D. Debertin, S. Gael:

Analyzing the Future International Competitiveness of the US. Food
Industry — M.R. Reed, M.A. Marc/tam, L. Mather

Economic and Environmental Impacts of Water—Quality Protection
Policies on Kentucky Agriculture — H. Hall, J.R. Skees

Evaluation of Public Policy Alternatives Designed to Help US. Cash—
Crop Farmers Manage Risk — J.R. Skees, H. Hall

Financing Agriculture and Rural America: Issues of Policy, Structure,
and Technical Change — D. Freshwater

Fruit and Vegetable Supply—Chain Management, Innovations, and
Competitiveness — T. Woods

Impacts of Trade Agreements and Economic Policies on Southern
Agriculture — M.A. Marc/1am

Rural Economic Development: Alternatives in the New Competitive
Environment —S. Gaerz, D. Freshwater

Agronomy

The Department of Agronomy conducts research in four criti-
cal areas: soil science, crop ecology and management, crop ge—
netics, and plant biology. Our work ranges from crop produc-
tion tests in field plots to cutting—edge laboratory studies. We
strive to improve the yield and quality of crops while conserv-
ing soil and water resources. Examples of interesting and p0-
tentially important research during 1998 are described below.

Plant Breeding

- A new burley tobacco variety, KY 910, will be available
to producers in 1999. KY 910’s distinguishing character-
istics are high resistance to the common strain of black
shank and medium resistance to other black shank strains.
Because of its moderate yield potential, KY 910 will be
most beneficial to burley producers who must grow their
crops on black shank-infested land.

' A new soft red winter wheat variety, KY 86C—6l-8, was
released by the Kentucky Agricultural Experiment Station
in 1998 for its yield potential, disease resistance, winter-
hardiness, early maturity, and outstanding milling quality.

. Approximately 40 experimental populations of endophyte-
free tall fescue were synthesized during 1998. Some of
these represent the fourth cycle of selection and are in the
early stages of seed increase for possible cultivar release
in the near future.

0 In 1998, the Kentucky Agricultural Experiment Station
released soybean line KY 91-1214 as variety 7499, with
marketing rights assigned to UniSouth Genetics. This is a
late group IV variety released for its high yield in full—
season and double—cropped environments in Kentucky. It
is resistant to southern stem canker.

0 Variety testing programs are an essential resource for Ken-
tucky grain crop producers. Hybrid corn performance tests
were conducted at seven Kentucky locations for feed grain
hybrids and at three Kentucky locations for high—oil hy-
brids. Forty-eight wheat varieties and several hundred wheat
breeding lines were evaluated at seven locations. One hun—
dred and thirty soybean varieties and breeding lines were
also evaluated in yield trials grown at two locations.

Crop Production

° More than 4,000 corn grain samples were evaluated for
chemical composition in the Corn Grain Quality Labora—
tory, a cooperative effort with the Kentucky Corn Grow—
ers Association.

' Corn row width and plant population studies confirmed
that 20-inch rows do not give additional corn yield re-

sponse in Kentucky over 30-inch rows. Plant population
responses are more consistently observed, with economic
yield responses highest at 26,000 to 28,000 plants per acre
in 30—inch rows.

Kentucky growers should soon have opportunities to con-
tract production of novel soybean varieties at premium
prices. Designer soybean varieties include high oleics (for
vegetable oils), high sucrose (for soy milks), and low satu—
rates (for salad dressings). Quality of grain produced un—
der Kentucky conditions has been quite good, and yields
have been comparable to those obtained elsewhere.
Estimated losses associated with storage and feeding of the
4.8 million—ton hay crop in Kentucky exceed 40 percent of
the crop and $100 million in value. Wrapped, baled silage
represents a viable alternative to current practices. Our re—
search shows that high bale density, moistures between 45
and 65 percent, minimum delay before wrapping, and main—
tenance of anaerobic conditions during storage are impor-
tant management considerations.

Perennial broadleaf weeds (dicots) such as common
pokeweed, trumpet creeper, and honeyvine milkweed have
become more prominent in corn and soybean fields that
are subjected to continuous no-till production practices.
On-farm studies have been conducted in no-till corn and
soybean fields to evaluate weed management tactics for
these problem species.

Maleic hydrazide (MH) residues on tobacco continue to
be a concern. Newly developed sucker control programs
can reduce residues, yet improve sucker control and in—
crease yields. Random testing throughout Kentucky now
indicates a positive trend in residue levels.

Plant Biotechnology

- Solanaceous plants like tobacco respond to pathogens by

the production of antimicrobial compounds. Recent in—
vestigations of this response have identified specific mo-
lecular elements important for control of defense gene
expression.

Rapid curing of tobacco minimizes the accumulation of
tobacco-specific nitrosamines (TSNA) and will reduce the
amount of these compounds in smoke. Our continuing
studies of TSNA accumulation have shown that com-
pletely covering tobacco with plastic in outside curing
structures will increase TSNA levels in comparison to
conventional structures.

Research completed on soybean transformation has re-
sulted in more efficient gene transfer of useful foreign
genes from other organisms into soybean. During the year

we successfully introduced a protein-modifying gene, a
fatty acid—modifying gene, and a herbicide—tolerance gene
into adapted soybean cultivar backgrounds.

We are developing new methods for expressing multiple
genes in plants. We have tested a strategy for simulta—
neously expressing several enzymes in different subcel—
lular compartments of plants. We have successfully ap—
plied this technology to express antibodies in transgenic
plants.

Research showed that the toxic acyl-loline alkaloids in
endophyte-infected tall fescue ingested by cattle were con—
verted into harmless substances during digestion and then
excreted. Conversely, the toxic ergopeptide alkaloids were
apparently converted into potent derivatives, such as ly-
sergic acid amide.

We have discovered a novel mechanism for elongation of
both branched and straight medium—chain fatty acids in
plants. The novel mechanism appears to be restricted to
trichome glands.

Environmental Studies

Laboratory experiments with large undisturbed soil blocks
will enhance our ability to classify soils according to trans—
port rates and aid in the development of best management
practices for agricultural chemicals applied to partially
saturated soils.

Poultry litter applied to no-till soils could result in in-
creased runoff of fecal bacteria. We examined the effect
of residue level and no-tillage on runoff of fecal bacteria
from soils during rainfall. Total fecal bacteria losses (but
not bacterial concentration) were reduced in no—tillage
because surface runoff was minimized and infiltration was
maximized.

Carbon storage in soils is important to forest ecosystems.
Analysis of digital soil survey data has produced an esti-
mate of soil carbon storage in forested landscapes of south—
eastern Kentucky. More detailed examination of carbon
storage will be used to investigate its possible response to
changing management practices or climate.

Laboratory and field leaching experiments with metal-
contaminated soils indicated that colloids in flushing so-
lutions may enhance desorption and remobilization of the
metals. These findings point to greater potential for
groundwater contamination at some sites but to opportu—
nities for more effective remediation at others.

Research Projects

Amount and Quality of I-Ierbage Ingested by Cattle Grazing Tall Fes—
cue Clover Grasslands —— CT Daugherty

Analysis omeNA Polyadenylation and Metabolism in Plants —A.G.
Hunt

Animal Mantirc and Waste Utilization Treatment and Nuisance Avoid-
ance for a Sustainable Agriculture — G.L. Cromwell, J.H. Grove

Breeding Improved Varieties of Wheat, Oats, and Barley for Kentucky
— DA. Van Sanford

Characteristics of a Plant Poly (A) Polymerase — A.G. Hunt

Characterization, Classification, and Use Interpretations of Kentucky
Soils —— A.D. Karat/rations

Characterization of Phytoalexin and Sterol Biosynthetic Genes in To—
bacco — J. Chappell

Classifying Soils for Solute Transport as Affected by Soil Properties
and Landscape Position —— E. Perfect

Cloning and Heterologous Expression of Pesticide Metabolizing Cy—
tochrome P450 —— M. Barrett

Corn Breeding and Genetics: White Endosperm Breeding, Food Quality
Inheritance, and Hybrid Performance Tests — CG. Poneleit

Determining Rates of Several Nutrient Sources for Optimum Crop
Production and Soil — W.0. Thom

Distribution of Constituents within Tobacco Leaf— H.R. Burton, L.P.
Bush

Early Maturing Soybean Cropping System: Identifying Appropriate
Cultivars — L.J. Grabau

Effect of Tillage and Land Use on Physical and Chemical Properties
of Kentucky Soils — G.W. Thomas, R.L. Blevins, J.A. Thompson

Effects of Suckering Practices on Growth Characteristics, Yield, and
Quality of Burley, Dark Fire—Cured, and Dark Air—Cured Tobac—
cos — J.R. Calvert

Evaluation of Burley Tobacco Varieties — J. Calvert, 3. Kennedy

Evaluation of Perennial Forage Crop Varieties — R. Spitaleri

Evaluation of Soybean Varieties and Breeding Lines for Use in Ken—
tucky — T. w. Rfetﬂ'er

Forage Crop Genetics and Breeding to Improve Yield and Quality —
N.L. Taylor

Integrated Management of Arthropod Pests of Livestock and Poultry
— CT Daugherty

Manipulation and Regulation of Oxylipin Formation in Plant Tissues
— D.F. Hildebrand

Mechanisms for Vacuolar Storage/Sequestration of Cd, Zn, Mn, Ni —
GJ. Wagner

Mineralogical Controls on Colloid Dispersion and Solid»Phase Spe-
ciation of Soil Contaminants — R.I. Barn/rise!

Multiplicative (Linear-Bilinear) Models for Genotype X Environment
Interaction in Crop Cultivars — P.L. Cornelius

Pest Control Strategies for Grazing Livestock Using Grass-Endophyte
Associations — CT Daugherty, F.W. Knapp, L.P. Bush

Phenology, Population Dynamics, and Interference: A Basis for Un—
derstanding Weed Biology and Ecology — WW. Witt

Plant Genetic Resource Conservation and Utilization — N.L. Taylor

Regulation of C6—Aldehyde and Alcohol Formation in Plant Tissues
— D.F. Hildebrand

Relationship between Photosynthesis, Assimilate Supply, and the Size
of the Reproductive Sink — D.B. Egli

Seed Biology and Technology Investigations — D.M. TeKrony, D.B.
Egli, R. Geneve, A. Downie

Significance of Loline Alkaloids in Ecosystems Predominated by
Grass/Endophyte Associations — L.P. Bush

Soil and Crop Nitrogen Testing to Improve Nitrogen Management for
Burley Tobacco — R.C. Pearce, J. G. Grove, D. C. Ditseh

Somatic Cell Genetics of Crop Plants —— GB. Collins

Species and Crop Management Effects on the Yield and Quality of
Round Bale Silage —— M. Collins

Studies of and Efforts to Engineer the Metabolism in Plant Trichomes
— GJ. Wagner

The Role of Ammonium—Potassium-Calcium Exchange Interactions
in Regulating Nitrification Rates in Soil — V.P. Evangelou, M.S.
Coyne

Understanding Recombination and Modifying Its Frequency in Soy—
bean and Corn — T.W. Pfet't'fer

Animal Sciences

Income from livestock fluctuates drastically from year to year.
The past year was a harsh reminder of this fact. While some
commodities fared well, others were devastated by farm gate
prices. Through good times and bad, research remains an essen—
tial component of successful livestock and food production. We
have emphasized efﬁcient utilization of forages, adding value
to our animal products, maintaining a safe food supply, increased
efficiency of production, and research methods that help ensure
sustainable agricultural practices. Livestock makes up more than
50 percent of the total cash receipts from agriculture in Ken-
tucky and is one of the Commonwealth’s most vital economic
segments.

Nonruminant Nutrition

Research was conducted with a mutant corn that contained
a majority of its phosphorus in an inorganic form rather than
as phytic acid, which is poorly bioavailable to nonruminants.
The phosphorus in low—phytate corn was three to four times
as bioavailable to pigs and chicks as the phosphorus in nor-
mal corn. In diets containing low—phytate corn, less inorganic
phosphorus was needed to maximize performance and bone
mineralization. Phosphorus excretion was reduced by 30 to
40 percent in pigs fed low-phytate corn.

The bioavailability of phosphorus in meat and bone meal
was found to be 85 to 90 percent for pigs. Particle size, pro—
cessing temperature, and origin (bovine versus porcine) had
no effect on phosphorus bioavailability.

Porcine somatotropin (pST) was found to increase accre—
tion rates of carcass lean tissue and whole body protein in
growing pigs. Finishing pigs receiving pST required greater
dietary amounts of calcium and phosphorus than control pigs.

Reducing the dietary protein level and adding amino acids
reduced the amount of nitrogen excretion in pigs and reduced
ammonia release from their manure. Similarly, feeding a low—
phosphorus diet supplemented with microbial phytase or feed-
ing low-phytate corn reduced the phosphorus excretion in the
manure.

A by-product resulting from the process of extraction of
heparin from porcine intestines was found to have excellent
properties as a protein source for weanling pigs. Weanling
pigs demonstrated a preference for a diet containing the by—
product as one of the animal protein sources compared to a
diet without it.

Graded levels of five B-vitamins (niacin, riboflavin, folic
acid, pantothenic acid, and B12) to a low vitamin diet im-
proved growth rate and carcass lean gain in pigs. Growth
rate and lean gain improved with vitamin supplementation.

Potential interactive effects of chromium supplementa—
tion with dietary energy level, protein level, or energy source
in growing pigs were assessed. There was no effect of, or
any interactions with, chromium in regard to growth rate or
carcass composition.

Two important environmental problems faced by the poul-
try industry are excessive ammonia emissions from broiler
litter and excess nitrogen in the litter. Reducing protein in-
take can minimize these problems but can also result in poor
growth. Three experiments were conducted feeding broiler
chickens low protein corn-soybean meal diets with various
supplements of essential and nonessential amino acids and
additional dietary energy. The results provided information
on the concentrations of essential amino acids required for
optimum body weight gain and feed conversion using low
protein (17 percent) diets. These can be useful in formulat—
ing broiler diets that can lower litter nitrogen concentrations
and ammonia levels in the broiler houses.

Ruminant Nutrition

Experiments were conducted evaluating the effect of small
intestinal protein on intestinal digestion in ruminants. Infu-
sions were used to control the amount of protein reaching
the small intestine. Increasing protein supply to the small
intestine increased intestinal carbohydrate disappearance and
increased the pancreatic secretion of amylase. These studies
suggest protein may have a regulatory role in how nutrients
are assimilated in the small intestine of cattle. This informa-
tion may be key in determining limitations to intestinal di-
gestion and may be useful in optimizing nutrient utilization.

Another effort has been the characterization and cloning
of amino acid transport proteins that are expressed in the
gastrointestinal epithelia, liver, pancreas, and kidney of cattle
and sheep. This is novel research for ruminant species and
will be used to improve the efficiency of amino acid absorp—
tion and metabolism by designing diets that contain opti—
mized ratios of amino acids, based on a knowledge of amino
acid transporter physiology.

Research with calves indicates supplementation with as
little as 15,000 IU/d of vitamin A may decrease growth and
vitamin E in blood.

Rumen Microbiology

Our rumen microbiology laboratory has confirmed the
isolation of a previously unrecognized group of propionate—
producing bacteria that use succinic acid as a sole carbon

source. The organisms represent a new species of ruminal
bacteria that appear to play a critical role in propionate me-
tabolism in the rumen.

Fibrous carbohydrates in plant material are an important
source of carbon and energy for anaerobic bacteria inhabit-
ing the digestive tract of ruminants. In addition, these carbo-
hydrates are found in agricultural, municipal, and forestry
waste and could serve as renewable resources for chemical
production via bacterial fermentations. The hemicellulose
fraction of plant fiber is comprised of pentose sugars such as
xylose, but pentose utilization by anaerobes is generally not
well understood. Several genes were identified that are re—
sponsible for xylose metabolism in the anaerobic thermo-
phile, Thermoanaerobacter etlzanolicus. A novel xylose
binding protein was also characterized that could be useful
in the development of thermostable biosensors. These are
the first in—depth genetic studies of xylose utilization in a
thermophilic bacterium and represent a significant advance-
ment in the understanding of these biotechnologically im-
portant organisms. The information obtained from the
thermophile studies is currently being used to identify simi-
lar xylose utilization genes in