ANIMAL NUTRITION TECHNOLOGY EXCHANGE
                       January 20,2000
   A Conference Developed by the Agricultural Nutrient Reduction Workgroup
                            of the
                    Chesapeake Bay Program's
                      Nutrient Subcommittee
   This document is a summary of the Animal Nutrition Technology Exchange.
Support for this conference and the development of this document were provided by
                        The Reiily Group

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  ANIMAL NUTRITION TECHNOLOGY EXCHANGE
                          January 20, 2000


                     TABLE OF CONTENTS

INTRODUCTION	5
PROGRAM PRESENTATIONS	6
Watershed and Regional Nutrient Balance Issues - Dr. Les Lanyon, Professor of Soil Fertility,
      Penn State University
Managing the Nutrient Content of Rations to Achieve Animal Production Goals and also Minimize
      Environmental Consequences - Dr. William B. Roush, Associate Professor of Poultry
      Science, Penn State University
PANEL 1	10
"Optimizing Nutrient Levels in Feed Through Balanced Mixes While Minimizing
Nutrient Outputs"
•  Dairy - Dr. Charles Stallings, Professor/Extension Dairy Scientist, Virginia Tech
*  Swine - Dr. Ken Kephart, Associate Professor of Animal Science, Penn State University
PROGRAM PRESENTATIONS, cont	12
Economics of Enzyme Technology and Cost/Benefits - Dr. Darrell Bosch, Professor of Agricultural
      and Applied Economics, Virginia Tech
PANEL 2	13
The Status and Progress of Implemented Feeding Strategies"
•  Poultry - Winston Turner, Broiler Production Manager, Tyson Foods
*  Dairy - Dr. Rick Kohn, Associate Professor of Animal Science, University of Maryland
*  Swine & Poultry - Joe Garber, Nutritional and Analytical Services Coordinator, Wenger Feed,
   Inc.
SUMMARY FROM THE BREAKOUT GROUPS	16
Ğ  Identify barriers to adoption and ways to increase adoption
*  What practices can work now - economically and environmentally?
*  Identify knowledge gaps and future research needs
SUMMARY OF THE PROCEEDINGS	18



LIST OF REGISTRANTS	19

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                                INTRODUCTION

 During the past several years, considerable attention has been directed at the potential
 environmental impacts of agriculture in the Chesapeake Bay Watershed. A primary focus has
 been on the potential nutrient loadings to surface and groundwater resulting from animal
 agriculture sources. In this context, a wide array of alternative practices and uses have been
 suggested to reduce the effects of current manure management practices.

 There is an emerging body of science-based information on the formulation of animal rations that
 have the potential to cost-effectively achieve the objectives of producers and also result in
 potential reductions in the nutrient content of manures at the point of excrement. These
 reductions can be achieved in a number of ways. One example is the incorporation of enzymes
 into rations (required in Maryland beginning in 2001)  in order to improve the ability of animals to
 utilize a greater proportion of the nutrients that are ingested.

 The Chesapeake Bay Program's Agricultural Nutrient Reduction Workgroup (AgNRWG) planned
 a technology exchange in the Winter of 2000 to serve as a mechanism to begin to develop a
 broader understanding of the latest advances in animal nutrition and the ability of these advances
 to provide cost-effective tools to reduce the nutrient content of animal waste at the point of
 excrement.

 The technology exchange involved individuals from each of the jurisdictions representing:
        state lead agencies
        state associations of swine, livestock, dairy and poultry producers
        state environmental organizations
        state agribusiness associations that represent processors and suppliers
        Agricultural Experiment Stations
        state Cooperative Extension
        state conservation agencies, and
        state offices of the Natural Resource Conservation Service and the Farm Service Agency

The objectives of the Animal Nutrition Technology Exchange were to engage participants in
discussions to:
    •    Assess the current science-based technology avaiiable to produce cost-effective animal
        feeds tha,t minimize the nutrient content of animal manures at the point of excrement
    •    Assess the current level of adoption of these technologies by feed producers
    •    Identify and assess the barriers to adoption of these feed technologies by feed producers
    •    Identify and assess the barriers to adoption and utilization of nutrient reduction feeding
       strategies by farmers; and
    •    Identify the technology needs required to accelerate the adoption and utilization of
       appropriate reduction  strategies in animal agriculture in the Chesapeake Bay Watershed,

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                                 PROGRAM

                              January 20, 2000


Moderator: Roydan Powell, Assistant Secretary Maryland Department of Agriculture.

9:00 AM - Welcome - Dr. Thomas Simpson, Chair, Chesapeake Bay Program, Nutrient
              Subcommittee

9:10 AM - Watershed and Regional Nutrient Balance Issues - Dr. Les Lanyon, Professor of
              Soil Fertility, Penn State University

9:55 AM - Managing the Nutrient Content of Rations to Achieve Animal Production Goals
              and also Minimize Environmental Consequences - Dr. William B. Roush,
              Associate Professor of Poultry Science, Penn State University

10:55 AM - Panel 1: Optimizing Nutrient Levels in Feed Through Balanced Mixes While
              Minimizing Nutrient Outputs"
              Dairy - Dr. Charles Stallings, Professor and Extension Dairy Scientist, Virginia
                           Tech
              Swine - Dr. Ken Kephart, Associate Professor of Animal Science, Penn State
                           University.
              Poultry - Dr. William B. Roush, Associate Professor of Poultry Science, Penn
                           State University
12:45 PM - Economics of Enzyme Technology and Cost/Benefits - Dr. Darrell Bosch,
              Professor Agricultural and Applied Economics, Virginia Tech

1.25 PM - Panel 2: The Status and Progress of Implemented Feeding Strategies"
              Poultry - Winston Turner, Broiler Production Manager, Tyson Foods
              Dairy - Dr. Rick Kohn, Associate Professor of Animal Science, University of
                            Maryland
              Swine & Poultry - Joe Garter, Nutritional and Analytical Services Coordinator,
                           Wenger Feed, Inc.,

2:35 PM - Breakout Groups.
Breakout Group discussion topics include:
              1. Identify barriers to adoption and ways to Increase adoption.
              2. What practices can work now - economically and environmentally?
              3. Identify knowledge gaps and future research needs.

3:35 PM - Report from Breakout Groups and discussion. Chaired by Royden Powell

4:00 PM - Closing Remarks and Adjournment. Royden Powell.

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                                   ABSTRACTS


  Watershed and Regional Nutrient Balance issues -
  Dr. Les Lanyon, Professor of Soil Fertility, Perm State University

  Introduction
  Changes in the amount of nutrients available to agriculture have made possible changes in the
  organization of agriculture at field, farm, watershed, and regional levels.  The new patterns of
  organization in agriculture have resulted in new consequences from the production methods
  Reactions by various interest groups to these consequences are contributing to new expectations
  for agriculture. Because each action in agriculture has many consequences, the new expectations
  and the means to achieve them must be sensitive to the factors that have contributed to the
  specialization in agriculture and not just a react ion to a subset of the consequences.

  Increased Nutrient Availability
  Unease about the ability of agriculture to sustain itself because of nutrient scarcfty continued from
 the 19* century into the 20th century. As we begin the new millennium, concerns about nutrient
 scarcity have been replaced by concerns about the consequences of nutrient excesses. This
 dramatic change was based on the ability to fix nitrogen from the atmosphere by industrial
 processes that were pioneered to ensure the ability of nations to fight world wars. The nitrates so
 commonly used in agriculture can be, under the right conditions, explosives. It was the military
 dependence on the explosive character of nitrates that led many nations to build nitrogen fixation
 plants. These plants were later converted from military to agricultural purposes. Phosphorus is
 currently mined from geologic deposits rather than recaptured from biological sources such as
 animal and human bones. We no longer scour battlefields for bones, nor rely on recapturing the
 nutrients in the wastes from slaughtered animals  to sustain agricultural production.

 Changes in the Organization of Agriculture
 Although those who advocated for increased nutrient availability envisioned the need to offset
 nutrient deficiencies in crop production, changes in organization of agriculture were made possible
 by the continuous supply of nutrients from new sources. Because fertilizer could replace the
 nutrients exported from farms in harvested crops, recycling nutrients in manure from animals on
 tiie farm was no longer an essential tactic to sustain the productivity of farms. Fertilizer made it
 possible for some farms to specialize in crop production and other farms to specialize in animal
 production. In addition to the production advantages that are often due to specialization, the result
 was a new pattern of nutrient flow. Nutrients from primary sources such as the atmosphere and
 geologic deposits were processed into fertilizer and shipped to cash crop farms. The nutrients
 built soil reserves and were taken up into harvested crops that were transported to specialized
 animal production facilities. Although there are some nutrient balance issues related to crop
 production, they are mostly related to the efficiency of nutrient recovery by crop plants. Nutrient
 balance in animal agriculture is another issue. Animals naturally excrete a large proportion of the
 feed nutrients they consume as "waste." Ecologically this  excretion is critical to the functioning of
 natural systems. So, unlike crop production in which improved efficiency can reduce the nutrients
 required for production, animal agriculture will always have a large part of the nutrients consumed
 by the animals end up in the waste because the biology of animals defines trie limits.

Consequences of New Patterns of Organization
The concentration of animal agriculture has contributed to the accumulation of nutrients in some
areas in excess of the crop utilization potential of nearby fields. These excesses can be lost as
nitrate leaching into groundwater or as phosphorus being lost in runoff from agricultural
landscapes. The degradation of water resources has attracted attention in many locations and

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stimulated calls for cleaning up the sources of pollution. At the same time, the associated
economies of scale and advantages of size in agriculture have created a widely distributed and
very powerful system of production. Instead of being constrained by the local crop production for
feeding animals, this new system is able to access feed and other production inputs from many
locations. Thus, the concentrated animal production units can be fueled with the lowest cost feeds
that are available in the market These units also have power in marketing products for processing
or may actually be integrated with the processing units. Local, small scale production that can not
take advantage of "low-cost" inputs, nor negotiate with processors is at a disadvantage in
comparison to the concentrated and integrated operations.

Reacting to the Consequences of Agricultural Production
Although many programs are underway to reduce the loss of excess nutrients from agriculture,
these often address symptoms of the organization of agriculture as perceived by special interest
groups. For instance, those interested in water quality in a particular area may not realize that the
concentration of animals is based on very rational business principles and a host of factors that
encourage the organizations involved. Furthermore, there may be social advantages for the
farmers involved because intensive animal agriculture may be the most viable of the agricultural
alternatives available to them in an intensely competitive agricultural economy.  Responses by
governments to those concerned about the consequences of agriculture wilt also have their own
collateral consequences in addition to the intended impacts on water quality improvement. Future
actions must take into account the full spectrum of consequences, not focus solely on the
intended outcomes. Decision-makers must factor into their decisions the implications of their
actions for the next iteration in the evolution of agriculture. They will be creating a new set of
conditions and factors to which businesses and farmers will react. As the seemingly simple
introduction of fertilizer to offset nutrient deficiencies in agriculture made entirely new patterns of
organization possible, the new business environments they create will stimulate new relationships
and organization.

Reacting to the consequences of watershed  and regional nutrient balances is not like fixing a
broken food producing machine. It involves the setting of parameters for a dynamic, evolving
system whose managers will explore the possibilities of those parameters and fashion new
patterns of organization. Those in agriculture and those affected by the consequences of
agriculture have stakes in the outcomes of the new patterns. It is likely to be in the best interest of
all to respond with this in mind.

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  Managing the Nutrient Content of Rations to Achieve Animal
  Production Goals and Also Minimize Environmental
  Consequences -
  Dr. William B. Roush, Associate Professor of Poultry Science, Penn State
  University

  Feed formulation management has the potential to reduce nitrogen and phosphorus pollution at
  the nutrient input stage. This management strategy includes: (1) the development of analytical
  physical and nutritional enhancements for ingredients, (2)  the  accurate determination of the
  nutritional requirements of animals, and (3) examination of alternatives to linear programming to
 more accurately meet requested nutrient levels.

 Analytical, physical and nutritional  enhancement of ingredients includes the improvement of the
 availability and digestibility of nutrients and the determination (prediction) of nutrient levels and
 their variance in ingredients.  Artificial neural networks have been shown to be an  effective
 alternative  to  regression analysis  for predicting amino acid  levels  in  ingredients based on
 proximate analysis values.

 Treatments and  additives that reduce excess concentrations of nitrogen indude supplementing
 the diet with commercially available amino acids and feed formulation based on digestible amino
 acid values and ideal amino acid profiles. Phosphorus pollution can be reduced by formulating on
 the basis of available phosphorus and by adding enzymes to the diet mat will release phosphorus
 from phytate.  Also, nutrient pollution can be reduced by  phase-feeding  diets to  match the
 changing nutrient needs of the animal.

 Multivariate experimental designs (response surface methodology) can efficiently and effectively
 define the requirements of animals  for nitrogen and phosphorous and their interaction with other
 nutrients and energy factors. Computer modeling for ruminants, swine and poultry holds promise
 for defining nutrient requirements under varying environmental  conditions.

 Algorithm alternatives to linear programming are being investigated for more effective formulation
 of rations to meet  nutritional  and economic  goals. These computer algorithms  provide  a
 framework upon which the analytical, physical and nutritional enhancements of ingredients can be
 effectively balanced to reduce nutrient pollution  while  meeting  economic  goals.   Stochastic
 programming,  goal  programming  and genetic  algorithms  are  being  compared  to  linear
 programming (with a margin of safety). Stochastic programming involves the formulation of rations
 based on nutrient variability at a specified level of probability.  Goal programming is an approach
 that allows more than one objective (e.g.. minimizing cost and  nutrient variance) to be  met in the
formulation process. Genetic algorithm formulation of rations is based on the principles of genetic
 selection. The variables of the ration are evolved into an optimal solution.

 In summary, research is being conducted on analytical, physical, and nutritional enhancement of
ingredients. Stochastic programming, goal programming and genetic algorithms, as alternatives to
linear programming, are being investigated for feed formulation. These nutrient management
developments promise to more accurately meet animal nutritional requirements and reduce the
consequences of nutrient pollution in the environment.

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                                    PANEL 1


"Optimizing Nutrient Levels in Feed Through Balanced Mixes
While Minimizing Nutrient Outputs"

Dairy • Dr. Charles Staliings, Professor and Extension Dairy Scientist •
Nutrition, Virginia Tech

Dairy cattle nutritionists and milk producers have been pushing for higher milk production in order
to remain competitive in a challenging economic environment.  In the process, cattle are many
times over-supplemented with nutrients, especially protein (nitrogen, N) and phosphorus (P).  This
excess will be excreted in the feces (N and P) and urine (primarily N). In addition, many times
forms with herd sizes of less than 130 cows do not have facilities to group and feed cows by
production, a practice commonly encountered in larger herds. The majority of Virginia herds are
less than 130 lactating cows. Feeding only one group contributes to over supplementation
because the ration is balanced to challenge higher producers but will supply excessive amounts to
lower producers. A fairly typical one group ration  balanced to supply 17% protein (2.72%
nitrogen) and ,77 Meals net energy/lb. of dry matter would contain 20 Ibs. aifatfa silage. 50 Ibs.
corn silage, 4.5 Ibs. whole cottonseeds, 1 1b. fish meat, 5.5 Ibs. soybean meal, and 12 Ibs. shelled
com. At milk yields ranging from 30 to 100 lbs./cow/day the following demonstrates the degree of
overfeeding.
 Lbs./cow/dav                actf    4m    50# _ §QJ _ Z0J
 Dry matter intake             33     37     39     43     46     49     52     55

 Protein consumed             5.5     6.2     6.6    7.3     7.8    8.3    8.8    9.3
 Protein required              3.4     4.2     5.1    5.9     6.8    7.6    8.4    9.3
 Excess                      2.1     2.0     1.5     1.4     1.0     .07     .04    0
  (% excess)                (38)   (32)    (23)    (19)    (13)    (8)     (5)    (0)
 Phosphorus consumed        .14    .16    .17    .19    .20    .21     .22     .24
 Phosphorus required         .09    .11    .13    .15    .17    .18    .20     .22
 Excess                     -05    .05    .04    .04    .03    .03    .02     .02
  (% excess)                (36)   (31)    (24)    (21)    (15)    (14)    (9)     (8)

 The ration above had no supplemental P but still contained .43% P on a dry basis. Approximately
 two-thirds of the P came from whole cottonseeds, fish meal, soybean meal, and corn. These are
 feeds usually imported onto the farm. The alfalfa and com silage usually grown on the farm
 supplied only about one-third of the P. Only about 30% of consumed P is captured in milk and
 exported off the farm, so typically, there is a net importation of P onto a dairy farm. To further
 confound the problem P is normally supplemented in inorganic form. For instance adding a pound
 of 4-1 mineral (calciumtphosphorus ratio) supplement to the ration increases the P content to
  55%. Research has documented that this high level is not needed and lower levels are
 recommended. In conclusion, N and P excretion can  be reduced by grouping and feeding by
 production and reducing or eliminating supplemental P when amount in feeds are adequate.
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  Swine - Dr. Ken Kephart, Associate Professor of Animal Science, Penn
  State University

  Overview of Swine Production Systems
  Nearly two-thirds of all nutrients consumed by the pig are excreted rn the manure, but it has only
  been in the last decade that animal agriculture has recognized the importance of nutrient
  excretion. Recently, more precise feed formulation and the use of feed additives have helped to
  reduce nutrient excretion.  But important challenges remain in animal production systems and the
  land application of manure.

  Today, the vast majority of swine producers operate an all-in-all-out system - grouping pigs
 closely by age and weight. This has important implications for nutrient excretion. Since body
 weights are fairly precise within a group, we can formulate diets to exacting specifications- saving
 both dollars, and nutrients.

 But in the last 20 years, swine farms have increased in size to help offset diminishing profit
 margins.  In addition, many units are now operated under contract. Both trends mean that all feed
 nutrients are now imported to the farm.

 For contract grower-finisher units, most or all of the manure produced is applied on the home
 farm. Large sow units, however, usually produce an excess of manure causing the application of
 manure to sometimes become a disposal issue. As a result, manure is surface-applied to
 increase nitrogen volatilization, and crop yields are projected at the upper limit, in order to
 maximize manure application rates. Since the P:N ratio in manure is already, higher than is
 required by most crops, these high manure application rates increase the deposition of P in the
 soil.

 Partial Solutions to Nutrient Imbalance and Nutrient Excretion
 The use of lysine and other amino acids in swine diets enable the feed manufacturer to decrease
 the amount of protein, and therefore the nitrogen, in the diet. This practice can reduce nitrogen
 excretion by more than 20%; unfortunately this practice increases the P:N ratio In the manure
 even further. The use of dietary phytase, an enzyme that enhances the digestion of plant-borne
 phosphorus, can reduce phosphorus excretion by at least 20%. Furthermore, with the recent
 edition of the Nutrient Requirement of Swine (1998), and an awareness of nutrient excretion,
 nutritionists follow recommended guidelines fairly closely.

 Future Needs for Swine Production Systems
The use of phytase is a sound tool for reducing phosphorus excretion, but methods are needed
for further reductions, or for extracting P from the manure.  Equipment is needed to provide fast
and economical injection or incorporation of manure without destroying conservation practices.
Water waste has been reduced in swine production, but further improvements are needed to
decrease the cost of hauling swine manure long distances.
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Economics of Enzyme Technology and Cost/Benefits -
Dr. Darrell J. Bosch, Professor, Agricultural and Applied Economics,
Virginia Tech

Runoff from soils which are very high in phosphorus (P) can be detrimental to surface water
quality. High soil P may result from repeated applications of manure with higher P content than
can be used by crops. Genetically engineered microbial phytase can improve swine and poultry
utilization of natural P in feedstuffs, reduce the need for supplemental feed P, and lower P content
in animal manure. Producers must weigh phytase costs against its potential economic benefits.
Costs include purchasing the enzyme formulation, adapting the feed system to accommodate the
enzyme formulation,  management time to learn to manage the new feed ration, and risk. Benefits
include lower feed P  supplement costs, lower manure disposal costs, and lower costs of
commercial fertilizer. Case studies of a Virginia turkey operation and a North Carolina swine
operation were conducted to evaluate the farm-level costs and benefits of microbial phytase under
a P-standard where manure applications cannot exceed crop P recommendations.

Potential net returns  from microbial phytase for turkeys were estimated as savings in
supplemental feed P costs plus savings in commercial fertilizer costs, plus increased prices of
litter sold off the farm, minus costs of microbiai phytase. Estimated costs of phytase formulation
to reduce P content in litter by 35 percent were $2,500. Phytase reduced supplemental P feed
costs by an estimated $1,431, When the P content of litter was reduced, more litter could be
applied on farm and the cost of supplemental commercial fertilizer was reduced by $390.
Reduced P content of litter would reduce the amounts of excess litter exported by poultry
producers,  increase  the amounts that non-poultry farms could import, and enhance prices of litter
sold off the farm. When the litter price enhancement effect is included, it is likely that economic
benefits of phytase would exceed its cost.

Potential net returns from microbial phytase for swine were estimated as savings in swine lagoon
liquid application costs plus savings in supplemental feed  P costs minus costs of microbial
phytase  Estimated  costs of phytase formulation to reduce litter P content by 28% were $4,735.
Savings in  supplemental feed P formulation were estimated as $2,713.  Savings in lagoon liquid
application were $9,356 when lagoon liquid was applied to bermudagrass hay, resulting in a
$7,334 net return to  phytase. When lagoon liquid was applied to com,  savings in lagoon liquid
application to com were $1,686 resulting in a negative net return of $-336 to phytase.

 Phytase can lower but not eliminate the cost to poultry and swine farmers of limiting manure
 applications to crop  P requirements. The more widely the P standard is applied, the greater the
 potential cost savings from phytase use.  Effective phytase use requires cooperation between
 integrators and contracting producers and development of ways to manage production risks.
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                                    PANEL 2


  "The Status and Progress of Implemented Feeding Strategies"

  Poultry - Winston Turner, Broiler Production Manager, Tyson Foods

  The concept of using phytase in feed has been used in Europe for some period of time  In the
  USA it was tested by E.T. Kornegay for six years at Virginia Tech.

 m^n^ħ2^                           that is P°°^ dj9ested ^ these
                                                                          nd is
 Phytase is organic and sensitive to heat and must be applied after the pelleting process  BASF
 came "P with a fluid form of phytase that uses 1 .5 gallons of water with 12 pounds of natuphos
 per one ton of feed. A computer controlled Doppler Radar Unit measures the flow into the spray

 naiuphos                                                                     "
 Starting i in mid February 1998, Tyson Foods ran extensive tests to be sure phytase would work in
 the poultry world  Th,stest concluded there was no difference in bird performance between
 phytase and control. The big advantage was the DeFlour phosphate was reduced from 1 7
 pounds per ton to 6 pounds per ton of finished feed. Manure test results during the performance
 testing penod indicated that phytase in 85% of our feed would reduce P205 bv 28 30%  when
 used in 100% of the feed the reduction should be 33.30%.

 Dr. Paul Ruszler of Virginia Tech recently summarized Virginia's annual poultry manure
 production at 469.312 tons at 30% moisture or 438,008 tons at 25% moisture  Using the
 Department of Conservation and Recreation (OCR) default of 62 pounds per ton; 13,578 pounds
of phosphorus is produced. Using Tyson  Foods of Harrisonburg projection at  100%
implementation of 46 pounds per ton; 10,074 tons of phosphate is produced, the reduction will be
3 503 tons. Tyson continues to run tests with Virginia Tech to continue improving the reduction of
phosphorus.
                                      13

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Dairy - Dr. Rick Kohn, Associate Professor of Animal Science, University
of Maryland

Milk urea nitrogen (MUM) is a means to evaluate nutritional status in lactating dairy cows because
it is an indirect measure of protein utilization. With adequate energy in the diet, MUN is indicative
of protein status. Variation in MUN has also been suggested to be related to the protein to energy
ratio of the diet consumed.

Nitrogen (in the form of protein and non-protein nitrogen, NPN) consumed by the dairy cow has
three ultimate fates.  Part of the N is undigested and excreted in the feces. The remaining N is
absorbed into the blood stream from diffusion of ammonia across the rumen wall and transport of
amino acids and peptides from the small intestine. Ammonia is toxic to the animal and is
therefore rapidly converted to urea in the liver.  Some of the absorbed amino acids and peptides
are utilized for milk synthesis. Excess absorbed amino acids and peptides are deaminated in the
liver for energy and N is converted to urea.

The urea is filtered from the blood by the kidney and  is excreted from the body in urine. Blood
flow through the kidney is constant within an animal,  which ensures a constant urea filtration rate
(milliliters of blood filtered per minute) regardless of urine volume.  Because urea is a small neutral
molecule, it readily diffuses across cellular membranes. As milk Is secreted in the mammary
gland, urea diffuses into and out of the mammary gland, equilibrates with urea in the blood.
Because of this process, MUN equilibrates with and is proportional to blood urea N. A
mathematical model based on these principles was developed to predict urinary N excretion from
MUN.

When excess N is consumed by a dairy cow, urea in the blood increases. Subsequently an
Increase in MUN and urinary excretion of N occur. Conversely when little excess N is consumed.
urea in the blood is low and lower MUN and urinary excretion of N result. Therefore high MUN
concentrations indicate excess protein in the diet while low MUN levels show  protein may be
deficient. Furthermore, high MUN indicates high levels of urinary N excretion. However, a
definitive method for determining target MUN concentrations has been lacking.

The objectives of our study are: 1) to establish target MUN concentrations for cows fed according
 to National Research Council recommendations throughout a 305-d lactations, 2} to compare
 target values with correct MUN concentrations from  Lancaster Dairy Herd Improvement
 Association, and 3) to examine the environmental and economic impact of overfeeding protein in
 the Chesapeake Bay drainage basin.
                                           14

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 Swine and Poultry-Joe Garber, Nutritional and Analytical Services
 Coordinator, Wenger Feed, Inc.

 New feeding strategies for swine and poultry have been successfully implemented at Wenger
 Feed Mill, Inc.  For phosphorus, the strategies include reduced dietary levels, supplemental
 phytase and source of inorganic phosphorus.  During 1993. the reduction of phosphorus levels in
 swine feed was initiated going from 0.63% to 0.51 %. Currently, efforts are underway to include
 phytase and approach the 0.40% levels recommended by the National Research Council. The
 phytase enzyme liberates phytate bound phosphorus and is heat unstable, so it must be post-
 pellet applied.  In addition, it provides amino acid and energy benefits. However, phytase
 application may impact manufacturing efficiency. Inorganic phosphorus availability values were
 analyzed. Trace mineral "tie-up" of phosphorus and using extra clean sources were found to be
 important factors.  Feed nitrogen reduction was also achieved using synthetic amrno acids and
 digestible amino acid formulations.  These methods reduce total nitrogen levels needed to satisfy
amino acid requirements and currently focus on lysine and methionine. Activities include using
ingredients at its true digestible value, increasing efficiency of nitrogen utilization and altering the
previous "value" for ingredients. Similar reductions and efficiencies have occurred in poultry
feeding operations. Use of phytase in poultry feed started in 1996. These efforts have lowered
feed costs and  increased nutrient efficiency, while meeting animal nutrition requirements.
                                         15

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       SUMMARY FROM THE BREAKOUT SESSIONS


Introduction
This portion of the meeting was devoted to breakout groups that were charged with discussing the
three specific topics identified below. Each of the three groups discussed all three of the topics,
but were tasked to concentrate on a specific one. Participants were assigned to each of the three
breakout groups randomly in order to ensure a mixture of backgrounds and viewpoints. The
structure of the breakout groups was a "brainstorming session" facilitated by a moderator, and
recorded by a note taker. This section summarizes the ideas put forth by the breakout groups.


Rarriers to the Adoption of New Animai Nutrition Technology in
Environmental. Agricultural  and Governmental Sectors, and
Ways to Increase Adoption


Barriers
•  Lack of a clear understanding, on the part of the farmers, millers and processors, of the costs
   and effects of feed additives and high phytase com to more efficiently utilize nutrients in feed
•  Uncertainty across the animal industry about the nature and amount of risk associated with
   new methods for managing nutrients in feed
•  Lack of cost-share programs to off-set capital investment costs
ğ  Current inability to produce feed with more precise and consistent nutrient content
Ğ  Lack of a common understanding among the animal agriculture industry, environmental
   community and governmental agencies on the role and implications of managing nutrients in
   animal feeds as a tool for reducing nutrients in manure
•  Lack of clear, consistent management recommendations to farmers by animal nutritionists,
   animal health care professionals, millers and proprietary industry interests

Opportunities to Increase Adoption
•   Strengthen education/technology transfer programs for the animal agriculture industry
    (farmers, millers, animal health professionals, processors) on appropriate technology, costs
    and benefits of adoption, animal health implications, and environmental consequences
•   Develop new and strengthen current mechanisms for communication between the animal
    agriculture industry, the environmental community and governmental agencies
•   Initiate consistent, and where appropriate, collaborative responses in tie implementation and
    use of the technology across jurisdictions, e.g.  Cost-share/incentive programs that are
    consistent,  science based education and technology transfer programs, technology
    development and consistent regulations
 Practices that can Work Now
 •  Utilize Milk Urea Nitrogen (MUN) screening as a nutrition guide for formulating rations in
    lactating dairy cows
 ğ  Use of high phytase com in formulating rations for the appropriate segments of the animal
    production industry
 •  Improving on-farm nutrient efficiency by increasing the adoption of animal grouping practices
 •  I ncorporating phytase as a feed additive to increase phosphorus utilization
 *  Utilize amino acid supplements in feed formulations to increase the efficiency of nutrient
    utilization
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 Knowledge Gaps and Research Needs
 •  Current National Research Council (NRC) nutritional standards for many animals are not
    current, and in some instances are based upon data from animal genotypes that are no longer
    used in production.  More precise nutrition standards that are designed for current genotypes
    and production practices should be established
 •  Improve the technology in the production of feed to ensure a more consistent and uniform
    nutrient content
 •  Develop science based assessments of the economic, animal health, and environmental
    benefits and risks of utilizing formulated feeds that more precisely meet animal nutrition needs
 •  Improve the technology for the cost-effective incorporation of additives into feeds to enhance
    nutrient utilization
 •  Develop science based assessments of the influence of feed additives on changes in the
    potential fate and transport of excreted nutrients
 •  Develop a science based definition of the role of cost-effective, environmentally sound animal
    nutrition management as an element of a watershed wide sustainable animal agriculture
                 ADDITIONAL DISCUSSION ITEMS


There were a number of items that participants discussed that they recognized were indirectly
related to animal nutrition. However, there was genera! agreement that these issues were of
sufficient importance and should be identified and enumerated in these proceedings. Most of the
topics arose during discussions of knowledge gaps and research needs. They include:

•   A very real need to develop science based estimates of the spatial and temporal distribution
    of ammonia emissions from animal agriculture
•   A need for cost-effective management practices to reduce odors from animal agriculture for
    farms across the entire watershed
•   Farmers need manure management alternatives to composting and land application that
    include the economics of implementation and sound market development practices, especially
    for those farms with existing high soil phosphorus levels
•   A need for wastewater treatment technology/practices for animal agriculture. A high priority
    should be given to systems that recycle wastewater on-farm
•   A continuing need exists to develop practices that allow for incorporation of all types of
    manure without disturbing conservation practices
                                         17

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                    SUMMARY OF PROCEEDINGS


The technology exchange provided a forum for broadening the understanding of current and
potential animal nutrition practices and their effects on animal agriculture in the Chesapeake Bay
Watershed. The participants represented a diverse array of stakeholders from across the
watershed. Examples of current progress in the science of animal nutrition and the adoption of
new nutrition management practices were examined and discussed. Barriers to accelerated
adoption were identified and explored. Participants concurred that significant opportunities do
exist to incorporate into the major animal production systems, practices and technologies that can
improve the efficiency with which animals utilize nutrients in feed, and feeds that can be produced
to more precisely meet the nutritional needs of animals. There was general agreement that
substantial reductions in the nutrient content of manure at the point of excrement are possible
through the adoption of these practices and technologies. However, participants agreed that
before wide-scale adoption of these practices and technologies could take place, substantive
improvements must be made in the quality and extensiveness of the science available to support
them. There are concerns about the  currency of data on nutrient requirements that support
animal nutrition data bases used for formulating feeds. It was recognized that a more definitive
understanding of animal nutrition requirements coupled with the ability to more precisely formulate
feeds to meet those needs could substantially reduce the excess nutrients currently in feeds.
Participants also noted that the widespread adoption, in this watershed, of animal nutrition
practices that would minimize nutrients in manure at the point of excrement, could only be
achieved with a sustained education and technical assistance program to teach farmers, millers,
processors, and animal health professionals how to adapt and use the practices.
                                          18

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                         LIST OF REGISTRANTS
 Dr. Rosafina Angel
 Assistant Professor of Poultry
 Univ. of MD
 Dept. of Animal and Avian Sciences
 College Park, MD 207422311
 Telephone: 3014058494
 Facsimile: (301) 314-9059
 ra95@umail.umd.edu

 Norman Astle
 MD Dept. of Agriculture
 50 Harry Truman Pkwy.
 Annapolis, MD 21401
 Telephone: 4108415863
 Facsimile: (410) 841-5736
 astlene@mda.state.md. us

 Janine Baratta
 MD Cooperative Extension
 2005 Largo Rd
 Upper Marlboro, MD 20774
 Telephone: 3016278440
 Facsimile: (301) 627-3273
 JB107@UMAIL.UMD.EDU

 Daniel Bard
 MD Dept. of Agriculture
 The Wayne A. Cawley Bldg. 50 Harry S
 Truman Pkwy
Annapolis, MD 214017080
 Telephone: 3016949290
 Facsimile: (301) 694-2618

Timothy Barrick
State Conservation Commission
2301 North Cameron Street
Harrisburg, PA 171109408
Telephone: 7177051688
Facsimile: {717) 705-3778
TBarrick@state.pa.us
 Eric S. Bendfeldt
 VA Cooperative Extension
 965 Pleasant Valley Rd.
 Harrisonburg, VA 228019630
 Telephone: 5405643080
 Facsimile: (540) 564-3093
 ebendfel@vt.edu

 Johan Berger
 PDA Bureau of Plant Industry
 Nutrient Mgmt. Section
 2301 N. Cameron St. Rm G13
 Harrisburg, PA 17110
 Telephone: 7177724189
 Facsimile: (717) 783-3275
 joberger@state.pa.us

 Tom Blair
 MD Dept. of Agriculture
 Nutrient Management Program
 50 Harry S. Truman Parkway
 Annapolis, MD 21401
 Telephone: 4108415959
 Facsimile: (420) 841-5950
 blairtg@mda.state.md.us

 Karl Blankenship
 Alliance for the Chesapeake Bay, Bay
 Journal
 619OakwoodDr
 Seven Valleys, PA 17360
 Telephone: 7174282819
 Facsimile: (717)428-0273
 70363.13@compuserve.com

 Dr. DarreH Bosch
 Professor, Agricultural and Applied
 Economics,
Virginia Tech
 Dept. of Agricuture & Applied Economics
308 Hutcheson Hall
 Blacksburg, VA 24061
Telephone: 5402315265
 Facsimile: (545) 023-1741
bosch@vt.edu
                                       19

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Kenneth Bounds
Delmarva Poultry Industry, Inc.
RD 6 Box 47
Georgetown, DE 19947
Telephone: 4104792323
Facsimile: (410)479-3345
kbounds@yahoo.com

Eldridge Collins
Biological Systems Engineering, Va Tech
211 Seitz Hail
Blacksburg, VA 240610303
Telephone: 5402317600
Facsimile: (540) 231-3199
ecollins@vt.edu

Jeff Corbin
Chesapeake Bay Foundation
1001 E. Main Street, Suite 710
Richmond, VA 23219
Telephone: 8047801392
Facsimile: (804) 648-4011
jcorbin@CBF.org

Renato Cuizon
MD Dept. Of Agriculture
50 Harry S. Truman PKWY
Annapolis, MD 21401
Telephone: 4108415959
Facsimile:
cuizonrm@mda.state.md.us

David P. Doss
State Conservationist
USDA NRCS
339 Busch's Frontage Road, Suite 301
Annapolis. MD 21401
Telephone: 4107570861
Facsimile: (410) 757-0687
ddoss@md.nrcs.usda.gov

Zhengxia Dou
Univ. of PA
Center for Animal Health and Productivity
382 W. Street Rd.
Kennett Square, PA 19348
Telephone: 6104445800
Facsimile: (610) 925-8123
dou@cahp2.nbc.upenn.edu
Karen Engel
Southern States Coop, Inc.
6203 Keysville Rd
Keymar, MD 21757
Telephone: 4107566423
Facsimile: (410)756-6423
karen.engel@sscoop.com

Henry Engster
Purdue Frams
P.O. Box 1537
Salisbury, MD 21801
Telephone: 4105433411
Facsimile:
hank.engster@purdue.com

Lief Eriksen
MD Cooperative Extension Service
18330 Keedysville Rd., WMREC
Keedysviile, MD 21756
Telephone: 3014322767
Facsimile: (301) 432-4089
geriksen@wam.umd.edu

Michael Erskine, D.V.M.
Veterinarian
Damascus Equine Associates
17716 Quail Covey Court
Woodbine, MD 21797
Telephone: 3018545689
Facsimile: (301) 854-5687

Stanley Fultz
MD Cooperative Extension
330 Montview Lane
Frederick, MD 21702
Telephone: 3016941594
Facsimile: (301) 694-1588
sf28@umail.umd.edu

Joe Garber
Nutrition and Research Coordinator
Wenger Feed Mills
101 W. Harrisburg Ave.
Rheems, PA 17570
Telephone: 8006926008
Facsimile: (717) 367-5913
jmgarber@redrose.net
                                         20

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 Christoph M. Gross
 USDA-NRCS
 339 Busch's Frontage Road, Suite 301
 Annapolis, MD 21401
 Telephone: 4107570861
 Facsimile: (410) 757-0687
 cgross@MD.nrcs.usda.gov

 James E. Hannawald
 USDA-NRCS
 339 Busch's Frontage Road, Suite 301
 Annapolis, MD 21401
 Telephone:  4107570861
 Facsimile: (410) 757-0687
 jhannawaid@md.usda.gov

 Mark Hedrick
 Wampler Foods
 208 S. Main Street
 Moorefield,  WV 26836
 Telephone:  3045387737  "
 Facsimile: (304) 538-6808
 hedrickma@wlrfoods.com

 Heather Heider Nicely
 Southern States Feed  Division
 13490 Wilt Store Road
 Leesburg,VA20176
 Telephone:  8004851708
 Facsimile: (703) 777-9708
 Heather.Heider@sscoop.com

 Janet Hutzel
 Univ. of MD
 Department of Natural Resource Sciences
 2102 Plant Sciences Bldg
 College Park, MD" 20742
 Telephone: 3014050139
 Facsimile: (301)314-9041
jh331 @umail.umd.edu

 David Inman
 Perdue Farms Incorporated
 PO Box 1537
 Salisbury, MD 21802
Telephone: 4105433749
 Facsimile: (410) 341-2517
david.inman@perdue.com
 Tom Juengst
 PADEP
 Bureau of Water Quality
 11 th floor RCSOB, PO Box 8465
 Harrisburg,PA17105
 Telephone: 7177725646
 Facsimile: (717) 772-5156
 Juengst. thomas@dep.state.pa. us

 David Kann
 MD Dept of Agriculture
 604 SolarexCt Suite 105
 Frederick, MD 21703
 Telephone: 3016949290
 Facsimile: (301)694-5744

 Dr. Ken Kephart
 Professor of Animal Science
 Penn State University
 324 Henning Bldg.
 University Park
 University Park, PA 16802
 Telephone: 8148633671
 Facsimile: (814) 865-7442
 kbk2@psu.edu

 Dr. Richard Kohn
 Univ. of MD
 Department of Animal & Avian Sciences
 College Park, MD 207422311
 Telephone: 3014054583
 Facsimile: (301)314-9059
 rkohn@wam.umd.edu

 Dr. Les Lanyon
 Professor, Soil Fertility
 Penn State University
 Department of Agronomy
 116ASIBIdg.
 University Park, PA 16802
Telephone: 8148631614
 Facsimile: (814) 863-7043
lel@psu.edu

Louise Lawrence
MD Dept. of Agriculture
50 Harry Truman Pkwy
Annapolis, MD 21401
Telephone: 4108415863
Facsimile: (410) 841-5736
lawrenl@mda.state.md.us
                                        21

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James Lewis
Caroline County Extension Office
207 South Third Street
Denton, MD 21629
Telephone: 4104794030
Facsimile: (410) 479-4042
jI139@umail.umd.edu

Daniel Ludwig
MD Cooperative Extension - Montgomery
County
18410MuncasterRd
Derwood, MD 20855
Telephone: 3015902813
Facsimile: (301) 590-2828
d!159@umail.umd.edu

Carl G. Luebben
Sheandoah Valley Soil and Water
Conservation Dist.
1934 Deyerle Ave., suite B
Harrisonburg, VA 22801
Telephone: 5404332853
Facsimile: (540) 422-9998

Jay Marshal]
VADCR
98 Alexandria Pike, Suite 33
Warrenton, VA 20186
Telephone: 5403476420
Facsimile: (540) 347-6423
jmm@dcr.state.va.us

Jerry Martin
Penn State Extension
2301 North Cameron St., Room #100
Harrisburg, PA17110
Telephone: 7177839704
Facsimile: (717) 783-3275
JMARTlN@PSU.EDU

Tim Maupin
Rocco, Inc.
1 Kratzer Road
Harrisonburg, VA 22802
Telephone: 5405681482
Facsimile: (540) 568-1401
tmauDin@rocco.coia
Russ Perkinson
VADCR
203 Governor St. Ste 206
Richmond, VA 23219
Telephone: 8043710061
Facsimile: (804) 786-1798
nperkinson@dcr.state.va.us

Robert Peters
Univ. of MD
Dept. of Animal & Avian Sciences
College Park, MD 20742
Telephone: 3014051401
Facsimile: (301) 405-8831
rp17@umail.umd.edu

Royden Powell
Assistant Secretary,  MDA Resource
Conservation
MD Dept. of Agriculture
50 Harry S. Truman  Pkwy
Annapolis, MD 21401
Telephone: 4108415959
Facsimile: (410)841-5950
powellm@mda.state.md.us ,

Peggy Preusch
Univ. of MD Cooperative Extgenston
Nutrient Management Program
2102 Plant Sciences Bldg.,  NRSL
College Park, MD 20742
Telephone: 3014051312
Facsimile: (301) 314-9041
pp78@umail.umd.edu

Dr. Charles  Ramberg
Univ. of PA
School of Veterinary Medicine
382 West Street Road
Kennett Square, PA  193481692
Telephone: 6104445800
Facsimile: (610)444-0126

Francis J, Reilly, Jr.
The Reilly Group
67 Meyer Lane
Stafford, VA 225543430
Telephone: 5402860072
Facsimile: (540) 286-0073
ReillyGroup@msn.com
                                        22

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Patricia M. Reilly
The Reilly Group
67 Meyer Lane
Stafford, VA 225543430
Telephone: 5402860072
Facsimile: (540) 286-0073
ReillyGroup@msn.com

Leon Ressier
Extension Agent
Penn State Cooperative Extension
Lancaster County
1383 Arcadia Road, Room  1
Lancaster, PA 176013184
Telephone: 7173946851
Facsimile: (717) 394-3962
LRESSLER@PSU.EDU

John C. Rhoderick
Administrator, Resource Conservation
Operations
MD Dept. of Agriculture
Office of Resource Conservation
50 Harry S. Truman Parkway
Annapolis, MD 21401
Telephone: 4108415876
Facsimile: (410) 841-5736
rhoderjc@mda.state.md.us

Maggie Rhodes
Assistant State Conservationist
USDA/NRCS
339 Busch's Frontage Road, Suite 301
Annapolis, MD 21401
Telephone: 4107570861
Facsimile: (410) 757-0687
mrhodes@md.nrcs.usda.gov

Cart Rohr
PADEP
Bureau of Watershed Conservation
PO Box 8555, 400 Market Street, 10th Floor
Harrisburg, PA 171058555
Telephone: 7177875259
Facsimile: (717) 787-9549
Dr. William B. Roush
Associate Professor of Poultry Science
Penn State University
213 Henning BIdg.
University Park
University Park, PA 16802
Telephone: 8148630655
Facsimile: (814) 863-7043
wbr@psu.edu

Fred Samadani
MD Dept. of Agriculture
Nutrient Management Program
50 Harry S. Truman Parkway
Annapolis, MD 21401
Telephone: 4108415959
Facsimile: (410)841-5950
samadaf@mda.state.md.us

Bill Satterfield
Delmarva Poultry Industry, Inc.
RD 6 Box 47
Georgetown, DE 19949575
Telephone: 3028569037
Facsimile: (302) 856-1845
satterfield.dpi@ce.net

Brian Scoralick
MD Dept. of Agriculture
Resource Conservation
604 Solarex Ct. Suite 105
Frederick, MD 21703
Telephone: 3016949290
Facsimile: (301)694-2618

Kevin Seibert
Lancaster County Conservation District
1383 Arcadia Rd
Lancaster, PA 17601
Telephone: 7172995361
Facsimile: (717) 299-9459
iccd@redrose.net

Randall Shank
VADCR
Nutrient Management Program
203 Governor St., Suite 206
Richmond, VA 23219
Telephone: 8043718884
Facsimile: (804) 786-1798
rshank@vt.edu
                                         23

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Paul Shipley
Univ. of MD
Dept. NRSL, Room 1103 HJ. Patterson
Mall
College Park, MD 20742
Telephone:3014052563
Facsimile: (301) 314-9041
PSSO@umail.umd.edu

Dr. Thomas W. Simpson
Chair, CBP Nutrient Subcommittee
Univ. of MD/ MD Dept. of Agriculture
50 Harry S.Truman Pkwy., Room 307
Annapolis, MD 21401
Telephone: 4108415865
Facsimile: (410)841-5736
ts82@umail.umd.edu

Dr. Charles Stallings
Professor and Extension Dairy Specialist
Virginia Tech
2090 Litton Reaves Hall
Blacksburg.VA 24061
Telephone:5402314758
cstallin@vt.edu

Julie Trask
CRC/Chesapeake Bay Program
410 Severn Avenue, Suite 109
Annapolis, MD 21403
Telephone: 4102675753
Facsimile:  (410) 267-5777
trask.julie@epamail.epa.gov

Winston Turner
Broiler Production Manager
Tyson Foods
501N. Liberty Street
Harrisonburg. VA 22802
Telephone: 5404330721

Mark Waggoner
USDA-NRCS
339 Busch's Frontage Road, Suite 301
Annapolis, MD 21401
Telephone: 4107570861
Facsimile: (410)757-0687
mwaaaoner@md.usda .aov
Andrew J. Weber
Liaison, Chesapeake Bay Program
CSREES/USDA
410 Severn Ave., Suite 109
Annapolis, MD 21403
Telephone: 4102679875
Facsimile: (410)267-5777
WEBER.ANDREW@epamail.epa.gov

Anne-Meredith Webster
MD Cooperative Extension
27664 Nanticoke Rd
Salisbury, MD 218018437
Telephone: 4107428788
Facsimile: (410) 742-1922
ah99@umail.umd.edu

Melanie Wertz
Ag. Policy Specialist
Chesapeake Bay Foundation
Old Water Works BWg.
Harrisburg, PA17101
Telephone: 7172345550
Facsimile: (717) 234-9632
mwertz@savethebay.cbf.org
                                       24

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