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Modeling Vegetative Filter Performance With Vfsmod, Matthew J. Helmers, Dean E. Eisenhauer, Michael G. Dosskey, Thomas G. Franti Apr 2002

Modeling Vegetative Filter Performance With Vfsmod, Matthew J. Helmers, Dean E. Eisenhauer, Michael G. Dosskey, Thomas G. Franti

Matthew J. Helmers

The model VFSMOD was used to investigate the effect of varying watershed characteristics and buffer dimensions on the sediment trapping efficiency of vegetative filters. This investigation allows for a better understanding of how watershed characteristics, buffer dimensions, and storm characteristics impact the performance of vegetative filters. Using VFSMOD, relationships that estimate sediment trapping efficiency from the ratio of filter area and field area were developed for different sites. These relationships have been applied for field assessment of concentrated flow.


Estrogen Concentrations In Dairy And Swine Waste Storage And Treatment Structures In And Around Tennessee, D. Raj Raman, Elizabeth L. Williams, Robert T. Burns, Alice C. Layton, Adam S. Daugherty, Michael D. Mullen Jan 2002

Estrogen Concentrations In Dairy And Swine Waste Storage And Treatment Structures In And Around Tennessee, D. Raj Raman, Elizabeth L. Williams, Robert T. Burns, Alice C. Layton, Adam S. Daugherty, Michael D. Mullen

D. Raj Raman

Naturally occurring estrogens in animal wastes may cause negative environmental impacts in some watersheds. However, there is little published data regarding the concentrations of these estrogenic compounds in full-scale animal waste treatment and storage structures, thus making risk assessment difficult. To address this knowledge gap, the research described in this paper explores estrogen concentrations in 19 animal waste storage and treatment structures at dairy and swine production facilities in and around Tennessee.

Samples have been collected from eight dairy and eleven swine facilities, representing a range of waste storage and treatment structures typical of Tennessee, and much of the southeastern …


Liquid Dairy Waste Transport And Land Application Cost Comparisons Considering Herd Size, Transport Distance, And Nitrogen Versus Phosphorus Application Rates, Robert T. Burns, A. S. Daugherty, T. L. Cross, D. Raj Raman, G. F. Grandle Jul 2001

Liquid Dairy Waste Transport And Land Application Cost Comparisons Considering Herd Size, Transport Distance, And Nitrogen Versus Phosphorus Application Rates, Robert T. Burns, A. S. Daugherty, T. L. Cross, D. Raj Raman, G. F. Grandle

D. Raj Raman

This study provides cost comparisons for the transport and application of dairy waste slurries based on both phosphorus and nitrogen application rates. Estimated cost comparisons are made for several commonly used systems for dairy waste transport and application. Five dairy sizes ranging from 50 to 2,000 cows using 13 transport and application systems were evaluated. For each dairy size, the costs associated with the transport and application system combinations were determined for transport distances of 0.5, 1.5, and 4.5 miles for both nitrogen and phosphorus-based application rates. Total annual system cost, cost per acre, cost per cow, and manure value …


Incidence Of Escherichia Coli O157:H7, Listeria Monocytogenes , And Salmonella Species On A Tennessee Dairy Farm, T. L. Ervin, R. E. Yoder, F. A. Draughon, Robert T. Burns, D. Raj Raman Jul 2001

Incidence Of Escherichia Coli O157:H7, Listeria Monocytogenes , And Salmonella Species On A Tennessee Dairy Farm, T. L. Ervin, R. E. Yoder, F. A. Draughon, Robert T. Burns, D. Raj Raman

D. Raj Raman

In response to public awareness of foodborne pathogens due to recent outbreaks of illness, a study was conducted on the incidence of Escherichia coli O157:H7, Listeria monocytogenes , and Salmonella species on a dairy farm in middle Tennessee. Sampling locations included water samples from up- and down-stream in a creek running through the farm, free stall bedding, silage, separator liquids, separator solids, pumped liquid from a holding pond, feed, and bulk tank milk. Three samples were taken monthly at each location for 12 months. These samples were tested to determine the incidence of pathogens on the dairy farm and to …


Determination Of 17ss-Estradiol Concentrations In Runoff From Plots Receiving Dairy Manure, A. R. Dyer, D. Raj Raman, M. D. Mullen, Robert T. Burns, Lara B. Moody, A. C. Layton Jan 2001

Determination Of 17ss-Estradiol Concentrations In Runoff From Plots Receiving Dairy Manure, A. R. Dyer, D. Raj Raman, M. D. Mullen, Robert T. Burns, Lara B. Moody, A. C. Layton

D. Raj Raman

Because of growing concern about estrogenic compounds in animal wastes, the objective of this research was to measure 17 ß -estradiol concentrations in runoff from plots fertilized with liquid dairy waste. Nine plots were established at The University of Tennessee Dairy Experiment Station located at Lewisburg, Tennessee, and dairy manure was applied to six of the nine plots. Three of the plots received manure at a rate sufficient to meet the nitrogen (N) requirement for winter wheat; three received manure at a rate sufficient to meet the phosphorus (P) requirement for winter wheat, and three received no manure. Runoff samples …


Enhancing Dairy Lagoon Performance With High-Rate Anaerobic Digesters, Gary L. Hawkins, D. Raj Raman, Robert T. Burns, Ronald E. Yoder, Tim L. Cross Jan 2001

Enhancing Dairy Lagoon Performance With High-Rate Anaerobic Digesters, Gary L. Hawkins, D. Raj Raman, Robert T. Burns, Ronald E. Yoder, Tim L. Cross

D. Raj Raman

In a two–stage study, the possibility of using high–rate anaerobic digesters to enhance the performance of dairy lagoons was explored. Four anaerobic sequencing batch reactors (ASBR) and four downflow anaerobic filters (DFAF) were tested, with two of each type operated at 25C, and the other two at 35C. The first stage of the experiment explored using the high–rate digesters on liquid effluent from a screw–press treating dairy manure slurry. The first–stage experiment demonstrated that settling processes, rather than biodegradation, accounted for most of the organic matter reduction in both reactor types, when operated at a 0.5–d hydraulic retention time. Specifically, …


Degradation Of Estrogens In Dairy Waste Solids: Effects Of Acidification And Temperature, D. Raj Raman, Alice C. Layton, Lara B. Moody, James P. Easter, Gary S. Sayler, Robert T. Burns Jan 2001

Degradation Of Estrogens In Dairy Waste Solids: Effects Of Acidification And Temperature, D. Raj Raman, Alice C. Layton, Lara B. Moody, James P. Easter, Gary S. Sayler, Robert T. Burns

D. Raj Raman

Manure–borne estrogens are increasingly recognized as a potential ecological hazard. However, sample–handling protocols for these compounds are not clearly delineated in the literature, nor are comparisons between assays for estrogens. A study was conducted to explore the degradation of estrogen in separated dairy manure waste solids (press cake), using three popular assay types. Estrogens were measured by enzyme–linked immunosorbent assay (ELISA), gas–chromatography mass–spectroscopy (GC–MS) and a recombinant yeast estrogen reporter assay. As measured by GC–MS, background estrone concentrations were approximately 100 ppb, while 17β–estradiol concentrations were one–third of the estrone concentration, and 17β–estradiol concentrations were below the detection limit (10 …


Evaluation Of Fabric Swatch Types For Relative Odor Intensity At Beef Cattle Feedyards, Sean D. See, David B. Parker, Brent W. Auvermann, Jacek A. Koziel, John Sweeten Jan 2001

Evaluation Of Fabric Swatch Types For Relative Odor Intensity At Beef Cattle Feedyards, Sean D. See, David B. Parker, Brent W. Auvermann, Jacek A. Koziel, John Sweeten

Jacek A. Koziel

A research project was conducted to determine which type of fabric swatch was best suited for on-site sampling of odor intensity at open-lot beef cattle feeding operations. Five different types of fabric were tested: cotton flannel, cotton muslin, acetate, polyester and polyester felt. Square swatches (20 × 20 cm) were suspended 1 m above the ground surface downwind of cattle pens for 24 hours. The swatches were placed in glass jars and presented to 8-10 human panelists who were asked to rank the swatches based on relative odor intensity. Five trials were conducted at 3 feedyards. Sums of ranks and …


Air Sampling With Solid Phase Microextraction, Jacek A. Koziel, Fabio Augusto, Janusz Pawliszyn Jan 2001

Air Sampling With Solid Phase Microextraction, Jacek A. Koziel, Fabio Augusto, Janusz Pawliszyn

Jacek A. Koziel

Solid phase microextraction (SPME) presents many advantages over conventional analytical methods by combining sampling, pre-concentration and direct transfer of the VOCs into a standard gas chromatography (GC) system. Since its introduction SPME has been applied to the sampling and analysis of environmental samples including airborne VOCs and particulates. The first part of this paper presents theory of air sampling with SPME and an overview of the a few current methods for quantitative air sampling and VOC determination with SPME using grab (‘instantaneous”) and time-weighted average (TWA) modes. The second part of this paper is focused on the recent development of …


Extension Workers As Orchestrators Of Civic Renewal Through Civic Professionalism, Nancy K. Franz Dec 2000

Extension Workers As Orchestrators Of Civic Renewal Through Civic Professionalism, Nancy K. Franz

Nancy K. Franz

I have a passion and a bias. I am passionate about the important role of the Cooperative Extension System (CES) in civic renewal. My bias is that extension workers (also known as agents or educators) are the key to civic renewal throughout the United States. No other institution has the same ability to reach all of America with education and organizing efforts. With extension workers in every county in the nation, this group of professionals and their work cut across age, race, ethnicity, religion, geography and many other demographic characteristics. Extension has a long history of being active in civic …


Avhrr Estimates Of Surface Temperature During The Southern Great Plains 1997 Experiment, Amy L. Kaleita, Praveen Kumar Aug 2000

Avhrr Estimates Of Surface Temperature During The Southern Great Plains 1997 Experiment, Amy L. Kaleita, Praveen Kumar

Amy L. Kaleita

In this study we aim to (1) explore the differences in the accuracy of satellitederived land-surface skin temperature for day and nighttime observations, (2) assess the effects of large solar zenith angles, and (3) develop an understanding of the spatial variability of the observed temperatures. Land-surface skin temperatures are obtained using the split-window technique from observations of the AVHRR instrument aboard the NOAA-12 and NOAA-14 satellites for the SGP97 (Southern Great Plains 1997) hydrology experiment. From the study of several days of observations we find that observed biases with respect to the ground temperature, both during day and night, are …


Countrysides Transformed, Pamela Riney-Kehrberg Mar 2000

Countrysides Transformed, Pamela Riney-Kehrberg

Pamela Riney-Kehrberg

Rural and agricultural history provide their readers different perspectives on the ways in which the countryside has changed over the course of American history. Rural history approaches the question of change from the perspective of communities and families, while agricultural history generally eschews the social perspective for issues of crop production. Such is the case of two recent and important books in rural and agricultural history, Hal Barron's Mixed Harvest: The Second Great Transformationin the Rural North, 1870-1930 and Steven Stoll's The Fruits of Natural Advantage: The Making of the Industrial Countryside in California. While both authors are intimately concerned …


The Historical Development Of Agriculture In Illinois, Pamela Riney-Kehrberg Jan 1999

The Historical Development Of Agriculture In Illinois, Pamela Riney-Kehrberg

Pamela Riney-Kehrberg

Illinois' agricultural history is long and complex. Illinois' first settlers, the Native Americans, practiced hunting, gathering, and fishing and made use of the resources of the woods and prairies. By the tenth century, Native Americans combined men's hunting with women's agricultural activities to meet the needs of their communities. The earliest crop Native American women cultivated was corn, imported to Illinois from the Southwest.


Use Of Ultimate Load Theories For Design Of Drilled Shaft Sound Wall Foundations, Matthew J. Helmers Jun 1997

Use Of Ultimate Load Theories For Design Of Drilled Shaft Sound Wall Foundations, Matthew J. Helmers

Matthew J. Helmers

A study was performed to investigate the factors that affect the accuracy of the procedures used by the Virginia Department of Transportation for design of drilled shaft sound wall foundations. Field load tests were performed on eight inch and nine inch diameter drilled shafts, and the results were compared to theoretical solutions for ultimate lateral load capacity. Standard Penetration Tests were run in the field and laboratory strength tests were performed on the soils from the test sites. It was found that published correlations between blow count and friction angle for sands and gravels can be used to estimate friction …


Internet Childhood Safety And Health Resource Guide, Steven A. Freeman, Scott D. Whitman, Roger L. Tormoehlen, Karla M. Embleton Apr 1997

Internet Childhood Safety And Health Resource Guide, Steven A. Freeman, Scott D. Whitman, Roger L. Tormoehlen, Karla M. Embleton

Steven A. Freeman

Purdue University's Agricultural Safety and Health Program, historically a paper-based directory of childhood safety and health resources, is now available on the World Wide Web (WWW). Advantages to WWW publication include: widespread availability, continuous updates, and low distribution costs. Disadvantages include: lack of acceptance by some Extension clientele, loss of portability, and initial difficulties in finding the publication's WWW location. The use of on-line resources has been moderate to date. However, a significant increase in utilization is expected as Internet access becomes less expensive and Extension educators and external clientele become more accustomed to using on-line resources.


Sensors For Site-Specific Management, Stuart J. Birrell, J. W. Hummel, K. A. Sudduth Jan 1997

Sensors For Site-Specific Management, Stuart J. Birrell, J. W. Hummel, K. A. Sudduth

Stuart J. Birrell

Site-specific management (SSM, also known as precision farming, precision agriculture, prescription farming, etc.) is a management strategy that seeks to address within-field variability and to optimize inputs such as pesticides and fertilizers on a point-by-point basis within a field. By reducing over-application and under-application of nutrients and pesticides, this strategy has the potential to improve profitability for the producer and also to reduce the threat of groundwater or surface water contamination from agrichemicals. SSM is being adopted by innovative producers across the country. Agricultural equipment manufacturers, farm input suppliers, and a host of other businesses are working along with publicsector …


An Insect-Based Detector Of Bovine Manure Odors, D. Raj Raman, Reid R. Gerhardt Jan 1997

An Insect-Based Detector Of Bovine Manure Odors, D. Raj Raman, Reid R. Gerhardt

D. Raj Raman

We designed, constructed, and tested a single-stream insect odormeter for the measurement of bovine manure odors. The biosensing element in the odormeter is a group of six gravid face flies (Musca autumnalis DeGeer) in a 360 mL chamber. A microphone, mounted above the chamber, senses sounds made by the flies’ activity. The microphone signal is processed by an analog root-mean-square power-measuring circuit connected to a computer data acquisition system. The apparatus allows electronic measurement of insect activity. Initial experiments demonstrate the feasibility of this system for odor detection (yes/no). Kinetic experiments show that a dose-response curve can be produced by …


Comparison Of Sensors And Techniques For Crop Yield Mapping, Stuart J. Birrell, Kenneth A. Sudduth, Steven C. Borgett Feb 1996

Comparison Of Sensors And Techniques For Crop Yield Mapping, Stuart J. Birrell, Kenneth A. Sudduth, Steven C. Borgett

Stuart J. Birrell

The implementation of site-specific crop management is dependent on the variations in yield and yield potential within a field. Crop yield maps are important for both the implementation and evaluation of site-specific crop management strategies. Management decisions and evaluations based on yield maps must take into consideration the accuracy and resolution of the maps.

An impact-based yield monitor and a volumetric yield monitor were compared. The effect of different dynamic models of combine grain flow on the calculated instantaneous yields were investigated. Both simple time delay models and first order models could be used to model the grain flow. In …


Evaluation Of Gps For Applications In Precision Agriculture, Steven C. Borgelt, John D. Harrison, Kenneth A. Sudduth, Stuart J. Birrell Jan 1996

Evaluation Of Gps For Applications In Precision Agriculture, Steven C. Borgelt, John D. Harrison, Kenneth A. Sudduth, Stuart J. Birrell

Stuart J. Birrell

Location coordinate information is needed in precision agriculture to map in-field variability, and to serve as a control input for variable rate application. Differential global positioning system (DGPS) measurement techniques were compared with other independent data sources for sample point location and combine yield mapping operations. Sample point location could be determined to within 1 m (3 ft) 2dRMS using C/A code processing techniques and data from a high-performance GPS receiver. Higher accuracies could be obtained with carrier phase kinematic positioning methods, but this required more time and was a less robust technique with a greater potential for data acquisition …


Nutrient Mapping Implications Of Short-Range Variability, Stuart J. Birrell Jan 1996

Nutrient Mapping Implications Of Short-Range Variability, Stuart J. Birrell

Stuart J. Birrell

Successful site specific nutrient application depends on accurate soil nutrient maps, which are generally developed from grid samples. The implication of short range variability for soil nutrient mapping is investigated. Interpretation of soil nutrient maps must consider the level of confidence associated with estimated values.


Analysis Of Spatial Factors Influencing Crop Yield, K. A. Sudduth, S. T. Drummond, Stuart J. Birrell, N. R. Kitchen Jan 1996

Analysis Of Spatial Factors Influencing Crop Yield, K. A. Sudduth, S. T. Drummond, Stuart J. Birrell, N. R. Kitchen

Stuart J. Birrell

The spatial relationship between crop yields and soil and site parameters was modeled using several methods. Yield maps estimated by projection pursuit regression and neural network analysis agreed well with measured yields. These methods also allowed generation of response curves for estimated yield as a function of each of the input parameters. These response curves were useful for investigating the relationship between yields and individual soil and site parameters.


Missouri Precision Agriculture, N. R. Kitchen, K. A. Sudduth, Stuart J. Birrell, S. C. Borgelt Jan 1996

Missouri Precision Agriculture, N. R. Kitchen, K. A. Sudduth, Stuart J. Birrell, S. C. Borgelt

Stuart J. Birrell

A number of projects related to different facets of precision agriculture are being carried out by an interdisciplinary team of scientists and engineers with the University of Missouri and the USDA Agricultural Research Service. This paper provides an overview of those projects.


Clonal-By-Environment Interactions Influence Isoflavonoid Accumulation In Cicer Milkvetch, Andrew W. Lenssen, C. E. Townsend, S. S. Martin May 1995

Clonal-By-Environment Interactions Influence Isoflavonoid Accumulation In Cicer Milkvetch, Andrew W. Lenssen, C. E. Townsend, S. S. Martin

Andrew W. Lenssen

Cicer milkvetch (Astragalus cicer L.) is a perennial, nonbloatinducing forage legume adapted to temperate environments. For unknown reasons, however, ruminants grazing cicer milkvetch in pure stands have become photosensitized, or sunburned, in some environments, Isoflavonoids are involved with diverse biological activities, including estrogenism, disease resistance, and, potentially, photosensitization. We conducted a series of studies from 1991 to 1993 to identify factors that influence the accumulation of isoflavonoids. In separate greenhouse studies, elicited leaflets from the parental clones of ‘Monarch’ and. ‘Windsor’ cicer milkvetch were analyzed for isoflavonoid accumulation. Growth chamber studies were conducted to investigate the clonal variability of leaflet …


Crop Yield Mapping: Comparison Of Yield Monitors And Mapping Techniques, Stuart J. Birrell, Steven C. Borgelt, Kenneth A. Sudduth Jan 1995

Crop Yield Mapping: Comparison Of Yield Monitors And Mapping Techniques, Stuart J. Birrell, Steven C. Borgelt, Kenneth A. Sudduth

Stuart J. Birrell

Although the variability in soil nutrients and crop yields has been well documented since the turn of the century (Robinson & Lloyd, 1915; Fairfield Smith, 1938), the mechanization of agriculture and the trend to larger implements has led to larger areas being treated as a single unit. Recent advances, however, in machine technology and improvements in data management have made it possible to reverse this trend by implementing site specific crop management (Goering, 1993).


Comparison Of Variable Rate To Single Rate Nitrogen Fertilizer Application: Corn Production And Residual Soil No3-N, N. R. Kitchen, D. F. Hughes, K. A. Sudduth, Stuart J. Birrell Jan 1995

Comparison Of Variable Rate To Single Rate Nitrogen Fertilizer Application: Corn Production And Residual Soil No3-N, N. R. Kitchen, D. F. Hughes, K. A. Sudduth, Stuart J. Birrell

Stuart J. Birrell

The questions most often asked by farmers when discussing variable rate (VR) fertilizer inputs are "How much will it cost?" and "How will it affect my yields?" Many farmers and custom application services share a reluctance to invest in the time and technology required for variable fertilizer application since studies to answer these questions are few and results have been inconsistent.


Technical Notes: Bidirectional Serial-To-Parallel Converter For Data Acquisition And Control, Stuart J. Birrell, Scott T. Drummond, Kenneth A. Sudduth Jan 1995

Technical Notes: Bidirectional Serial-To-Parallel Converter For Data Acquisition And Control, Stuart J. Birrell, Scott T. Drummond, Kenneth A. Sudduth

Stuart J. Birrell

A bidirectional serial-to-parallel converter was created to allow collection of serial data through the parallel port on a portable laptop computer. The converter consisted of both hardware conversion circuitry and control software. The converter supported both input and output at a variety of transmission formats and adjustable transmission rates. The control software made use of the various I/O registers of the parallel port to collect data and control the hardware circuitry.


Forage Yield, Quality, Compatibility, And Persistence Of Warm-Season Grass—Legume Mixtures, G. L. Posler, Andrew W. Lenssen, G. L. Fine May 1993

Forage Yield, Quality, Compatibility, And Persistence Of Warm-Season Grass—Legume Mixtures, G. L. Posler, Andrew W. Lenssen, G. L. Fine

Andrew W. Lenssen

Development of compatible, persistent, warm-season grass-legume mixtures could increase forage yield and quality during summer months. We established a trial to determine forage yield, quality, species compatibility, and persistence of binary mixtures of warm-season grasses with selected legumes, five of which are native to the central USA. Grass entries were switchgrass (Panicum virgatum L.), sideoats grama (Bouteloua curtipendula Michx.), and indiangrass [Sorghastrum nutans (L.) Nash]. Legume entries were purple prairieclover [Dalea purpurea Vent.; syn. Petalostemon purpureum (Vent.) Rydb.], roundhead lespedeza (Lespedeza capitata Michx.), leadplant (Amorpha canescens Pursh), Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMill., B. Robins. & Fern.], catclaw sensitive brier …


Diversity Among Rhizobia Effective With Robinia Pseudoacacia L, Janet Mccray-Batzli, William R. Graves, Peter Van Berkum Jul 1992

Diversity Among Rhizobia Effective With Robinia Pseudoacacia L, Janet Mccray-Batzli, William R. Graves, Peter Van Berkum

William R Graves

The diversity of rhizobia that form symbioses with roots of black locust (Robinia pseudoacacia L.), an economically important leguminous tree species, was examined by inoculating seedling root zones with samples of soil collected from the United States, Canada, and China. Bacteria were isolated from nodules, subcultured, and verified to be rhizobia. The 186 isolates varied significantly in their resistance to antibiotics and NaCl, their growth on different carbohydrates, and their effect on the pH of culture media. Most isolates showed intermediate antibiotic resistance, the capacity to use numerous carbohydrates, and a neutral to acid pH response. Isolates had greater similarity …


Feeding Patterns Of Growing Pigs At Warm Constant And Cyclic Temperatures, Hongwei Xin, James A. Deshazer Jan 1992

Feeding Patterns Of Growing Pigs At Warm Constant And Cyclic Temperatures, Hongwei Xin, James A. Deshazer

Hongwei Xin

Feeding behavior of ad libitum-fed^ 39-kg, crossbred gilts was investigated under mean ambient temperatures of 30.8° C with 0, 7, and 16.6° C cycles. Average meal size, 160 to 170 g/pig; meal duration, 13.3 to 14.3 min; and ingestion rate, 12.2 g/min-pig did not appear to be influenced by the temperature conditions. However, meal frequency, 9 to 11 per day, tended to be reduced by elevated hours of exposure to high temperatures. Consequently daily feed intake of the pigs was signiflcantly less in the 16.6° C cycle treatment than in the 0 or 7° C cycle treatments (P<0.01). Feed consumed during the lighting period (0600 h to 2100 h) accounted for 75%, 61%, and 37% of daily feed intake for the 0, 7, and 16.6° C cycle treatments, respectively. Pigs under the 0° C cycle had most feeding activities in the afternoon and evening (55% of daily feed intake). In contrast, pigs under the 16.6° C cycle had most feeding events at night and early morning (91 % of daily feed intake).


Responses Of Pre-Fasted Growing Turkeys To Acute Heat Exposure, Hongwei Xin, James A. Deshazer, Mary M. Beck Jan 1992

Responses Of Pre-Fasted Growing Turkeys To Acute Heat Exposure, Hongwei Xin, James A. Deshazer, Mary M. Beck

Hongwei Xin

Nicholas turkeys at the age of 15 to 16 weeks were fasted for 24 hours in a moderate environment and then subjected to acute heat exposures of various dry-bulb and wet-bulb temperatures (T^u, and T^jj). Total feed intake was not influenced by T^^ of 32*' C, 36"* C or 40° C (P > 0.10), although differences existed in dynamic feeding profiles. Total heat production rate (THP) varied quadratically with T^^, and respiratory quotient (RQ) decreased linearly with T^u,. The lower RQ values at the higher T^i^ levels may have resulted from reduced feed assimilation. No differences were detected on feed intake, …