@article{xu_lin_stark_ferket_williams_brake_2017, title={Effects of dietary coarsely ground corn and 3 bedding floor types on broiler live performance, litter characteristics, gizzard and proventriculus weight, and nutrient digestibility}, volume={96}, ISSN={0032-5791}, url={http://dx.doi.org/10.3382/ps/pew485}, DOI={10.3382/ps/pew485}, abstractNote={&NA; The effects of zero or 50% dietary coarsely ground corn (CC) in pelleted and screened grower and finisher diets on broilers reared on 3 bedding floor types (plastic net [NET], new pine wood shavings litter [NEW], or old pine wood shavings litter [OLD]) on broiler live performance, litter characteristics, gizzard and proventriculus weight, and apparent ileal digestibility (AID) were studied in a 2 × 3 factorial arrangement of treatments. Fine corn was produced with a hammermill (271 &mgr;m) and CC with a roller mill (1145 &mgr;m). Utilization of CC reduced milling cost by 9.47 cents per MT with similar nutrient content of screened pellets. The 50% CC treatment exhibited improved (P ≤ 0.05) feed intake at 42 d (2.5%) and 49 d (3.0%), and BW (5.4%) and FCR from 28 d (1.4%). Birds on NEW litter exhibited improved (P < 0.05) BW at 28 and 35 d and 42 d FCR as compared to NET and 49 d FCR compared to NET and OLD. The 50% CC treatment exhibited increased (P < 0.05) gizzard weight but decreased proventriculus weight at 49 d. NEW litter birds exhibited increased (P ≤ 0.05) gizzard weight at 28 d and 49 d and decreased proventriculus weight as compared to NET at 49 days. The 50% CC treatment exhibited decreased (P ≤ 0.05) litter moisture at 35 and 42 d, litter N at 35 and 49 d, and litter pH at 49 days. OLD litter birds exhibited greater (P < 0.05) litter N at 14, 35, and 49 d, as well as litter moisture, pH, and ammonia concentration at 49 days. The 50% CC group also exhibited improved AID of nitrogen (P < 0.05). Broilers fed pelleted and screened diets containing 50% CC exhibited improved live performance and reduced litter moisture while use of NEW litter resulted in a somewhat similar effect, which indicated that consumption of NEW litter also facilitated gastric development and function.}, number={7}, journal={Poultry Science}, publisher={Elsevier BV}, author={Xu, Y. and Lin, Y.M. and Stark, C.R. and Ferket, P.R. and Williams, C.M. and Brake, J.}, year={2017}, month={Jul}, pages={2110–2119} }
 @article{xu_stark_ferket_williams_auttawong_brake_2015, title={Effects of dietary coarsely ground corn and litter type on broiler live performance, litter characteristics, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and intestinal morphology}, volume={94}, ISSN={["1525-3171"]}, DOI={10.3382/ps/peu016}, abstractNote={The objectives of this study were to evaluate the effects of the dietary inclusion of 2 coarsely ground corn (CC) levels (0 or 50%) in diets of broilers reared on 2 litter types (new wood shavings or used litter) on live performance, litter characteristics, gastrointestinal tract (GIT) development, apparent ileal digestibility (AID) of energy and nitrogen (N), and intestinal morphology. No interaction effects between CC level and litter type were observed on live performance. No litter effect was observed on live performance. Dietary inclusion of 50% CC increased BW at 35 d (P<0.01) and improved cumulative feed conversion ratio (FCR) at 35 and 49 d of age (P<0.01). The 50% CC treatment increased absolute and relative gizzard weight (P<0.01) and decreased jejunum unit weight (g/cm) (P<0.01). The new litter treatment (litter N) increased absolute and relative proventriculus weight (P<0.05) but did not affect gizzard weight. An interaction effect between CC level and litter type was observed for litter N, where the 50% CC treatment reduced litter N regardless of litter type (P<0.01), but litter N was reduced by new litter only among birds fed 0% CC (P<0.05). The 50% CC inclusion increased litter pH (P<0.05) and improved the AID of energy and N by 6.8% (P<0.01) and 3.5% (P<0.05), respectively. The 50% CC treatment increased jejunum villi tip width (P<0.05) and villi surface area (P<0.01), and decreased the muscularis layer thickness (P<0.01), whereas new litter increased jejunum villi and ileum villi height (P<0.05), jejunum villi surface area (P<0.01), and the ratio of jejunum villi height to crypt depth (P<0.01). This study showed that birds fed pelleted and screened diets containing 50% CC exhibited improved BW, FCR, and AID of energy and N, in conjunction with altered morphology of the GIT and intestinal mucosa. Litter type affected some GIT traits and functions but did not affect live performance.}, number={3}, journal={POULTRY SCIENCE}, author={Xu, Y. and Stark, C. R. and Ferket, P. R. and Williams, C. M. and Auttawong, S. and Brake, J.}, year={2015}, month={Mar}, pages={353–361} }
 @article{xu_stark_ferket_williams_brake_2015, title={Effects of feed form and dietary coarse ground corn on broiler live performance, body weight uniformity, relative gizzard weight, excreta nitrogen, and particle size preference behaviors}, volume={94}, ISSN={["1525-3171"]}, DOI={10.3382/ps/pev074}, abstractNote={In this 14-d cage study, the effects of feed form (mash and crumble) and 6 coarse ground corn ( CC: ) inclusions [0, 10, 20, 30, 40, and 50% CC that replaced fine corn ( FC: )] on broiler live performance, BW uniformity, gizzard weight, excreta nitrogen, and particle size preference were investigated. The geometric mean diameter by mass ( DGW: ) of mash diets increased from 422 μm to 431, 471, 509, 542, and 640 μm, respectively, as the percentage of CC increased. Feed intake and BW were decreased by CC and mash at 7 d. Interactions between feed form and CC were observed for feed conversion ratio ( FCR: ) at 7 d of age (P < 0.01), and feed intake (P < 0.05), BW (P < 0.01), and gizzard weight (P < 0.01) at 14 d of age. Feed intake for all CC inclusions in crumble diets was similar and exceeded (P < 0.01) that of mash diets at 14 d. Among mash diets, the 10 and 30% CC feed intake was greater (P < 0.05) than 40 and 50% CC with 0 and 20% CC intermediate. Crumble diets produced a similar BW but greater 14-d BW than mash diets (P < 0.01). Within mash diets, 40 and 50% CC produced a smaller BW (P < 0.01). The FCR at 7 d of CC inclusions in crumble diets was improved (P < 0.01) versus the same CC in mash diets. Within mash diets, 40% CC performed poorer than 0, 10, 20, and 30% CC diets with 50% CC diet intermediate (P < 0.01). Crumble diets improved FCR at 14 d, but CC worsened FCR. Gizzard weight at 14 d was not affected by CC in crumble diets, while it increased with CC in mash diets (P < 0.01). Excreta nitrogen was increased (P < 0.01) by crumble diets. These data demonstrated that pelleting and crumbling reduced the impact of CC, produced a more consistent feed intake, and reduced selective feeding, and that CC stimulated gizzard weight in a linear manner in mash diets.}, number={7}, journal={POULTRY SCIENCE}, author={Xu, Y. and Stark, C. R. and Ferket, P. R. and Williams, C. M. and Brake, J.}, year={2015}, month={Jul}, pages={1549–1556} }
 @article{xu_stark_ferket_williams_nusairat_brake_2015, title={Evaluation of litter type and dietary coarse ground corn inclusion on broiler live performance, gastrointestinal tract development, and litter characteristics}, volume={94}, ISSN={["1525-3171"]}, DOI={10.3382/ps/peu057}, abstractNote={Two 49 d floor pen studies were conducted to evaluate the effects of litter type and dietary coarse ground corn (CC) inclusion on broiler live performance, gastrointestinal tract (GIT) development, and litter characteristics. Experiment 1 was a 2×2 factorial arrangement of 2 genders (male or female) and 2 CC levels (0 or 50%). From 15 to 35 d, the addition of CC decreased feed intake (P<0.01) and BW gain (P<0.05) of males but not females. The inclusion of CC decreased feed intake (P<0.01) and BW gain (P<0.01) from 0 to 49 d but improved adjusted feed conversion ratio (AdjFCR) from 35 to 49 d (P<0.05). Male broilers exhibited better live performance than females during the study as evidenced by greater feed intake (P<0.01) and BW gain (P<0.01), and improved FCR (P<0.01), but with increased mortality (P<0.05). The inclusion of CC increased relative gizzard weight (P<0.01) and decreased relative proventriculus weight (P<0.01) at 49 d. Experiment 2 was a 2×2 factorial arrangement of 2 CC levels (0 or 50%) and 2 litter types (ground old litter or new wood shavings litter). The inclusion of CC decreased feed intake throughout the experiment without affecting final BW when only males were used and improved FCR after 25 d (P<0.01). New litter improved FCR from 1 to 14 d (P<0.01). At 49 d, the birds fed the CC diet had reduced excreta nitrogen (P<0.05) and litter moisture (P<0.05). In conclusion, 50% CC inclusion initially produced negative effects on live performance that became positive as BW increased. The effects of CC became evident at an earlier age for males. New litter had only a marginal benefit on broiler live performance.}, number={3}, journal={POULTRY SCIENCE}, author={Xu, Y. and Stark, C. R. and Ferket, P. R. and Williams, C. M. and Nusairat, B. and Brake, J.}, year={2015}, month={Mar}, pages={362–370} }
 @article{lee_kullman_yost_meyer_worley-davis_williams_reckhow_2015, title={Predicting characteristics of rainfall driven estrogen runoff and transport from swine AFO spray fields}, volume={532}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2015.06.051}, abstractNote={Animal feeding operations (AFOs) have been implicated as potentially major sources of estrogenic contaminants into the aquatic environment due to the relatively minimal treatment of waste and potential mobilization and transport of waste components from spray fields. In this study a Bayesian network (BN) model was developed to inform management decisions and better predict the transport and fate of natural steroidal estrogens from these sites. The developed BN model integrates processes of surface runoff and sediment loss with the modified universal soil loss equation (MUSLE) and the soil conservation service curve number (SCS-CN) runoff model. What-if scenario simulations of lagoon slurry wastes to the spray fields were conducted for the most abundant natural estrogen estrone (E1) observed in the system. It was found that E1 attenuated significantly after 2 months following waste slurry application in both spring and summer seasons, with the overall attenuation rate predicted to be higher in the summer compared to the spring. Using simulations of rainfall events in conjunction with waste slurry application rates, it was predicted that the magnitude of E1 runoff loss is significantly higher in the spring as compared to the summer months, primarily due to spray field crop management plans. Our what-if scenario analyses suggest that planting Bermuda grass in the spray fields is likely to reduce runoff losses of natural estrogens near the water bodies and ecosystems, as compared to planting of soybeans.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Lee, Boknam and Kullman, Sethw. and Yost, Erin E. and Meyer, Michael T. and Worley-Davis, Lynn and Williams, C. Michael and Reckhow, Kenneth H.}, year={2015}, month={Nov}, pages={571–580} }
 @article{yost_meyer_dietze_williams_worley-davis_lee_kullman_2014, title={Transport of Steroid Hormones, Phytoestrogens, and Estrogenic Activity across a Swine Lagoon/Sprayfield System}, volume={48}, ISSN={["1520-5851"]}, DOI={10.1021/es5025806}, abstractNote={The inflow, transformation, and attenuation of natural steroid hormones and phytoestrogens and estrogenic activity were assessed across the lagoon/sprayfield system of a prototypical commercial swine sow operation. Free and conjugated steroid hormones (estrogens, androgens, and progesterone) were detected in urine and feces of sows across reproductive stages, with progesterone being the most abundant steroid hormone. Excreta also contained phytoestrogens indicative of a soy-based diet, particularly, daidzein, genistein, and equol. During storage in barn pits and the anaerobic lagoon, conjugated hormones dissipated, and androgens and progesterone were attenuated. Estrone and equol persisted along the waste disposal route. Following application of lagoon slurry to agricultural soils, all analytes exhibited attenuation within 2 days. However, analytes including estrone, androstenedione, progesterone, and equol remained detectable in soil at 2 months postapplication. Estrogenic activity in the yeast estrogen screen and T47D-KBluc in vitro bioassays generally tracked well with analyte concentrations. Estrone was found to be the greatest contributor to estrogenic activity across all sample types. This investigation encompasses the most comprehensive suite of natural hormone and phytoestrogen analytes examined to date across a livestock lagoon/sprayfield and provides global insight into the fate of these analytes in this widely used waste management system.}, number={19}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Yost, Erin E. and Meyer, Michael T. and Dietze, Julie E. and Williams, C. Michael and Worley-Davis, Lynn and Lee, Boknam and Kullman, Seth W.}, year={2014}, month={Oct}, pages={11600–11609} }
 @article{yost_meyer_dietze_meissner_worley-davis_williams_lee_kullman_2013, title={Comprehensive Assessment of Hormones, Phytoestrogens, and Estrogenic Activity in an Anaerobic Swine Waste Lagoon}, volume={47}, ISSN={["1520-5851"]}, DOI={10.1021/es4026408}, abstractNote={In this study, the distribution of steroid hormones, phytoestrogens, and estrogenic activity was thoroughly characterized within the anaerobic waste lagoon of a typical commercial swine sow operation. Three independent rounds of sampling were conducted in June 2009, April 2010, and February 2011. Thirty-seven analytes in lagoon slurry and sludge were assessed using LC/MS-MS, and yeast estrogen screen was used to determine estrogenic activity. Of the hormone analytes, steroidal estrogens were more abundant than androgens or progesterone, with estrone being the predominant estrogen species. Conjugated hormones were detected only at low levels. The isoflavone metabolite equol was by far the predominant phytoestrogen species, with daidzein, genistein, formononetin, and coumestrol present at lower levels. Phytoestrogens were often more abundant than steroidal estrogens, but contributed minimally toward total estrogenic activity. Analytes were significantly elevated in the solid phases of the lagoon; although low observed log KOC values suggest enhanced solubility in the aqueous phase, perhaps due to dissolved or colloidal organic carbon. The association with the solid phase, as well as recalcitrance of analytes to anaerobic degradation, results in a markedly elevated load of analytes and estrogenic activity within lagoon sludge. Overall, findings emphasize the importance of adsorption and transformation processes in governing the fate of these compounds in lagoon waste, which is ultimately used for broadcast application as a fertilizer.}, number={23}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Yost, Erin E. and Meyer, Michael T. and Dietze, Julie E. and Meissner, Benjamin M. and Worley-Davis, Lynn and Williams, C. Michael and Lee, Boknam and Kullman, Seth W.}, year={2013}, month={Dec}, pages={13781–13790} }
 @article{vibart_washburn_green_benson_williams_pacheco_lopez-villalobos_2012, title={Effects of feeding strategy on milk production, reproduction, pasture utilization, and economics of autumn-calving dairy cows in eastern North Carolina}, volume={95}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2011-4755}, abstractNote={A balance among stocking rate (SR), pasture management, and supplementary feeding is required to optimize overall farm performance and profitability in pasture-based dairying. Beginning in September 2003, a seasonal, autumn-calving, pasture-based farming system was established to address the effects of feeding strategy (FS; i.e., a unique combination of stocking and supplementation rate) on productive, reproductive, and economic performance of lactating herds over 3 yr. Eighty lactating cows (1/3 Holsteins, 1/3 Jerseys, and 1/3 crosses of those breeds) were randomly assigned to either a lesser stocking, lesser supplementation group [LSR; 2.2 cows/ha, 6.3 kg of dry matter (DM) of a corn-based concentrate consumed daily, n=40] or a greater stocking, greater supplementation group (HSR; 3.3 cows/ha, 9.2 kg of DM of a corn-based concentrate consumed daily, n=40). Pasture/forage crop rotations included annual ryegrass and sorghum-Sudan (50%), annual ryegrass and bermudagrass (20%), and a tall fescue-white clover pasture (30%). Pre- and postgrazing herbage mass values and grazing intervals (3,347±255.8 kg of DM/ha, 1,861±160.6 kg of DM/ha, 23.6±1.9 d) did not differ between FS. The nutritive value of fresh and conserved forages was similar between feeding strategies, except for acid detergent fiber in freshly grazed bermudagrass (29.6 vs. 26.3% of DM for LSR and HSR, respectively). Cows on HSR tended to spend more time on an adjacent feeding area where conserved forages were offered (85 vs. 61 d/yr) as opposed to grazing paddocks (204 vs. 228 d/yr). Lactation performance was greater for HSR; cows on HSR produced 10.8% more milk fat and 6.3% more milk protein than cows on LSR. Holstein cows produced the greatest amounts of mature-equivalent milk, but did not differ from crossbred cows in terms of energy-corrected milk, and mature-equivalent fat and protein yields. Reproductive efficiency did not differ among feeding strategy, but breed differences were observed; conception rates at first and all services, as well as pregnancy rates, were greater for Jersey and crossbred cows compared with Holsteins. The greater stocking rate required additional supplemental concentrate and time away from grazing paddocks, but reproductive efficiency was similar and overall lactation performance was greater. The greater stocking rate resulted in increased productivity and greater income over feed costs per unit of land.}, number={2}, journal={JOURNAL OF DAIRY SCIENCE}, author={Vibart, R. E. and Washburn, S. P. and Green, J. T., Jr. and Benson, G. A. and Williams, C. M. and Pacheco, D. and Lopez-Villalobos, N.}, year={2012}, month={Feb}, pages={997–1010} }
 @article{ko_simmons, iii_likirdopulos_worley-davis_williams_sobsey_2010, title={Endotoxin Levels at Swine Farms Using Different Waste Treatment and Management Technologies}, volume={44}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/es9026024}, DOI={10.1021/es9026024}, abstractNote={Concentrated animal feeding operations (CAFOs) are a major source of airborne endotoxins, which are air pollutants that can cause adverse health effects to both on-site farmers and neighbors. Release of airborne endotoxins to the environment can be reduced using proper waste treatment and management technologies. In this study, the levels of endotoxins released from two swine CAFOs using conventional lagoon-sprayfield technology were compared to those of 15 farms using various alternative waste management technologies in North Carolina. Over a 2-year period, 236 endotoxin samples were collected from the 17 farm units and analyzed using the Limulus amebocyte lysate (LAL) test. Concentrations of airborne endotoxins near barn exhaust fans were significantly higher than at the upwind boundary of the farm and at other farm sites. For most of the study sites, mean concentrations of endotoxins at the downwind boundary of the farm were higher than those at the upwind boundary of the farm, indicating the release of endotoxins from swine CAFOs to the neighboring environment. Endotoxin levels were significantly associated with concentrations of airborne bacteria but not fungi. Environmental factors, such as temperature, relative humidity, and wind velocity, affected the levels of airborne endotoxins at the farms. Based on the ratios of airborne endotoxins in downwind and upwind samples from the farm units, at least five different alternative waste management technologies significantly reduced the release of endotoxins from swine CAFOs. These results suggest that swine CAFOs are important sources of airborne endotoxins, the levels of which can be reduced by applying more robust and effective waste management technologies.}, number={9}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Ko, GwangPyo and Simmons, III, Otto D. and Likirdopulos, Christina A. and Worley-Davis, Lynn and Williams, C. M. and Sobsey, Mark D.}, year={2010}, month={May}, pages={3442–3448} }
 @article{creamer_chen_williams_cheng_2010, title={Stable thermophilic anaerobic digestion of dissolved air flotation (DAF) sludge by co-digestion with swine manure}, volume={101}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2009.12.029}, abstractNote={Environmentally sound treatment of by-products in a value-adding process is an ongoing challenge in animal agriculture. The sludge produced as a result of the dissolved air flotation (DAF) wastewater treatment process in swine processing facilities is one such low-value residue. The objective of this study was to determine the fundamental performance parameters for thermophilic anaerobic digestion of DAF sludge. Testing in a semi-continuous stirred tank reactor and in batch reactors was conducted to determine the kinetics of degradation and biogas yield. Stable operation could not be achieved using pure DAF sludge as a substrate, possibly due to inhibition by long-chain fatty acids or to nutrient deficiencies. However, in a 1:1 ratio (w/w, dry basis) with swine manure, operation was both stable and productive. In the semi-continuous stirred reactor at 54.5 degrees Celsius, a hydraulic residence time of 10 days, and an organic loading rate of 4.68 gVS/day/L, the methane production rate was 2.19 L/L/day and the specific methane production rate was 0.47 L/gVS (fed). Maximum specific methanogenic activity (SMA) in batch testing was 0.15 mmoles CH(4) h(-1) gVS(-1) at a substrate concentration of 6.9 gVS L(-1). Higher substrate concentrations cause an initial lag in methane production, possibly due to long-chain fatty acid or nitrogen inhibition.}, number={9}, journal={BIORESOURCE TECHNOLOGY}, author={Creamer, K. S. and Chen, Y. and Williams, C. M. and Cheng, J. J.}, year={2010}, month={May}, pages={3020–3024} }
 @inproceedings{williams_2009, title={Development of environmentally superior technologies in the US and policy}, volume={100}, number={22}, booktitle={Bioresource Technology}, author={Williams, C. M.}, year={2009}, pages={5512–5518} }
 @article{aneja_arya_rumsey_kim_bajwa_arkinson_semunegus_dickey_stefanski_todd_et al._2008, title={Characterizing ammonia emissions from swine farms in eastern North Carolina: Part 2 - Potential environmentally superior technologies for waste treatment}, volume={58}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-53849100726&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.58.9.1145}, abstractNote={Abstract The need for developing environmentally superior and sustainable solutions for managing the animal waste at commercial swine farms in eastern North Carolina has been recognized in recent years. Program OPEN (Odor, Pathogens, and Emissions of Nitrogen), funded by the North Carolina State University Animal and Poultry Waste Management Center (APWMC), was initiated and charged with the evaluation of potential environmentally superior technologies (ESTs) that have been developed and implemented at selected swine farms or facilities. The OPEN program has demonstrated the effectiveness of a new paradigm for policy-relevant environmental research related to North Carolina’s animal waste management programs. This new paradigm is based on a commitment to improve scientific understanding associated with a wide array of environmental issues (i.e., issues related to the movement of N from animal waste into air, water, and soil media; the transmission of odor and odorants; disease-transmitting vectors; and airborne pathogens). The primary focus of this paper is on emissions of ammonia (NH3) from some potential ESTs that were being evaluated at full-scale swine facilities. During 2-week-long periods in two different seasons (warm and cold), NH3 fluxes from water-holding structures and NH3 emissions from animal houses or barns were measured at six potential EST sites: (1) Barham farm—in-ground ambient temperature anaerobic digester/energy recovery/greenhouse vegetable production system; (2) BOC #93 farm—upflow biofiltration system—EKOKAN ; (3) Carrolls farm—aerobic blanket system—ISSUES-ABS; (4) Corbett #1 farm—solids separation/gasification for energy and ash recovery centralized system—BEST; (5) Corbett #2 farm—solid separation/reciprocating water technology—ReCip; and (6) Vestal farm—Recycling of Nutrient, Energy and Water System—ISSUES—RENEW. The ESTs were compared with similar measurements made at two conventional lagoon and spray technology (LST) farms (Moore farm and Stokes farm). A flow-through dynamic chamber system and two sets of open-path Fourier transform infrared (OP-FTIR) spectrometers measured NH3 fluxes continuously from water-holding structures and emissions from housing units at the EST and conventional LST sites. A statisticalobservational model for lagoon NH3 flux was developed using a multiple linear regression analysis of 15-min averaged NH3 flux data against the relevant environmental parameters measured at the two conventional farms during two different seasons of the year. This was used to compare the water-holding structures at ESTs with those from lagoons at conventional sites under similar environmental conditions. Percentage reductions in NH3 emissions from different components of each potential EST, as well as the whole farm on which the EST was located were evaluated from the estimated emissions from water-holding structures, barns, etc., all normalized by the appropriate nitrogen excretion rate at the potential EST farm, as well as from the appropriate conventional farm. This study showed that ammonia emissions were reduced by all but one potential EST for both experimental periods. However, on the basis of our evaluation results and analysis and available information in the scientific literature, the evaluated alternative technologies may require additional technical modifications to be qualified as unconditional ESTs relative to NH3 emissions reductions.}, number={9}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, Viney P. and Arya, S. Pal and Rumsey, Ian C. and Kim, D. -S. and Bajwa, K. and Arkinson, H. L. and Semunegus, H. and Dickey, D. A. and Stefanski, L. A. and Todd, L. and et al.}, year={2008}, month={Sep}, pages={1145–1157} }
 @article{aneja_arya_rumsey_kim_bajwa_williams_2008, title={Characterizing ammonia emissions from swine farms in eastern North Carolina: Reduction of emissions from water-holding structures at two candidate superior technologies for waste treatment}, volume={42}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449117100&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.08.037}, abstractNote={Abstract Program OPEN (Odor, Pathogens, and Emissions of Nitrogen) was an integrated study of the emissions of ammonia (NH 3 ), odor and odorants, and pathogens from potential environmentally superior technologies (ESTs) for swine facilities in eastern North Carolina. This paper, as part of program OPEN, focuses on quantifying emissions of NH 3 from water-holding structures at two of the best ESTs and compares them with the projected emissions from two conventional lagoon and spray technologies (LSTs). The evaluated ESTs are: (1) Super Soils at Goshen Ridge; and (2) Environmental Technologies at Red Hill. The water-holding structures for these two ESTs contained no conventional anaerobic lagoon. A dynamic flow-through chamber was used to measure NH 3 fluxes from the water-holding structures at both the ESTs and at the conventional LST farms. In order to compare the emissions from the water-holding structures at the ESTs with those from the lagoons at the conventional sites under similar conditions, a statistical-observational model for lagoon NH 3 emissions was used. A mass-balance approach was used to quantify the emissions. All emissions were normalized by nitrogen-excretion rates. The percentage reductions relative to the conventional lagoons were calculated for the two ESTs. Results showed substantial reductions in NH 3 emissions at both ESTs. Super Soils had reductions of 94.7% for the warm season and 99.0% for the cool season. Environmental Technologies had slightly larger reductions of 99.4% and 99.98% for the cool and warm season, respectively. As a result of such large reductions in ammonia emissions, both technologies meet the criteria to be classified as ESTs for ammonia emissions.}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, Viney P. and Arya, S. Pal and Rumsey, Ian C. and Kim, D-S. and Bajwa, K. S. and Williams, C. M.}, year={2008}, month={Apr}, pages={3291–3300} }
 @article{aneja_arya_kim_rumsey_arkinson_semunegus_bajwa_dickey_stefanski_todd_et al._2008, title={Characterizing ammonia emissions from swine farms in eastern north carolina: Part 1-conventional lagoon and spray technology for waste treatment}, volume={58}, ISSN={["1047-3289"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-53849107841&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.58.9.1130}, abstractNote={Abstract Ammonia (NH3) fluxes from waste treatment lagoons and barns at two conventional swine farms in eastern North Carolina were measured. The waste treatment lagoon data were analyzed to elucidate the temporal (seasonal and diurnal) variability and to derive regression relationships between NH3 flux and lagoon temperature, pH and ammonium content of the lagoon, and the most relevant meteorological parameters. NH3 fluxes were measured at various sampling locations on the lagoons by a flow-through dynamic chamber system interfaced to an environmentally controlled mobile laboratory. Two sets of open-path Fourier transform infrared (FTIR) spectrometers were also used to measure NH3 concentrations for estimating NH3 emissions from the animal housing units (barns) at the lagoon and spray technology (LST) sites.Two different types of ventilation systems were used at the two farms. Moore farm used fan ventilation, and Stokes farm used natural ventilation. The early fall and winter season intensive measurement campaigns were conducted during September 9 to October 11, 2002 (lagoon temperature ranged from 21.2 to 33.6 °C) and January 6 to February 2, 2003 (lagoon temperature ranged from 1.7 to 12 °C), respectively. Significant differences in seasonal NH3 fluxes from the waste treatment lagoons were found at both farms. Typical diurnal variation of NH3 flux with its maximum value in the afternoon was observed during both experimental periods. Exponentially increasing flux with increasing surface lagoon temperature was observed, and a linear regression relationship between logarithm of NH3 flux and lagoon surface temperature (T l) was obtained. Correlations between lagoon NH3 flux and chemical parameters, such as pH, total Kjeldahl nitrogen (TKN), and total ammoniacal nitrogen (TAN) were found to be statistically insignificant or weak. In addition to lagoon surface temperature, the difference (D) between air temperature and the lagoon surface temperature was also found to influence the NH3 flux, especially when D > 0 (i.e., air hotter than lagoon). This hot-air effect is included in the statistical-observational model obtained in this study, which was used further in the companion study (Part II), to compare the emissions from potential environmental superior technologies to evaluate the effectiveness of each technology.}, number={9}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, Viney P. and Arya, S. Pal and Kim, D. -S. and Rumsey, Ian C. and Arkinson, H. L. and Semunegus, H. and Bajwa, K. S. and Dickey, D. A. and Stefanski, L. A. and Todd, L. and et al.}, year={2008}, month={Sep}, pages={1130–1144} }
 @article{creamer_williams_chen_cheng_2008, title={Implications of urine-to-feces ratio in the thermophilic anaerobic digestion of swine waste}, volume={80}, ISSN={["1554-7531"]}, DOI={10.2175/106143007X184717}, abstractNote={Thermophilic anaerobic digestion of swine manure represents a potential waste treatment technology to address environmental concerns, such as odor emissions and removal of pathogenic microorganisms. However, there are concerns relative to the stability of this process when swine manure is the sole substrate. In this study, the potential of biogas production from swine manure as the sole substrate under thermophilic (50°C) conditions was investigated in the laboratory, to determine whether separation of urine and feces as part of the waste collection process would benefit anaerobic digestion. Effluent from a continuously stirred tank reactor was used as the inoculum for batch tests, in which the substrate contained three different concentrations of urine (urine‐free, as‐excreted urine‐to‐feces ratio and double the as‐excreted urine‐to‐feces ratio). Inocula were acclimated to these same urine‐to‐feces ratios to determine methane production. Results show that both urine‐free and as‐excreted substrates were not inhibitory to anaerobic inocula. Anaerobic microorganisms can be readily acclimated to substrate with double the as‐excreted urine concentration, which contained nitrogen concentrations up to 7.20 g/L. Cumulative methane production reached similar levels in the batch tests, regardless of the substrate urine concentration.}, number={3}, journal={WATER ENVIRONMENT RESEARCH}, author={Creamer, K. S. and Williams, C. M. and Chen, Y. and Cheng, J. J.}, year={2008}, month={Mar}, pages={267–275} }
 @article{showers_williams_jennings_2006, title={Impact of large poultry operations on groundwater: Stable 15N isotopes of nitrate assessment}, volume={5}, ISBN={1682-8356}, DOI={10.3923/ijps.2006.318.329}, number={4}, journal={International Journal of Poultry Science}, author={Showers, W. J. and Williams, C. M. and Jennings, G. D.}, year={2006}, pages={318} }
 @article{schiffman_williams_2005, title={Science of odor as a potential health issue}, volume={34}, number={1}, journal={Journal of Environmental Quality}, author={Schiffman, S. S. and Williams, C. M.}, year={2005}, pages={129–138} }
 @article{bottcher_keener_munilla_williams_schiffman_2004, title={DUST AND ODOR EMISSIONS FROM TUNNEL VENTILATED SWINE BUILDINGS IN NORTH CAROLINA AND COMPARISON OF DIFFERENT ODOR EVALUATION METHODS}, volume={20}, ISSN={1943-7838}, url={http://dx.doi.org/10.13031/2013.16064}, DOI={10.13031/2013.16064}, abstractNote={Tunnel ventilation of swine buildings conveys odorous dust and gases out of the production buildings. Measurement of dust and odor levels and other environmental parameters is necessary for characterizing emissions and evaluating control options. During evaluations of odor control systems, measurements of dust and odor levels in building inlet and exhaust air were obtained. Odor and dust levels were consistent with data obtained in other states and Europe. Odor concentrations and emission rates were based on odor measurements from the Duke University Taste and Smell Laboratory at several dilution levels, as well as a calibration curve for odor panelists based on swine manure odor. The computed odor concentration based on measurements over a range of dilutions was greater than the predicted odor concentration based on the calibration curve, for two field visits. This result may be due to odorous dust particles increasing odor persistence above that of vaporous odorants from swine manure. Odor measurements were also obtained using headspace sampling of unaspirated and aspirated cotton swatches. Aspirating the swatches increased odor intensity compared to unaspirated swatches and improved correlation with air sample odor intensities.}, number={3}, journal={Applied Engineering in Agriculture}, publisher={American Society of Agricultural and Biological Engineers (ASABE)}, author={Bottcher, R. W. and Keener, K. M. and Munilla, R. D. and Williams, C. M. and Schiffman, S. S.}, year={2004}, pages={343–347} }
 @article{armstrong_cook_ward_williams_spears_2004, title={Effect of dietary copper source (cupric citrate and,cupric sulfate) and concentration on growth performance and fecal copper excretion in weanling pigs}, volume={82}, DOI={10.1093/ansci/82.4.1234}, number={4}, journal={Journal of Animal Science}, author={Armstrong, T. A. and Cook, D. R. and Ward, M. M. and Williams, C. M. and Spears, J. W.}, year={2004}, pages={1234–1240} }
 @article{miner_humenik_rice_rashash_williams_robarge_harris_sheffield_2003, title={Evaluation of a permeable, 5 cm thick, polyethylene foam lagoon cover}, volume={46}, DOI={10.13031/2013.15442}, abstractNote={Anaerobic lagoons and liquid manure storage basins are widely used for the treatment and storage of livestock and poultry manure. Although relatively inexpensive to construct, these devices have been widely criticized based upon their odor and ammonia release. A floating, permeable, composite cover manufactured from recycled polyethylene chips topped with a geotextile layer containing zeolite particles was evaluated under both laboratory and field conditions. Under laboratory conditions, the cover was found essentially to eliminate odor release and to reduce ammonia emissions by approximately 80%. When installed on a 0.4 ha swine manure lagoon in eastern North Carolina, the cover survived severe storms and allowed even intense rainfall to pass through without causing cover inundation. Under these field conditions, the cover was found to reduce ammonia emissions approximately 80%. Odor emissions measured twice during one month of the study were consistently low in concentration and near neutral relative to quality, as determined by an analysis by a trained odor panel. Microbiological examination of the cover after four months of use showed an active population of aerobic bacteria and protozoa; analysis showed that nitrifying, sulfide oxidizing, and methanotrophic bacteria were likely trophic components of the microbial populations observed. The surface of the cover became covered with an algal population within two weeks of installation. This and other vegetative growth had no discernable impact on the performance of the cover.}, number={5}, journal={Transactions of the ASAE}, author={Miner, J. R. and Humenik, F. J. and Rice, J. M. and Rashash, D. M. C. and Williams, C. and Robarge, W. and Harris, D. B. and Sheffield, R.}, year={2003}, pages={1421–1426} }
 @article{grimes_williams_godwin_smith_2003, title={Heat treatment of turkey litter for reuse as bedding}, volume={2}, ISBN={1682-8356}, DOI={10.3923/ijps.2003.287.292}, abstractNote={Local and national laws regulating poultry litter (PL) land application may require that PL be applied based on crop needs and PL nutrient content such as N and P. In addition, some may require monitoring of soil metals such as Cu and Zn. Even with efforts to decrease fecal nutrient excretion, there is also a need to extend the useful life of current bedding materials and to develop alternative uses of spent PL. Heat treatment of PL may extend bedding life and offer alternative uses of PL. The objective of this study was to determine if heat processed turkey litter (TL) can be reused as bedding for turkeys. Pine shavings (PS) which had been used as bedding to rear Large White male turkeys from hatch to 20 weeks of age was processed at 95 and 220 C in an enclosed auger system. Four litter treatments (LT) were used: 1) control - new PS (T ), o 1 2) TL processed at 95 C (T ), 3) a 70:30 (w/w) mixture of TL processed at 95 or 220 C (T ) and 4) a 95:5 o o 2 3 (w/w) mixture of TL processed at 95 or 220 C (T ). These bedding mixtures were placed in 36 floor pens in o 4 a randomized block design to provide 9 replicate pens per LT. Thirty Large White turkey hen poults were placed in each pen on day of hatch. The birds were reared to 14 wk. Mortality and feed consumption were monitored. Period and cumulative feed conversion (FC) ratios were calculated. Regression analysis of SAS, Inc. was used for data analysis. The LS Means procedure was used to separate treatment means (P<0.05). At 6 wks, T hens were heavier than T (1.78 kg), T (1.80 kg) or T (1.81 kg) hens. There were no differences 3 1 2 4 in BW at 10 (5.42 kg) or 14 wk (8.67 kg) among treatments. There were no differences in FC. The LT did not affect bird mortality. Litter treated by the heat process used for this study produces a bedding material suitable for rearing market turkeys.}, number={5}, journal={International Journal of Poultry Science}, author={Grimes, J. L. and Williams, C. M. and Godwin, J. L. and Smith, J. C.}, year={2003}, pages={287} }
 @misc{grimes_smith_williams_2002, title={Some alternative litter materials used for growing broilers and turkeys}, volume={58}, ISSN={["1743-4777"]}, DOI={10.1079/wps20020037}, abstractNote={This paper discusses materials used as bedding or litter for the rearing of broilers and turkeys in the U.S.A. The U.S. poultry industry has historically used pine shavings as the litter of choice for many years. Sawdust has replaced pine shavings in many areas, however, not by choice, but because pine shavings have become increasingly difficult to obtain. Regionally, rice hulls, straw, and peanut hulls can be found in use by poultry producers for litter. Re-cycled paper products have received a lot of research and development, but have not had a great deal of acceptance by the poultry industry. Sand is another alternative bedding that is currently being tested in southern climates. Alternative litter materials for poultry will continue to be researched and evaluated, and pine shavings or sawdust will probably continue to be used as the benchmark comparison. However, while bird performance will always be a threshold criterion, cost and availability will ultimately determine the adoption of new or alternative litter materials by poultry growers and the poultry industry.}, number={4}, journal={WORLDS POULTRY SCIENCE JOURNAL}, author={Grimes, JL and Smith, J and Williams, CM}, year={2002}, month={Dec}, pages={515–526} }
 @article{williams_2001, title={Technologies to address air quality issues impacting animal agriculture}, volume={44}, ISSN={["0273-1223"]}, DOI={10.2166/wst.2001.0547}, abstractNote={The continued productivity, profitability and sustainability of animal production agriculture in most parts of the world will be dependent upon implementation of effective technologies and management practices to mitigate perceived and documented environmental impacts resulting from confined animal operation emissions. North Carolina State University Animal and Poultry Waste Management Center (APWMC) program efforts to identify such technologies through support of research, development and demonstration projects involve collaborative efforts with approximately 20 other universities (nationally and internationally). Many of these projects are well beyond the laboratory developmental stage and some are yielding encouraging results. Performance data, to date, has shown that swine manure treatment systems including a covered in-ground anaerobic digester, a sequencing batch reactor, and an upflow biological aerated filter system significantly improved odor emission variables.}, number={9}, journal={WATER SCIENCE AND TECHNOLOGY}, author={Williams, CM}, year={2001}, pages={233–236} }
 @article{bottcher_keener_munilla_williams_schiffman_2000, title={Dust and odor emissions from tunnel ventilated swine buildings in North Carolina}, ISBN={1892769123}, journal={Air pollution from agricultural operations : proceedings of the 2nd international conference, October 9-11, 2000, Des Moines, Iowa}, publisher={St. Joseph, Mich. : American Society of Agricultural Engineers}, author={Bottcher, R. W. and Keener, K. M. and Munilla, R. D. and Williams, C. M. and Schiffman, S. S.}, year={2000}, pages={196} }
 @article{grimes_williams_carter_godwin_2000, title={Heat processing of turkey litter for re-use as a bedding material}, ISBN={0962768267}, journal={Proceedings, 2000 National Poultry Waste Management Symposium}, publisher={Auburn University, AL : National Poultry Waste Management Symposium Committee}, author={Grimes, J. L. and Williams, C. M. and Carter, T. A. and Godwin, J. L.}, year={2000}, pages={353} }
 @article{armstrong_williams_spears_schiffman_2000, title={High dietary copper improves odor characteristics of swine waste.}, volume={78}, ISSN={0021-8812}, url={http://dx.doi.org/10.2527/2000.784859x}, DOI={10.2527/2000.784859x}, abstractNote={We conducted two experiments to determine the effects of dietary copper concentration and source on odor characteristics of swine waste. In both experiments, 192 weanling gilts and barrows were allotted to 24 pens. Pens were randomly assigned to one of six dietary treatments, consisting of control (10 ppm Cu as cupric sulfate, CuSO4), 66 or 225 ppm Cu as CuSO4, or 33, 66, or 100 ppm Cu as cupric citrate (Cucitrate). An antibiotic was included in the diets for Exp. 1, but not Exp. 2. On d 28, fecal samples were randomly obtained from one pig per pen and stored at -20 degrees C until preparation and evaluation by an odor panel. The odor panel consisted of 10 individuals, and each panelist evaluated the odor intensity, irritation intensity, and odor quality of the samples. In Exp. 1, the odor and irritation intensity of the feces were lower (P < .05) from animals consuming diets containing 225 ppm Cu as CuSO4 and 66 or 100 ppm Cu as Cu-citrate compared to the control. The odor quality of the waste from animals consuming diets containing 225 ppm Cu as CuSO4 and 66 or 100 ppm Cu as Cu-citrate was improved (P < .05) compared to the 33 ppm Cu treatment. In Exp. 2, the odor intensity of the feces of pigs receiving diets supplemented with all concentrations of Cu-citrate was lower (P < .05) than that of feces from the control animals. Irritation intensity of the feces was not affected by treatment. Odor quality of waste of pigs supplemented with 225 ppm Cu from CuSO4 and all concentrations of Cu-citrate was improved (P < .05) compared to that of waste of the control pigs. Two gilts and two barrows from each nursery pen in Exp. 1 were continued through the growing-finishing phase on their respective experimental diets. The growing-finishing phase lasted 103 d, and fecal samples were randomly obtained from one pig per pen at the completion of the phase. During the growing-finishing phase, the odor intensity and the irritation intensity of the feces were lower (P < .05) from pigs supplemented with 66 and 225 ppm Cu as CuSO4 and 66 and 100 ppm Cu from Cu-citrate than from the control pigs. The odor quality of the waste was improved (P < .05) in all animals receiving supplemental Cu. These data indicate an improvement in odor characteristics of swine waste with the supplementation of Cu. In addition, lower concentrations of an organic nonsulfate Cu source resulted in similar odor characteristics of swine waste as 225 ppm CuSO4.}, number={4}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Armstrong, T A and Williams, C M and Spears, J W and Schiffman, S S}, year={2000}, pages={859} }
 @article{bottcher_keener_munilla_williams_schiffman_2000, title={Scent of a swine building: Tunnel ventilation problems test engineers' ingenuity}, volume={7}, ISBN={1076-3333}, number={10}, journal={Resource, Engineering & Technology for a Sustainable World}, author={Bottcher, R. W. and Keener, K. M. and Munilla, R. D. and Williams, C. M. and Schiffman, S. S.}, year={2000}, pages={13} }
 @article{williams_barker_sims_1999, title={Management and utilization of poultry wastes}, volume={162}, DOI={10.1007/978-1-4612-1528-8_3}, abstractNote={Waste by-products such as excreta or bedding material that are generated by the worldwide annual production of more than 40 million metric tons (t) of poultry meat and 600 billion eggs are generally land applied as the final step of a producer's waste management strategy. Under proper land application conditions, the nutrients and organisms in poultry wastes pose little environmental threat. Environmental contamination occurs when land application of poultry wastes is in excess of crop utilization potential, or is done under poor management conditions causing nutrient loss from environmental factors such as soil erosion or surface runoff during rainfall. Environmental parameters of concern are N, P, and certain metals (Cu and Zn in particular), as well as pathogenic microorganisms that may be contained in poultry waste. The biochemical cycle of N is very dynamic, and N contained in poultry waste may either be removed by crop harvest, leave the animal production facility, waste treatment lagoon, or application field as a gas (NH3, NO, NO2, N2O, or N2), or, due to its mobility in soil, be transported in organic or inorganic N forms in the liquid state via surface runoff or leaching into groundwater. Elevated concentrations of NO3-N in groundwater used for human consumption is a health risk to infants that are susceptible to methemoglobinemia. An environmental impact resulting from elevated NO3-N is eutrophication of surface waters. Ammonia loss from poultry waste is an environmental concern because of volatilized wet and dry deposits of NH3 into nitrogen-sensitive ecosystems. Phosphorus in poultry wastes may contribute to environmental degradation by accelerating the process of eutrophication. Unlike N, P is very immobile in soil and must first be transported to a surface water environment to have an environmental impact. It is generally accepted, however, that this nutrient affects receiving waters via transport in eroding soil as sediment-bound P or in surface runoff as soluble inorganic or organic P. Numerous studies have reported that excess P contained in land-applied manures may contribute to eutrophication. Soils containing P concentrations that greatly exceed the agronomic potential of crops may require years or even decades to return to levels that are crop limiting for this nutrient. Environmental concerns include the capacity of such soils to adsorb new P and the amount of P loss from these soils from erosion, runoff, drainage, or leaching to groundwater. Although much information is available regarding the loss of P from agricultural fields from erosion and runoff, less information is available regarding P losses from fields receiving poultry wastes. However, studies have shown that there are many challenges to controlling P losses from fields receiving manures. In addition, subsurface transport of P resulting from repeated application of poultry manure onto soils that are artificially drained is an environmental concern where drainage waters enter or interact with water bodies sensitive to eutrophication. Trace elements such as As, Co, Cu, Fe, Mn, Se, and Zn are often added in excess to poultry feed to increase the animal's rate of weight gain, feed efficiency, and egg production and to prevent diseases. Because most of the excess trace elements are not absorbed by the bird, the concentration of elements excreted in the manure will reflect dietary overformulation. Because trace elements are generally required in very small quantities for crop growth and, like P, are immobile in most soil types, their concentrations will increase with repeated land application of poultry wastes. Of particular concern are accumulations of Cu and Zn in certain soil types utilized for certain crops. Copper and Zn toxicity for some crops have been documented in some areas receiving repeated land-applied poultry wastes. A potential environmental concern relative to poultry litter and trace elements in receiving soils involves the transpor}, number={1999}, journal={Reviews of Environmental Contamination and Toxicology}, author={Williams, C. M. and Barker, J. C. and Sims, J. T.}, year={1999}, pages={105–157} }
 @article{williams_grimes_mikkelsen_1999, title={The use of poultry litter as Co-substrate and source of inorganic nutrients and microorganisms for the ex situ biodegradation of petroleum compounds}, volume={78}, ISSN={["0032-5791"]}, DOI={10.1093/ps/78.7.956}, abstractNote={The purpose of this investigation was to determine the feasibility of utilizing poultry litter as a source of microorganisms, C co-substrate, N, and P to enhance the biodegradation of petroleum compounds in contaminated soil. An initial laboratory-scale study utilized soil contaminated with approximately 3,000 mg/kg (ppm) total petroleum hydrocarbons (TPHC) as diesel fuel. Biotreatment units, each containing 10 L of contaminated soil, were supplemented (0, 1, 10, and 20%, total weight basis) with broiler litter containing 3.65% N and 1.89% P. Petroleum-degrading microorganisms previously enriched from broiler and turkey litter were also inoculated into the litter-treated units. A significant first order rate of TPHC biodegradation was measured for all treatment units containing broiler litter (P < 0.05). Based on these results, a subsequent study was conducted at the site of a commercial facility permitted to treat soil (ex situ) contaminated with hazardous compounds. Soil treatment plots, each containing approximately 1 ton of soil contaminated with approximately 1,200 to 1,600 mg/kg diesel fuel were established. Each plot was replicated four times and the experiment was conducted for 35 d. Treatments were as follows: control, soil only; soil + commercial blend of bioremediation nutrients; soil + commercial fertilizer; soil + poultry litter (1% by volume); soil + poultry litter (10% by volume); soil + pelleted poultry litter (10% by volume). The results showed that the remediation of soil contaminated with petroleum compounds is significantly (P < 0.05) enhanced when supplemented with poultry litter (pelleted or nonpelleted) in concentrations of 10% soil volume. These results demonstrate the potential for a specialized market for the use of poultry litter.}, number={7}, journal={POULTRY SCIENCE}, author={Williams, CM and Grimes, JL and Mikkelsen, RL}, year={1999}, month={Jul}, pages={956–964} }
 @article{horne_brake_williams_1998, title={Economics of controlling ammonia emission from commercial layer farms}, volume={7}, ISSN={["1056-6171"]}, DOI={10.1093/japr/7.1.61}, abstractNote={Abstract This article presents a model to calculate the level of ammonia emission from commercial layer houses. The first part of the model calculates nitrogen excretion; the second part gives the total ammonia emission from layer houses, manure storage, and manure application. The results show that improved application methods can reduce the ammonia emission in a region at a lower cost than low-nitrogen feed or manure belt drying systems. Results of the separate measures for reducing ammonia emission are not additive. As there are no direct revenues from lowering ammonia emission, governmental regulations requiring such measures, as implemented in the Netherlands, will increase costs for U.S. poultry producers.}, number={1}, journal={JOURNAL OF APPLIED POULTRY RESEARCH}, author={Horne, PLM and Brake, J and Williams, CM}, year={1998}, pages={61–68} }
 @misc{shih_williams_1992, title={Purified Bacillus licheniformis PWD-1 keratinase}, volume={5171682}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Shih, J. C. H. and Williams, C. M.}, year={1992} }
 @article{williams_lee_garlich_shih_1991, title={EVALUATION OF A BACTERIAL FEATHER FERMENTATION PRODUCT, FEATHER-LYSATE, AS A FEED PROTEIN}, volume={70}, ISSN={["0032-5791"]}, DOI={10.3382/ps.0700085}, abstractNote={Abstract Feeding trials were designed to evaluate the nutritive value of feathers treated by a feather-degrading bacterium, Bacillus licheniformis (Strain PWD-1). An initial experiment compared feathers that had been treated under aerobic or anaerobic conditions with untreated feathers as 25% of the feed protein in the diet. The test diets were fed to growing broiler chicks from Day 6 through Day 21 posthatch. The anaerobically fermented product, feather-lysate, resulted in improved growth responses of 6.9 and 19.3% over the aerobic- and nonbacterial-treated feather feed products, respectively, but 6.4% less than a standard com-soybean-based diet In a subsequent experiment, 3 or 6% of feather-lysate, untreated feathers, and commercial feather meal were fed to chicks on a basal diet containing only 10% protein. The linear growth response slopes were compared with the slope resulting when chicks were fed diets containing soybean protein in graded levels from 10 to 19% of the total feed. Feather-lysate supplemented with lysine, methionine, and histidine produced a growth curve identical to that of soybean meal. Commercial feather meal supported an improved growth rate over the untreated feathers but significantly less than feather-lysate. These results indicate that the anaerobic fermentation of feathers offers a potential new process for feather waste treatment to provide a nutritious feed protein.}, number={1}, journal={POULTRY SCIENCE}, author={WILLIAMS, CM and LEE, CG and GARLICH, JD and SHIH, JCH}, year={1991}, month={Jan}, pages={85–94} }
 @misc{shih_williams_1991, title={Method of degrading keratinaceous material and bacteria useful therefor}, volume={5063161}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Shih, J. C. H. and Williams, C. M.}, year={1991} }
 @misc{shih_williams_1990, title={Feather-lysate, a hydrolyzed feather feed ingredient and animal feeds containing the same}, volume={4908220}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Shih, J. C. H. and Williams, C. M.}, year={1990} }
 @article{williams_richter_mackenzie_shih_1990, title={Isolation, identification, and characterization of a feather-degrading bacterium}, volume={56}, number={6}, journal={Applied and Environmental Microbiology}, author={Williams, C. M. and Richter, C. S. and MacKenzie, J. M., Jr. and Shih, J. C. H.}, year={1990}, pages={1509} }
 @misc{shih_williams_1990, title={Method of degrading keratinaceous material and bacteria useful therefore}, volume={4959311}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Shih, J. C. H. and Williams, C. M.}, year={1990} }
 @article{williams_shih_1989, title={ENUMERATION OF SOME MICROBIAL GROUPS IN THERMOPHILIC POULTRY WASTE DIGESTERS AND ENRICHMENT OF A FEATHER-DEGRADING CULTURE}, volume={67}, ISSN={["0021-8847"]}, DOI={10.1111/j.1365-2672.1989.tb04951.x}, abstractNote={Methane‐producing, cellulolytic, feather‐degrading, and total anaerobic microbial populations were enumerated in four laboratory‐scale (l l) thermophilic (50°C) poultry waste digesters over a 40d period. Four different operation conditions were: 5 d retention time (RT), 6% volatile solids (VS); 5 d RT, 3% VS; 10 d RT, 6% VS; and 10 d RT, 3% VS. Laying hen manure was the sole source of substrate and micro‐organisms. At theoretical steady state (day 40) the biogas volumetric rate was near 3.0 l/l digester volume (l/l/d) in all but the 10 d RT, 3% VS digester which was 2 l/l/d. The total viable anaerobic population was > 106 cfu/ml digester fluid at the first sampling and stabilized at 107–108 cfu/ml between days 20 and 40 in all digesters. Methane‐producing bacteria increased from ≤ 10/ml early in the sampling period to 105/ml at steady state in all but the 5 d RT, 3% VS digester which was highest at 107/ml. Cellulolytic micro‐organisms were low throughout the 40 d, generally less than 10/ml. Feather‐degrading micro‐organisms ranged from near 102–105 at steady state and were decreasing in number near day 40 in all but the 10 d RT, 6% VS digester which maintained 105/ml after day 20. A feather‐degrading culture was enriched from this digester and subsequently adapted to grow in a medium with feather as the sole source of carbon. Results of this study provide information regarding potential biological upgrading of poultry waste digesters for increased operational efficiency and potential industrial application of a feather‐hydrolytic micro‐organism.}, number={1}, journal={JOURNAL OF APPLIED BACTERIOLOGY}, author={WILLIAMS, CM and SHIH, JCH}, year={1989}, month={Jul}, pages={25–35} }
 @article{williams_colwell_rose_1980, title={GENETIC-RESISTANCE OF CHICKENS TO AFLATOXIN ASSESSED WITH ORGAN-CULTURE TECHNIQUES}, volume={24}, ISSN={["0005-2086"]}, DOI={10.2307/1589708}, abstractNote={A chick tracheal-organ-culture model system was used to evaluate the sensitivity of various strains of chickens to aflatoxin B1. Tissues from different genetic stocks showed highly significant differences in in vitro sensitivity to aflatoxin. Tracheal tissues from brown-egg layers were most sensitive, meat-type birds intermediate, and white-egg layers most resistant. Within-category strains and sex differed significantly in sensitivity to damage by aflatoxin, with male chicks more resistant than female chicks.}, number={2}, journal={AVIAN DISEASES}, author={WILLIAMS, CM and COLWELL, WM and ROSE, LP}, year={1980}, pages={415–422} }