Poult. Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


Poult Sci 2007. 86:182-190
© 2007 Poultry Science Association
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wu-Haan, W.
Right arrow Articles by Applegate, T. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wu-Haan, W.
Right arrow Articles by Applegate, T. J.

PRODUCTION, MODELING, AND EDUCATION

Effect of an Acidifying Diet Combined with Zeolite and Slight Protein Reduction on Air Emissions from Laying Hens of Different Ages

W. Wu-Haan*, W. J. Powers*,1, C. R. Angel{dagger}, C. E. Hale, III{ddagger} and T. J. Applegate§

* Iowa State University, Ames 50011; {dagger} University of Maryland, College Park 20742; {ddagger} Rose Acres Farms, Seymour, IN 47274; and § Purdue University, West Lafayette, IN 47907

1 Corresponding author: wpowers{at}iastate.edu


    ABSTRACT
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 REFERENCES
 
The objectives of the study were to evaluate the effectiveness of a reduced-emission (RE) diet containing 6.9% of a CaSO4-zeolite mixture and slightly reduced CP to 21-, 38-, and 59-wk-old Hy-Line W-36 hens (trials 1, 2, and 3, respectively) on egg production and emissions of NH3, H2S, NO, NO2, CO2, CH4, and non-CH4 total hydrocarbons as compared with feeding a commercial (CM) diet. At each age, 640 hens were allocated, randomly to 8 environmental chambers for a 3-wk period. On an analyzed basis, the CM diet contained 18.0, 17.0, and 16.2% CP and 0.25, 0.18, and 0.20% S in trials 1, 2, and 3, and the RE diet contained 17.0, 15.5, and 15.6% CP and 0.99, 1.20, and 1.10% S in trials 1, 2, and 3. Diets were formulated to contain similar Ca and P contents. Average daily egg weight (56.3 g), average daily egg production (81%), average daily feed intake (92.4 g), and BW change (23.5 g), across ages, were unaffected by diet (P > 0.05) over the study period. Age effects were observed for all performance variables and NH3 emissions (P < 0.05). In trials 1, 2, and 3, daily NH3 emissions from hens fed the RE diets (185.5, 312.2, and 333.5 mg/bird) were less than emissions from hens fed the CM diet (255.1, 560.6, and 616.3 mg/bird; P < 0.01). Daily emissions of H2S across trials from hens fed the RE diet were 4.08 mg/bird compared with 1.32 mg/bird from hens fed the CM diet (P < 0.01). Diet (P < 0.05) and age (P < 0.05) affected emissions of CO2 and CH4. A diet effect (P < 0.01) on NO emissions was observed. No diet or age effects (P > 0.05) were observed for NO2 or non-CH4 total hydrocarbons. Results demonstrated that diet and layer age influence air emissions from poultry operations.

Key Words: hen • air emission • diet • ammonia • hydrogen sulfide


    INTRODUCTION
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 REFERENCES
 
It is documented that gaseous emissions from laying hen feeding operations can have potential negative effects on the environment and on human and bird health. Feeding diets formulated to reduce excess CP reduced N excreted, resulting in lower NH3 emissions (Elwinger and Svensson, 1996). Acidogenic materials reduce manure pH, resulting in the protonation of NH3 to NH4+, which is less volatile (McCrory and Hobbs, 2001). Gypsum is one of the acidogenic compounds that has been tested and can also serve to partially replace limestone as a Ca source in laying hen diets without reducing laying hen performance (Keshavarz, 1991). Zeolite has been shown to be a beneficial feed additive that exhibits a strong preference for binding nitrogenous cations like NH4+, resulting in lower, but inconsistent, NH3 emission (Nakaue and Koelliker, 1981) when included at 10%. A study conducted by Hale (2005) showed that using a reduced-protein diet in combination with acidogenic materials, such as CaSO4 and nitrogenous binding compounds like zeolite, decreased NH3 concentration (as measured in vitro) from laying hen excreta. However, the effectiveness of feeding such a diet on all gaseous emissions in vivo has not been reported. The objectives of the current study were to evaluate the effectiveness of feeding a reduced-emissions (RE) diet containing 6.9% of a CaSO4-zeolite mixture that replaced 35% of the limestone and slightly reduced protein to laying hens of different ages on short-term hen performance and emissions of NH3, H2S, NO, NO2, CO2, CH4, and non-CH4 total hydrocarbon (NMTHC) as compared with feeding a commercial (CM) diet.


    MATERIALS AND METHODS
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 REFERENCES
 
Experimental Birds and Design
The study consisted of 3 trials utilizing Hy-Line W-36 hens, starting at 21 (trial 1), 38 (trial 2), and 59 wk (trial 3) of age. During each experimental age, laying hens were fed for a 3-wk period. All hens were obtained at the respective ages from commercial high-rise laying hen houses (Rose Acre Farms, Stuart, IA) within 1 h of the research location. Laying hens were moved to the research location 5 d before the start of each trial.

The experiment was designed with 2 treatments. During each experimental phase, a total of 640 hens (initial BW = 1.36, 1.47, and 1.52 kg in trials 1, 2, and 3, respectively) were allocated randomly to 1 of 8 chambers (indirect calorimeters) that were built to allow for continuous monitoring of emissions from livestock. In each chamber, 80 birds were divided among 4 2-cage units (10 birds/cage, 355 cm2 of cage space/bird). Diets were assigned randomly to each of the 8 chambers (4 chambers/diet), with the chamber constituting the experimental unit.

Diets and Management
All diets were formulated to meet NRC (1994) nutrient requirements for laying hens. Feed (approximately 95, 97, and 99 g/hen per d in trials 1, 2, and 3, respectively) was offered twice daily (0600 and 1600 h) in a mash form, and feed intake was recorded weekly on a 2-cage unit basis (20 birds/unit). Samples of diets were retained weekly for determination of nutrient content. Composition of experimental diets is shown in Table 1Go.


View this table:
[in this window]
[in a new window]

 
Table 1. Composition (as-fed basis) of the reduced emission (RE) diet and the commercial (CM) diet fed to 21-, 38- and 59-wk-old laying hens
 
Temperatures in all chambers were maintained at 22 ± 2°C. The humidity ranged from 20 to 80%. Light (10 to 20 lx) was provided from 0600 to 1800 h for 21-wk-old birds and from 0600 to 2200 h for the 38-wk and 59-wk-old birds. The light program was managed to mimic that of the commercial farm and the recommendations of the Hy-Line W-36 Commercial Management Guide (Hy-Line International, 2003). Hens were provided ad libitum access to water via nipples.

Bird Measures
Hens were weighed at the beginning and end of each age period. Body weight change (BWC) within each chamber was calculated by subtracting the average chamber BW at the beginning of each trial from the average chamber BW at the end of each trial. Average daily feed intake (ADFI) of each chamber was calculated based on that week’s total feed consumption, divided by 7 d and the number of birds present. Eggs were collected daily from each 2-cage unit, and egg weight and number were recorded daily. Excreta production was determined at the end of each age phase, and a subsample was collected for compositional analysis. Average daily egg weights (ADEW), average daily egg production (ADEP), ADFI, and BWC over the study period were calculated at the end of each trial.

Measurements of Gaseous Concentrations
Eight chambers (2.14 x 3.97 x 2.59 m) were designed to continuously measure incoming and exhaust concentrations of NH3, H2S, NO, NO2, CO2, CH4, and NMTHC. Ammonia and NO were measured using a chemiluminescence NH3 analyzer (model 17C, Thermal Environmental Instruments, Franklin, MA), which is a combination of an NH3 converter and NO-NO2-NOx analyzer. Hydrogen sulfide was analyzed using pulsed fluorescence H2S-SO2 analyzer (model 450C, Thermal Environmental Instruments). Carbon dioxide was monitored using the BINOS 100 2M dual gas detector (Rosemount Analytical Inc., Orrville, OH). Methane and NMTHC were measured by flame ionization detector (model 200, VIG Industries Inc., Anaheim, CA). During trial 1, NMTHC data were not available due to the absence of calibration gases. Through software control, gaseous concentration monitoring of each chamber occurred in a sequential manner, beginning first with incoming air for 20 min, then through each of the 8 chambers’ exhaust airs for 15 min, with all gases measured simultaneously within a sample stream. Airflow rates into and out of each chamber were measured accurately using orifice plates, calibrated for each chamber under specific ranges of conditions. Cumulative NH3, H2S, NO, NO2, CO2, CH4, and NMTHC emissions from each chamber were calculated daily by averaging all recordings for that day (10 to 11 daily observations per chamber). Based on light periods, daytime and nighttime emissions were determined. The average daily gaseous emissions in each chamber were expressed as emission rate (mg/min), cumulative total mass (mg), daytime mass (mg), nighttime mass (mg), milligrams per kilogram of BW, and milligrams per hen.

Statistical Analyses
Performance data were analyzed using a GLM procedure, and emissions data were analyzed using a MIXED procedure of SAS (SAS Institute, 1990). For ADEW, ADEP, ADFI, and BWC variables, the model included the fixed effects of chamber and diet (CM and RE diets), the interaction between chamber and diet. For emissions data, the model tested the fixed effects of diet, age, and the interaction of diet and age on emission. Date was treated as a random variable. Significant differences among the means were declared at P ≤ 0.05.


    RESULTS AND DISCUSSION
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 REFERENCES
 
Hen Performance
The effect of feeding an acidified diet combined with zeolite and slightly reduced protein on ADEW, ADEP, and ADFI is presented in Table 2Go. Across ages, the ADEW (56.3 g), ADEP (81.0%), ADFI (92.4 g/hen per d), and BWC (23.5 g/hen) of hens fed the RE diet were not different from hens fed the CM diet.


View this table:
[in this window]
[in a new window]

 
Table 2. Egg weight, egg production, feed intake, and BW change data from laying hens fed a commercial (CM) or reduced emission (RE) diet at 21, 38, and 59 wk of age
 
Age affected ADEW (51.9, 58.9, and 58.1 g at 21, 38, and 59 wk of age, respectively), ADEP (86.6, 83.4, and 73.1% at 21, 38, and 59 wk of age, respectively), ADFI (86.8, 95.6, and 94.7 g at 21, 38, and 59 wk of age, respectively), and BWC (65.4, 17.3, and –12.0 g at 21, 38, and 59 wk of age, respectively). Egg weights in the 59- and 38-wk-old hens were greater than egg weights from 21-wk-old hens. Egg production of 59-wk-old hens was less as compared with that of the 21- or 38-wk-old hens. The highest feed consumption was in 38-wk-old hens. Body weight increased the most in 21-wk-old hens, followed by the 38-wk-old hens, whereas the 59-wk-old hens lost weight.

Across ages, birds fed both the CM and RE diets performed similarly to the performance outlined for Hy-Line W-36 laying hens (Hy-Line International, 2003). Our findings were similar to work conducted by Keshavarz (2003), who reported ADEW of 51.5, 56.2, and 59.7 g; ADEP of 81.2, 73.9, and 69.3%; and ADFI of 91.1, 91.5, and 96.0 g at 20 to 35, 36 to 51, and 52 to 63 wk of age, respectively.

NH3 Emissions
Across ages, the RE diet reduced the daily mass of NH3 emitted (mg/hen) by 39% (Table 3Go). Daily emissions of NH3 from hens fed the RE diet (185.5, 312.2, and 333.5 mg/hen) were significantly less than from hens fed the CM diet (255.1, 560.6, and 616.3 mg/hen) in the 21-, 38-, and 59-wk trials, respectively. Feeding the RE diet decreased the daily emission rate of NH3 emitted from all 3 age groups (16.3 vs. 26.9 mg/min, Table 3Go). The RE diet also reduced the cumulative NH3 emission mass (mg) over the 3 ages studied by 39% (22,628 compared with 37,269 mg, Table 3Go). Daily emission of NH3 adjusted for total live weight from hens fed the RE diet (203.4 mg/kg of BW) was less than daily emissions of NH3 from hens fed the CM diet (334.1 mg/kg of BW).


View this table:
[in this window]
[in a new window]

 
Table 3. Average daily NH3 emissions over a 3-wk period from laying hens of different ages fed the reduced emission (RE) diet and the commercial (CM) diet
 
An age effect existed for the emission of NH3 from laying hens. Emissions of NH3 from the 21-wk age group (277.0 mg/hen, Table 3Go) were less than from the 38-wk (402.1 mg/hen) and the 59-wk (447.5 mg/hen) age groups. Age differences may have been caused by environmental factors that reduced the airflow, and, therefore, emission, because the 21-wk-old hens were fed during April and May, whereas the other age groups were fed in warmer months (June through early September). This is supported by the lack of an age effect for NH3 concentration (Table 3Go) but is difficult to confirm based on the H2S data reported (Table 4Go). A significant interaction between diet and age was observed, because feeding the RE diet to the 21-wk-old hens resulted in less reduction in NH3 emissions, compared with the CM diet, than was observed in the other 2 age groups.


View this table:
[in this window]
[in a new window]

 
Table 4. Average daily H2S emissions over a 3-wk period from laying hens of different ages fed the reduced emission (RE) diet and the commercial (CM) diet
 
The large reduction in NH3 emissions that was observed in the current study is the result of a combined effect of including a diet acidulant (CaSO4), a binding material (zeolite), and offering a slightly reduced protein content in the diet. The diet acidulant was likely the single largest contributor to the reduced emissions, based on studies conducted by others. Hale (2005) reported that using CaSO4 as a substitute for a portion of the limestone in laying hens diets reduced pH of the manure from about 8.3 standard units to a slightly acidic pH (<7 standard units) level with a concurrent 15% reduction in NH3 emissions from manure. Kim et al. (2004) found that an acidogenic Ca and P source (CaSO4-H3PO4) in swine diets could decrease the urinary pH and reduce NH3 emission by 30% from swine facilities. Nakaue and Koelliker (1981) evaluated zeolites first as a broiler-feed additive and found that incorporation of 10% clinoptilolite (1 type of zeolite) to the feed of the birds throughout their lifetime reduced aerial NH3 concentration by up to 8% in one study, but the reverse was observed in a second study. These findings are in agreement with several other researchers using zeolites as a feed additive (Airoldi et al., 1993; Cabuk et al., 2004). Kerr et al. (1995) suggested that for every 1 percentage unit decrease in dietary protein offered, a 10% decrease in NH3 emissions could be expected. In the current study, the decrease in protein content of the RE diets was not exceptionally large (1.5 to 2.5 percentage units) and, alone, would not be expected to produce the magnitude of effect observed.

Heber et al. (2004) measured emissions from a modern high-rise egg laying house using a chemiluminescence method along with multipoint extractive gas sampling and found that the average daily means of NH3 concentrations were 2.4, 16.1, and 43.3 mg/m3 for inlet, cage, and exhaust air, respectively, and the net NH3 emission rate was 387 ± 25 kg/d or 1.57 ± 0.10 g/d per hen. Liang et al. (2005) reported an annual average NH3 emission rate of 0.87 ± 0.29 g/d per hen for the high-rise houses, 0.094 ± 0.062 g/d per hen for the manure-belt houses with semiweekly manure removal, and 0.054 ± 0.026 g/d per hen for the manure-belt houses with daily manure removal. In the current study, NH3 emissions were determined in chambers over a 3-wk period with manure accumulation for the duration of the test period. Average NH3 emission was 0.47 ± 0.03 g/d per hen when fed a CM diet, which was lower than the value reported by Liang et al. (2005) for high-rise houses but greater than reported values for houses employing a manure belt. This suggests that had the experimental period been longer than 3 wk, average daily NH3 emissions may have been more similar to emissions reported from high-rise housing.

H2S Emissions
Daily H2S emissions from hens fed the RE diet (1.6, 7.1, and 3.7 mg/hen) were greater than from hens fed the CM diet (0.5, 1.9, and 0.8 mg/hen) at 21, 38, and 59 wk of age, respectively (Table 4Go). Feeding the RE diet also increased the cumulative H2S emission mass 3-fold across all 3 age groups (322.8 vs. 104.9 mg). Daily H2S emission adjusted for total live weight from hens fed the RE diet (2.9 mg/kg of BW) was more than that from hens fed the CM diet (0.9 mg/kg of BW). Lim et al. (2003) reported H2S emissions from high-rise laying hen houses of 0.432 mg/kg of BW, which is about half of the emission observed in the current study when hens were fed the CM diet. Differences are likely due to the amount of time that excreta had been stored. Although H2S emissions increased 3-fold as a result of feeding the RE diet, the increase was not to the extent that most laying hen operations would trigger federal reporting requirements. Over 10 million hens would be needed on a single site for those reporting requirements to be exceeded.

Whitney et al. (1999) found that a mean reduction of 23% in the S concentration of nursery pigs diets during a 5-wk period tended to reduce H2S emissions from the stored manure, although this tendency was not significant. It was shown by J. Shurson, M. Whitney, and R. Nicolai (Univ. Minnesota, St. Paul, personal communication) that S excretion was reduced by 30%, by selecting low-S feed ingredients, without affecting their growth. In the current study, CaSO4, a S-containing compound, was added to the diet as an acidifying agent. This additional dietary S combined with the acidifying effect of the CaSO4 likely caused the increased H2S production. Because feed is ultimately the major source of manure S, 1 method of mitigating manure H2S emissions is to reduce dietary S. This can be done by reducing excess nutrients, selecting low-S ingredients, or including additives that improve digestive efficiency or alter the microflora in the large intestine (Clark et al., 2005). In addition, a reduction in pH from pH 7.0 to 6.0 has been shown to result in a doubling of the proportion of molecular H2S (Xue et al., 1998). Use of a dietary acidulant in the current study contributed to increased S emissions, suggesting that alternative acidulants should be considered to avoid exacerbating sulfurous emissions.

CH4 Emissions
Across ages, feeding the RE diet reduced daily CH4 emission (mg/hen) by 17% (Table 5Go). Daily emissions from hens fed the RE diet (66.4 mg/hen) were less than emissions from hens fed the CM diet (80.2 mg/hen). Across ages, the RE diet decreased the daily emission rate of CH4 emitted (3.8 and 4.6 mg/min for RE and CM diets, respectively; Table 5Go). The RE diet also reduced the cumulative CH4 emission mass (5,272 vs. 6,394 mg/d for RE and CM diets, respectively; Table 5Go). Daily emission adjusted for total live weight of hens housed in each chamber from hens fed the RE diet (47.1 mg/kg of BW) was less than daily emission from hens fed the CM diet (57.1 mg/kg of BW). Twenty-one-week-old hens produced greater emissions of CH4 than did 38- and 59-wk-old hens when CH4 emissions are expressed on a per bird and per kilogram of BW basis. Although the reason for this is not evident, it does follow the same pattern as NH3 emissions, except that in the case of CH4, concentration is greater for the 21-wk old hens compared with both the 38- and 59-wk-old hens. No data are available to support differences in cecal fermentation patterns among hens of different ages, but differences, if they did exist, could explain the effect on CH4 production.


View this table:
[in this window]
[in a new window]

 
Table 5. Average daily CH4 emissions over a 3-wk period from laying hens of different ages fed the reduced emission (RE) diet and the commercial (CM) diet
 
Methane along with N2O and CO2 are the primary greenhouse gasses produced by agriculture (Phetteplace et al., 2001). Hilhorst et al. (2001) concluded that CH4 production has an optimal pH near 7 and proposed manure acidification as 1 mitigation strategy to reduce CH4 emissions. Misselbrook et al. (1998) demonstrated that slurry from pigs fed a reduced-protein diet had a higher DM content and lower pH and volatile fatty acid (VFA) content with a similar total C content compared with slurry from pigs fed a standard CM diet. They also concluded that CH4 emissions were better related to VFA content than to total C content, with less CH4 emitted from the slurry from pigs fed the lower CP diet. Kim et al., (2004) found that an acidogenic Ca and P source (CaSO4-H3PO4) in swine diets could decrease the urinary pH and reduce CH4 emission by 14% from swine facilities. In the current study, a reduction in manure pH or perhaps reduced manure VFA could explain the observed 17% reduction in CH4 emissions from hens fed the RE diet compared with hens fed the control diet. Koerkamp et al. (1998) reported that CH4 emission was 0.03 kg/year per kilogram of BW from laying hens housed in cages or free-range hens.

CO2 Emissions
Daily CO2 emissions from hens fed the RE diet (74,548 mg/hen) were less than from hens fed the CM diet (78,432 mg/hen; Table 6Go), as was daily emission adjusted for total live weight in the chamber (53,013 mg/kg of BW and 55,900 mg/kg of BW for hens fed the RE diet and the CM diet, respectively; Table 6Go).


View this table:
[in this window]
[in a new window]

 
Table 6. Average daily CO2 emissions over a 3-wk period from laying hens of different ages fed the reduced emission (RE) diet and the commercial (CM) diet
 
Keshavarz (1991) demonstrated that dietary acid-base balance plays an important role in hen performance by demonstrating that high dietary levels of acidogenic anions such as CaSO4 altered blood acid-base balance and could affect respiration rate, resulting in more CO2 production to maintain normal pH. In the current study, CaSO4 was added to the diet as an acidifying agent, which may change the cation-anion balance of the diet. However, the reduction in CO2 emissions from hens fed the RE diet contradicts the idea that feeding CaSO4 would increase respiration rate and therefore result in greater CO2 production in an attempt to maintain normal pH.

NO and NMTHC
Daily NO emissions from hens fed the RE diet (0.2 mg/hen) were less than NO emissions from hens fed the CM diet (0.4 mg/hen; Table 7Go). No age effects were observed (Table 7Go). No diet or age effects on emissions of NO2 (Table 8Go) and NMTHC (Table 9Go) were observed in the current study. No data for these emissions were found in the literature for comparative purposes.


View this table:
[in this window]
[in a new window]

 
Table 7. Average daily NO emissions over a 3-wk period from laying hens of different ages fed the reduced emission (RE) diet and the commercial (CM) diet
 

View this table:
[in this window]
[in a new window]

 
Table 8. Average daily NO2 emissions over a 3-wk period from laying hens of different ages fed the reduced emission (RE) diet and the commercial (CM) diet
 

View this table:
[in this window]
[in a new window]

 
Table 9. Average daily non-CH4 total hydrocarbon emissions over a 3-wk period from laying hens of different ages fed the reduced emission (RE) diet and the commercial (CM) diet
 
In summary, this study suggests that diet and layer age influence air emissions from laying hen feeding operations. A plausible means of reducing emissions of NH3 and CH4 from laying hen houses is through a dietary mitigation strategy of feeding a reduced-CP diet combined with an acidifying feed additive (CaSO4) and an adsorbent additive (zeolite). However, in the current study, because the acidulant fed contributed to additional dietary S, increased H2S production was observed. Further research is needed to find a better acidifying feed additive or to determine an effective dose that minimizes increases in S emissions.


    ACKNOWLEDGMENTS
 
This material is based upon work supported by the National Research Initiative Air Quality Program of the Cooperative State Research, Education, and Extension Service, USDA, under agreement no. 2005-35112-15356 and funding received by the Iowa Egg Council (Urbandale). We would also like to thank Sarah Zamzow and Martha Jeffrey for their laboratory assistance during the course of this project.

Received for publication June 19, 2006. Accepted for publication August 22, 2006.


    REFERENCES
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 REFERENCES
 
Airoldi, G., P. Balsari, and R. Chiabrando. 1993. Odour control in swine houses by the use of natural zeolites: First approach to the problem. Pages 701–708 in Livestock Environment IV. E. Collins and C. Boon, ed. ASAE, St. Joseph, MI.

Cabuk, M., A. Alcicek, M. Bozkurt, and S. Akkan. 2004. Effect of yucca schidigera and natural zeolite on broiler performance. Int. J. Poult. Sci. 10:651–654.

Clark, O. G., B. Morin, Y. H. Zhang, W. C. Sauer, and J. R. Feddes. 2005. Preliminary investigation of air bubbling and dietary sulfur reduction to mitigate hydrogen sulfide and odor from swine waste. J. Environ. Qual. 34:2018–2023.[Abstract/Free Full Text]

Elwinger, K., and L. Svensson. 1996. Effect of dietary protein content, litter, and drinker type on ammonia emission from broiler houses. J. Agric. Res. 64:197–208.

Hale, E. C. 2005. Reduction of ammonia emission and phosphorus excretion in laying hen manure through feed manipulation. Symp. State Sci.: Anim. Manure Waste Manage., San Antonio, TX. North Carolina State Univ., Raleigh.

Heber, A. J., T. Lim, and J. Ni. 2004. Air emissions from layer houses. Poult. Sci. 83(Suppl.1):191.

Hilhorst, M. A., H. C. Willers, C. M. Groenestein, and G. J. Monteny. 2001. Effective strategies to reduce methane emissions from livestock. 2001 ASAE Annu. Int. Meet., Sacramento, CA. ASAE, St. Joseph, MI.

Hy-Line International. 2003. Hy-Line W-36 Commercial Management Guide. Hy-Line Int., West Des Moines, IA.

Kerr, B. J., F. K. McKeith, and R. A. Easter. 1995. Effect on performance and carcass characteristics of nursery to finisher pigs fed reduced crude protein, amino acid-supplemented diets. J. Anim. Sci. 73:433–440.[Abstract]

Keshavarz, K. 1991. The effect of calcium sulfate (gypsum) in combination with different sources and forms of calcium carbonate on acid-base balance and eggshell quality. Poult. Sci. 70:1723–1731.

Keshavarz, K. 2003. The effect of different levels of non-phytate phosphorus with and without phytase on the performance of four strains of laying hens. Poult. Sci. 82:71–91.[Abstract/Free Full Text]

Kim, I. B., P. R. Ferket, W. J. Powers, H. H. Stein, and T. A. T. G. VanKempen. 2004. Effects of different dietary acidifier sources of calcium and phosphorus on ammonia, methane and odorant emission from growing-finishing pigs. Asian-australas. J. Anim. Sci. 17:1131–1138.

Koerkamp, P. W. G. G., L. Speelman, and J. H. M. Metz. 1998. Litter composition and ammonia emission in aviary houses for laying hens. 1. Performance of a litter drying system. J. Agric. Eng. Res. 70:375–382.

Liang, Y., H. Xin, H. Li, E. F. Wheeler, R. S. Gates, J. S. Zajaczkowski, P. Topper, K. D. Casey, and F. J. Zajaczkowski. 2005. Ammonia emissions from U.S. laying houses in Iowa and Pennsylvania. Trans. ASAE 48:1927–1941.

Lim, T. T., A. J. Heber, and J. Q. Ni. 2003. Air quality measurements in a laying hen house: Odor and hydrogen sulfide. Pages 273–282 in Proc. Int. Symp. Gaseous Emissions Anim. Prod. Facil., Horsens, Denmark. CIGR, Bonn, Germany.

McCrory, D. F., and P. J. Hobbs. 2001. Additives to reduce ammonia and odor emissions from livestock wastes: A review. J. Environ. Qual. 30:345–355.[Abstract/Free Full Text]

Misselbrook, T. H., D. R. Chadwick, B. F. Pain, and D. M. Headon. 1998. Dietary manipulation as a means of decreasing N losses and methane emissions and improving herbage N uptake following application of pig slurry to grassland. J. Agric. Sci. 130:183–191.

Nakaue, H. S., and J. K. Koelliker. 1981. Studies with clinoptilolite in poultry. I. Effect of feeding varying levels of clinoptilolite (zeolite) to dwarf Single Comb White Leghorn pullets and ammonia production. Poult. Sci. 60:944–949.

National Research Council. 1994. Nutrient Requirements of Poultry. 9th ed. NRC, Washington, DC.

Phetteplace, H. W., D. E. Johnson, and A. F. Seidl. 2001. Greenhouse gas emissions from simulated beef and dairy livestock systems in the United States. Nutr. Cyc. Agroecosys. 60:99–102.

SAS Institute. 1990. SAS User’s Guide: Statistics. Version 6.3 ed. SAS Inst. Inc., Cary, NC.

Whitney, M. H., R. Nicolai, and G. C. Shurson. 1999. Effects of feeding low sulfur starter diets on growth performance of early weaned pigs and odor, hydrogen sulfide, and ammonia emissions in nursery rooms. J. Anim. Sci. 77(Suppl. 1):70.[Abstract/Free Full Text]

Xue, S. K., S. Chen, and R. E. Hermanson. 1998. Measuring ammonia and hydrogen sulfide emitted from manure storage facilities. Trans. ASAE 41:1125–1130.




This article has been cited by other articles:


Home page
Poult. Sci.Home page
T. Applegate, W. Powers, R. Angel, and D. Hoehler
Effect of Amino Acid Formulation and Amino Acid Supplementation on Performance and Nitrogen Excretion in Turkey Toms
Poult. Sci., March 1, 2008; 87(3): 514 - 520.
[Abstract] [Full Text] [PDF]


Home page
Poult. Sci.Home page
W. Wu-Haan, W. J. Powers, C. R. Angel, C. E. Hale III, and T. J. Applegate
Nutrient Digestibility and Mass Balance in Laying Hens Fed a Commercial or Acidifying Diet
Poult. Sci., April 1, 2007; 86(4): 684 - 690.
[Abstract] [Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wu-Haan, W.
Right arrow Articles by Applegate, T. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wu-Haan, W.
Right arrow Articles by Applegate, T. J.


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS