1. In a pen study, NH
3
flux estimates were performed when clean wheat straw or wood shavings were used as bedding materials in combination with two NH
3
control amendments: sodium bisulphate and a ...commercial premix of phosphoric + hydrochloric + citric acids.
2. Ammonia emissions from wood shavings were 19% greater than from wheat straw around waterers, but statistically similar around feeders. These results could be due to the greater caking observed when wheat straw was used.
3. Sodium bisulphate reduced NH
3
emissions significantly only in the first half of the rearing period; the loss of efficacy in the second half resulted in total NH
3
volatilisation not statistically different from the untreated control. The treatment containing phosphoric + hydrochloric + citric acids did not have a significant effect in decreasing NH
3
emissions.
4. Bird mortality was not affected by the treatments, but broiler weight gain when wheat straw was used was significantly lower than with wood shavings, which could have been caused by the greater caking observed with wheat straw.
SUMMARY
Biomasses such as peanut hulls or tree clippings have the potential for use in the production of chars, which can in turn be used as tools for environmental improvements. The purpose of this ...study was to evaluate the effectiveness of chars on reducing NH3 volatilization from poultry litter when used as a surface-applied treatment. The chars used were produced from 3 biomasses: peanut hulls, pine chips, and coconut husks. Peanut hull char (pH 9.2) was produced by pyrolyzing peanut hulls at 400°C for 30 min. The pine chip and coconut husk chars were acidified with sulfuric acid at a final concentration of 53% and had a pH of 2.0. Application rates were 0, 0.24, 0.37 + 0.37, and 0.73 kg/m2 to the floor of pens containing broilers at a commercial density (0.07 m2/bird). The addition of peanut hull char did not reduce NH3 concentrations in the air compared with untreated pine shavings bedding material. However, the use of acidified chars resulted in significant linear reductions in NH3 concentrations. The reduction in NH3 by the acidified chars was likely due to a combination of litter pH reduction and NH3 immobilization by the H2SO4 on the char. Bird performance was not adversely affected by any of the char treatments.
Near-Infrared Reflectance Spectroscopy (NIRS) offers advantages over gravimetric water content and dry combustion nitrogen determinations that could be significant for routine laboratory operations. ...Water content in ground and blended poultry litter samples was successfully estimated by NIRS, but total nitrogen predictions differed significantly from measured ones. The failure to predict total nitrogen could be related to the unspecific nature of the relation and to the quality of the data used for calibration. Additionally, a model was established that permits the estimation of water content in poultry litter in its original state from that measured after grinding and blending.
In the laboratory, excessive variability in molybdate reactive phosphorus (MRP) concentrations in water extracts of poultry litter that appeared to be associated with storage by freezing was ...frequently observed. In one experiment, repeated twice, the effects of a factorial combination of storage temperatures freezing (-16 to -15 degrees C) or room temperature (21-24 degrees C) was studied for 60-62 h with poultry litter type (three broiler and one pullet) on MRP concentrations in water extracts. An additional experiment was conducted to compare the effects on phosphorus (P) concentration of a 1 mg P L(-1) standard of spiking with 1 mg L(-1) of Fe(+3) or Al(+3) and storage under room temperature or freezing for two and five days. No statistical differences were observed in MRP levels of extracts kept at room temperature measured immediately after the extraction, after 62 h or eight days. Freezing, however, consistently decreased MRP concentrations measured immediately after thawing compared to measurements in extracts kept at room temperature. Reductions ranged from less than 1% to 46%, depending on poultry litter composition, especially total iron (Fe) and aluminum (Al) concentrations. Freezing effects were reversible and after five days MRP concentrations were comparable to those of extracts kept always at room temperature. Spiking with Al(+3) did not affect P solubility but spiking with Fe(+3) and freezing for five days reduced the MRP concentrations in the P standard when measured immediately or two days after thawing. The results from the P, Fe(+3), and Al(+3) experiment plus the observation of precipitates containing P and Fe in some of the poultry litter extracts suggested complexing between these elements as a partial explanation of these responses. Organic compounds and Al(+3) might also be involved. The solubilization of the floccules upon thawing might be retarded by changes induced by freezing. In consequence, freezing of water extracts of poultry litter can bring about significant, albeit transient, decreases in soluble orthophosphate concentrations.
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