Broiler Litter Samples Research Articles

Non-thermal technologies for broiler litter processing: Microbial safety, chemical composition, nutritional value, and fermentation parameters in vitro.

Annually, a massive amount of broiler litter (BL) is produced in the world, which causes soil and surface water pollution due to its high nitrogen content and microbial count. While ruminants can use this non-protein nitrogen (NPN) source for microbial protein synthesis. This issue becomes more critical when protein sources are unavailable or very expensive. One of the sources of NPN is BL which is produced at a considerable amount in the world yearly. This aim of this research was to conduct a survey of non-thermal technologies such as electrocoagulation (EC), ultraviolet (UV) radiation, and ultrasound (US) waves on the microbial safety and nutritional value of BL samples as a protein source in ruminant diets. The methodology of this study was based on the use of an EC device with 24V for 60min, UV-C light radiation (249nm) for 1 and 10min, and US waves with a frequency of 28kHz for 5, 10 and 15min to process BL samples compared with shade-dried samples. Chemical composition and nutritional values of processed samples were determined by gas production technique and measurement of fermentation parameters in vitro. Based on the results, microbial safety increased in the samples processed with the US (15min). The EC method had the best performance in reducing the number of fungi and mould. However, none of the methods could remove total bacteria and fungi. Digestibility of BL was similar in shade-dried, EC, and US (10min) treatments. In general, the use of EC and US15 without having adverse effects on gas production caused a decrease in the concentration of ammonia nitrogen. In contrast, it caused a decrease in neutral detergent fibre (NDF) in the investigated substrate. In general, it can be concluded that the use of US5 and EC methods without having a negative effect on the parameters of gas production and fermentation in vitro, while reducing NDF, causes a significant reduction in the microbial load, pathogens, yeast, and mould. Therefore, it is suggested to use these two methods to improve feed digestibility for other protein and feed sources.

Microbial Community and Abundance of Selected Antimicrobial Resistance Genes in Poultry Litter from Conventional and Antibiotic-Free Farms.

In this study, a culture-independent approach was applied to compare the microbiome composition and the abundance of the antimicrobial resistance genes (ARGs) aadA2 for aminoglycosides, tet(A), tet(B), tet(K), and tet(M) for tetracyclines, and mcr-1 for colistin in broiler litter samples collected from conventional and antibiotic-free flocks located in Central Italy. A total of 13 flocks and 26 litter samples, collected at the beginning and at the end of each rearing cycle, were submitted to 16s rRNA sequence analysis and quantitative PCR for targeted ARGs. Firmicutes resulted in the dominant phylum in both groups of flocks, and within it, the Clostridia and Bacilli classes showed a similar distribution. Conversely, in antibiotic-free flocks, a higher frequency of Actinobacteria class and Clostridiaceae, Lactobacillaceae, Corynebacteriaceae families were reported, while in the conventional group, routinely treated with antibiotics for therapeutic purposes, the Bacteroidia class and the Enterobacteriaceae and Bacillaceae families were predominant. All investigated samples were found to be positive for at least one ARG, with the mean values of aadA2 and tet(A) the highest in conventional flocks by a significant margin. The results suggest that antibiotic use can influence the frequency of resistance determinants and the microbial community in poultry flocks, even though other environmental factors should also be investigated more deeply in order to identify additional drivers of antimicrobial resistance.

First report of multidrug-resistant Salmonella Infantis in broiler litter in Tolima, Colombia.

Background and Aim:Salmonella has been identified as one of the most widely distributed zoonotic pathogens in broiler litter. Multidrug-resistant strains have been isolated from salmonellosis outbreaks, compromising the success of their treatment. This study aimed to isolate and identify Salmonella spp. serovars in healthy broiler litter in Tolima (Colombia), determine their resistance to different antimicrobials, and detect genes associated with b-lactam resistance that could be useful to control Salmonella spp. in poultry.Materials and Methods:In total, 45 broiler litter samples were collected. Salmonella spp. was isolated and identified using selective and differential culture media and biochemical tests. Molecular confirmation of the pathogen was performed with the invA gene and serotyping by Kauffman–White scheme. Antimicrobial susceptibility to 15 antibiotics was determined by Kirby–Bauer method. In cefotaxime-resistant strains, blaCTX-M-F, blaCTX-M-1, blaCMY, and blaTEM genes were evaluated by polymerase chain reaction (PCR).Results:In total, 817 presumptive strains were obtained from xylose lysine deoxycholate and Salmonella Shigella agars and subcultured on xylose-lysine-tergitol 4 and MacConkey agars, from which 150 strains were isolated; 29 of these strains were presumptive for Salmonella spp. after performing biochemical tests and 16 were confirmed by PCR as Salmonella Infantis (15) and Gallinarum (1). All strains were found to be multiresistant to antibiotics, showing three different profiles and isolates resistant to cefotaxime, and the blaCTX-M gene was detected.Conclusion:This is the first study to isolate S. Infantis from broiler litter in Colombia. All isolates exhibited resistance to the evaluated antimicrobials, suggesting the misuse of antimicrobials in small- and medium-sized poultry farms. The presence of Salmonella enterica serovar Infantis is a public health problem. Thus, regular monitoring of poultry litter is recommended, as these bacteria can be transmitted to humans through animal products or contaminated environments.

Association of Broiler Litter Microbiome Composition and Campylobacter Isolation.

Infection with Campylobacter species is one of the leading causes of bacterial diarrhea in humans in the US. Chickens, which become colonized on the farm, are important reservoirs of this bacterium. Campylobacter can establish itself in the broiler house via a variety of sources, can survive in the litter of the house, and possibly persist over successive flock cycles. However, the role of the broiler litter microbiome on Campylobacter persistence is not clear. A matched case-control study was conducted to determine whether the broiler litter microbiome composition was associated with Campylobacter isolation within the broiler house. Flocks were classified as cases when either Campylobacter jejuni or Campylobacter coli was isolated in boot sock samples, or as controls otherwise. Case and control flocks were matched at the broiler house level. Composite broiler litter samples were collected and used for DNA extraction and 16S rRNA gene V4 region sequencing. Reads were processed using the DADA2 pipeline to obtain a table of amplicon sequence variants. Alpha diversity and differential bacterial relative abundance were used as predictors of Campylobacter isolation status in conditional logistic regression models adjusting for flock age and sampling season. Beta diversity distances were used as regressors in stratified PERMANOVA with Campylobacter isolation status as predictor, and broiler house as stratum. When Campylobacter was isolated in boot socks, broiler litter microbiome richness and evenness were lower and higher, respectively, without reaching statistical significance. Campylobacter isolation status significantly explained a small proportion of the beta diversity (genus-level Aitchison dissimilarity distance). Clostridium and Anaerostipes were positively associated with Campylobacter isolation status, whereas Bifidobacterium, Anaerosporobacter, and Stenotrophomonas were negatively associated. Our results suggest the presence of bacterial interactions between Campylobacter and the broiler litter microbiome. The negative association of Campylobacter with Bifidobacterium, Anaerosporobacter, and Stenotrophomonas in litter could be potentially exploited as a pre-harvest control strategy.

NEW DRUGS AGAINST OOCIST OF COCKIDIA IN BIRDS – VIRUKILL 260

The production culture in industrial poultry has risen to a high level and continues to improve in recent years. Profitability of production is the main task of poultry farming, as for any industrial branch. This is due to the intensification of production, a reduction in the period of sanitary preparation of premises, and a high concentration of poultry stock on a limited area. These conditions contribute to the spread of parasitic diseases and eimeriosis is the leading among them. The experiments were carried out on 14-day-old Cobb-500 cross broiler chickens in the laboratory and vivarium of the institute in 2019. First, Virukill 260 working solutions in different concentrations, WSH buffer solution, and bird feces preservative were prepared. Virukill is a multicomposite drug in the form of a liquid, this medicine is used to disinfect and disinfestation objects of veterinary surveillance and the prevention of infectious and invasive animal diseases. Chickens of the first, second and third groups were assigned 1 ml of a suspension of Eimeria oocysts treated with 0.5; 1 and 2% solutions of the drug Virukill 260, inside using a micropipette; the fourth - also 1 ml of a suspension of Eimeria oocysts treated with a 4% phenol solution. Young animals of the fifth group were injected with sporulated Eimeria oocysts at a dose of 2000 / ml of a suspension not treated with a disinfectant (infected control); and the sixth - only 1 ml of WSH buffer solution (uninfected control). The chickens were subjected to daily clinical observations, taking into account the general condition, behavior, appetite, visible physiological changes throughout the experiment. The intensity of Virukill 260 in 0.5-, 1- and 2% concentrations against coccidium oocysts was 94.15; 97.6 and 98.17%, respectively, and phenol at 4% concentration was 88.75%. The following Eimeria species were identified: Eimeria acervulina (21.4%), E. brunetti (15.7%), E. maxima (29.6%) and E. tenella (33.3%) in broiler litter samples from the first to the fifth group.

Selection of indigenous indicator micro-organisms for validating desiccation-adapted Salmonella reduction in physically heat-treated poultry litter.

The thermal resistance of desiccation-adapted Salmonella Senftenberg 775/W was compared with those of indigenous enterococci and total aerobic bacteria in poultry litter. Aged broiler litter and composted turkey litter with 20, 30, 40 and 50% moisture contents were inoculated with desiccation-adapted Salm. Senftenberg 775/W, and then heat-treated at 75 and 85°C. Compared to total aerobic bacteria, there were better correlations between mean log reductions of desiccation-adapted Salm. Senftenberg 775/W and indigenous enterococci in broiler litter samples with 20, 30, 40 and 50% moisture contents at 75°C (R2 >0·91), and 20, 30 and 40% moisture contents at 85°C (R2 >0·87). The mean log reductions of Salm. Senftenberg 775/W were better correlated with those of indigenous enterococci in turkey litter samples with 20, 30, 40 and 50% moisture contents at 75°C (R2 >0·88), and 20 and 30% moisture contents at 85°C (R2 =0·83) than those of total aerobic bacteria, which had a better correlation in turkey litter sample with 40% (R2 =0·98) moisture content at 85°C. Indigenous enterococci may be used to validate the thermal processing of poultry litter, as it predicts the survival behaviour of Salmonella under some treatment conditions. This study provides some scientific data for poultry litter processors when validating the effectiveness of thermal processing.

Phytate Quantification using HPIC in the Presence of Iron and Aluminum

Phytate is an organic form of P that is difficult to analyze in complex matrices. To test if high concentrations of aluminum (Al) and iron (Fe) hinder accurate quantification of phytate in dairy manure and broiler litter when measured by high-performance ion chromatography (HPIC), researchers spiked dairy manure and broiler litter samples with Al, Fe, and phytate. Samples were alkaline extracted, acidified, and filtered, and then phytate spike recovery was analyzed with HPIC. High concentrations of Fe did not hinder phytate recovery in manure or litter samples. While phytate recovery was complete at typical manure and litter Al concentrations, high concentrations of Al inhibited phytate recovery in litter samples and in some manure samples. Overall, alkaline extraction of dairy manure and broiler litter and analysis with HPIC proved to be relatively accurate, fast, and cheap within normal Al and Fe ranges, compared to the commonly used nuclear magnetic resonance (NMR) method.

Capacitance and near-infrared techniques for the real-time moisture measurement of broiler litter

The feasibility of capacitance and near-infrared (NIR) techniques for measuring the real-time moisture content (MC) of broiler litter was evaluated. Data collection consisted of recording differential voltage signal and spectral absorption values (1200–2200 nm) for a capacitance and a NIR sensor, respectively, for broiler litter samples within 19.3%–75.1% d.b. (16.2%–42.9% w.b.) MC. Initial data analysis indicated that litter density impacted the capacitance sensor voltage. The sensor generated a linear response between 19.3% and 45.8% d.b. MC at the given bulk density (BD) and the operating moisture range further decreased as the litter BD increased. NIR data analysis indicated that the absorption bands within the 1400–1440 nm and 1900–1950 nm wavelength regions were highly correlated to the litter MC. Linear regression models relating the output data (differential voltage and absorption spectral values for capacitance and NIR, respectively) to the litter MC exhibited a high linear correlation (R2 = 0.89–0.99). Model validation results also generated high correlation values (R2 = 0.87–0.95) between the predicted and measured MC's. Overall results suggested that the NIR technique performed better than the capacitance technique because of its ability to provide rapid, non-intrusive and density-independent measurements within the selected moisture range. The NIR technique is recommended for future real-time moisture measurement on litter conveying and application equipment.

Evaluation of different selective media and culturing techniques for the quantification of Campylobacter ssp. from broiler litter

Poultry is a major reservoir for Campylobacter, the leading cause of foodborne illness in the United States, but how broilers become initially colonized is still under debate. Broiler litter is a potential source, but the best technique for quantifying Campylobacter from litter is still unknown. Therefore, our objectives were to determine if certain media are more selective for quantifying Campylobacter and if enrichment allows for the detection of stressed or viable but nonculturable cells from broiler litter samples. In this trial, 5 media and 2 culturing techniques were used to enumerate Campylobacter from broiler litter. The media used were campy-Line agar (CLA), campy-cefex agar (CCA), modified CCA, Campylobacter agar plates (CAP), and modified charcoal cefoperazone deoxycholate agar. Litter samples were obtained from a commercial broiler house. Each sample was equally divided and diluted 10-fold into peptone, for direct plating, or 4-fold into Campylobacter enrichment broth. Samples diluted in peptone were direct-plated onto each media and incubated under microaerophilic conditions for 48 h at 42 degrees C. Samples diluted in enrichment broth were incubated under the same conditions for 24 h, then further diluted to 10-fold before plating. Plates from enriched samples were incubated for an additional 24 h after plating. After incubation, all plates (direct and enriched) were counted and presumptive positive colonies were confirmed using a Campylobacter latex agglutination kit. Results indicated that there was no difference in the ability of any of the selective media tested to grow Campylobacter. Direct-plated samples had a higher Campylobacter isolation rate compared with enriched samples. The CLA and CAP were able to suppress total bacterial growth better than modified charcoal cefoperazone deoxycholate, modified CCA, and CCA. The CLA and CAP were the only media able to detect total bacterial population shifts over time. In conclusion, it is important before making a final decision on a selective medium to consider the medium's ability to suppress total bacterial growth as well as isolate Campylobacter.

Nitrogen Values of Liquid Dairy Manure and Dry Broiler Litter as Affected by Preservation Treatment

Liquid dairy manure and dry broiler litter samples were laboratory tested to determine the effects of four preservation techniques on the form and concentration of nitrogen. 300-mL samples of fresh manure from Virginia dairy and poultry farms were analyzed for total Kjeldahl, ammonium, and nitrate/nitrite nitrogen within 24 h of farm sampling and at the end of seven days. The four preservation techniques considered were storage of the samples; (i) at ambient temperature (26C), (ii) by refrigeration (4C), (iii) by freezing (-22C), and (iv) by acidification with concentrated sulfuric acid (H2SO4) to pH < 2 plus refrigeration (4C). Organic and inorganic nitrogen concentrations from the preserved manures were compared to the corresponding fresh concentrations of nitrogen in each manure control. Ambient storage, refrigeration, and freezing did not significantly affect (a = 0.05) the seven-day nitrogen concentration of the 10 manures tested. Acidification reduced most N concentrations due to the aggressive physical action of the acid, which accelerated both mineralization of organic N and volatilization of ammonia. Conclusions of this study indicate ambient storage as the most practical nitrogen preservative technique for liquid dairy manure and dry poultry litter.

Dietary Quality and Safety in the Reuse of Broiler Litter as a Feed Ingredient through Fermentation and Pelleting

Suppadit, T., Parukatpichai, K. and Talakhun, N. 2008. Dietary quality and safety in the reuse of broiler litter as a feed ingredient through fermentation and pelleting. J. Appl. Anim. Res., 33: 109–112. To modify broiler litter (BL) by fermentation and/or pelleting as a feed ingredient, BL samples were collected from twenty randomly selected farms in Saraburi province, Thailand in December, 2006. All the farms used rice husks as the bedding materials. Prior to and after the modifications, the nutritive values and health risks were assessed. After fermentation, most of the nutrient contents tended to decrease (P<0.05). By contrast, moisture and gross energy content increased (P<0.05). Pelleting did not alter the nutrient content of the BL. Parasites, aflatoxins and antibiotics were not found in any BL samples. Pathogenic microorganisms, heavy metals and sodium chloride were detected in all samples. All pathogens and heavy metals decreased after processing. In conclusion, fermentation followed by pelleting could eliminate health risks and increase the potential scope for utilizing BL as an animal feed.

Application of Near‐Infrared Reflectance Spectroscopy to Estimate Chemical Constituents in Broiler Litter

Near‐infrared reflectance spectroscopy (NIRS) has potential to provide rapid estimates of phosphorus (P) and nitrogen (N) concentrations in broiler litter to assist managers in establishing application rates of litter to grazing lands that fall within productive and environmentally safe levels. An experiment was conducted to determine accuracy of NIRS estimates of moisture, P, N, and acid detergent fiber (ADF) concentrations in broiler litter. Broiler litter samples were collected from various farms to develop sample sets that were either with or without bedding material, and each sample set was subdivided into processed (i.e., dried and ground) and unprocessed samples to develop local equations for each constituent. Equations were developed by using all samples from each set and using samples following random removal of 20% of total for equation validation. Moisture was determined to be accurately measured by using NIRS based on a high R2 (≥0.96), low SEC (<10 g kg−1), and high sx/SECV (>5.0). ADF also had a high R2 (0.96), but the Sx/SEC (3.00) value was too low for the equation to be considered truly accurate. Estimations of P and N by calibrations that included all samples had a moderate to high R2 values, but estimations for the validation set were relatively low in R2 (≤0.78) and Sx/SEC (≤2.00). Concentrations of P and N were not estimated by NIRS with a high degree of accuracy, but other methodologies could enhance the usefulness of this technology to rapidly provide these nutrient measures. Mention of trade names or commercial products in the article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.

Evaluation of an additive efficacy in broiler litter microbial level control in field: preliminary results

The present study was conducted to evaluate in field the efficacy of an additive (SOP® C POULTRY), as an agent for the control of micro-organisms in broiler litter. The Total aerobic Microbial Count (TMC), Staphylococcus species (spp.), Coliforms, and Salmonella spp. in broiler litter samples of both the Houses, 2 (H2) and 3 (H3), were determined, and also at the end of each cycle the mortality rate was recorded. The results showed significant reduction of all the microbial counts: P= 0.0078 (CMT), 0,0021 (Staphylococcus spp.) and 0.0541 (Coliforms), and mortality (P= 0.00106) in treated litter samples H2 and the control H3.

Feed Hygiene and Meat Safety of Cattle Fed Processed Rice Hulls-bedded Broiler Litter

A study was conducted to determine the safety of feeding processed broiler litter (BL) to beef cattle. The litter was processed by deepstacking, ensiling and composting. The health issues addressed relevant to the safety of feeding litter included pathogenic bacteria, mycotoxins, heavy metals, medicinal drugs and pesticide residues. Exp. 1 evaluated the feed hygiene of processed rice hulls-bedded BL. The presence of pathogenic bacteria in BL was determined before and after deepstacking. A total of 21 BL samples were collected over a 3-year period of commercial and experimental production of BL for beef cattle. Exp. 2 evaluated the safety of meat of cattle fed deepstacked BL. In Exp. 1, there were no pathogenic bacteria, such as coliform, E. coli, E. coli O157:H7, Salmonella, Listeria and Proteus, in deepstacked BL. Levels of heavy metals (Cu, Fe, Mn and Zn) and toxic heavy metals (As, Pb, Cd and Hg) were lower than the commercial feed tolerances. Aflatoxin, medicinal drug and pesticide residues were detected at extremely low levels. In Exp. 2, the meat of the BL-fed animals exhibited few differences in all analyzed items from that of the control group, showing safety from pathogenic microorganisms and heavy metals. When BL was withdrawn for 14 days prior to slaughtering the BL- fed cattle, no medicinal drug residues were detected in the meat. Pesticides in the tissues of either group of animals were much lower than the tolerances. In conclusion, processed rice hulls-bedded BL and the meat of cattle fed BL were safe from the potential hazards of pathogenic bacteria, heavy metals, aflatoxin, medicinal drugs and pesticide residues. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 11 : 1509-1517)

Identification of Lactobacillus spp. from broiler litter in Brazil

Lactobacillus spp. were identified in 100 broiler litter samples collected from different poultry-rearing regions in Brazil. Ten different Lactobacillus species were identified: L. plantarum, L.casei subsp. pesudoplantarum, L. delbrueckii subsp. delbrueckii, L. reuteri, L. murinus, L. agilis, L. delbrueckii subsp. lactis, L. salivarus subsp. salicinus, L. viridenscens and L. amylophilus.

Trace and nontrace element contents of broiler litter*1

Poultry production is rapidly growing in the United States. In 1999, Alabama, the third largest poultry producer in the United States, produced 971.2 million birds and generated about 1.5 million Mg of broiler litter that was mainly applied to agricultural lands as an organic fertilizer. To increase disease resistance of poultry birds, trace elements are often added to poultry diets. However, some of the trace elements are toxic to living systems when present in sufficient concentrations. There is growing concern about accumulation of trace elements in broiler litter added as a soil amendment to agricultural lands and its effects on the soil, groundwater, and the food chain. When added to soils, these elements may compromise safe food and feed production. Broiler litter contains also nontrace elements that normally do not adversely affect directly plant health and soil biological system, but still need to be monitored because of possible effects on soil physicochemical properties. This study investigated the concentrations of thirteen trace [silver (Ag), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se), zinc (Zn)] and six nontrace [aluminum (Al), barium (Ba), calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na)] elements in 33 broiler litter samples collected from 12 Alabama counties. A 0.5-g sample was digested by the EPA 3052 method using a Microwave Assisted Reaction System. Results showed a wide variability of element concentrations in the samples. None of the samples tested contained measurable amounts of Ag or Pb at detection limits of 0.2 mg L−1 and 2.0 mg L−1, respectively. Expressed in mg kg−1, the range and median values for the other eleven trace elements were: As (<2.0–70.4, 18.8), Cd (<0.2–1.7, <0.2), Co (<0.2–2.3, <0.2), Cr (<0.2–17.6, 3.2), Cu (211–789, 410), Fe (718–6691, 1596), Mn (254–720, 356), Mo (<0.2–4.9, <0.2), Ni (<0.2–25.1, 1.0), Se (<2.0–24.3, <2.0), and Zn (224–706, 371). Corresponding values expressed in g kg−1 for the nontrace elements were: Al (0.6–8.4, 1.4), Ba (0.014–0.036, 0.025), Ca (18.9–40.2, 27.3), Mg (4.8–10.0, 6.1), K (18.1–36.5, 25.9), and Na (3.6–9.2, 7.1). Substantial amounts of As in the samples and the presence of Cd, Co, and Cr in measurable amounts in some samples are of an environmental concern. *Journal Paper No. 319 of the George Washington Carver Agricultural Experiment Station, Tuskegee, AL 36088. This work was supported by the USDA/Capacity Building Program. The authors thank Bennie Moore, USDA/NRCS, Laverne AL 36049 and USDA offices in Alabama counties for selecting participating farmers.

Rapid methods to determine potentially mineralizable nitrogen in broiler litter.

Although broiler (chicken, Gallus gallus domesticus) litter has long been used as a fertilizer, estimating the rate required to supply a desired amount of plant-available N is still hampered by the lack of rapid methods to estimate potentially mineralizable nitrogen (PMN). Previous research has suggested that near infrared reflectance spectroscopy (NIRS) and certain poultry litter characteristics, such as water-soluble organic nitrogen (WSON), may be useful for estimating PMN. The objectives of this study were to evaluate NIRS and WSON as tools to estimate PMN in broiler litter. Sixty sieved (2 mm) and freeze-dried broiler litter samples were mixed with Cowarts sandy loam soil (fine-loamy, kaolinitic, thermic Typic Kanhapludult) and incubated at 25 degrees C for 112 d. Cumulative net N mineralized with time was fitted to a single-pool exponential model to determine PMN for each broiler litter sample. The PMN values obtained were regressed against NIRS (780 to 2500 nm) and WSON measurements. We found strong relationships between measured- and NIRS-predicted PMN (R2 = 0.82), and between measured PMN and WSON (R2 = 0.87). These results demonstrate the feasibility of using either of these two methods to estimate PMN in broiler litter. Future work should further test both methods for their ability to estimate mineralizable N in whole, moist broiler litter under field conditions.

Survival of Fecal Coliforms in Fresh and Stacked Broiler Litter

Fecal coliforms are indicator bacteria that are used for determining water quality. Poultry growers may be implicated when fecal coliforms are found in surface waters following runoff events from broiler litter-amended pastures and hayfields. This study determined the numbers of fecal coliforms in fresh and stacked broiler litter. In 1998, 10 of 20 fresh and all 19 stacked broiler litter samples from eight different Georgia counties contained less-than-detectable numbers of fecal coliforms (< 10 fecal coliforms per g of dry weight litter). In 1999, all 13 interior and 12 of 13 exterior samples of stacked litter from one South Carolina and two Georgia counties contained less-than-detectable numbers of fecal coliforms. When high numbers of fecal coliforms (> 10,000,000 fecal coliforms per g of dry weight litter) were added to five different broiler litter samples, numbers of fecal coliforms declined to below detectable levels within 8 days. When water was added to two of the five stacked litter samples, survival of fecal coliforms did not increase, but survival did increase when the temperature was lowered from 28 to 18 °C. The data suggest that poultry growers should consider stacking broiler litter for a reasonable period of time (> 8 days) to eliminate fecal coliforms in runoff from landspread broiler litter.

The impact of pH on nitrogen retention in laboratory analysis of broiler litter

Land application of broiler litter must fully regard agronomic and environmental issues, which requires increased precision in all aspects of land application of poultry litter. Previous researchers note that litter experiences significant nitrogen loss due to ammonia volatilization during the drying process. Others note that pH of poultry houses and litter significantly affects nitrogen loss due to ammonia volatilization. Recent work shows that acidifying agents effectively reduce ammonia generation in poultry production facilities. This concept is used in this study to adjust the pH of broiler litter samples prior to drying to reduce nitrogen loss during the drying process. Samples from four sources were used. Untreated litter was compared to litter treated with Al2(SO4)3, (10:1 wet weight basis) either in small (10 g) or large (100 g batches). Both Al2(SO4)3 treatment methods significantly lowered litter sample pH. No significant differences were observed in litter moisture analysis values. Regardless of source, litter treated in small batches had significantly higher nitrogen values than untreated litter. Large batches of treated litter did not consistently have higher nitrogen values than untreated litter. Treatment of litter samples with Al2(SO4)3 prior to drying resulted in more accurate quantification of nitrogen in litter, which can ultimately result in more accurate utilization of litter in agronomic applications.

Effect of timing of simulated rain on ammonia volatilization from surface‐applied broiler litter

Surface application of animal manures may lead to significant nitrogen (N) losses through ammonia (NH3) volatilization. Understanding the factors that control these NH3 losses is important for predicting the amount of manure N that will be available to crops. Field studies have shown that rain following cattle manure application can reduce NH3 volatilization. Similar results may be expected with broiler litter due to its high concentration of water‐soluble N. The objective of this work was to evaluate the effect of timing of simulated rainfall on NH3 volatilization and N mineralization from surface‐applied broiler litter. In one study, broiler litter from six broiler houses was applied (224 kg N ha‐1) on the surface of packed soil columns that received 40 mm of simulated rain either immediately before or immediately after litter application. Following treatments, the columns were placed in a flow‐through system (25°C) that trapped NH3 volatilized for 21 days. In another study, packed soil columns received no rain or 20 mm of rain at 0 to 4 days after broiler litter application. On average, the addition of 40 mm of rain immediately after litter application reduced NH3 losses by 49% when compared to the addition of rain immediately before litter application. Soil inorganic N data supported the hypothesis that percolating rain solubilized litter N and transported it into the soil, thereby reducing NH3 losses. For most broiler litter samples, net N mineralization was not affected by the rain treatments. The addition of 20 mm of rain at 0 to 4 days after broiler litter application temporarily increased the rate of NH3 loss when compared to the treatment that did not receive rain. In the long‐term, however, the addition of 20 mm of rain tended to decrease total NH3 losses. Our results suggested that total NH3 losses from surface‐applied broiler litter may be reduced by rain or irrigation received immediately after manure application. These results warrant further studies on the effect of rain on NH3 volatilization from surface‐applied broiler litter under field conditions.