Influence of substrate/inoculum ratio, inoculum source and ammonia inhibition on anaerobic digestion of poultry waste

Poultry wastes are rich in organic matter, allowing their use as substrates for biogas production by anaerobic digestion (AD). The major difficulty in the anaerobic digestion of this protein-rich waste is ammonia inhibition. Different results of biochemical methane potential (BMP) were obtained after the mesophilic anaerobic digestion of different avian waste in batch mode. It was shown that using two different inoculum (Liger and Saint-Brieuc) sources and different substrate-to-inoculum (S/I) ratios does not have a significant effect on the biochemical methane potential of organic laying hen droppings (OLHD); an average of 0.272 Nm3 CH4·kg-1·VS was obtained with both inocula. Otherwise, it affects the hydrolysis constant KH, and it decreases when the substrate-to-inoculum ratio increases. Furthermore, Liger is the most suitable inoculum for our substrate because it shows stability during the process even with different organic loads. Comparing the biochemical methane potential of multiple avian wastes such as organic laying hen droppings and different slaughterhouse waste highlights the importance of slaughterhouse waste in the anaerobic digestion process because of the high methane yield observed especially with the viscera (0.779 Nm3 CH4·kg-1 VS, SD = 0.027 Nm3 CH4·kg-1 VS). Moreover, methane production was affected by increasing the ammonia concentrations; when [N-NH3] > 9.8 g·N-NH3·L-1, the biochemical methane potential decreases and the lag phase increases (λ > 30 days); a total inhibition of the process was observed when ammonia concentration is above 21.8 g·L-1.

Impact of feeding biochar sources in rohu (Labeo rohita): Evaluating the growth, nutrient absorption, carcass composition, haematology and mineral status

Biochar, an organic carbonaceous matter, is a unique feed additive that is now being used in aquaculture industry to formulate a cost-effective and eco-friendly diet. This experiment (in door) was conducted over course of 90 days to determine the most effective form of biochar, produced from various sources, for supplementation in Moringa oleifera seed meal-based diet. These sources were: farmyard manure biochar, parthenium biochar (PB), vegetable waste biochar, poultry waste biochar (PWB) and corncob waste biochar, added at 2 g/kg concentration to determine the effect of supplementation on the growth indices, nutrient absorption, carcass composition, haematology and mineral status of Labeo rohita (rohu) fingerlings. The research design consisted of six test diets with three replications (6 × 3) of each. Total of 270 fingerlings (6.30 ± 0.020 g) were fed at 5% body weight and 15 of them were kept in separate steel tanks. The results indicated that PWB was most effective in improving weight gain (285.58 ± 4.54%) and feed conversion ratio (1.060 ± 0.040) compared to control diet and other test diets. The same type of biochar (PWB) produced the best results for nutrient digestibility, that is, crude protein, crude fat and gross energy and carcass composition. In terms of haematology and mineral status, PWB showed the best results. In conclusion, it was found that PWB significantly enhanced (p < 0.05) L. rohita fingerling's growth, carcass composition, nutrient digestibility, haematological parameters (red blood cells, white blood cells, platelets and haemoglobin) and mineral composition (Ca, Na, P, Mg, Fe, Mn, Zn, K and Cu) whereas PB negatively affected all parameters. It is anticipated that the potential use of biochar will increase in aquaculture industry, as research on its incorporation in fish feeds is still limited.

Whole-Genome Sequencing and Biotechnological Potential Assessment of Two Bacterial Strains Isolated from Poultry Farms in Belgorod, Russia

Bacteria, designated as A1.1 and A1.2, were isolated from poultry waste based on the ability to form ammonia on LB nutrient medium. Whole genome sequencing identified the studied strains as Peribacillus frigoritolerans VKM B-3700D (A1.1) and Bacillus subtilis VKM B-3701D (A1.2) with genome sizes of 5462638 and 4158287 bp, respectively. In the genome of B. subtilis VKM B-3701D, gene clusters of secondary metabolites of bacillin, subtilisin, bacilisin, surfactin, bacilliacin, fengycin, sactipeptide, and ratipeptide (spore killing factor) with potential antimicrobial activity were identified. Clusters of coronimine and peninodin production genes were found in P. frigoritolerans VKM B-3700D. Information on coronimine in bacteria is extremely limited. The study of the individual properties of the strains showed that the cultures are capable of biosynthesis of a number of enzymes, including amylases. The B. subtilis VKM V-3701D inhibited the growth of bacterial test cultures and reduced the growth rate of the mold fungus Aspergillus unguis VKM F-1754 by 70% relative to the control. The antimicrobial activity of P. frigoritolerans VKM V-3700D was insignificant. At the same time, a mixture of cultures P. frigoritolerans VKM B-3700D/B. subtilis VKM B-3701D reduced the growth rate of A. unguis VKM F-1754 by 24.5%. It has been shown that strain A1.1 is able to use nitrogen compounds for assimilation processes. It can be assumed that P. frigoritolerans VKM V-3700D belongs to the group of nitrifying or denitrifying microorganisms, which may be important in developing methods for reducing nitrogen load and eutrophication.

Poultry farmers' knowledge, attitude, and practices toward poultry waste management in Bangladesh

Background and Aim

The improper handling of poultry litter and waste poses risks to humans and environment by introducing certain compounds, elements, and pathogenic microorganisms into the surrounding environment and food chain. However, understanding the farmers' knowledge, attitude, and practices (KAP) could provide insights into the constraints that hinder the appropriate adoption of waste management. Therefore, this study aimed to assess poultry farmers' KAP regarding waste management issues.

Materials and Methods

A cross-sectional KAP study was conducted with native poultry keepers and small-scale commercial poultry farmers in seven districts of Bangladesh. In the survey, 385 poultry producers were interviewed using validated structured questionnaires through face-to-face interviews to collect the quantitative data in their domiciles.

Results

The overall KAP of farmers regarding poultry waste management issues demonstrated a low level of KAP (p = 0.001). The analysis shows that roughly 5% of farmers have a high level of knowledge of poultry waste management issues, followed by around one-third of respondents having a moderate level of knowledge. Considering the attitude domain, more than one-fifth of native poultry keepers and nearly two-thirds of commercial producers demonstrated a low level of attitude toward poultry waste management. Considering the overall analysis, roughly half of the respondents found a high level of attitude, and over half of the farmers showed a moderate level of attitude toward poultry waste management issues. The analysis showed that the level of good practices for native and commercial poultry production systems is estimated at 77.3% versus 45.9%, respectively, despite the farmers' lesser knowledge and attitudes toward poultry waste management systems. Overall, analysis showed that nearly 60% and 40% of poultry producers had high and moderate levels, respectively, of good practices in poultry waste management issues.

Conclusion

Analysis of the KAP data shows that farmers had a low level of KAP toward poultry waste management. The result of this study will assist in formulating appropriate strategies and to adopt poultry waste management solutions by poultry farmers to reduce environmental degradation.

Biodegradable Nonwovens with Poultry Feather Addition as a Method for Recycling and Waste Management

Geotextiles are used for separation, drainage, filtration and anti-erosion protection sealing, as well as to improve plant vegetation conditions. The research objective of this study was to verify the influence of the addition of poultry feathers on accelerating the biodegradation of nonwovens in cultivated soil. The tests were carried out in laboratory conditions and were based on the assessment of weight loss. The experiments confirmed the positive effects of the presence of waste that was rich in keratin on the time required for the biodegradation of the tested materials (the period of biodegradation was 8–24 weeks). Additionally, the influence of the biodegradation of the tested materials on the ecotoxicity was investigated and showed no negative effects on the microbiological activity (10⁶ cfu). The research also included the determination of the carbon to nitrogen ratio of the test medium (blank, 12–14:1; with feather addition, 19–20:1). A statistical analysis revealed a correlation between the mechanical properties and the period of biological decomposition. This research was an important step for the management of poultry feather waste in agricultural applications. The tested materials could be seen an alternative that meets all ecological criteria, which seems to be a golden solution that not only allows the delivery of important nutrients to the soil, but also manages waste in an environmentally safe manner.

Environmental Impact of Heavy Metals from Poultry Waste Discharged into the Olosuru Stream, Ikire, Southwestern Nigeria

BACKGROUND

Water supplies can be contaminated by anthropogenic activities. The poultry industry uses a variety of heavy metals as additives in chicken feed, but excretion, runoff and dumping of heavy metals can threaten water bodies and have adverse effects on human health.

OBJECTIVES

The aim of the present study was to determine the environmental impact of heavy metals from poultry waste discharged into the Olosuru stream, located in Ikire, southwest Nigeria.

METHODS

In order to study changes in heavy metal loads, samples were collected six times during the wet season (September, October 2014 and April 2015) and dry season (November 2014, January and February 2015). The inhabitants of Olosuru village use water for domestic and agriculture purposes from the Olosuru stream which is located only a few meters from a poultry farm discharge point. Three stations were sampled, upstream to downstream, with 500 meter distance between each point.

RESULTS

Selected heavy metals concentrations in the Olosuru stream were all above the World Health Organization (WHO) standard for drinking water. The highest mean concentrations of heavy metals were recorded at the downstream station, while arsenic, iron and lead showed significant spatial and seasonal differences. Seasonally, the highest iron concentrations were recorded in the dry season (0.104±0.401 mg/L), while the mean concentrations of other heavy metals recorded during the sampling period were higher during the wet season.

CONCLUSIONS

Concentrations of heavy metals in the present study were above acceptable limits. Poultry waste discharged into the Olosuru stream, can have negative impacts on the stream and health implications for local residents.

COMPETING INTERESTS

The authors declare no competing financial interests.

Microbial keratinases: industrial enzymes with waste management potential

Proteases are ubiquitous enzymes that occur in various biological systems ranging from microorganisms to higher organisms. Microbial proteases are largely utilized in various established industrial processes. Despite their numerous industrial applications, they are not efficient in hydrolysis of recalcitrant, protein-rich keratinous wastes which result in environmental pollution and health hazards. This paved the way for the search of keratinolytic microorganisms having the ability to hydrolyze "hard to degrade" keratinous wastes. This new class of proteases is known as "keratinases". Due to their specificity, keratinases have an advantage over normal proteases and have replaced them in many industrial applications, such as nematicidal agents, nitrogenous fertilizer production from keratinous waste, animal feed and biofuel production. Keratinases have also replaced the normal proteases in the leather industry and detergent additive application due to their better performance. They have also been proved efficient in prion protein degradation. Above all, one of the major hurdles of enzyme industrial applications (cost effective production) can be achieved by using keratinous waste biomass, such as chicken feathers and hairs as fermentation substrate. Use of these low cost waste materials serves dual purposes: to reduce the fermentation cost for enzyme production as well as reducing the environmental waste load. The advent of keratinases has given new direction for waste management with industrial applications giving rise to green technology for sustainable development.

The effect of ash composition on gasification of poultry wastes in a fluidized bed reactor

The effect of ash composition on the fluidized bed gasification behaviour of poultry wastes was investigated by operating a pre-pilot scale reactor with two batches of manure obtained from an industrial chicken farm. The experimental runs were carried out by keeping the fluidized bed velocity fixed (at 0.4m s(-1)) and by varying the equivalence ratio between 0.27 and 0.40, so obtaining bed temperature values between 700 and 800 °C. The performance of the gasification process was assessed by means of mass balances as well as material and feedstock energy analyses, and reported in terms of cold gas efficiency (CGE), specific energy production, low heating value of obtained syngas and yield of undesired by-products. The experimental results indicate the crucial role of ash amount and composition of the two poultry wastes. In particular, higher ash content (25.1% instead of 17.2%) and higher fractions of calcium, phosphorous and potassium (with an increase of 24, 30 and 28%, respectively) induce a dramatic reduction of all the process performance parameters: CGE reduces from 0.63 to 0.33 and the specific energy from 2.1 to 1.1 kWh kg(fuel)(-1). At the same time, the formation of alkali compounds and their behaviour inside the fluidized bed reactor determine an increase of feedstock energy losses, which is related to occurrence of sintering and bridging between bed particles.

Arsenic: a roadblock to potential animal waste management solutions

The localization and intensification of the poultry industry over the past 50 years have incidentally created a largely ignored environmental management crisis. As a result of these changes in poultry production, concentrated animal feeding operations (CAFOs) produce far more waste than can be managed by land disposal within the regions where it is produced. As a result, alternative waste management practices are currently being implemented, including incineration and pelletization of waste. However, organic arsenicals used in poultry feed are converted to inorganic arsenicals in poultry waste, limiting the feasibility of waste management alternatives. The presence of inorganic arsenic in incinerator ash and pelletized waste sold as fertilizer creates opportunities for population exposures that did not previously exist. The removal of arsenic from animal feed is a critical step toward safe poultry waste management.