The use of Yucca schidigera and microbial preparation for poultry manure deodorization and hygienization

Characterization of three novel dimethyl disulfide degrading bacteria and their potential degradation pathways

Dimethyl disulfide (DMDS) is an odor compound characterized by the lowest olfactory threshold and high toxicity. It is indispensable to explore the bacteria with high resistance and degradation efficiency to DMDS. Acinetobacter lwoffii, Pseudomonas mendocina, and Myroides odoratus were isolated from kitchen waste. After 6 days of individual treatment, the removal rates were 34.22 %, 40.95 %, and 41.94 % respectively. The DMDS metabolic pathways based on metagenomic assays were discovered to be incomplete due to the insufficient annotation of some key genes in the current database. Following 3 days of treatment with bacterial consortia at ratios of 5:1 for A. lwoffii C2/ M. odoratus C7 and 1:1:1 for the three strains achieved 100 % DMDS removal. Additionally, the consortia reduced hydrogen sulfide (H2S) and dimethyl sulfide (DMS).This discovery broadens the spectrum of bacteria exhibiting high tolerance and efficient degradation of DMDS, with significant implications for DMDS removal and odor treatment.

Efficacy of composite bacterial deodorant constructed with Camellia sinensis and its in-situ deodorization mechanism on pig manure

Here, we constructed a novel bacterial deodorant (BD) composed of Delftia tsuruhatensis, Paracoccus denitrificans, Pediococcus acidilactici, and Bacillus velezensis. The BD alone removed 64.84 % of NH3, 100 % of H2S, and 63.68 % of comprehensive odor (OU) during a five-day fermentation of pig manure. The effect was enhanced by introducing Camellia sinensis in the composite bacterial deodorant (CBD) treatment, with the removal efficiency (RE) of NH3 and OU being 88.68 % and 88.14 %, respectively. In prolonged trials, maximum RE of NH3, H2S and OU RE reached 90.16 %, 92.32 % and 100 % in CBD group. Bacterial composition of manure revealed that the abundance of odor-producing microbes (Kurthia, Solibacillus, Proteiniphilum and Acholeplasma) and potential pathogens decreased after CBD application. Functional prediction and correlation analyses indicated that the process of nitrification, denitrification and S/N assimilation were facilitated, while S/N mineralization and methanogenesis processes might be inhibited. This deodorant promoted the conversion of malodorous substances into non-odorous forms, establishing an efficient odor removal system in hoggery. Therefore, the bacterial deodorant compounded with C. sinensis has been shown to be an effective method for deodorizing pig farms. This approach will advance the livestock industry toward greener practices and environmental protection, contributing positively to the development of a sustainable agro-ecosystem.

Analysis of latrine fecal odor release pattern and the deodorization with composited microbial agent

As an important source of malodor, the odor gases emitted from public toilet significantly interfered the air quality of living surroundings, resulting in environmental problem which received little attention before. Thus, this paper explored the odor release pattern of latrine feces and deodorization effect with composited microbial agent in Chengdu, China. The odor release rules were investigated in sealed installations with a working volume of 9 L for 20 days. The odor units (OU), ammonia (NH3), hydrogen sulfide (H2S) and total volatile organic compounds (TVOC) were selected to assess the release of malodorous gases under different temperature and humidity, while the highest malodor release was observed under 45℃, with OU and TVOC concentration was 643.91 ± 2.49 and 7767.33 ± 33.50 mg/m3, respectively. Microbes with deodorization ability were screened and mixed into an agent, which composited of Bacillus amyloliquefaciens, Lactobacillus plantarum, Enterococcus faecalis and Pichia fermentans. The addition of microbial deodorant could significantly suppress the release of malodor gas during a 20-day trial, and the removal efficiency of NH3, H2S, TVOC and OU was 81.50 %, 38.31 %, 64.38 %, and 76.86 %, respectively. The analysis of microbial community structure showed that temperature was the main environmental factor driving the microbial variations in latrine feces, while Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes were the main bacteria phyla involved in the formation and emission of malodorous gases. However, after adding the deodorant, the abundance of Bacteroidetes, Proteobacteria and Actinobacteria were decreased, while the abundance of Firmicutes was increased. Furthermore, P. fermentans successfully colonized in fecal substrates and became the dominant fungus after deodorization. These results expanded the understanding of the odor release from latrine feces, and the composited microbial deodorant provided a valuable basis to the management of odor pollution.

Sustainable management and valorization of biomass wastes using synthetic microbial consortia

In response to the persistent expansion of global resource demands, considerable attention has been directed toward the synthetic microbial consortia (SMC) within the domain of microbial engineering, aiming to address the sustainable management and valorization of biomass wastes. This comprehensive review systematically encapsulates the most recent advancements in research and technological applications concerning the utilization of SMC for biomass waste treatment. The construction strategies of SMC are briefly outlined, and the diverse applications of SMC in biomass wastes treatment are explored, with particular emphasis on its potential advantages in waste degradation, hazardous substances control, and high value-added products conversion. Finally, recommendations for the future development of SMC technology are proposed, and prospects for its sustainable application are discussed.

Effects of microbial deodorizer on pig feces fermentation and the underlying deodorizing mechanism

Microbial deodorization is a novel strategy for reducing odor in livestock and poultry feces. Herein, 12 strains of ammonia (NH3) and 15 hydrogen sulfide (H2S) removing bacteria were obtained with a removal efficiency of 65.20-79.80% and 34.90-79.70%, respectively. A novel bacteria deodorant named MIX (Bacillus zhangzhouensis, Bacillus altitudinis, and Acinetobacter pittii at a ratio of 1:1:2) were obtained. MIX can shorten the temperature rising stage by 2 days and prolong the thermophilic stage by 4 days. The ability of MIX to remove NH3, H2S, and volatile fatty acids (VFAs) and the underlying removal mechanism were analyzed during pig feces fermentation. MIX can significantly reduce the concentrations of NH3 and H2S by 41.82% and 66.35% and increase the concentrations of NO3--N and SO42- by 7.80% and 8.83% (P < 0.05), respectively, on the 25th day. Moreover, the concentrations of acetic, propionate, iso-valerate, and valerate were significantly reduced. The dominant bacteria communities at the phylum level were Firmicutes, Proteobacteria, Bacteroidetes, and Spirochaetes. B. zhangzhouensis and B. altitudinis could convert NH4+-N to NO3--N, and A. pittii could transfer H2S to SO42-. This study revealed that bacteria deodorant can reduce the concentrations of NH3, H2S, and VFAs in pig feces and increase those of NH4+, NO3-, and SO42- and has excellent potential in deodorizing livestock and poultry feces composting.

Enhancement of protective vaccine-induced antibody titer to swine diseases and growth performance by Amino-Zn, yucca extract, and β-mannanase feed additive in wean-finishing pigs

The primary purpose of this research is to determine the effect of Amino-Zn (AZn), Yucca schidigera extract (YE), and β-mannanase enzyme supplementation on growth performance, nutrient digestibility, fecal gas emission, and immune response in pigs. A total of 180 crossbred pigs (6.57 ± 1 kg) were randomly assigned to one of three dietary treatments: CON-corn soybean meal (basal diet); TRT1-CON +1,000 ppm AZn + 0.07% yucca extract (YE) + 0.05% β-mannanase; and TRT2-CON +2,000 ppm AZn + 0.07% YE+ 0.05% β-mannanase for 22 weeks. Each treatment had 12 replicates with 5 pigs per pen. Pigs fed a diet supplemented with AZn, YE, and β-mannanase linearly increased (p < 0.05) BW and average daily gain at weeks 6, 12, 17, and 18. In contrast, the gain-to-feed ratio showed a linear increase (p < 0.05) from weeks 6 to 17 and the overall trial period. Moreover, the inclusion of experimental diets linearly decreased (p > 0.05) noxious gas emissions such as ammonia, hydrogen sulfide, acetic acid, carbon dioxide, and methyl mercaptans. The dietary inclusion of AZn, YE, and β-mannanase significantly increased the serological immune responses to Mycoplasma hyopneumoniae (MH) and foot-and-mouth disease virus (FMDV-O type) at the end of week 6 and porcine circovirus-2 (PCV-2) at week 19. Based on this result, we infer that the combination of AZn, YE, and β-mannanase supplement would serve as a novel in-feed additive to enhance growth performance and act as a boosting agent and immune stimulatory to increase the efficacy of swine vaccinations.

Comparison of the Effects of Yucca saponin, Yucca schidigera, and Quillaja saponaria on Growth Performance, Immunity, Antioxidant Capability, and Intestinal Flora in Broilers

The purpose of this study is to investigate the effects of Yucca saponin (YSa), Yucca schidigera (YS), and Quillaja Saponaria (QS) on growth performance, nitrogen metabolism, immune ability, antioxidant capability, and intestinal flora of yellow-feather broilers. This study randomly divided a total of 480 1-day yellow-feather broilers into 4 treatment groups. Factors in the 4 groups included CON group (basic diet), YSa group (basic diet mixed with 500 mg/kg YSa), YS group (basic diet mixed with 500 mg/kg YS), and QS group (basic diet mixed with 500 mg/kg QS). Throughout the 56-day study period, YSa, YS, and QS groups had higher average daily gain in broilers than the CON group (p < 0.01). The YS group had a lower feed gain ratio (F: G) in broilers than the CON group (p < 0.05). YSa, YS, and QS showed increased serum immunoglobin A (IgA), immunoglobin Y (IgY), immunoglobin M (IgM), and total antioxidant capacity (T-AOC) levels; enhanced acetic acid, butyric acid, and valeric acid levels of cecal content; and reduced contents of ammonia nitrogen, urea nitrogen, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and malondialdehyde (MDA) in serum in broilers (p < 0.05). The relative abundance of Lachnoclostridium in the QS group was decreased compared with that in the CON group (p < 0.05). Higher IgA and IgY sera contents were observed in the YS group compared to the YSa and QS groups (p < 0.05). In contrast with the QS group, the serum IL-6 concentration of the YS group was reduced (p < 0.05). In conclusion, YSa, YS, and QS promoted growth performance, nitrogen metabolism, immunity, antioxidant capability, and intestinal flora in broilers. Through the comparison of YSa, YS, and QS, it was found that YS is more suitable as a feed additive to ameliorate the healthy growth of broilers.

Assessments of productive performance, eggshell quality, excreta moisture, and incubation traits of laying breeder hens fed a proprietary blend of Quillaja and Yucca

A study was conducted to evaluate performance, eggshell quality, nutrient metabolizability, and incubation traits of laying breeder hens fed diets supplemented with an additive containing polyphenols and saponins of a proprietary blend from Quillaja saponaria and Yucca schidigera (QY) biomass. Hens were fed 4 feeds in 5 periods of 28 days each from 30 to 49 weeks of age. Experimental feeds were a Control diet; Control + virginiamycin (33 g/ton); Control + QY (250 g/ton) and Control + virginiamycin + QY. A total of 40 White Plymouth Rock and 44 Rhode Island Red breeder hens were allocated in individual cages using a completely randomized block design with 21 replicates. Performance parameters, evaluated per period, were egg production, egg weight, FCR, egg mass, and culled eggs. All eggs were collected in the last 4 days of each period to evaluate specific egg weight, percentage of albumen, yolk and shell, and Haugh unit as well as cuticle quality, shell strength, and shell thickness. At the end of the experiment, nutrient metabolizability assessment and four incubations were conducted. There were no interactions between diet and period in all evaluated responses (P > 0.05). Experimental diets did not affect daily egg production, egg weight, and egg mass as well as Haugh unit, yolk and albumen percentage, and yolk color (P > 0.05). However, hens fed Control + QY produced eggs with better shell strength, shell thickness, and cuticle quality than hens fed the Control (P < 0.05). Hens fed Control + QY or Control + virginiamycin + QY had lower culled eggs, better FCR and higher egg specific weight, shell percentage, and yolk strength compared to breeder hens fed the Control (P < 0.05). In general, hens fed QY achieved enhanced performance and egg quality compared to virginiamycin. In conclusion, laying breeder hens fed diets supplemented with Quillaja and Yucca additive, from 30 to 49 weeks of age, maintained their productive performance, had improved eggshell and cuticle quality and reduced culled, dirty and contaminated eggs.

Effect of Mineral-Microbial Deodorizing Preparation on the Value of Poultry Manure as Soil Amendment

Poultry farming involves the production of poultry manures (PMs), which, if properly managed, are excellent organic soil amendments. Poultry farms generally do not have adequate arable land, and therefore, valuable fertilizer becomes a problematic waste. During the production and storage of PMs, odorous VOCs, NH₄, H₂S, and potent greenhouse gases such as CH₄, CO₂ are emitted. It influences the productivity of poultry and negatively affects the working conditions of working staff. In the present study, mineral-microbial deodorizing preparations (MMDP) based on perlite and bentonite as well as the following microorganism strains Lactobacillus plantarum, Leuconostoc mesenteroides, Bacillus megaterium, B. subtilis, and Pseudomonas fluorescens were added to the litter of turkey broilers (TB) and egg-laying hens (LH). PMs were compared with treatments without the addition of MMDP, and maize, sunflower, and rapeseed forage crops were tested. The influence on soil parameters such as pH, EC, HAC, SBC, CEC, BS, N_tot, C_tot, and plant yield and parameter of photosynthesis, i.e., SPAD index, was tested. Soil amending with manure resulted in an increase in pH and a decrease in HAC; in addition, an increase in EC, which was counteracted by the addition of MMDP, was noted. MMDP positively affected parameters such as SBC, CEC, and BS. It was shown that PMs, with the addition of MMDP, improved crops' yield in the first year of the study, whereas this effect was not seen for the after-crop plants (lupine). The main 'added value' related to the usage of MMDP in poultry production is the improvement in the properties of PMs, which mainly had a positive effect on soil indicators.

Antibacterial and Antioxidant Properties of Extracts of Yucca Baccata, a Plant of Northwestern Mexico, against Pathogenic Bacteria

Introduction

Bacterial agents and oxidative reactions are involved in health and food preservation issues, and Yucca baccata (Y. baccata) can be a source of compounds with practical applications in both areas, but its investigation remains limited.

Materials and Methods

Butanolic (YBE) and aqueous (YAE) extracts were obtained from the stem of Y. baccata. The total saponin, phenolic, and flavonoid contents were analyzed in the YBE and YAE. The antioxidant capacity of the extracts was determined by the DPPH, TEAC, FRAP, and ORAC assays. Seven Gram-positive and five Gram-negative pathogenic bacteria strains were used to determine the MIC and MBC.

Results

Saponin contents were 30% and 1.81% (w/w) in the YBE and YAE, respectively. The total phenolic and flavonoid contents in the extracts were 29.5 μg GAEmg⁻¹ (2.95%) and 5.58 μg GAEmg⁻¹ (0.56%) in the YBE and 69.92 μg QEmg⁻¹ (7.0%) and 1.65 μg QEmg⁻¹ (0.165%) in the YAE. The antioxidant capacity values of YBE were 29.18 μg TEmg⁻¹, 121.8 μg TEmg⁻¹, 33.41 μg TEmg⁻¹, and 156.84 μg TEmg⁻¹ by the DPPH, TEAC, FRAP, and ORAC assays, respectively. YAE had lower antioxidant values than YBE (P < 0.05). Values of 80 mgmL⁻¹ and 100 mgmL⁻¹ were estimated for MIC and MBC of YBE against the Gram-positive bacteria. Values of 100 mgmL⁻¹ and 120 mgmL⁻¹ for MIC and MBC of YBE were estimated against the Gram-negative bacteria. No MIC and MBC were obtained for YAE.

Conclusion

YBE exhibited higher antioxidant activity than YAE. Apparently, antibacterial properties of the YBE tended to be higher than those of the YAE.

Effects of Feed-Through Sulfur on Growth Performance, Atmospheric Ammonia Levels, and Footpad Lesions in Broilers Raised Beginning with Built-Up Litter

To the poultry industry, ammonia accumulation within poultry houses can be a costly issue, as this can lead to problems with bird performance, damage to economically important parts such as paws, and customer disapproval due to animal welfare concerns. Common management practices for ammonia control can be quite effective; however, these methods are used variably from farm to farm, which necessitates ammonia control measures that poultry companies can more uniformly implement across all contract growers. One possible measure is ammonia control through feed additives, which would allow poultry companies more direct control over the treatment. This project explored the efficacy of elemental sulfur added directly to the feed (feed-through sulfur) in controlling litter ammonia levels, live performance, and paw quality of broilers raised on built-up litter over three successive flocks. Feed-through sulfur on its own showed inconsistent effects on performance or footpad lesions after 38 days of production compared to sodium bisulfate or control treatments. However, combination of feed-through sulfur and sodium bisulfate showed a potential synergistic effect on ammonia levels and litter pH, although there were few differences between treatments and controls; therefore, additional research must be explored to confirm these observations.

Biodesulfurization of thiosulfate by a Pseudomonas strain PSP1 and the investigation of underlying metabolic mechanisms

The increasing public expectations for good air quality have necessitated the development of biodeodorization technology. Among different malodorous pollutants, H₂S has attracted extensive attention and diverse biodesulfurization technology has been developed for efficient H₂S removal. In this study, a novel heterotrophic Pseudomonas strain, PSP1, was isolated from biogas slurry and its biodesulfurization ability was investigated. Culture conditions of 30 °C and 200 rpm were determined as the optimal for both cell growth and thiosulfate conversion. Under such conditions, the highest OD₆₀₀ value was observed as 6.74 and 50 mM thiosulfate within 10 h. PSP1 was found to convert thiosulfate to sulfane which could be decomposed into elemental sulfur and therefore achieved desulfurization. However, this process was relatively weak as more than 60% thiosulfate was converted into soluble tetrathionate. The whole genome sequencing and functional annotation identified the genes in PSP1 associated with sulfur metabolism and the RT-qPCR analysis quantified the expression level of corresponding genes. The expression level of tsdA, which was responsible for tetrathionate production, was around 60 folds higher than genes for sulfane production (e.g. TST1, cysI). Further research would focus on the enhancement of sulfane production pathway through metabolic engineering tools.

The Odor Release Regularity of Livestock and Poultry Manure and the Screening of Deodorizing Strains

Human living environments and health are seriously affected by the odor produced from fermentation of livestock and poultry manure. In order to reduce the odor pollution caused by livestock and poultry manure, efficient strains were screened and two methods were tried in this study. The orthogonal test design was used to analyze the gas produced by pig manure under different conditions of temperature, time, wheat straw doping amount and calcium carbonate doping amount. Then, according to ammonia, hydrogen sulfide and comprehensive odor removal effects, the high efficiency of deodorizing strains were screened. The results showed that pig manure produced the least odor when the temperature was 20 °C, added 0% calcium carbonate, 20% wheat straw and waited for 48 h. Three strains were screened to inhibit the odor production of pig manure: Paracoccus denitrificans, Bacillus licheniformis and Saccharomyces cerevisiae, showed that their highest removal rate of ammonia and hydrogen sulfide gas could reach 96.58% and 99.74% among them; while for three strains of end-control pig manure stench: Pichia kudriavzevii, P. denitrificans and Bacillus subtilis, the highest removal rate of ammonia and hydrogen sulfide gas reached 85.91% and 90.80% among them. This research provides bacteria resources as the high-efficiency deodorizing function for the source suppression and the end treatment of the odor gas of pig manure, which has high application value for the control of odor pollution.

Can Yucca schidigera Be Used to Enhance the Growth Performance, Nutrient Digestibility, Gut Histomorphology, Cecal Microflora, Carcass Characteristic, and Meat Quality of Commercial Broilers Raised under Tropical Conditions?

This study aims to study the effect of Yucca shidigera as a phytobiotic supplementation in enhancing the production performance of commercial broilers reared under tropical environments. A total of 300 male day-old Ross 308 broiler chicks were randomly allocated into six treatment groups. Treatment 1 broilers were fed with commercial diets without antibiotics. Treatment 2 broilers were fed with commercial diets added with 100 mg/kg oxytetracycline antibiotic. Treatment 3, 4, 5, and 6 were fed with the same commercial diets added with 25, 50, 75, and 100 mg/kg Y. shidigera, respectively, without antibiotic. Throughout the six weeks study period, body weight and feed intake were recorded weekly for each replicate to calculate the body weight gain and feed conversion ratio. In addition, the nutrient digestibility, gut histomorphology, cecal microflora population, carcass characteristics, and meat quality were determined. The results showed significant differences (p < 0.05) in the growth performance, apparent ileal nutrient digestibility, gut histomorphology, carcass traits, and meat quality. Overall, T6 broilers supplemented with 100 mg/kg Y. shidigera demonstrated the best production performances as compared to the other treatment broilers. In summary, information from this study will be valuable for the usability of Y. schidigera, which could be developed as a feed additive to replace antibiotics in the poultry sector in the tropics.

Dietary Yucca schidigera Extract Supplementation During Late Gestating and Lactating Sows Improves Animal Performance, Nutrient Digestibility, and Manure Ammonia Emission

This study was conducted to investigate the effect of dietary Yucca schidigera extract (YSE) supplementation to sow performance, nutrients digestibility and ammonia emission of manure. Total 80 sows were randomly divided into 4 groups and fed with either control, control + 0.06% YSE, control + 0.12% YSE or control + 0.24% YSE diet from day 80 of gestation to day 21 of lactation. The results showed that dietary YSE supplementation resulted in trends toward a reduced number of stillbirth piglets (P = 0.08), weak piglets (P = 0.06), pre-weanling mortality (P = 0.04) and diarrhea (P = 0.03), and improved apparent digestibility of dry matter (P = 0.04). Besides, YSE supplementation significantly increased catalase activity (P = 0.02) while decreasing malonaldehyde levels (P = 0.04) in sow blood. Furthermore, the loss of total nitrogen, urea nitrogen and ammonia nitrogen in sow manure were significantly reduced with supplementation of YSE. In summary, supplementation of YSE in sow diet during late gestation and lactation could improve sow and litter performance, nutrient digestibility, and reduce nitrogen loss in sow manure during storage.

Impact of microbial waste additives and glucose on ammonia emissions from broiler litter in the lab

Ammonia (NH₃) produced inside livestock houses can adversely affect animal welfare and performance and degrade the environment. In broiler houses, NH₃ levels are mitigated by applying acidifiers to the litter but acidifiers provide short-term NH₃ suppression requiring heavy or repeated applications. Microbial additives may provide longer-term NH₃ control through nitrogen (N) immobilization and nitrification. The objective of this 50-d lab study was to evaluate the impact of two microbial additives (Environoc 301 and Environoc 501), 2% glucose, and distilled water (control) treatments applied to broiler litter on NH₃ emissions and litter properties. During the first 34 d, glucose significantly but modestly reduced NH₃ emissions vs. the other treatments which were not significantly different from one-another. For the entire study, when glucose was excluded (due to lost replicates), the three treatments were not significantly different. The unreplicated glucose treatment had higher final litter nitrate concentration than the other treatments. Litter properties were unaffected by the two microbial additive and control treatments. The effectiveness of glucose in reducing NH₃ emission could have been due to greater N immobilization and nitrification vs. the other treatments. More research on cost-effective labile carbon sources and higher application rates to achieve greater NH₃ reduction is required.

Pre-treatment Strategies for Value Addition in Poultry Litter

We studied different pre-treatments of poultry litter aiming to add economic value to this residue. Strategies were applied to extract ammonium nitrogen with the aim of allowing its further use as fertilizer, and to promote the hydrolysis and solubilization of lignocellulosic components with the aim of facilitating its subsequent conversion to biogas. Ammonia extraction was performed by solubilization in water in a one-step process and by successive extraction steps (3 times 60 min). Successive extractions presented greater removal of total ammonia nitrogen than did one-step extraction, solubilizing about 36% of the ammonia in water. In parallel pre-treatment using ultrasound was performed to increase carbon bioavailability for anaerobic digestion. Using this tool, 24.7 g kg⁻¹ of total organic carbon and 13.0 g kg⁻¹ of total reducing sugars were solubilized, employing 10% dry mass sample amount, 100% amplitude ultrasound at frequency of 20 kHz amplitude and 2.5 min of treatment (energy input of 299 ± 7 kJ L⁻¹; 3,822 ± 95 kJ kg⁻¹). Anaerobic digestion of ultrassound pre-treated biomass was evaluated using a biological biogas production assay, and an increase of 10% of biogas production was obtained compared to untreated samples (147.9 and 163.0 mL g⁻¹ for crude and pre-treated PL, respectively). The findings suggest that these are environmentally friendly and sustainable strategies to add economic value to poultry litter, reducing the environmental impacts of improper disposal.

Determining the influence of chromium propionate and Yucca schidigera on growth performance and carcass composition of pigs housed in a commercial environment

Two experiments were conducted to determine the effects of feeding chromium propionate (Cr; Kemin Industries, Inc., Des Moines, IA) and a Yucca schidigera-based extract (YS; Distributors Processing, Inc., Porterville, CA) on growth performance of finishing pigs housed in commercial conditions. In experiment 1, a total of 1,188 pigs (PIC 337 × 1050; initially 27.3 ± 0.48 kg body weight [BW]) with 27 pigs per pen and 11 pens per treatment were split by sex upon arrival at the facility and were randomly allotted to groups of four pens blocked by BW. Diets were corn-soybean meal-dried distillers grains with solubles-based and were fed in five phases. Treatments were arranged as a 2 × 2 factorial with main effects of Cr (0 vs. 200 µg/kg) or YS (0 vs. 62.5 mg/kg YS-based feed grade concentrate). Overall, adding Cr alone increased (P = 0.049) average daily feed intake (ADFI), and inclusion of YS resulted in a marginally significant increase (P = 0.077) in ADFI. Backfat depth was increased (P = 0.043) and lean percentage was decreased (P = 0.011) with added Cr. In experiment 2, a total of 2,430 pigs (PIC 359 × 1050; initially 29.3 ± 0.43 kg BW) were placed in balanced mixed-sex pens with 27 pigs per pen, blocked by average pen BW, and randomly assigned to one of six dietary treatments with 14 pens per treatment. Diets were corn-soybean meal-based and were formulated in five dietary phases. Treatments were arranged in a 2 × 3 factorial with main effects of Cr (0 vs. 200 µg/kg added Cr), and YS extract (0, 62.5, or 125 mg/kg YS-based feed grade concentrate). Overall, a marginally significant (linear, P = 0.072) Cr × YS interaction was observed for average daily gain (ADG) where there was insufficient evidence of a difference with increasing YS in diets not including added Cr (P ≥ 0.109); however, ADG increased (quadratic, P = 0.026) with YS addition in treatments fed 200 µg/kg added Cr. For overall ADFI, a marginally significant (linear, P = 0.071) Cr × YS interaction was observed where YS increased ADFI with 200 µg/kg added Cr (linear, P = 0.031), however, did not when diets contained no added Cr (P = 0.700). A marginally significant reduction in gain:feed ratio was observed when 62.5 mg/kg YS was included (quadratic, P = 0.053), and final BW and hot carcass weight were lowest with 62.5 mg/kg YS (quadratic, P = 0.012). In summary, adding Cr propionate along with YS led to modest changes in performance with the greatest benefit observed with 200 µg/kg Cr and 125 mg/kg YS-based feed grade concentrate.

Technologies for deodorization of malodorous gases

There is an increasing number of citizens' complaints about odor nuisance due to production or service activity. High social awareness imposes pressure on entrepreneurs and service providers forcing them to undertake effective steps aimed at minimization of the effects of their activity, also with respect to emission of malodorous substances. The article presents information about various technologies used for gas deodorization. Known solutions can be included into two groups: technologies offering prevention of emissions, and methodological solutions that enable removal of malodorous substances from the stream of emitted gases. It is obvious that the selection of deodorization technologies is conditioned by many factors, and it should be preceded by an in-depth analysis of possibilities and limitations offered by various solutions. The aim of the article is presentation of the available gas deodorization technologies as to facilitate the potential investors with selection of the method of malodorous gases emission limitation, suitable for particular conditions.