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1.
Previous studies have indicated that reducing dietary CP may improve N utilization and effectively diminish manure ammonia emissions; however, the response of manure odor emissions to such dietary modifications has been inconsistent. The objective of the current experiment was to induce decreased lactobacilli (DL) numbers in the distal gastrointestinal tract (dGIT; cecum + colon) of finishing pigs offered both high- and low-CP diets through consumption of chitosan, and examine the influence of this model on manure ammonia and odor emissions when compared with a positive control diet. It was hypothesized that an DL population would be accompanied by an increase in markers of protein fermentation. When compared with normal lactobacilli populations in the dGIT, generation of an DL population would result in increased manure odor emissions from pigs offered both dietary CP concentrations. A 2 × 2 factorial arrangement of treatments was conducted to investigate the effect of including chitosan [0 (positive control) vs. 20 g/kg of feed] and high or low dietary CP concentration (200 vs. 150 g/kg of feed) on nutrient digestibility, N utilization, selected bacterial populations, and metabolite composition of the dGIT and manure emissions from finisher pigs (60.3 kg). Consumption of chitosan had no influence (P > 0.05) on nutrient digestibility or N utilization. In both high- and low-CP diets, consumption of chitosan decreased the lactobacilli-to-Enterobacteriaceae ratio (P < 0.01), generating an DL population, and increased pH (P < 0.01) in the dGIT and ammonia (P = 0.02) in the cecum compared with diets that supported normal lactobacilli populations. Consumption of chitosan decreased molar proportions of butyric acid (P < 0.01) and increased valeric acid (P < 0.01) in the dGIT compared with unsupplemented diets. Furthermore, consumption of chitosan increased manure odor emissions (P = 0.05) compared with unsupplemented diets. There was no effect (P > 0.05) of chitosan consumption on manure ammonia emissions from 0 to 240 h. The current study demonstrates that dietary chitosan suppressed populations of lactobacilli in the dGIT. In response, a considerable increase in Enterobacteriaceae, markers of protein fermentation, and manure odor emissions was observed compared with the positive control diet. These effects were observed in pigs offered both high-and low-CP diets. The current study indicates a possible role for lactic-acid bacteria in modulating manure odor emissions relatively independent of the proportions of dietary CP available for fermentation in the dGIT.  相似文献   

2.
It was hypothesized that supplementation of an oat-extracted mixed-linkage (1 → 3), (1 → 4)-β-d-glucan (β-glucans) to a wheat-based diet may beneficially mitigate manure odor and ammonia emissions associated with intensive pig production, without depressing nutrient digestibility as has been observed with oat-based diets. An experiment was conducted to investigate the effect of dietary β-glucan source and the inclusion of an enzyme composite containing β-glucanase on energy and nutrient digestibility, N utilization, distal gastrointestinal tract (GIT) fermentation, and manure emissions from finisher boars. Twenty-eight boars (BW = 74.2 ± 3.6 kg) were assigned to 1 of 4 dietary treatments (n = 7/treatment): 1) an oat-based diet (oat), 2) an oat diet + enzyme composite (OE), 3) a wheat-based diet + purified β-glucans (WG), and 4) a wheat-based diet + purified β-glucans + enzyme composite. The wheat-based diets containing purified β-glucans were formulated to contain concentrations of total β-glucans comparable with the oat-based diet. Consumption of the WG diet resulted in a greater digestibility of GE (P = 0.001) and an increase in the urine:feces N excretion ratio (P = 0.049) compared with the oat diet. In the distal GIT, pigs offered the WG diet contained fewer bifidobacteria (P = 0.027) and lactobacilli (P = 0.050) compared with the oat diet. Pigs offered the WG diet had increased manure odor emissions compared with the oat diet (P = 0.023). In conclusion, although supplementing wheat-based diets with extracted oat-β-glucan did not reduce nutrient digestibility, there was a negligible effect in beneficially influencing manure emissions from pigs when compared with a conventional oat formulation.  相似文献   

3.
The objective of this study was to determine the effects of specific crystalline AA supplementation to a diet on odor emission, odor intensity, odor hedonic tone, and ammonia emission from pig manure, and on manure characteristics (pH; ammonia N; total nitrogen; sulfurous, indolic, and phenolic compounds; and VFA concentrations). An experiment was conducted with growing pigs (n = 18) in a randomized complete block design, with 3 treatments in 6 blocks. Treatment groups were (1) a 15%-CP basal diet with 3 times the requirement of sulfur-containing AA (14.2 g/kg of diet, as-fed basis); (2) the basal diet with 2 times the requirement of Trp and Phe+Tyr (2.9 and 20.4 g/kg of diet, respectively, as-fed basis); and (3) the basal diet with AA supplementation to levels sufficient for maximum protein gain. Pigs with an initial BW of 41.2 +/- 0.8 kg were individually penned in partly slatted floor pens and offered a daily feed allowance of 2.8 times the maintenance requirement for NE (293 kJ/kg of BW(0.75)). Feed was mixed with water at 1:2.5 (wt/wt). Feces and urine of each pig was allowed to accumulate in separate manure pits under the slatted floor. After an adaptation period of 2 wk, and after cleaning the manure pits, manure was subsequently collected. In wk 5 of the collection period, separate samples were collected directly from each manure pit for odor, ammonia, and manure composition analyses. Air samples were analyzed for odor concentration and for hedonic tone and odor intensity above the odor detection threshold. Results showed that supplementing crystalline S-containing AA in surplus of the requirement increased odor emission (P < 0.001) and odor intensity (P < 0.05) and reduced odor hedonic tone (P < 0.05) from the air above the manure pits. Supplementing crystalline Trp, Tyr, and Phe in surplus of the recommended requirements did not affect odor emission, odor intensity, or odor hedonic tone. Regardless of dietary treatment, all pigs had similar performance levels. No differences were observed in ammonia emission from manure of pigs fed different levels of AA supplementation (P = 0.20). To reduce odor from pig manure, dietary S-containing AA should be minimized to just meet the recommended requirements.  相似文献   

4.
Nutrition, key factor to reduce environmental load from pig production   总被引：2，自引：0，他引：2  
In different parts of Europe animal production is highly concentrated. Pig production generally is the main animal production activity in these areas. Main concerns of these large numbers of pigs are the amount of surplus nutrients in excreta and gaseous losses to the environment. Main nutrients of concern are N, P, and heavy metals and main gaseous losses of concern are ammonia, odour, and methane. Although losses are inevitable to a certain extent, nutrition seems to be a key factor in reducing these losses. Main nutritional strategies to reduce N and P excretions from pigs are: phase feeding (N, P), supplementation of limiting amino acids to the diet (N), and addition of phytase to the diet (P). Nutritional strategies to reduce heavy metals excretions from pigs are: finding alternative, natural, growth promoters that could replace Cu and Zn in the diet; using feedstuffs for the diet that are less contaminated with Cd. Main strategies to reduce ammonia emissions are: 1) lowering crude protein intake in combination with addition of limiting amino acids; 2) Shifting nitrogen excretion from urine to faeces by including fermentable carbohydrates in the diet; 3) lowering pH of urine by adding acidifying salts to the diet; 4) lowering the pH of faeces by inclusion of fermentable carbohydrates in the diet. These strategies proved to be independent from each other and effects are additive. By combining these strategies a total reduction of ammonia emission in growing-finishing pigs of 70% could be reached. Strategies to reduce odour emission are: 1) reducing protein fermentation by balancing available protein and fermentable carbohydrates in the large intestine; 2) Minimizing breakdown of absorbed sulphur amino acids. More studies are needed in this area of research, but results until now are very promising. A clear relationship exists between fermentable carbohydrates in the diet and methane emissions. This disadvantage should be considered when tackling ammonia emission by this strategy. It is concluded that there is a large potential to reduce environmental load within pig dense areas by nutritional means.  相似文献   

5.
Summary

This paper focuses on research with pigs carried out primarily at the ID‐DLO in the Netherlands with the aim to reduce environmental pollution with nitrogen and phosphorus by changing the diet of the animals while maintaining their health and performance. The excretion of phosphorus (P) per growing pig has been more than halved in the last 20 years as a result of intensive nutritional research on P digestibility, requirements for P, and on the efficacy of microbial phytase in pig feeds. Also, nitrogen (N) excretion can be reduced substantially, but this knowledge has not been put into practice as yet. Preliminary results show that ammonia production can be reduced considerably by altering the diet. Studies to reduce the overproduction of sow manure (up to 98% water) showed that voluntary water consumption by non‐pregnant sows under thermal neutral conditions was approximately 1.4 higher than the requirements. A water:feed ratio of 2:1 for pregnant sows kept at an ambient temperature of 18–20°C had no detrimental effect on health and nutrient digestibility, but diminished urine production by 3.6 L/day, as compared to that with ad libitum water consumption.  相似文献   

6.
Odor intensity (5,437 observations), determined by human panelists (100 different panelists over the course of the experiment), and a number of chemical odorant concentrations were determined for manure-related samples (326) obtained from effluents from conventional stirred-tank reactor (CSTR) and fixed-film anaerobic digesters, effluents to which commercial additives or KMnO4 or H2O2 were added, and feces, urine, and mixed manure from cows fed a control or additive-containing diet. Mostly, samples were held in stoppered, Erlenmeyer flasks for 3 d at room temperature before evaluation by panelists and with chemical analyses, but shorter holding times also were tested. Anaerobic digestion reduced odor intensity linearly with increasing hydraulic retention time (HRT) up to 20 d; fixed-film digestion with 1.5- or 2.3-d HRT reduced odor intensity similarly to that observed with 10-d HRT in CSTR. Addition of commercial products and chemicals altered some odorant concentrations (e.g., ammonia) but did not reduce odor intensity; some products increased odor intensity. Addition of a commercial yeast-based product to a dairy cow diet had no detectable effect. The cow diet study showed that fresh urine and feces alone were less odorous than a mixed combination (manure). Fresh manure was less odorous than manure held for 3 d. Total phenol was the odorant most highly correlated with odor intensity. Individual and total volatile fatty acids also contributed. Ammonia did not seem to be a major contributor to odor in this data set.  相似文献   

7.
Odors from broiler production facilities are the consequence of odorant molecules produced by microbial activity in the litter. The impact of odor on the public can be evaluated by the frequency, intensity, duration, and offensiveness of the odors. Currently, much of the work reported in the scientific literature is directed toward measurement of odor intensity by determination of the odor concentration through threshold olfactometry. Several researchers have reported values for odor concentration in or near broiler production facilities, ranging from 80 to 2,000 odor units, and some researchers have reported odor emission rates. This paper briefly reviews measurement methods for odor concentration and intensity, summarizes the values reported in the literature for odor concentration for broiler houses, discusses the relationship between odor concentration measurements and odor intensity, and reviews the literature to determine if a correlation between odor concentration and ammonia and dust emissions exists.  相似文献   

8.
可发酵碳水化合物减少猪场臭气的机理和应用   总被引：2，自引：0，他引：2  
可发酵碳水化合物,添加在猪日粮中到达后肠作为微生物发酵的底物,通过改变猪肠道和粪便中的微生物及其发酵过程,改变粪尿的理化特性,来减少氨的挥发以及臭气的产生.本文对臭气和除臭方法进行了简单的介绍,并综述了通过在猪日粮中添加可发酵碳水化合物来控制猪场臭气的机理和应用效果.  相似文献   

9.
可发酵碳水化合物,添加在猪日粮中到达后肠作为微生物发酵的底物,通过改变猪肠道和粪便中的微生物及其发酵过程,改变粪尿的理化特性,来减少氨的挥发以及臭气的产生。本文对臭气和除臭方法进行了简单的介绍,并综述了通过在猪日粮中添加可发酵碳水化合物来控制猪场臭气的机理和应用效果。  相似文献   

10.
The excretion of major odor-causing and acidifying compounds in response to dietary supplementation of chicory inulin extract was investigated with six Yorkshire barrows, with an average initial BW of 30 kg, according to a balanced two-period cross-over design. The animals were fed a control diet containing no inulin extract and a treatment diet with 5% inulin extract (as-fed basis) at the expense of cornstarch. Each diet was formulated (as-fed basis) to contain 16% CP from corn (51%) and soybean meal (29%). Each experimental period lasted 14 d, with 10 d for dietary adaptation and 4 d for collection of fecal and urine samples. The fecal samples were analyzed for four major classes of odor-causing and acidifying compounds: 1) VFA; 2) N-containing compounds, including total N and ammonia; 3) volatile sulfides measured as hydrogen sulfide units; and 4) phenols and indoles, including p-cresol, indole, and skatole. Supplementation of chicory inulin at 5% had no effects on the fecal excretion of VFA (P = 0.29), ammonia (P = 0.96), total volatile sulfides (P = 0.56), p-cresol (P = 0.56), and indole (P = 0.75). Fecal excretion of total N (inulin = 6.13 vs. control = 5.10 g/kg DMI) was increased (P < 0.05), whereas urinary total N excretion (inulin = 15.1 vs. control = 16.4 g/[pig x d]) was not affected (P = 0.17) by the inulin supplementation compared with the control group. Furthermore, fecal excretion of skatole (inulin = 9.07 vs. control = 18.93 mg/kg DMI) was decreased (P < 0.05) by the inulin supplementation compared with the control group. In conclusion, dietary supplementation of 5% chicory inulin extract is effective in decreasing the fecal excretion of skatole in growing pigs fed corn and soybean meal diets.  相似文献   

11.
Emissions of ammonia, as well as other gases and particulates, to the atmosphere are a growing concern of livestock producers, the general public, and regulators. The concentration and ruminal degradability of CP in beef cattle diets may affect urinary and fecal excretion of N and thus may affect ammonia emissions from beef cattle feed yards. To determine the effects of dietary CP concentration and degradability on potential ammonia emissions, 54 steers were randomly assigned to nine dietary treatments in a 3 x 3 factorial arrangement of treatments. Treatments consisted of three dietary CP concentrations (11.5, 13, and 14.5%) and three supplemental urea:cottonseed meal ratios (100:0, 50:50, and 0:100 of supplemental N). Steers were confined to tie stalls, and feces and urine excreted were collected and frozen after approximately 30, 75, and 120 d on feed. One percent of daily urine and feces excretion were added to polyethylene chambers containing 1,550 g of soil. Chambers were sealed, and ammonia emissions were trapped in an acid solution for 7 d using a vacuum system. As the protein concentration in the diet increased from 11.5 to 13%, in vitro daily ammonia emissions increased (P < 0.01) 60 to 200%, due primarily to increased urinary N excretion. As days on feed increased, in vitro ammonia emissions also increased (P < 0.01). Potential ammonia losses were highly correlated (P < 0.01) to urinary N (r2 = 0.69), urinary urea-N (r2 = 0.58) excretion, serum urea-N concentration (r2 = 0.52), and intake of degradable protein N (r2 = 0.23). Although dietary composition can affect daily ammonia losses, daily ammonia emissions must be balanced with effects on animal performance to determine optimal protein concentrations and forms in the diet.  相似文献   

12.
The objective of this study was to identify feed additives that reduce enteric methane emissions from cattle. We measured methane emissions, total tract digestibility (using chromic oxide), and ruminal fermentation (4 h after feeding) in growing beef cattle fed a diet supplemented with various additives. The experiment was designed as a replicated 4 x 4 Latin square with 21-d periods and was conducted using 16 Angus heifers (initial BW of 260 +/- 32 kg). Treatments were: control (no additive), fumaric acid (175 g/d) with sodium bicarbonate (75 g/d), essential oil and spice extract (1 g/d), or canola oil (4.6% of DMI). The basal diet consisted of 75% whole-crop barley silage, 19% steam-rolled barley, and 6% supplement (DM basis). Four large chambers (2 animals fed the same diet per chamber) were equipped to measure methane emissions for 3 d each period. Adding canola oil to the diet decreased (P = 0.009) total daily methane emissions by 32% and tended (P = 0.09) to decrease methane emissions as a percentage of gross energy intake by 21%. However, much of the reduction in methane emissions was due to decreased (P < 0.05) feed intake and lower (P < 0.05) total tract digestibility of DM and fiber. Digestibility of all nutrients was also lowered (P < 0.05) by feeding essential oil, but there were no effects on ruminal fermentation or methane emissions. In contrast, adding fumaric acid to the diet increased total VFA concentration (P = 0.03), increased propionate proportions (P = 0.01), and decreased the acetate:propionate ratio (P = 0.002), but there was no measurable effect on methane emissions. The study demonstrates that canola oil can be used to reduce methane losses from cattle, but animal performance may be compromised due to lower feed intake and decreased fiber digestibility. Essential oils had no effect on methane emissions, whereas fumaric acid caused potentially beneficial changes in ruminal fermentation but no measurable reductions in methane emissions.  相似文献   

13.
An educational program was developed for extension agents, faculty, and graduate students to illustrate the effect of diet composition on odor from swine manure. Participants in this program first received a 2-h detailed review on odorous compounds in manure and the effect of diet on odor. For the second portion of the training, nine manure samples were used from pigs fed diets formulated with feed ingredients predicted to have different effects on odor emission or a nutritionally adequate corn-soybean meal diet. Participants were instructed to rate the odor from these samples for pleasantness, irritation, and intensity on a scale of 0 (best) to 8 (worst), using manure from the corn-soybean meal fed pig as the reference with a score defined as 4 for each variable. Results obtained were summarized and discussed before concluding the program. Participants were Cooperative Extension Agents (n = 13) with swine responsibilities and graduate students and faculty (n = 8). The manure from the diet with the worst odor scores (1% garlic) was rated at 70% more odorous across the three odor variables (P < 0.05) than the diet with the least odorous manure (purified diet). Even though a reference sample was used, individual participants differed in their perception of irritation across samples (P < 0.05), ranging in average score across diets from 2.4 (moderately better than reference) to 5.0 (slightly worse than reference). With extension agents, a 1 to 7 scale (very interesting to not at all interesting) was used for evaluation of the training session. Participants found the material to be interesting (mean = 1.7, SD = 0.7) and the training exercise to be well organized and coherent in its presentation (mean = 1.8, SD = 0.7). Participants enjoyed this training and learned that differences in odor are achievable through altering diet composition, and that the response to swine odor depends on individual odor perception.  相似文献   

14.
Two feeding studies were conducted to examine the impact of dietary inclusion of specific feed ingredients on manure characteristics and manure odor. In one study, 72 finishing pigs were used to evaluate the effects of distillers dried grains with solubles (DDGS) on pig performance, manure characteristics, and odorous emissions. Three diets containing 0, 5, and 10% DDGS were fed during six 4-wk feeding periods. Week 1 served as a dietary adjustment period. Animals were housed in two feeding rooms (six pigs/room) with one treatment/room. A new group of animals (average initial BW = 85.8 kg) was used for each feeding period. Diets were replicated four times. Rooms were equipped with individual shallow manure storage pits that were cleaned once weekly (d 7). On d 4 and 7 of each week, manure pit samples, for chemical analyses, and air samples, for olfactometry analysis, were collected from each room. Odor dilution threshold was greater on d 7 than on d 4 of manure storage across all treatments (P < 0.01). No treatment differences in manure composition were noted. In the second study, weaned pigs (approximately 5 wk old) were fed isonitrogenous diets containing 0, 1.5, or 3% bloodmeal. Pigs were housed by diet (three pigs/diet) in one of four individual feeding rooms. A new group of pigs was used for each of the two, 4-wk feeding periods. During period 1, the 3% bloodmeal diet was fed in two of the four rooms; the 0% bloodmeal diet was fed in two rooms during period 2. Manure samples, for chemical analyses, and air samples, for olfactometry analysis, were collected 2 d per week (d 4 and d 6) from each room during wk 2 through 4. No significant treatment differences were observed for odor dilution threshold (P = 0.30). Longer manure storage time, 6 d vs 4 d, resulted in a larger odor dilution ratio (P < 0.01). Manure composition was unaltered by storage time. Results suggest that odor intensifies during storage.  相似文献   

15.
In order to reduce N, P and trace elements in pig manure, research toward a better agreement between supply and requirement has been undertaken in recent years, and ways to improve the biological availability of these elements in feedstuffs have been investigated. Substantial reduction in N excreted by pigs can be achieved by phase feeding combined with a better adjustment of the dietary amino acid balance. Feeding pigs with low N diets also allows a reduction of ammonia emission and to some extent the production of malodorous compounds. Phase feeding is also effective in reducing P excretion. However, low digestibility of P in feeds remains the main problem, although it is partly alleviated by the supplementation of pig diets with microbial phytase and the use of highly digestible mineral phosphates. In the same way, lowering Cu and Zn dietary supply is obviously an efficient way to reduce pigs' excretion of Cu and Zn. In a whole-farm perspective, improving the efficiency of nutrient utilisation by the animals is an efficient way to reduce import of nutrients from outside the farm and decrease the environmental risks.  相似文献   

16.
影响猪场氨气排放的因素及控制措施   总被引：3，自引：0，他引：3       下载免费PDF全文
 猪舍是环境中氨气排放的重要来源,多年来,许多研究者对影响氨气排放的因素以及减少其排放技术进行了研究。影响氨气排放的主要因素包括地板类型、粪污处理系统、猪舍环境条件、日粮组成以及饲喂技术等。论文主要综述了影响氨气排放的各种因子以及减少氨气排放的各种措施,为生产中减少氨气污染,提高猪的健康,节约资源等提供理论指导。  相似文献   

17.
A literature review on production and control of nuisance odor from land application, processing, and storage of broiler litter is presented in this paper. The review identifies several odor production factors and odor control strategies based upon research conducted on litter and manure from poultry and other species. Published research lacks information on odor emissions and control of odor as affected by litter moisture conditions, loading and transportation of litter, application site factors, and weather conditions (prior, during, and after litter application). For this reason, several studies, mostly from peer-reviewed publications on ammonia emissions from broiler operations and various species were included. It was inferred that conditions that cause increased ammonia emissions may also be favorable for the production and increase in odor from land application, processing and storage of broiler litter. New nuisance odor assessment tools, such as the model odor from feedlots setback estimation tool (OFFSET), provide a better control on setback distances for improved community relations. Consideration of wind speed, direction, and weather condition during land application, incorporation of land-applied litter, covering of litter in storage and while in transportation, and processing, such as composting of litter and mortality, were all considered as practices that help minimize odor emission.  相似文献   

18.
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19.
Odors from swine production facilities are associated with the storage and decomposition of manure. Diet is linked to manure composition and will likely affect odor, but the microbial mechanisms responsible for manure decomposition and odor production are poorly understood. To identify the sources of odor during manure fermentation, substrates (starch, casein, and cellulose) were added to slurries of fresh swine manure, and the anaerobic accumulation of fermentation products and the consumption of substrates were measured relative to no addition of substrates. Volatile fatty acids and alcohols were the dominant fermentation products in all treatments. The total VFA concentration from starch treatment was greater (P < 0.001) than for all other treatments. Branched-chain VFA and aromatic compounds accumulated in all treatments, but accumulation in the casein treatments was greater (P < 0.001) than in all other treatments. Thus, addition of carbohydrate to swine manure slurries did not circumvent protein fermentation, as was previously observed in cattle manure slurries. Based on substrate loss, starch and protein fermentation were equivalent in all treatments, with losses of each exceeding 4% of the DM. Substrate additions had a limited effect on the overall accumulation of odor compounds in manure and on odor compound composition. Compared with the results of the earlier fermentation study of fresh cattle manure, swine manure fermentation produced less lactate and more products of protein fermentation (branched-chain VFA and aromatic ring compounds). We hypothesize that differences in manure organic matter composition between cattle and swine, a result of diet and digestion, select for bacterial communities that are adapted to the available substrate composition.  相似文献   

20.
畜禽场排放的氨气、硫化氢、挥发性有机物等恶臭污染严重危害人畜健康和周边环境,恶臭污染问题亟待解决。目前,畜禽场除臭方法多样,包括物理法、化学法和生物法。本文论述了微生物除臭技术的原理及在畜禽场以微生物添加剂的形式用于源头除臭、以生物过滤和喷洒的形式用于过程除臭、以发酵液等形式用于末端除臭的应用和研究进展,对微生物除臭技术现状和发展趋势进行简要分析。  相似文献   

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