Evaluation of Factors Influencing the Generation of Ammonia in Different Bedding Materials Used for Horse Keeping

Bedding material is an important factor in determining stable air quality in terms of ammonia formation. The objective of this study was to analyze different bedding materials used for horse stables under standardized conditions, to determine which material is best suited for improving the climate of a stable. The particular concern was a reduction in gaseous ammonia concentrations. Therefore, the following materials were examined: wheat straw, wood shavings, hemp shives, linen shives, wheat straw pellets, and paper cuttings. Twelve containers were constructed in an environmentally controlled room, and the same material was placed into two containers, with the amount of material used being determined by its carbon content. A defined ratio of horse manure/urine mixture was added daily to each container over a period of 14 days. The concentrations of gaseous ammonia, carbon dioxide, nitrous oxide, and water vapor were measured continuously above the bedding within the containers. Means of gaseous ammonia were found to be 178.0 mg/m³ for wheat straw, 155.2 mg/m³ for wood shavings, 144.6 mg/m³ for hemp, 133.7 mg/m³ for linen, 60.3 mg/m³ for straw pellets, and 162.6 mg/m³ for paper cuttings. In conclusion, the results of this study have shown that straw pellets are suitable for horse stables, not only to improve air quality but also, first and foremost, in relation to ammonia binding and ammonia transformation within the bedding material, respectively. However, straw pellets may also have disadvantages. The high substrate temperatures that were measured in straw pellets could favor the growth of pathologic germs that can adversely affect animals' health.     

The Influence of a Particle Separation Technology on the Generation of Airborne Particles from Different Roughages and Bedding Materials Used for Horses

Four different types of bedding materials (wheat straw, wood shavings, hemp shives, flax shives) and two roughages (hay, haylage) were treated using an air-driven particle separation technology. The airborne particle and mold generation of both treated and untreated samples were then analyzed under standardized laboratory conditions. In addition, samples of all the treated materials were stored for 8 weeks either in a pressed or incoherent form and then analyzed again for their ability to generate airborne particles. The airborne particle concentrations were detected online with the gravimetrically measuring analyzer tapered element oscillating microbalance (TEOM) 1400a that was equipped successively with different inlets to measure the particle fractions PM₂₀, PM₁₀, PM_2.5, and PM_1.0 (PM = Particulate matter). The particle separation resulted in a reduction in the airborne particle (PM₂₀) generation in all materials: hay 49.16 to 22.79 mg/m³ (53.6%), haylage 28.57 to 25.04 mg/m³ (12.3%), wood shavings 141.68 to 15.04 mg/m³ (89.4%), wheat straw 143.08 to 22.97 mg/m³ (83.9%), flax 135.11 to 53.31 mg/m³ (60.5%), and hemp 63.67 to 17.64 mg/m³ (72.3%). The 8-week storage of the treated materials as compressed materials led to a renewed significant increase in the airborne particle (PM₁₀) concentration in the haylage (+29.9%), wheat straw (+104.0%), wood shavings (+40.4%), and hemp shives (+30.7%). Storage of the incoherent materials caused a significant increase in these particles only in the wheat straw (+44.2%). The separation treatment reduced the mold production by 92.4% in the wood shavings, 88.0% in the wheat straw, and 85.8% in the hay.     

Generation of Airborne Particles from Horse Feeds Depending on Type and Processing

Among other factors (eg, bedding material, roughage), feed has an important effect on the airborne particle concentration in the stable air, in particular directly in the breathing zone of the horse during feeding. Therefore, this study was designed to analyze and compare the generation of different airborne particle fractions of diverse feed types and feed processing techniques under standardized laboratory conditions. Oats and barley as well as two commercially formulated ready-prepared pellets and two different commercially formulated ready-prepared mixes were analyzed. Oats were subjected to four different forms of processing (whole uncleaned, whole cleaned, rolled uncleaned, rolled cleaned), barley was subjected to steam flaking in addition to the same forms of processing as oats. In total, 13 feeds were analyzed. Airborne particle concentrations were detected online with a gravimetrically measuring analyzer that was equipped successively with different inlets to measure the particle fractions PM 1, PM 2.5, PM 10, and PM 20. The measurements were carried out in a closed chamber (1 × 1 × 1.5 m) including a bowl (diameter = 0.5 m), which simulated the trough. The sample inlet was situated at a height of 1.0 m above the bowl. Rolling oats and barley led to a significantly increased generation of the PM 20 fraction and a significantly decreased generation of the PM 2.5 fraction. The mechanical cleaning of oat and barley brings a clear decrease in dust generation from straights whether they are left whole or are rolled after cleaning. A considerable reduction in dust generation can be achieved if steam-flaked barley or commercially prepared feeds are used.     

Effects of Three Different Liquid Additives Mixed with Whole Oats or Rolled Oats on the Generation of Airborne Particles from an Experimental Simulating Horse Feeding

This study was designed to analyze the reduction potential of three different liquid additives (water, rapeseed oil, and molasses) in three different concentrations mixed with cleaned whole or rolled oats on the generation of airborne particles under standardized laboratory conditions. In addition, the influence of two different drop heights (20 and 40 cm) was analyzed. Airborne particle concentrations were detected online with the gravimetrically measuring analyzer TEOM 1400a that was equipped successively with different inlets to measure the particle fractions PM₂₀, PM₁₀, and PM_2.5. The mixing of oats with just 1% (w/w) of each of the liquid additives led to a significant reduction in airborne particle generation in all three particle fractions with respect to the samples without additives (P < .0001). By the addition of 1% oil, a reduction in the PM₂₀ fraction of 90.6% (120.3 μg/m³) could be achieved. The same dosage of water or molasses only resulted in a reduction of 60.4% (504.6 μg/m³) or 69.1% (393.2 μg/m³), respectively. In general, the highest significant reduction in the PM₂₀ fraction was achieved using 3% rapeseed oil: 96.5% as compared with 75.6% for 3% water and 81.9% for 3% molasses. The drop height only had a significant effect on the generation of the PM₁₀ fraction, with it being lower at 20 cm than at 40 cm (P = .0261).     

Characteristics of Gas Generation (NH3, CH4, N2O, CO2, H2O) From Horse Manure Added to Different Bedding Materials Used in Deep Litter Bedding Systems

The aim of this study was to analyze the influence of horse manure added to different bedding materials on the generation of gases (ammonia (NH₃), nitrous oxide, carbon dioxide, methane, water vapor) from deep litter bedding under standardized laboratory conditions. Two different types of straw (wheat and rye) and wood shavings were analyzed. The deep litter (substrate) was made of 25 kg of the respective bedding material, 60 kg horse feces, and 60 L ammonium chloride solution (urea), and spread out in identical chambers over 19 days (n = 3). On days 1, 8, 15, and 19, total nitrogen, total carbon, and dry matter content of the substrate, as well as the pH in 500-g samples, were measured along with. At the end of each test period, the nitrite nitrogen, nitrate nitrogen, and ammonium nitrogen contents of the leachate were analyzed. The wheat straw substrate emitted the highest concentration of NH₃ (4.31 mg/m³; P < .0001) and the wood shavings substrate emitted the lowest (1.73 mg/m³; P < .0001); the rye straw substrate generated 3.05 mg/m³. In addition, significant differences occurred during days 1 to 3 with respect to the generation of the gases NH₃, methane, nitrous oxide, carbon dioxide, and water vapor, and after the opening of the chamber on day 15. The nitrogen losses through the leachate occurred mainly in the form of nitrate, where the leachate from the wheat straw substrate had a significantly higher amount of nitrate nitrogen (44.56 mg) as compared with the leachates of the rye straw (14.49 mg; P ≤ .0001) and the wood shaving substrates (22.62 mg; P = .0010).     

Effects of Different Bedding Materials on the Behavior of Horses Housed in Single Stalls

The effects of three different bedding materials (straw, wood shavings, and straw pellets) on the behavior of six warmblood horses (four mares, two of them with foals) housed in single stalls were analyzed. Each material was used for 2 weeks in three consecutive runs. The behavior of the horses was videotaped and analyzed on the first and last 3 days for each bedding alternative in the last of the three runs. The time budgets for the behaviors including standing, eating, lying, occupation with bedding material, and other were generated. Compared with straw pellets and wood shavings, the application of straw bedding led to a significantly higher frequency and longer duration of occupation with bedding material and in turn, shorter fractions of standing and other behaviors. The total duration of lying was significantly longer on straw than on straw pellets. Straw pellets resulted in the least mean recumbency duration per occurrence of this behavior. Because occupation is one of the important functions that bedding material is supposed to fulfill, we concluded that in regard to horse behavior, straw bedding was the best among the three materials analyzed. Further investigations with a more homogeneous group of probands are necessary to verify the observed behavioral reactions.     

饲料中马、驴源性成分的分子生物学检测技术

根据马、驴线粒体DNA中的保守区段设计了一对引物，通过聚合酶链式反应（polymerase chain reaction，PCR）可以专一地检测扩增出马、驴源性成分的DNA片段，再经限制性内切酶Sau 3A和Alu Ⅰ的酶切鉴定可以区分马源性成分和驴源性成分．PCR扩增产物的测序结果验证了酶切鉴定结果的正确性。引物灵敏度测试培果表明该方法的检测低限均达0．3％．该对引物可以成为检测马、驴源性成分高效准确的检测工具。     

不同比例番茄酱渣与苜蓿制成的草颗粒对绵羊瘤胃降解率的影响

选用3只安装有永久性瘤胃瘘管的绵羊,采用尼龙袋法对不同配比的番茄酱渣与苜蓿、棉壳制成的草颗粒在瘤胃2、6、12、24、36和72 h的降解率进行研究,从而确定了番茄酱渣与苜蓿、棉壳合适的制草颗粒配比和混合草颗粒中各营养成分的动态降解率。结果表明,番茄酱渣∶苜蓿∶棉壳为60∶35∶5时正组合效应最高,该组降解率:dp(DM)=27+40.9×(1-e^-0.0139t)(n=6,R²=0.978);dp(CP)=31.9+32.6×(1-e^-0.071t)(n=6,R²=0.986);dp(NDF)=14.3+56.1×(1-e^-0.023t)(n=6,R²=0.994)。