Effects of anaerobic digestion and additives to effluent or cattle feed on odor and odorant concentrations.

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.     

Sources of maternal odors and the development of odor preferences in baby pigs

Seven experiments utilizing 77 litters of piglets were conducted to determine the relative preferences or aversion of piglets for maternal olfactory cues. A Y-maze was used to test piglet preferences for two substances at any one time. A preference index was calculated from Y-maze data to identify whether piglets expressed a preference or aversion to the two substances tested in each session. The first two experiments examined piglet preferences for maternal fecal odors, colostrum, milk, urine and skin washings at 12 h and 7 d of age. Piglets preferred the odor of nipple washings and sow feces at 12 h of age. Piglets preferred sow fecal odors at 7 d of age in one study. The third study showed that piglets could discriminate between their mother's fecal odor and fecal odors from other sows. The fourth study examined piglet preferences for maternal fecal odors at birth, 12 h and 1, 3 and 7 d of age. At all ages tested except birth, piglets preferred sow fecal odors over water. The final three studies showed that piglets did not prefer to be near novel odors (orange and banana odors), nor did they prefer to be near the putative rat maternal pheromone, deoxycholic acid. In conclusion, piglets learn their mother's odor within the first 12 h of life. Piglets are most attracted to the odors associated with maternal feces and skin secretions. Piglet odor discriminatory ability is specific for maternal odors (not just odorous substances) and very acute (they can discriminate between mother and non-mother odors). When modifying piglet behavior to improve survival, the piglet's well-developed olfactory ability should be considered.     

Development of a novel paradigm for the measurement of olfactory discrimination in dogs (Canis familiaris): A pilot study

Olfactory dysfunction in older human beings has been shown to be associated with an increased risk of cognitive decline, yet age-related changes in olfactory behavior have received little attention in the dog model of human aging. We developed an odor habituation and fine odor discrimination paradigm to test the hypothesis that dogs would show a novelty response toward unfamiliar urine from entire male conspecifics. We tested 26 odor detection dogs (14 females, 12 males) from the New South Wales police dog unit, ranging in age from 1 year 2 months to 11 years 10 months. First, dogs were familiarized with a master odor over 2 presentations. Second, we measured difference in investigation time of a master odor as compared with 5 odor mixtures using the following ratios of novel-to-master odor: 100:0, 80:20, 60:40, 40:60, and 20:80. Dogs habituated to the master odor after the first presentation (t(25) = 6.048, P < 0.001). After 2 dogs that failed to habituate were excluded, there was a nonsignificant trend (t(21) = ?1.968, P = 0.062) for aged dogs (>8 years, N = 6) to show reduced habituation as compared with middle-aged dogs (5-8 years, N = 9) and with all dogs aged <8 years (N = 18, t(21) = ?1.883, P = 0.072). Approximately half of the dogs tested (N = 11) failed to show a novelty response toward the 100:0, novel:master odor. The remaining dogs (N = 15) showed a significant novelty response toward this odor (mean difference = 1.89 seconds, confidence interval = 0.86-2.84). Investigation of the remaining odor mixtures was not significantly different from investigation of the master odor in all dogs. Further development of this paradigm is needed using naive pet dogs before it can be used as a reliable measure of fine odor discrimination. The current, weak trend for an age effect in habituation warrants further investigation in a larger cohort to determine if this effect becomes significant or if it is simply a manifestation of small sample size and low statistical power. It is recommended that future studies use dogs that have not been trained against or actively discouraged from investigating urine because previous learning may have had a significant effect on the outcomes of this study.     

Ammonia,volatile fatty acids,phenolics, and odor offensiveness in manure from growing pigs fed diets reduced in protein concentration

The objective of this study was to investigate whether reducing dietary CP concentration decreases fecal VFA, manure ammonia (NH3) emission and odor, and urinary phenolic metabolites. Six barrows were allotted to one of six dietary treatments in a Latin square design. Treatments consisted of four corn-soybean meal based diets containing 15, 12, 9, and 6% CP, a casein-based diet containing 15% CP, and a protein-free diet (0% protein). Crystalline AA were included in the 12, 9, and 6% CP diets. The casein-based and protein-free diets were used to determine basal endogenous contribution of VFA, phenolics, NH3, and manure odor. Pigs were housed individually in metabolism cages to allow total collection of feces and urine. Feces and urine were collected and pooled within pig and period. Feces and urine were analyzed for VFA and phenolic metabolite concentrations, respectively. Feces and urine were then mixed, stored, and fermented at room temperature for 30 d. For NH3 determination, headspace air was sampled from manure slurries at 24, 48, and 72 h after fermentation. Slurry samples were placed into vials, capped, and randomized before odor panel evaluation. Odor offensiveness was classified on severity: 1 = non-offensive; 2 = mildly offensive; 3 = moderately offensive; 4 = strongly offensive; and 5 = extremely offensive. Reducing dietary CP increased (P < 0.05) fecal VFA concentrations but did not affect phenolic concentrations in urine. Manure NH3 emission was reduced (P < 0.05) as dietary CP concentration decreased from 15 to 0%. The 15% diet had the least offensive manure slurry with odor qualitative ranking of 2.58 (i.e., mild-moderately offensive). Compared with the 15% CP diet, manure from the 9 and 6% CP diets was found to be more offensive (P < 0.05), with qualitative rankings of 2.92 and 3.10, respectively. Odor qualitative rank for the 12% CP, protein-free diet, and casein-based diet did not differ from that of the 15% CP diet. These results indicate that reduction in dietary CP concentrations decreases manure NH3 emission, but it does not diminish manure odor offensiveness and fecal VFA concentrations.     

Effects of phenylbutazone and oxyphenbutazone on basic drug detection in high performance thin layer chromatographic systems

Interference or 'masking' in thin layer chromatography occurs when the presence of one drug on a thin layer plate physically obscures or interferes with the detection of another drug. We investigated the ability of phenylbutazone and oxyphenbutazone to mask or interfere with the detection by high performance thin layer chromatography (HPTLC) of basic drugs used illegally in horse racing. Of fifty-five basic drugs called 'positive' since 1981 by laboratories affiliated with the Association of Official Racing Chemists (AORC), forty did not comigrate with phenylbutazone or oxyphenbutazone and could not, therefore, be masked. When 75 micrograms/ml of oxyphenbutazone was spiked into urine samples, subjected to an extraction procedure for basic drugs, and then run in our routine HPTLC systems, no 'spots' due to oxyphenbutazone appeared. 'Masking' by oxyphenbutazone, therefore, did not and could not occur in our test systems. When phenylbutazone at a concentration of 30 micrograms/ml was spiked into urine samples and run in the routine HPTLC system, phenylbutazone spots were visible under ultraviolet light and after certain specific oversprays were used to visualize basic drugs. These spots, however, did not interfere with routine thin layer testing for basic drugs. It was concluded that phenylbutazone and oxyphenbutazone had no significant ability to interfere with detection of the parent forms of these basic drugs under the conditions described in these experiments.     

Escherichia coli isolates from commercial chicken meat and eggs cause sepsis,meningitis and urinary tract infection in rodent models of human infections

The zoonotic potential of Escherichia coli from chicken‐source food products is important to define for public health purposes. Previously, genotypic and phenotypic screening of E. coli isolates from commercial chicken meat and shell eggs identified some E. coli strains that by molecular criteria resembled human‐source extraintestinal pathogenic E. coli (ExPEC). Here, to clarify the zoonotic risk of such chicken‐source E. coli, we compared selected E. coli isolates from chicken meat and eggs, stratified by molecularly defined ExPEC status, to human‐source ExPEC and to laboratory E. coli for virulence in rodent models of sepsis, meningitis and UTI, and evaluated whether specific bacterial characteristics predict experimental virulence. Multiple chicken‐source E. coli resembled human‐source ExPEC in their ability to cause one or multiple different ExPEC‐associated infections. Swimming ability corresponded with urovirulence, K1 capsule corresponded with ability to cause neonatal meningitis, and biofilm formation in urine corresponded with ability to cause sepsis. In contrast, molecularly defined ExPEC status and individual genotypic traits were uncorrelated with ability to cause sepsis, and neither complement sensitivity nor growth in human urine corresponded with virulence in any infection model. These findings establish that chicken‐derived food products contain E. coli strains that, in rodent models of multiple human‐associated ExPEC infections, are able to cause disease comparably to human‐source E. coli clinical isolates, which suggests that they may pose a significant food safety threat. Further study is needed to define the level of risk they pose to human health, which if appreciable would justify efforts to monitor for and reduce or eliminate them.     

周期性去叶对地毯草克隆生长的影响

以地毯草为研究对象,通过随机区组试验,初步研究不同去叶周期对地毯草克隆生长的影响。结果表明,不同的去叶周期之间存在显著或极显著性差异,中等强度去叶(D20)最适宜地毯草的生长。而过度去叶(D10)或长时间未去叶(D60)都抑制了地毯草的正常生长,从而导致地毯草草坪使用价值下降。因此,中度去叶有利于地毯草的克隆生长,提高成坪速率及其观赏价值。     

践踏对草垫式人造-天然混合草坪质量的影响

为研究践踏对草垫式混合草坪草质量和根系生长的影响，本研究以多年生黑麦草品种‘名仕’为研究材料，以无草垫处理为对照，通过践踏器模拟研究轻度、中度和重度践踏条件，进行为期4周的践踏处理，以此研究两种草垫对不同人造-天然混合草坪的坪观质量、生长特性和运动质量的影响。结果表明：在践踏条件下，草垫式混合草坪的色泽、盖度和坪观质量等综合表现优于天然草坪，且践踏强度越大差异越明显，其中在践踏4周后的重度践踏条件下，两个草垫试验组分别比对照组的色泽提高了45.5%和39.0%，盖度分别比对照组提高了136.4%和150.0%。在践踏处理下，草垫减缓了草坪的损伤程度，对草坪草地上和地下部分的生长起到了保护作用，对践踏具有缓冲作用，践踏4周后无背衬试验组的根长在轻度、中度和重度践踏下分别比对照组提高了105.3%、239.1%和152.6%。草垫在践踏胁迫下对草坪草生长起到了较为明显的保护作用，增加草坪的扭动摩擦，降低了摔倒的风险，但草垫增加了草坪的表面硬度和坪床紧实度，使得头部损伤风险加大，其中有背衬结构的风险较大。因此在草垫式混合草坪的使用中要采取适宜的养护措施，避免硬度过高带来风险。     

Swine manure composition affects the biochemical origins,composition, and accumulation of odorous compounds

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.     

草垫植入对混合草坪坪床稳定性和表观质量的影响

为研究人造草垫式混合草坪中不同的人造草垫对草坪表观质量和稳定性的影响,以多年生黑麦草品种“名仕”为研究材料,以无草垫处理为对照,研究了3种人造草垫植入对草坪表观质量、地上地下生物量和根系参数(根长、根表面积、根体积和根活力)的影响,并通过直剪试验对坪床稳定性进行测定。结果表明:各草垫处理均降低了草坪的色泽、归一化差异植被指数和密度,生长至116 d时,3个草垫处理组的密度分别比对照组降低了20.8%、8.7%和14.7%,有背衬的草垫结构增加了草坪草的均一度;同时,草垫处理降低了草坪草的地下生物量、根系长度、根总表面积和根系总体积,影响了垫上和垫下部分的根系活力。草垫处理增加了混合系统的抗剪强度和表面硬度,3个草垫处理组分别比对照组的内聚力增加了51.9%、162.7%和134.6%,硬度分别比对照组增加了34.6%、32.8%和45.8%。因此,人造草垫式混合草坪中,各种草垫在不同程度上抑制了根系生长,进而影响地上部分的生长和表观质量;人造草垫式混合系统稳定性高于天然草坪,且有背衬结构的草垫对提高坪床稳定性的效果更为明显,草垫对提高草坪的强度有积极作用。     

Effects of crystalline amino acid supplementation to the diet on odor from pig manure

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.     

Potential for reduction of odorous compounds in swine manure through diet modification

Recent public concern about air pollution from pork production units has prompted more research to develop methods to reduce and control odors. Masking agents, enzymes and bacterial preparations, feed additives, chemicals, oxidation processes, air scrubbers, biofilters, and new ventilation systems have been studied. Research relating the effects of the swine diet on manure odors has been scarce. Introducing feed additives to bind ammonia, change digesta pH, affect specific enzyme activity, and mask odors has been either costly or not consistently successful. Recent research emphasis has focused on manipulating the diet 1) to increase the nutrient utilization of the diet to reduce excretion products, 2) to enhance microbial metabolism in the lower digestive tract to reduce excretion of odor-causing compounds, and 3) to change the physical characteristics of urine and feces to reduce odor emissions. Primary odor-causing compounds evolve from excess degradable proteins and lack of specific fermentable carbohydrates during microbial fermentation. Reductions in ammonia emissions by 28 to 79% through diet modifications have been reported. Limited research on reduction of other odorous volatile organic compounds through diet modifications is promising. Use of synthetic amino acids with reduced intact protein levels in diets significantly reduces nitrogen excretions and odor production. Addition of nonstarch polysaccharides and specific oligosaccharides further alters the pathway of nitrogen excretion and reduces odor emission. Continued nutritional and microbial research to incorporate protein degradation products, especially sulfur-containing organics, with fermentable carbohydrates in the lower gastrointestinal tract of pigs will further control odors from manure.     

High dietary copper improves odor characteristics of swine waste

We conducted two experiments to determine the effects of dietary copper concentration and source on odor characteristics of swine waste. In both experiments, 192 weanling gilts and barrows were allotted to 24 pens. Pens were randomly assigned to one of six dietary treatments, consisting of control (10 ppm Cu as cupric sulfate, CuSO4), 66 or 225 ppm Cu as CuSO4, or 33, 66, or 100 ppm Cu as cupric citrate (Cucitrate). An antibiotic was included in the diets for Exp. 1, but not Exp. 2. On d 28, fecal samples were randomly obtained from one pig per pen and stored at -20 degrees C until preparation and evaluation by an odor panel. The odor panel consisted of 10 individuals, and each panelist evaluated the odor intensity, irritation intensity, and odor quality of the samples. In Exp. 1, the odor and irritation intensity of the feces were lower (P < .05) from animals consuming diets containing 225 ppm Cu as CuSO4 and 66 or 100 ppm Cu as Cu-citrate compared to the control. The odor quality of the waste from animals consuming diets containing 225 ppm Cu as CuSO4 and 66 or 100 ppm Cu as Cu-citrate was improved (P < .05) compared to the 33 ppm Cu treatment. In Exp. 2, the odor intensity of the feces of pigs receiving diets supplemented with all concentrations of Cu-citrate was lower (P < .05) than that of feces from the control animals. Irritation intensity of the feces was not affected by treatment. Odor quality of waste of pigs supplemented with 225 ppm Cu from CuSO4 and all concentrations of Cu-citrate was improved (P < .05) compared to that of waste of the control pigs. Two gilts and two barrows from each nursery pen in Exp. 1 were continued through the growing-finishing phase on their respective experimental diets. The growing-finishing phase lasted 103 d, and fecal samples were randomly obtained from one pig per pen at the completion of the phase. During the growing-finishing phase, the odor intensity and the irritation intensity of the feces were lower (P < .05) from pigs supplemented with 66 and 225 ppm Cu as CuSO4 and 66 and 100 ppm Cu from Cu-citrate than from the control pigs. The odor quality of the waste was improved (P < .05) in all animals receiving supplemental Cu. These data indicate an improvement in odor characteristics of swine waste with the supplementation of Cu. In addition, lower concentrations of an organic nonsulfate Cu source resulted in similar odor characteristics of swine waste as 225 ppm CuSO4.     

木质纤维分解菌群筛选及其对秸秆分解与畜禽粪便除臭能力评价

为获得高效的木质纤维素分解菌群,并研究该菌群的分解能力及对畜禽粪便利用能力。以牛、鸡粪混合储粪池中土样为材料,利用限制性培养技术筛选了一组木质纤维素分解菌群;以未经化学处理的秸秆(小麦秸秆、稻草秸秆、玉米秸秆)为材料,利用失重法测定木质纤维素分解菌群的分解能力及抗杂菌污染能力;以自然风干的畜禽粪便为唯一营养源,初步评定了该菌群对畜禽粪便的利用能力和除臭能力。结果表明,筛选的木质纤维素分解菌群48 h将培养基内滤纸崩解成糊状,滤纸分解率达84.55%;灭菌条件下接种木质纤维素分解菌群培养6 d,小麦秸秆、稻草秸秆、玉米秸秆总重量分别减少47.00%,48.62%,50.21%,接入杂菌条件下接种木质纤维素分解菌群培养6 d,小麦秸秆、稻草秸秆、玉米秸秆总重量分别减少42.14%,44.99%,53.74%;分别以5 g的猪粪、3 g的鸡粪为唯一营养源制作100 mL粪便培养液(添加0.35%滤纸),接入木质纤维素分解菌群后,滤纸分别在第3天和第4.5天被分解成糊状,第8天粪便培养液臭味强度(微弱臭气味)较对照(强烈臭气味)明显减弱。木质纤维素分解菌群能高效降解未经化学处理的玉米秸秆等木质纤维材料,抗外来杂菌能力强,能够利用畜禽粪便快速分解纤维素,并具有一定的除臭能力,在农业废弃资源无害化处理及资源化利用等领域具有研究和开发价值。     

Steroid hormone pathways in the pig, with special emphasis on boar odor: a review

Although castration of male pigs grown for meat production has long been a commercial practice in order to eliminate an undesirable odor emanating from the meat upon heating, intact males (boars) grow faster, utilize feed more efficiently and produce leaner carcasses. This review outlines the biochemical pathways of steroid hormone formation in the pig, placing special emphasis on the C19-delta 16-steroids, which have been shown to produce the "urine- or perspiration-like" odor of boar meat. Analytical methods currently available for quantitation of the C19-delta 16-steroids are also reviewed, including gas chromatography-mass spectrometry, radioimmunoassays and enzyme-linked-immuno-absorbent-assays (ELISA). Finally, methods for preventing boar odor are discussed, such as environmental methods of rearing boars, genetic selection against boar odor and autoimmunization against C19-delta 16-steroids. Autoimmunization techniques appear to offer the most promise for inhibiting production of the compounds responsible for boar odor in male pigs raised for meat production, while still maintaining the advantages of improved efficiency and greater leanness.     

Urinalysis and associated laboratory procedures

Macroscopic examination of urine is an integral part of urinalysis, and blood and bile pigments are a common cause of abnormal coloration. Urine SG is a convenient index of urine concentration and should be correlated with the patient's hydration status to determine the ability of the kidneys to concentrate and dilute urine. The pH of urine of dogs and cats normally is dietary dependent, but alkaline urine may suggest that the urinary tract is infected with a urea splitting organism. The dipstick test for proteinuria is convenient but less reliable than the sulfosalicylic acid method. The dipstick test for blood should not be used as a substitute for microscopic examination of urine but is of value in detecting hemoglobinuria and myoglobinuria, when red cells may be absent in the sediment. The finding of glucose, ketones, and bilirubin in urine, when interpreted properly, may indicate the presence of disease processes not associated with the urogenital tract. Microscopic examination of urine sediment must be interpreted in combination with the physical and chemical composition of urine, but excessive numbers of cells, casts, crystals, and bacteria may provide evidence of disease. The absence of these structures in the sediment, however, does not eliminate the possibility of disease. The ability of the kidneys to concentrate urine is dependent on normal kidney function and the production and release of ADH. A urine SG greater than 1.030 in dogs and 1.035 in cats indicates that the functions associated with concentrating urine are adequate. In the evaluation of the patient's ability to form concentrated urine, the status of hydration must be considered; this may require water deprivation tests or administration of ADH. The estimation of blood urea nitrogen concentration, with the use of test strips, may provide a convenient but not specific measure of renal function.     

Accumulation and consumption of odorous compounds in feedlot soils under aerobic, fermentative, and anaerobic respiratory conditions.

Agricultural odors present an increasingly difficult challenge to livestock producers, yet very little information is available on the microbiology of odor production or microbial factors that regulate the emission of odors. This study examined the microbial potential for odor production and odor consumption in two soils from a cattle production facility in central Nebraska. The two soils tested were collected from a feedlot pen and a runoff ditch below the pen and contained high- and low-fecal matter content, respectively. These soils were tested for their ability to produce and consume a mixture of VFA and aromatic compounds (phenols and indoles) under aerobic, fermentative, and anaerobic respiratory conditions, with NO3-, Fe(III), Mn(IV), and SO4(2-) serving as anaerobic terminal electron acceptors, over a 6-wk incubation. The pen soil had greater (P < 0.05) initial total VFA content (40 micromol/g soil) and produced more VFA during incubation than the feedlot ditch soil, whereas total aromatic compound concentrations were not significantly different between soils. The general pattern of odor compound accumulation and consumption did not differ between soils. Oxygen and nitrate treatments produced very little VFA and consumed acetate more rapidly than the other treatments, which produced large quantities of short-chain VFA and consumed acetate only after all other VFA were consumed. When VFA and aromatic compound consumption was compared across all the treatments, aerobic incubation proved most effective, and all compounds were rapidly consumed by the second day of incubation. Of the anaerobic treatments examined, nitrate proved most effective, followed by Fe, with VFA consumed by d 5 and 21, respectively. Anaerobic incubation with sulfate produced more VFA than the fermentative incubation, and anaerobic incubation with oxidized Mn produced the largest quantities of VFA, which remained high throughout the six-wk incubation. Aromatic compounds were more easily consumed aerobically and were only slowly consumed in the anaerobic treatments. We conclude from this study that cattle feedlot soils possessed a varying, potentially exploitable capacity for odor consumption when alternate electron acceptors were available.     

Assessment of Poisson, probit and linear models for genetic analysis of presence and number of black spots in Corriedale sheep

Black skin spots are associated with pigmented fibres in wool, an important quality fault. Our objective was to assess alternative models for genetic analysis of presence (BINBS) and number (NUMBS) of black spots in Corriedale sheep. During 2002-08, 5624 records from 2839 animals in two flocks, aged 1 through 6 years, were taken at shearing. Four models were considered: linear and probit for BINBS and linear and Poisson for NUMBS. All models included flock-year and age as fixed effects and animal and permanent environmental as random effects. Models were fitted to the whole data set and were also compared based on their predictive ability in cross-validation. Estimates of heritability ranged from 0.154 to 0.230 for BINBS and 0.269 to 0.474 for NUMBS. For BINBS, the probit model fitted slightly better to the data than the linear model. Predictions of random effects from these models were highly correlated, and both models exhibited similar predictive ability. For NUMBS, the Poisson model, with a residual term to account for overdispersion, performed better than the linear model in goodness of fit and predictive ability. Predictions of random effects from the Poisson model were more strongly correlated with those from BINBS models than those from the linear model. Overall, the use of probit or linear models for BINBS and of a Poisson model with a residual for NUMBS seems a reasonable choice for genetic selection purposes in Corriedale sheep.     

土其代羊及土×藏杂种羊羊毛物理性能测定

测定了青海省海北州引入的土其代羊（♂、♀）和土×藏杂种羊（含土其代羊血分别为１／２♂、♀，３／４♂和１／４♀）的羊毛纤维类型，各类型纤维的伸直长度、细度、强度和伸度，以及羊毛的净毛率、含脂率。结果表明：土其代羊和土×藏杂种羊羊毛伸直长度大，毛粗，强伸度大，净毛率较高，羊毛含脂率适中，羊毛纤维类型组成比例适合地毯毛要求，是生产地毯的优质毛原料。     

Kinetic gait analysis of healthy dogs on two different surfaces

Objective— To determine the effects of 2 different, commonly used surfaces with different coefficients of friction on ground reaction forces in normal dogs.
Study Design— Prospective, observational, single cross-over study.
Animals— Dogs (n=10) with no gait abnormalities.
Methods— Dogs were acclimated to the force plate and 5 valid trials for each dog and each limb were recorded. Velocity and acceleration were tightly controlled. Each dog was tested on both surfaces sequentially in different sequences. Data analysis was done on peak vertical force, peak impulse, breaking and propulsion peak forces and impulses. Three-way repeated measures analysis of variance was used to separately evaluate the effect of floor type on force plate measures in fore and hind limbs, while controlling for side (left versus right) and experimental replicate. P -values<.05 were considered significant. Mean force and 95% confidence interval for the 6 variables analyzed for all limbs on each surface were calculated.
Results— There were no significant differences in ground reaction forces between the linoleum and the carpet surface for thoracic or pelvic limbs for all gait variables measured. There were no significant differences between each individual gait trial per dog between the right and left thoracic limbs trials nor differences between the right and left pelvic limb trials.
Conclusions— Normal dogs had no change in their ground reaction forces on linoleum and carpet surfaces.
Clinical Relevance— Kinetic results from multi-center or comparative trials will not be affected by use of either linoleum or carpet surfaces.