高效微生物除臭剂在畜禽粪便堆制中的应用效果及其除臭机理研究

为探索治理畜禽粪便所产生恶臭气体对环境污染的新途径,本研究将筛选的数株高效除臭菌和纤维素分解菌群优化组合后制备成复合微生物除臭剂,研究其对畜禽粪便堆肥过程中的除臭效果和对堆肥物料特性的影响,定量分析不同阶段氮元素和硫元素的动态转化和损失途径,初步探讨其除臭机理。结果表明,复合微生物除臭剂具有高效除臭功能,在堆肥的前20 d对氨气和硫化氢的去除率高达70%和60%以上,同时使堆肥的pH、含水率和C/N降低,堆体的温度上升时间加快,高温持续时间延长;猪粪和鸡粪在堆肥第25和20天堆体温度达到最高,高于50 ℃持续15和20 d。堆肥结束时,与自然堆肥相比,微生物除臭剂减少了猪粪和鸡粪堆肥中25.84%和28.65%的氮元素损失,全氮(TN)和硝态氮(NO₃^--N)含量显著高于自然堆肥(P<0.05);同时促进硫元素向无机硫(SO₄^2-)形式转化, SO₄^2- 含量显著高于自然堆肥(P<0.05)。表明该微生物除臭剂具有高效稳定的除臭作用,并能减少堆肥肥效损失,促进堆肥腐熟,在资源化、无害化处理畜牧业废弃物和治理环境污染方面具有较大的应用潜力。     

不同复合菌剂对羊粪堆肥发酵处理影响比较研究

[目的] 对比研究接种不同复合菌剂对羊粪堆肥腐熟进程的影响。[方法] 试验设4个组,空白组不接种任何发酵剂,试验组1接种课题组前期研制的粪污腐熟剂1,试验组2接种优化后的粪污腐熟剂2,试验组3接种市售粪污腐熟剂。在发酵不同时间段测定各组堆肥的温度、pH值、含水率、E₄/E₆值和种子发芽指数,记录堆肥颜色、气味和状态等表观特征。[结果] 堆肥过程中试验组2升温速率快于其他3组,空白组升温速率最慢。发酵第35天,试验组1、试验组2、试验组3、空白组堆肥的水分含量分别降至27.15%、25.97%、28.03%、42.30%;试验组1、试验组2、试验组3的pH值分别为8.03、7.98、8.09,空白组pH值最高,为8.58;试验组1、试验组2、试验组3的E₄/E₆值分别为2.35、1.80、2.53,均低于空白组（3.00）;试验组1、试验组2、试验组3的种子发芽指数分别为94.5%、108.5%、101.3%,均彻底完成无害化处理（堆肥完全腐熟）,而空白组为75.3%,堆肥未完全腐熟。在发酵终点,3个试验组的堆体呈深褐色,无臭味,较松散,有白色菌丝,不吸引蚊蝇,无虫卵,进一步说明堆肥已经完全腐熟;空白组堆体呈暗褐色,有微臭味,手感粗糙,局部有团块,吸引蚊蝇,深层孳生少量的虫卵,进一步说明堆肥未完全腐熟。[结论] 接种复合菌剂可以促使羊粪堆肥腐熟进程加快,提前完成无害化处理;接种优化后的腐熟剂2的堆肥种子发芽指数最高,腐熟度也最高,且加快堆肥腐熟进程效果更为明显。     

猪粪高效除臭微生物菌株筛选及发酵条件优化

为了探索微生物除臭剂对畜禽粪便环境污染的治理效果,本研究利用平板划线分离法从5份样品中分离出130株菌株,通过氨气和硫化氢选择性培养基定性初筛和硼酸吸收法、锌胺络盐吸收比色法定量复筛相结合的方法,分别筛选出了可高效抑制氨气、硫化氢释放的菌株5株和3株,其中命名为BX3的菌株对氨气和硫化氢的去除率分别达到80.07%和76.92%;采用L₈(2⁷)正交试验优化设计其高效除臭组合,结果表明,“AF2+DZ1+BX3+DZ3+BZ1+EZ3+AX4”组合氨气和硫化氢的释放量显著或极显著低于其他组合,为最佳组合;与空白对照相比,第5天时氨气和硫化氢的去除率达到82.14%和80.84%。对最佳组合除臭发酵工艺研究,在接种量分别为10%和15%,含水率40%和30%,麸皮添加量为10%时氨气和硫化氢的释放量最小。筛选的微生物在除臭剂制备及治理畜禽粪便对环境污染方面具有较大的应用潜力。     

微生态制剂对猪舍氨气去除效果评价及对猪生长性能影响的研究

旨在探讨微生态制剂对猪舍氨气的去除效果及其对猪生长性能的影响。在选取1栋猪舍(NO.1)开展验证试验的基础上,另选用1栋猪舍(NO.2)的育肥猪作为试验组,猪只基础日粮中添加5‰的益唯康和2.5%的瑞尔康,同时,采用喷洒和泼洒的方式,利用瑞尔加喷洒液对猪只体表和猪舍内各区域进行除臭,试验周期60 d;对照组猪舍(NO.3)中的育肥猪饲喂基础日粮,猪粪及猪舍内区域不用除臭剂进行处理,试验周期60 d。结果表明:与对照组相比,试验第3天试验组猪舍的氨气浓度降至5.6 mg/kg,去除率达到70.05%;试验期间试验组猪只的平均日增重提高了23.79%,日耗料量增加了4.45%,存活率高于对照组2个百分点,但料肉比降低了15.83%。综上提示,饲喂和喷洒微生态制剂能够有效去除猪舍氨气,并能提高猪的生长性能。     

育肥羊舍喷洒微生物除臭剂对氨气的去除效果研究

旨在研究育肥羊舍喷洒微生物除臭剂对氨气(NH_3)的去除效果。试验设3组,每天喷洒一次(1次/d)、每天喷洒两次(2次/d)和不喷洒除臭剂的对照舍。采用纳氏比色法对各组羊舍不同时间点(8:30～18:30,每隔2 h)、不同垂直高度(0.2～1.8 m)空间的NH_3浓度进行检测。结果表明,喷洒除臭剂后不同时间点NH_3浓度变化较大,喷洒2 h(10:30)和4 h(12:30)后,1次/d喷洒舍的NH_3浓度低于对照舍,NH_3降低效率分别达10.6%和41.5%。2种不同喷洒次数的羊舍NH_3浓度比较,各时间点1次/d喷洒舍的NH_3显著低于2次/d喷洒舍(P0.05)。从喷洒除臭剂后羊舍NH_3平均浓度看,1次/d的喷洒效果好于2次/d,1次/d的喷洒舍NH_3平均浓度为5.0 mg/m~3,而对照舍和2次/d喷洒舍的浓度分别为6.2和6.3 mg/m~3。     

低温等离子体技术对猪舍环境和生猪健康的影响

试验旨在探究低温等离子体技术的使用对猪舍内环境和猪群健康的影响。选取4栋猪舍、60头初始重约为60 kg的育肥猪和36头妊娠日龄为15 d的母猪作为试验样本，试验期60 d。试验组母猪和育肥猪猪舍内安装使用低温等离子体设备，对照组猪舍内未安装设备。采取现场采样、实验室分析的方法，对比试验组和对照组各猪舍内氨气(NH₃)、硫化氢(H₂S)、臭气浓度以及细菌菌群结构的差异，同时分析各处理组的饲料养分表观消化率和血清指标。结果表明：试验组育肥舍和母猪舍内空气中NH₃、H₂S和臭气浓度均低于对照组(P<0.05)；试验组育肥舍内气溶胶中细菌多样性和丰度均低于对照组(P>0.05)；试验组育肥猪和母猪的饲料养分表观消化率和血清生化指标与对照组均无显著差异，育肥猪试验组的IgM和IgG含量高于对照组(P<0.05)。低温等离子技术的使用能有效改善猪舍环境质量，且对育肥猪和母猪的健康无负面影响。     

东北地区封闭式保育猪舍有害气体分布规律研究

本试验旨在探讨东北地区封闭式保育猪舍内有害气体的分布规律及对仔猪健康的影响。选取辽宁省某一猪场内保育猪舍进行研究，该猪舍饲养着3 000头21日龄5.6 kg的断奶仔猪，饲养密度为0.35m³/头，研究于2021年3月—2021年4月对舍内温度、相对湿度以及氨气(NH₃)、硫化氢(H₂S)和一氧化碳(CO)浓度进行为期5周的监测研究，并统计分析了舍内前部和后部栏位猪只的健康指标。结果表明：现代化封闭式保育舍内NH₃、H₂S和CO气体浓度均符合《规猪场环境参数及环境管理》规定，日内呈现周期性变化，NH₃、CO白天浓度均低于夜间；舍内前部水平位置NH₃浓度低于中、后部区域(P<0.05)；垂直高度各气体浓度均无显著性差异；而不同周次间存在显著差异(P<0.05),NH₃和H₂S浓度随周次的增加而增加，CO浓度则反之；在温湿度与各气体的相关分析中，湿度与NH₃和C...     

一种无残留无毒性猪场环境除臭喷剂的研究

为了探索猪舍内空气的除臭减臭方法,提高饲养效果,采用薄荷提取物、马来酸等原料配制成环境除臭剂,选用60日龄"杜×长×大"三元杂交生长猪80头,随机分成4组,每组20头,对照组按照常规饲养,试验Ⅰ、Ⅱ、Ⅲ组分别喷洒除臭剂Ⅰ、Ⅱ、Ⅲ,每天喷洒1次,每次300 mL,进行1个育肥周期(120d)饲养试验。结果表明,试验Ⅰ、Ⅱ、Ⅲ组舍内空气中氨气(NH_3)、硫化氢(H_2S)、二氧化碳(CO_2)、一氧化碳(CO)含量显著障降低(P<0.01),试验Ⅲ组降低量最多,猪舍空气中NH_3含量比对照组、试验Ⅰ组、试验Ⅱ组分别减少51.9%(P<0.01)、44.0%(P<0.01)、28.6%(P<0.01); H_2S含量分别减少45.5%(P<0.01)、 29.4%(P<0.01)、14.11%(P<0.01); CO_2含量分别减少42.3%(P<0.01)、31.9%(P<0.01)、16.7%(P<0.01); CO含量分别减少48.0%(P<0.01)、23.51 (P<0.01)、7.1%(P<0.05);试验Ⅰ、Ⅱ、Ⅲ组肉猪平均日增重比对照组分别提高4.9%(P>0.05)、8.5%(P<0.05)、11.0%(P<0.01),试验组间差异不显著(P>0.05);试验Ⅰ、Ⅱ、Ⅲ组饲料系数比对照组分别减少3.28%(P>0.05)、4.59%(P>0.05)和6.23%(P<0.05),试验组间差异不显著(P>0.05);试验组和对照组的肉猪成活率均为100%。从以上结果可知,在猪舍中喷洒除臭剂可以显著减少空气中有害气体含量和臭味,有利于猪的生长和改善饲料转化效率,其中除臭剂Ⅲ的效果最好。     

草地施肥对牧草和放牧贵州半细毛羊的影响

为评价草地施肥对放牧贵州半细毛羊的影响,在威宁县凉水沟退化人工草地上进行了(NH₄)₂SO₄和NH₄NO₃施肥和放牧试验。结果表明,草地施肥极显著增加牧草氮(N)含量,但各施肥处理之间没有显著差异。(NH₄)₂SO₄施肥极显著增加牧草S、Mn和Zn含量,减少牧草Se含量。试验结束时,施(NH₄)₂SO₄草地半细毛羊血液中Cu、Fe和Se含量极显著低于施NH₄NO₃草地和对照草地,家畜血液Mn、Zn和S含量极显著高于NH₄NO₃施肥牧场和对照牧场。(NH₄)₂SO₄施肥牧场贵州半细毛羊血红蛋白(Hb)和红细胞压积容量(PCV)以及血清Cp含量、血清SOD活力、血清GSH-PX活力和血清CAT活力极显著低于NH₄NO₃施肥牧场和对照牧场,血液其他矿质元素和血液指标及血清生化值在2个施肥处理和对照之间均差异不显著。因此得出结论,威宁县凉水沟天然草地不适合用(NH₄)₂SO₄施肥。     

不同精粗比对牦牛粪便菌群结构的影响

本试验旨在研究不同精粗比对牦牛粪便菌群结构的影响。选取24头体重相近、健康的3岁公牦牛，随机分成2组，分别饲喂低精粗比饲粮(35∶65,C₃₅组)和高精粗比饲粮(65∶35,C₆₅组)。预试期为15 d，试验期为90 d。运用16S rDNA高通量测序技术对粪便菌群结构变化进行分析。结果表明：1)2组共检测出1702个操作分类单元(OTU)，其中两组共有的OTU数目为1273个，占总OTU数目的74.79%;C₃₅组的物种数、Chao1指数与Shannon指数显著高于C₆₅组(P<0.05)。2)在门水平下，C₃₅组牦牛粪便中髌细菌门和蓝藻菌门极显著高于C₆₅组(P<0.01)，放线菌门显著高于C₆₅组(P<0.05);C₆₅组牦牛粪便中拟杆菌门、螺旋体门显著高于C₃₅组(P<0.05)。3) C₃₅组牦牛粪便中瘤胃球菌属极显著高于C_6...     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein