紫花苜蓿苗期除草剂筛选及防效试验

对10.8%盖草能Ec、7.5%禾阔灵Ec、5%精禾草克Ec 3种除草剂不同浓度在苜蓿田中进行药剂筛选及防效试验,结果表明,以禾本科杂草为主,宜选用盖草能,在施药量上,10.8%高效盖草能285~495mL/hm2时效果最好。7.5%禾阔灵、5%精禾草克对单子叶杂草防除效果好,对双子叶杂草禾阔灵防效明显,盖草能、精禾草克基本无效。     

十四种化学除草剂对沧州地区苜蓿地杂草防效试验

选用14种除草剂对沧州地区苜蓿(Medicago sativa)地苗期的杂草进行了防除试验。对苜蓿株高,产量及杂草量的综合调查分析结果表明,高效盖草能、精禾草克、精稳杀得、拿捕净对禾本科杂草的防效为100%,苜蓿保系列各剂型在杂草株龄较大的情况下综合表现较好,其中苜蓿保2%EC将杂草率从80.6%(CK)降到了36.5%,苜蓿增产40.6%。沧州地区春播苜蓿幼苗期单独使用禾本科除草剂或阔叶草除草剂效果不理想。     

化学除草剂对越冬之星苜蓿杂草防除效果的试验

为探讨研究除草剂对越冬之星苜蓿苗期的杂草防除效果，以期筛选出适宜的除草剂品种，笔者进行了化学除草剂对越冬之星苜蓿的杂草防除试验，并对苜蓿株高、产量及杂草量作了综合调查与分析。结果表明，高效盖草能、精禾草克、精稳杀得、拿捕净对禾本科杂草的防效为100％，5％苜草净在杂草株龄较大的情况下综合表现较好。苜蓿无药害的除草剂品种推荐5％苜草净在杂草株龄较大的情况下喷雾。     

混配除草剂对燕麦田杂草的防效及燕麦产量的影响

为了筛选适宜燕麦(Avena sativa)田使用的安全、高效的混配除草剂组合,选用96%精异丙甲草胺乳油和10%苄嘧磺隆可湿性粉剂、57%2,4-D丁酯乳油和10%乙羧氟草醚乳油按照不同比例两两组合,混配后施于燕麦田,研究其对燕麦田杂草的防除效果以及对燕麦安全性和产量的影响。结果表明,不同除草剂处理对杂草的防效差异显著(P 0.05),混配处理的防效普遍高于各单剂处理。T5和T9对杂草的防效最好,但后者对燕麦有药害。综合安全性、除草效果及对燕麦的增产作用,筛选出综合效应最佳的混配组合,即57%2,4-D丁酯乳油438.5 mL·hm~(–2)+10%乙羧氟草醚乳油300 mL·hm~(–2)(T12);其药后30 d的鲜重防效达87.99%,燕麦干草产量为9 875.3 kg·hm~(–2),燕麦种子产量为4 314.3 kg·hm~(–2)。     

不同除草剂对黄芪田杂草防除效果及黄芪生物量、药材产量的影响研究

[目的]研究不同除草剂对黄芪地上生物量积累、药材产量及杂草防除效果的影响。[方法]对1年生蒙古黄芪移栽苗选用5种苗后除草剂按照推荐使用浓度进行施药处理,5种农药分别为药草除1号（YCC）、灭草松（MCS）、烯草酮（XCT）、盖草能（GCN）、拿捕净（NBJ）,以喷施清水为对照（CK）。每种施药处理3次重复,共18个小区。2021年6月初采用样方法统计各处理小区内杂草株数、鲜质量、干质量,于7月10日、8月10日、9月10日定期统计各处理小区蒙古黄芪地上生物量鲜重、干重,并测定当年11月采收季黄芪药材鲜重、干重。采用变异分析和单因素方差分析对统计数据进行分析。[结果]5种除草剂均表现出不同程度的杂草防除效果,其中,药草除1号处理组（YCC）杂草防效最好,株防效为77.81%,鲜质量防效为64.48%,干质量防效为80.81%。7、8、9月各除草剂处理组之间黄芪地上生物量鲜重、干重以及鲜干比之间无显著（P>0.05）差异;11月,药草除1号处理组（YCC）的黄芪药材产量鲜重和干重均显著（P<0.05）高于其他处理组。[结论]蒙古黄芪移栽田使用药草除1号进行杂草防除的效果较好,且...     

苜蓿种子地化学除莠的研究

着重探讨苯达松，草甘膦在苜蓿种子地的化学除莠作用。通过对两种农药的适用浓度和喷施期的研究表明，苯达松对防除苜蓿种子地杂草－田旋花，灰绿藜，匾蓄，地肤等有较好效果，在杂草幼苗期，０．５％浓度即可达到防除目的，且对苜蓿影响不大，值得推广；草城膦是灭生性农药，不宜在芷蓿地中喷施，但在苜蓿地头田边喷施有较好效果，０．２％浓度的杂草死亡率可达９５％以上。     

10种除草剂对裸燕麦田杂草的药效、燕麦产量及安全性影响

为筛选出黄土高原半干旱地区裸燕麦田的适宜高效除草剂,研究了10种除草剂在常规剂量下对田间杂草防效、燕麦产量及安全性的影响。结果表明:不同除草剂在燕麦田的表现差异显著(P0.05)。其中,苗期茎叶除草剂双氟·唑嘧磺草胺和人工除草的防效较高,均在80%以上;而双氟·唑嘧磺草胺对产量的增效高于人工除草,可使白燕2号干草及种子产量分别达到10 739.0、3 238.3kg/hm2,比对照增产28.7%。其次,播前土壤处理除草剂仲丁灵和播后苗前土壤处理精异丙甲草胺也具有较好的防效和增产效果。而除草剂氟乐灵、乙氧氟草醚、唑草酮对燕麦田杂草防除效果较差,且对燕麦表现出一定的药害,2,4-D丁酯还可使裸燕麦籽粒出现带壳现象。各产量构成指标中,施用除草剂对燕麦的株高、穗长、千粒质量等影响较小,对小穗数、穗粒数、干草产量、种子产量有较显著的影响。     

沟叶结缕草草坪杂草化学防治研究

采用苯达松、2,4-D丁酯、高效盖草能(10%乳油)3种除草剂对沟叶结缕草草坪进行了杂草化学防治研究.结果表明,苯达松(25%水剂)每15 kg水可加至80 ml左右,2,4-D丁酯(72%乳油)每15kg水可加至25 ml,高效盖草能(10%乳油)每15kg水可加至10～15 ml,每667m2控制用水25～30kg可取得较好效果.但高温季节除草剂容易对草坪产生药害,施用时应在杂草幼苗期进行,并降低药剂浓度,以提高对草坪的安全性.     

几种除草剂对科尔沁沙地苜蓿杂草的防控效果

在苜蓿三个叶龄期施用除草剂研究其对苜蓿产量和杂草防控效果的影响,结果表明:咪唑乙烟酸对燕麦的防效随苜蓿叶期增加而降低,株防效和鲜重防效均为四叶期五叶期六叶期;咪唑乙烟酸和高效氟吡甲禾灵混用可以显著提高对燕麦的防效,苜蓿产量提高100～1000kg/hm2;辛酰溴苯腈与高效氟吡甲禾灵混用会降低对反枝苋的防效,但可提升对燕麦的防效,同时显著提升苜蓿产量1000～2000kg/hm2。综合考虑除草剂对苜蓿的安全性、产量以及对燕麦、反枝苋的防控效果,科尔沁沙地苜蓿苗期化学除草可在苜蓿四叶期、五叶期选用咪唑乙烟酸1200ml/hm2+高效氟吡甲禾灵660ml/hm2或咪唑乙烟酸1800ml/hm2+高效氟吡甲禾灵660ml/hm2,也可采用辛酰溴苯腈1050ml/hm2+高效氟吡甲禾灵660ml/hm2和辛酰溴苯腈1500ml/hm2+高效氟吡甲禾灵660ml/hm2。     

几种选择性除草剂防除草坪双子叶杂草效果的研究

在1997 ～1998 年两年间,应用好事达、百草敌、使它隆、2 ,4 - D 丁酯四种选择性杂草防除剂对四川农业大学校园草坪杂草进行防除试验。结果表明:防除草坪中的双子叶杂草用72 % 的2,4 - D 丁酯2500ml/hm2 + 使它隆1000ml/hm2 ,株防效为90-3 % ,种防效为74 % ,效果最好,经方差检验,与其它几种处理的差异达到了显著或极显著的水平。     

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.     

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.     

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.     

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