不同紫花苜蓿品种在河西走廊盐碱地的适应性研究

通过田间试验测定不同紫花苜蓿品种的株高、分枝数、茎叶比、生物量、出苗率和越冬率,评价16个紫花苜蓿品种在河西走廊盐碱地的适应性,遴选出适宜河西走廊盐碱地种植的紫花苜蓿品种。结果表明:参试的16个紫花苜蓿品种,骑士T、SR4030和巨能的出苗率较高,甘农3号的出苗率最低;16个紫花苜蓿品种间株高差异不显著(P0.05);BR4010、WL343HQ、阿迪娜、亮苜2号和WL363HQ的分枝数显著大于标靶和金皇后的分枝数;岩石和德宝的叶茎比显著高于金皇后和骑士3的叶茎比;德宝、亮苜2号和骑士T的产量大于其他品种;亮苜2号和骑士3的越冬率显著高于甘农3号和SR4030的越冬率;阿迪娜和WL343HQ的倒伏率最小,骑士T和标靶的倒伏率最大。以株高、分枝数、茎叶比、生物量、出苗率和越冬率为变量因子,通过聚类分析将16个紫花苜蓿品种聚为6类,综合评判结果认为,亮苜2号、骑士T、德宝适宜种植于河西走廊盐碱地。     

在盐碱地上如何种草

1选择耐盐碱的牧草品种 如何提高草种的成活率和生长速度是盐碱地种草成败的关键。为了解决这一难题，首先要选好适宜的草种。牧草的抗盐碱能力，因草种而异。一般重盐碱地应选种耐盐碱强的碱茅、沙打旺、紫穗槐、沙蒿、柠条、长穗冰草、垂穗披碱草、窄颖赖草等；中度盐碱地可种耐盐碱中等的草木樨、紫花苜蓿、毛苕子、披碱草等。     

内蒙古干旱草原区紫花苜蓿引种评价

对内蒙古干旱草原区引进的21个紫花苜蓿品种进行生态引种试验,并对生长及遗传性状进行测试分析,越冬率测定表明,国内4个紫花苜蓿品种越冬率均在80％以上,国外引进紫花苜蓿品种越冬率在80％以上只有4个,分别来自于美国和加拿大,从澳大利亚引进的4个品种均不能越冬。按越冬率为标准将21个品种聚类为4组,分析组问形态特征差异,结果表明花色、叶片长、株丛高度、生长习性4个特征在组间差异显著。然后对产量和营养价值分析,筛选出适宜该地区种植的国内外紫花苜蓿品种,以丰富该地区紫花苜蓿品种资源,同时为苜蓿抗寒及耐牧根蘖型苜蓿新品种培育提供研究基础。     

32个苜蓿品种田间耐盐性引种筛选试验

为了筛选出在不同盐碱程度的耕地上生长良好的苜蓿品种,试验在不同盐碱程度的耕地引进32个国内外紫花苜蓿品种进行引种筛选。结果表明:32个紫花苜蓿品种在盐碱地的出苗率、越冬-返青率、株高、鲜草产量指标中,甘农1号、苜蓿王、中苜1号、陇东苜蓿、42IQ、盐宝、TG3、龙牧801、普沃、劲能、A-25在田间表现较好,这几个品种在盐碱地种植成活率高,土地的覆盖面积大,可减少地表水分蒸发,降低耕层盐碱含量,可在轻中度盐碱地进行示范种植,也为今后选育耐盐苜蓿新品种提供科学依据。综合分析,甘农1号、苜蓿王、中苜1号、陇东苜蓿、42IQ、盐宝、TG3、普沃等品种耐盐性较强,可作为盐碱地引种品种进行示范种植。     

紫花苜蓿品种比较试验

引进紫花苜蓿品种14个，在赤峰地区进行生态适应性试验，并对初花期和晚花期的主要营养成分进行分析测试，结果表明，国外引进紫花苜蓿品种与国内紫花苜蓿品种在气候生态型上存在着明显的差异，国内紫花苜蓿品种越冬率均在98％以上，国外引进紫花苜蓿品种越冬率为84％～92％的占国外引进紫花苜蓿品种数的56％，越冬率为32％～46％的占44％；国内紫花苜蓿品种在赤峰地区生态适应性良好，而国外引进紫花苜蓿品种在赤峰地区的生态适应性相对较差。供试紫花苜蓿品种初花期和晚花期的粗蛋白和粗纤维平均含量分别为20．73％，24．37％，19．68％，26．77％。     

地膜覆盖对盐碱地紫花苜蓿生长性状及产量的影响

地膜覆盖是盐碱地增产的重要途径之一,为了推进地膜覆盖在盐碱地紫花苜蓿(Medicago sativa)生产中的应用,在河西走廊玉门市黄花农场开展了大田试验,研究了不同盐浓度条件下地膜覆盖对紫花苜蓿生长性状和产量的影响。结果表明,随盐浓度增加,紫花苜蓿出苗率、存活率、越冬率和产量呈降低的变化态势,而地膜覆盖显著增加了紫花苜蓿出苗率、存活率、越冬率、株高、茎叶比和产量,且在地膜覆盖和盐浓度为0.5%时紫花苜蓿总产量显著高于盐浓度为0.3%无地膜覆盖时的紫花苜蓿总产量,说明地膜覆盖可以应用于盐碱地紫花苜蓿的种植。     

紫花苜蓿萌发出苗期的耐盐鉴定方法

紫花苜蓿（Medicago sativa）有一定的喜盐性,培育耐盐苜蓿品种可以开发和利用我国的盐碱地。但是,目前还没有一种能够简单、直接、便捷且高效的苜蓿耐盐性鉴定方法。本研究选择生产上常用的5个不同耐盐性的紫花苜蓿品种,利用发芽试验法、营养液法和自然盐水法3种方法对苜蓿芽期和苗期的耐盐性进行鉴定。通过相对发芽率、平均相对发芽势、平均相对根长等多项评价指标计算出耐盐指数,根据耐盐指数对5个紫花苜蓿品种进行耐盐性评价。结果表明,营养液法是苜蓿材料耐盐性鉴定的最优方法。     

怎样选择引种牧草品种

我国地域广阔,气候、土壤条件差别较大,在选择和引种牧草时,要注意以下几个问题. (一)根据当地环境选择牧草品种首先,要了解土壤的类型,中性偏碱土壤,适合耐碱性强的品种,如紫花苜蓿、沙打旺等;中性偏酸土壤,适合耐酸性强的品种,如红三叶、白三叶等;盐碱地只适合种植耐盐碱的品种,如沙打旺、黑麦草、籽粒苋、羊草、碱草、苏丹草等.     

巧选牧草品种

1 根据气候选品种 黄淮地区、黄土高原中东部、东北平原及内蒙古高原东部等,适宜种植中等抗旱的牧草品种,如内蒙古冰草、偃麦草等;长江以北地区适宜种植抗旱能力较强又可抵抗严寒的品种,如紫花苜蓿等. 2根据土壤选品种 中性偏碱土壤适宜种植耐碱性强的品种,如紫花首蓿、沙打旺等;中性偏酸土壤适宜种植耐酸性强的品种,如红三叶、白三叶等;盐碱地只适宜种植耐盐碱的品种,如沙打旺、黑麦草、苏丹草等.     

紫花苜蓿种植管理技术研究

在内蒙古金河现代农业示范园区进行的紫花苜蓿规模化种植管理技术研究结果表明盐碱地改良、根瘤菌接种、播种、杂草防除等种植与管理措施均对紫花苜蓿饲草的生产有着直接的影响.在大规模进行紫花苜蓿产业化开发时,只有全面考虑上述各种因素,采用科学合理的种植与田间管理技术,并使之集成、熟化和配套,才能使紫花苜蓿最大限度地发挥其高产、稳产及优良品质等优势.     

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.     

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.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -