不同施氮量对高山草甸草地牧草产量及营养成分的影响

对高山草甸草地施氮５０ｋｇ／ｈｍ＾２和８０ｋｇ／ｈｍ＾２的试验结果：产草量提高１１０．２％和１７２．２７％，粗蛋白质产量提高１２６．３９％和１９６．１０％，但施氮对牧草其它营养成份无明显影响。实施本项技术措施后，能提高高山草甸冬春牧地的载畜量，具有显著的经济效益和生态效益。     

河西走廊几种盐化草地第一性生产力的研究：Ⅰ地上生物量与地下生物量…

对河西走廊三盐渍化草地生物量进行定位研究的结果表明：１）海韭菜草地、小灯心草地和芦苇＋赖草草地上生物量变化均表现为单峰曲线，最大值均出现在７月上旬，其值分别为５４６、１２ｇ．ＤＭ／ｍ＾２，２６８．２６ｇ／ｍ＾２和１４０．９９ｇＤＭ／ｍ＾２三个草地当年地上部净生产力分别为５５９．０４ｇ／ＤＭ／ｍ＾２．ａ，２２６．８６ｇ．ＤＭ／ｍ＾２．ａ，８３．７４ｇ．ＤＭ／ｍ＾２．ａ。２）海韭菜草地地下生物量呈连续     

高寒草甸草地在全封育下的植物量变化

用钢丝网封育高寒草甸类的高山嵩草－异针茅草地０．３６ｈｍ￣２，封育时间１９９０—１９９３年。对封育草地内地上及地下植物量测定结果：封育第一年优良牧草鲜草量增加明显，由原来的１７４．０ｇ／ｍ￣２增加到３２５．０ｇ／ｍ￣２（Ｐ＜０．０１），第２、３年产量变化不明显（Ｐ＞０．０５）；封育的第１、２年，优良牧草成份呈上升趋势，杂毒草成份呈下降趋势，封育的第３年优良牧草成份开始下降，杂毒草开始上升；地下植物总量（４０ｃｍ内），在封育的第１年下降明显，由原来的６４６９．５６ｇ／ｍ￣２下降到４７２１．６８ｇ／ｍ￣２（Ｐ＜０．０１），封育的第２、３年根量开始明显回升，至第３年上升为７３１０．０ｇ／ｍ￣２（Ｐ＜０．０１）。测定结果表明，高寒草甸草地封育时间以２年为佳。建议利用现有围栏，针对冬春草地采取冬季刮用枯草，早春禁牧（４—７月）的措施，封育退化草地两年，即可达到封育效果。     

计划火烧对林间草地产草量和营养成分的影响

有计划地人工控制火烧林间草地，可有效地提高牧草的营养成分含量。试验区牧草覆盖度为５４．１７％，平均产草量６６５ｇ／ｍ＾２，牧草含水量７１．８５％，干物质中无氮浸出物５５．４１％，粗纤维２３．６２％，粗蛋白质１０．２％，粗脂肪２．３１％，粗灰分８．４６％；而对照区（未烧区）牧草覆盖度为４８．７５％，平均产草量６９２．８８ｇ／ｍ＾２，牧草含水量７１．４３％，干物质中含无氮浸出物５３．６６％，粗纤维２６     

达握里胡枝子群落生物量初步研究

本文研究了陕化黄土高原森林草原地带达乌里胡枝子群落６、７月份生物量，测定了地上和地下生物量及其空间变化。结果表明，达乌里胡枝子群落６、７月份地上生物量分别为９６．６８ｇ／ｍ＾２ｔ １３６．２５ｇ／ｍ＾２和２１０．７２ｇ／ｍ＾２。地下生物量７月份偏低，这与达乌里胡枝子生长发育阶段的物质分配有关。     

种植碱茅对河西盐渍土壤盐离子组成的影响

文章对自张掖，酒泉等地区碱茅草地和盐渍荒地耕层土壤（０－４５ｃｍ）采集的２１个样品进行了全盐含量，有机质，ｐＨ和八大盐离子分析测定，在此基础上，用参数区间估测法求得了碱茅草地与盐渍荒的总体平均数差异。结果表明碱茅草地土壤全盐含量明显降低的同时，主要有害盐离子的含量及经例也有所降低，其中Ｎａ＾＋降低０．９６－４．９６ｍｅ／１００ｇ土，Ｍｇ＾２＾＋降低０．３５－２．２５ｍｅ／１００ｇ土，ＳＯ４＾２＾－     

高寒草甸“黑土型”退化草地的成因及生态过程

研究分析退化草地的植被组成、地上生物量、优良牧草比例、高原鼠免密度以及土经性质等特征,探讨“黑土型”退化草地的成因及生态过程。结果透明,中度退化草地生物量最高９５０．３ｇ／０．２５ｍ＾２）。原生植被优良牧草比例最高（７８．４０％）。重度退化草地最低（４．４９％）,轻度和中度退化草地居中（５７．２％和１６．４２％）。中度退化草地高原鼠兔平均密度较高（１４８只／ｈｍ＾２）,二者之间呈显著的正相关（ｒ＝     

黄河故道沙荒草地生物量及营养价值特性研究

对黄河故道沙荒草地生物量季节变化规律以及牧草营养物质出动态进行了分析，结果表明：（１）沙荒草地牧草生物量的增长呈二次曲线变化规律：ｙ＝１／（３．７９×１０＾－７ｔ＾２－９．３２×１０＾－５ｔ＋７．８３×１０＾－３），并且其生物量在９月份达到最大值；（２）从５月份开始沙荒草地牧草营养价值逐渐降低，且于物质消化率（ＤＭＤ）与其粗蛋白质（ＣＰ），木质素（ＬＩＧ）含量分别表现为显著正相关（ｒ＝０．９４）和     

利用荒漠和盐碱地建立人工草地的效益分析

１９９１～１９９２年，在海西州德令哈市利用荒漠建立半人工草地８６．１ｈｍ＾２，利用盐碱弃耕地建立人工草地７４．６ｈｍ＾２，取得了明显的生态、社会和经济效益，建植第三年的沙打旺人工草地植被盖度由原来的１５％提高至７０％～８０％，耕层（０－３０ｃｍ）总盐平均含量由原来的９．３ｇ．ｋｇ＾－１，下降１．２３ｇ．ｋｇ＾－１，脱盐率达８６．２６％，在受益期内，１６０．７ｈｍ＾２人工、半人工草地可新增牧草３６０     

“黑土型”退化草地毒杂草防除试验研究

用４种除草剂在“黑土型”退化草地上进行毒杂草防除试验,结果表明,混合除草剂具有良好的防除效果,药的第２年优良牧草干物质疸由９４．８ｇ／ｍ＾２提高到２２３．４ｇ／ｍ＾２,优良牧草盖度由６０％上升到９５％;毒杂草干物质产量由１３２．４ｇ／ｍ＾２下降到１８．０ｇ／ｍ＾２,盖度由９０％下降到１８％。特别是对棘豆属、马先蒿属、橐于属植物的灭效近１００％。     

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 -