高寒地区燕麦与箭箸豌豆混播增产效应的研究

在甘肃省天祝县高寒地区对一年生牧草燕麦和箭管豌豆混播增产效应进行了研究。结果表明，混播群落中燕麦与箭苦豌豆通过对光能、养分、水分等资源的相互协同利用，提高了资源利用效率，群落草层高度和单位面积干物质产量增加。其中，以燕麦76kg／hm^2＋箭管豌豆42kg／hm^2混播草地的种间协同效应最佳，干物质产量为5900kg／hm^2，比燕麦和箭管豌豆单播分别增产15．7％和68．6％。     

燕麦十箭Kuo豌豆混播草地的草层结构与产量

在青藏高原高寒地区燕麦＋箭Kuo豌豆混播草层的茎主要分布在0－30cm的高度，叶在0－100cm，花在80－100。混播草层在前、中、后各生育期，均能保持较高的光合作用面积并可获得高产，依各项测定指标综合评定，燕麦135kg/hm^2 箭Kuo豆豆45kg/hm^2为适宜混,播组合量，其干草产量比单播燕麦和箭Kuo豌豆分别增产13％和96％，混播草层每元投资的经济收益均比燕麦，箭Kuo豌豆单播高。     

石羊河上游一年生人工草地种间协同增产效应研究

研究了石羊河上游高寒草地一年生牧草燕麦与毛苕子的种间协同增产效应，结果表明，混播群落中燕麦与毛苕子对光能、养分、水分等资源利用的相互协同作用，提高了资源利用效率，促进了整个群落草层高度的增长和单位面积干物质产量的增加。其中以燕麦76kg／hm^2和毛苕子42kg／hm^2混播草地的种间协同效应最佳，干物质产量为5900kg／hm^2，比燕麦和毛苕子单播分别增产51％和37％；草地纯收入为3020元／hm^2，经济效益显著。可有效解决高寒牧区冬春牧场利用过度和冷季草畜供求矛盾的问题，对维持正常草原畜牧业生产及保护草原生态环境发挥积极的作用。     

高寒地区燕麦与箭筈豌豆混播增产效应的研究

在甘肃省天祝县高寒地区对一年生牧草燕麦和箭筈豌豆混播增产效应进行了研究.结果表明,混播群落中燕麦与箭管豌豆通过对光能、养分、水分等资源的相互协同利用,提高了资源利用效率,群落草层高度和单位面积干物质产量增加.其中,以燕麦76kg/hm2 箭管豌豆42kg/hm2播草地的种间协同效应最佳,干物质产量为5900kg/hm2,比燕麦和箭筈豌豆单播分别增产15.7%和68.6%.     

高寒牧区播期和氮肥对燕麦生长特性的影响

以燕麦(Avena sativa)永久444为材料,研究播期与氮肥对高寒牧区燕麦生育期、株高、分蘖数及其青干草产量的影响。结果表明:随播期的推迟,燕麦种子成熟期推迟,而施氮量对燕麦生育期无明显影响;播期和氮肥对燕麦株高、分蘖数及草产量皆有显著影响,均随施氮量增加而增加。以开花期收获青干草为目的,则4月下旬-5月上旬播种且施氮量为100 kg/hm2时,可获燕麦高产。     

天祝高寒地区甘引1号黑麦+燕麦混播试验研究

在天祝县高寒地区进行甘引1号黑麦与燕麦的混播试验,结果表明,混播比单播表现出更大的生物优越性,其甘引1号黑麦50%+燕麦50%的混播草地鲜草产量达48 140kg/hm2,比甘引1号黑麦和燕麦单播增产18.95%和22.97%。     

复种初岛燕麦╋中豌六号混播效应的动态研究

为解决冬春饲草料不足,充分利用夏收闲田复种饲草料作物,拓宽饲草料来源、提高土壤肥力,对复种初岛燕麦(Avena sativa)和中豌六号豌豆(Pisum sativum)单播及混播的一年生栽培草地进行生物量动态、牧草品质及种间竞争的研究。结果表明,最佳混播组合为初岛燕麦65%(195 kg/hm2)+中豌六号35%(42kg/hm2)和初岛燕麦50%(150 kg/hm2)+中豌六号50%(60 kg/hm2),9月10日刈割干草产量达7 246.44和7 133.91 kg/hm2;粗蛋白产量为624.64和670.6 kg/hm2;最佳刈割期以初岛燕麦开花-灌浆期为宜。初岛燕麦的干物质积累速率高,植株高度占优势,在竞争中一直处于优势地位,其竞争力强于中豌六号豌豆。     

不同播期对梦龙燕麦生产性能的影响

以梦龙燕麦为材料,连续2年研究了不同播期对梦龙燕麦株高、分蘖数、茎叶比及草产量的影响。结果表明,梦龙燕麦在高寒地区生长良好,适应性强,生产性能表现优良。不同播期对梦龙燕麦的株高、分蘖数、茎叶比和草产量有显著影响,在一定时期内随着播期的延迟其株高、分蘖数、茎叶比和草产量均有降低的趋势。4月30日、5月10日、5月20日、5月30日4个播期处理的两年平均干草产量分别为12 239、11 163、10 697、9 286kg/hm2,兼顾产量和品质综合分析,以4月30日播种最优,5月10日和5月20日较好,因此在川西北高寒地区应选择4月底至5月中上旬播种为宜。     

互助县燕麦与箭筈豌豆混播技术试验推广研究

互助县燕麦与箭筈豌豆混播试验推广结果表明,每公顷产鲜草64．01t,其中箭筈豌豆鲜草量占总产量的40．56％,比单播燕麦（平均产鲜草58．5t／hm^2）增产9．41％,比单播箭筈豌豆（平均产鲜草49．41/hm^2）增产29．55％;燕麦株高增长5．9cm,箭筈豌豆株茎增长34．1cm。     

燕麦+箭筈豌豆混播草地的草层结构与产量

在青藏高原高寒地区燕麦 +箭豌豆混播草层的茎主要分布在 0～ 3 0cm的高度 ,叶在 0～ 10 0cm ,花在 80～10 0。混播草层在前、中、后各生育期 ,均能保持较高的光合作用面积并可获得高产。依各项测定指标综合评定 ,燕麦 13 5kg/hm2 +箭豌豆 45kg/hm2 为适宜混播组合量 ,其干草产量比单播燕麦和箭豌豆分别增产 13 %和 96%。混播草层每元投资的经济收益均比燕麦、箭豌豆单播高     

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.     

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 -