柠条平茬利用技术研究

本文从柠条平茬的角度出发,主要针对柠条饲料开发的必要性、利用方式、平茬与未平茬、逐年平茬与逐月平茬对柠条的高生长、地径和再萌发的影响等内容进行了重点观测和综合分析。确定出了柠条资源可持续利用的最佳平茬技术、平茬时期等,提出了柠条平茬技术中仍需解决的一系列问题。观测发现,无论围栏还是放牧区柠条当年最大高度都出现在8月,月最大生长量在7月。绘制出了平茬后2年内柠条高生长曲线。提出了放牧柠条草场可通过减少草场载畜量,实行轮牧、休牧和减少草场内山羊比例等可持续经营策略和适度放牧有利于柠条生物量的增加等观点。     

平茬对内蒙古典型草原小叶锦鸡儿群落植物的影响

为了了解平茬对灌丛群落草本植物的影响,本文以内蒙古典型草原小叶锦鸡儿（Caragana microphylla Lam）群落为研究对象,设置了不平茬、一年平茬1次和一年平茬2次共3种处理,分析了平茬前后群落特征与植被化学计量特征的变化。结果表明：与未平茬相比,两种平茬处理下群落内禾本科植物密度均显著增加,平茬第二年禾本科生物量显著高于未平茬处理;平茬后两年内草地群落物种多样性指数随平茬次数增加均有增加趋势,且一年平茬2次处理时,Margalef丰富度指数显著高于未平茬处理;草本群落总生物量随平茬次数增加呈现先下降后增加的变化趋势;平茬后植被C、N含量、C/N比无显著变化,但植被N/P比显著增加。可见,平茬处理改变了小叶锦鸡儿群落的结构特征,提高了群落物种多样性及禾本科植物的密度,有助于典型草原的植被恢复。     

大叶速生槐—新型奶牛饲料

1 开发大叶速生槐，发展牧业，利在当代 1.1生长速度快 大叶速生槐萌芽力强，生长速度快，温湿度适宜情况下日增长可达3-4厘米，干旱、半干旱地区，当年栽植生长高度也可达到两米以上。根茎萌芽力极强，沿地面平茬后，便墩状丛生，最多可见萌发42个枝条。每月收割一次，南方每年可收割5-6次，北方一年收割3-4次。     

平茬对得克萨斯南部四种鹿食灌木种营养成分的影响

<正> 试验以不平茬作对照,测定了得克萨斯南部白尾鹿所采食的四种灌木平茬后再生植株的营养成分。植株于1980年2、4、7月平茬,2月份平茬的植株及其对照分别于平茬后2、6、9个月时抽样分析。4月和7月平茬的植株其对照在平茬后2个月时取样分析。平茬后两个月再生植株的粗蛋白质和磷的含量一般比对照高。然而,平茬后6和     

灌溉量对紫花苜蓿水分利用效率和耗水系数的影响

采用大型非称重式蒸渗仪法,在河北省坝上地区研究了灌溉量对紫花苜蓿（Medicago sativa L．）水分利用效率和耗水系数的影响。结果表明：随着灌溉量的增加,第1、2、3莅和全生长季（1～3茬）生物产量和经济产量水分利用效率皆呈现先升后降的趋势;第1茬中灌溉量处理显著高于低和高灌溉量处理（P〈O．05）。随灌溉量增加,各茬次和全生长季（1—3茬）生物产量和经济产量耗水系数均呈先降后升趋势;第1茬中灌溉量处理显著低于低和高灌溉量处理（P〈0．05）。不同茬次间水分利用效率及耗水系数差异显著（P〈0．05     

盐分胁迫下箭筈豌豆生长前期生物量的变化

利用盆栽试验模似复合盐十个不同梯度，按期对箭豆幼苗灌溉5次后，观察幼苗生长状况，测定地上地下生物量等指标说明：箭豆属中等耐盐牧草，用0～0．6g／100ml的盐溶液灌溉5次即土壤总含盐量＜0．3％时，幼苗可正常生长；用0．9～1．8g／100ml盐溶液灌溉5次即土壤总含盐量在0．41～0．75％时，对幼苗的生长出现不同程度的抑制作用，但对地上生物量影响尚不显著；用2．1～2．7g／100ml盐溶液灌溉5次即土壤总含盐量在0．87～1．09％时，对幼苗生长有显著危害，甚至造成幼苗死亡。同时在生理耐盐极限范围内，箭豆对较高土壤盐分含量会产生适应性生理调节，植株含水量减少，积累干物质量相对增加。     

科尔沁沙地达乌里胡枝子生物量研究

达乌里胡枝子在科尔沁沙地播种当年即能形成种子，第二年返青较早；成熟枝条长达80.1cm，每株分枝可达8～11个，枝条基部可产生不定根；单株地上生物量20.73～42.76g，枝叶比较高，可达1∶1.22；第二年鲜、干草及种子产量分别为15607.81kg/hm2、6151.36kg/hm2和426.21kg/hm2，再生性较好，但早利用会使总产量降低；达乌里胡枝子根系发达，生长50d入土深达30cm，100d后深达50cm，生长2年后达100cm，多年野生植株根系可达140cm，水平根也较发达。     

灌溉量对科尔沁沙地紫花苜蓿产量和水分利用效率的影响

为探讨科尔沁沙地紫花苜蓿适宜灌溉量,以指针式喷灌机下建植两年紫花苜蓿为试验材料,根据联合国粮农组织推荐的Penman-Monteith方法,以日为步长计算紫花苜蓿实际需水量(ET_C)。基于ET_C设置四个灌溉水平W1(60%ET_C)、W2(80%ET_C)、W3(100%ET_C)、W4(120%ET_C),研究不同灌溉量对科尔沁沙地紫花苜蓿产量和水分利用效率的影响。结果表明:2018年刈割三茬的紫花苜蓿产量和水分利用效率随灌溉量增加呈现先增加后降低的趋势。其中第一茬内株高、生长速度、分枝质量随灌溉量的增加而增加,分枝数、地上生物量和水分利用效率随灌溉量增加变现为先增加后降低;第二茬产量在各处理间无显著性差异(P0.05),水分利用效率随灌溉量的增加逐渐降低;第三茬产量、水分利用效率在W2、W3处理下无显著性差异(P 0.05)。综合考虑产量、水分利用效率,建议生育期内采用W3的灌溉水平进行灌溉。     

不同饲养条件下金霉素对肉仔鸡的作用效果

金霉素在常规平养条件下，对肉仔鸡的生长有促进作用，可提高鸡群的成活率和肉鸡饲料转化率；在笼养条件下，特别是环境卫生较好、鸡群比较健康时，金霉素的作用效果不显著；料中含有40mg／kg的氟哌酸时，添加金霉素对地面平养条件下的肉鸡无明显的促生长效果，提高饲料转化率的作用也有减弱的趋势。     

科尔沁沙地达乌里胡枝子生物量研究

达乌里胡枝子在秒尔沁沙地播种当年即能形成种子，第二年返青较早；成熟枝条长达80.1cm，每株分枝可达8－11个，枝条基部可产生不定根；单株地上生物量20.74-42.76g，枝叶比较高，可达1：1.22，第二年鲜、干草及种子产量分别为15607.8kg/hm^2、6151.36kg/hm^2和426.21kg/hm^2，再生性较好，但早利用会使总产量降低；达乌里胡枝子根系发达，生长50d入土深达30cm，100d后深达50cm，生长2年后达100cm，多年野生植株系可达140cm ,水平根也较发达。     

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 -