内蒙古绒山羊公羊睾酮全年分泌规律的研究

本研究通过同位素放射免疫测定技术测定内蒙古绒山羊公羊全年的睾酮分泌规律。结果表明,雄性绒山羊的睾酮的群体平均水平在1月中旬最低,然后逐渐上升,在10月末达最高水平,再逐渐下降,到1月中旬回到最低。个体分泌规律也符合这一特点。     

控制光照对内蒙古白绒山羊褪黑激素含量的影响

为研究非长绒期控制光照对内蒙古白绒山羊褪黑激素(MLT)含量的影响,随机选取12只年龄、产绒量和体重基本一致的内蒙古白绒山羊母羊,分为控制光照组(试验组)和对照组,每组各6只,采集血液样品进行褪黑激素含量测定,利用SAS 9.0软件进行显著性检验和相关性分析。结果表明,控制光照(试验组)使白绒山羊血液中的MLT含量在20:00、21:40、6:40时高于对照组,20:00、6:40时两组白绒山羊MLT含量差异显著(P0.05),试验组白绒山羊血液中MLT含量的高峰期维持时间显著长于对照组。10月,试验组与对照组MLT含量变化基本一致,差异均不显著(P0.05);对照组中10月白绒山羊血液中的MLT含量明显高于6月,但控制光照的白绒山羊血液中的MLT含量最高,说明控制光照可改变皮肤毛囊发育及绒毛生长周期,最终使内蒙古白绒山羊在非长绒期绒毛提前生长。     

光控对内蒙古绒山羊血液中褪黑激素和催乳素及产绒性能的影响

光控增绒是一种高效、环保、低成本的绿色增绒技术,该技术的推广对于提高绒山羊的产绒量具有重要意义。但是,该技术调控绒山羊绒毛生长的机制尚不明确,本试验在此基础上,通过比较正常光照和缩短光照条件下,内蒙古阿尔巴斯型绒山羊血液中激素及产绒性状的差别,探讨缩短光照引发绒毛提前生长的原因。选取2-4岁的内蒙古阿尔巴斯型绒山羊母羊50只,通过进行光照时间限制的处理,对不同月份试验组和对照组血清中褪黑激素和催乳素的变化情况和绒毛性状等指标进行监测,结果表明:(1)光控后试验组褪黑激素水平有略微升高的趋势,而对照组急剧下降;短日照处理组催乳素水平在9月份光控组中显著下降。(2)褪黑激素、催乳素随次级毛囊生长呈现显著性周期变化。(3)试验组比对照组绒毛产量提高了54%,差异极显著(P0.01)。本试验揭示了光控增绒技术可能通过调节绒山羊血液中褪黑激素和催乳素水平,进而造成毛囊生长周期的改变,延长绒毛生长期,最终显著增加了绒山羊的年产绒量。该试验为光控增绒技术的推广提供了理论支撑。     

光照和埋植褪黑激素对非生绒期内蒙古白绒山羊体成分的影响及应用

本文从体成分的角度研究了褪黑激素对内蒙古白绒山羊营养分配的影响,研究结果显示光照时间和埋植褪黑激素显著影响绒山羊的有关激素水平,进而影响体成分组成。随着光照时间的缩短,绒山羊的体脂肪含量增加,体蛋白含量减少;光照相同条件下,埋植褪黑激素组的体脂肪含量高于不埋植组,体蛋白含量低于不埋植组,短光照和埋植褪黑激素之间有显著(P<0.01)的互作效应。证明了光照和褪黑激素在动物营养分配中的作用,为褪黑激素在生产实践中的合理应用提供理论依据。     

内蒙古绒山羊血清生化指标、电解质浓度和热休克蛋白基因表达的季节性变化研究

为了揭示内蒙古绒山羊血清生化指标、电解质浓度和热休克蛋白(HSPs)基因表达的季节性变化规律，试验选择11只全年放牧的2周岁内蒙古绒山羊母羊，在一年内每月颈静脉采集血液样品，测定血清生化指标、电解质浓度、激素水平和外周血单个核细胞HSPs基因的相对表达量。同时，记录放牧地环境温度、相对湿度、光照周期、降水量和天气情况，分析气象参数的全年变化规律。结果表明：血清促肾上腺皮质激素和皮质醇浓度及外周血单个核细胞中HSP60和HSP90基因表达量呈现明显的季节性变化规律，表现为冬夏季节较高，春秋季节较低。血清生化指标和电解质水平则未呈现一致性规律，具体表现为血清胆红素浓度秋季较低，血清镁浓度则秋季较高，血清肌酐和钾浓度夏季较低，血清氯浓度则夏季较高，血糖和血清磷浓度则为5月份最高，血清尿素浓度为冬夏季节较高，春秋季节较低。但血清钠浓度及外周血单个核细胞中HSP70和HSP110基因表达量未呈现季节性变化规律。说明季节性环境变量对内蒙古绒山羊血清生化指标和电解质浓度有影响，并促进了与适应过程有关的激素分泌和HSP基因表达。     

绒山羊血清胰岛素样生长因子-Ⅰ浓度的季节性变化规律及其与绒毛生长关系的研究

试验随机选择6月龄、平均体重15.21 kg±0.61 kg的河西白绒山羊20只(公母各半),从5月份脱绒后开始对试验羊连续跟踪12个月每月采集绒毛样品,并在每个季节采集血样。用手排长度法测定各月绒毛生长长度,用放射免疫法测定绒山羊血清胰岛素样生长因子(IGF-Ⅰ)浓度。结果表明:河西绒山羊绒毛在6月份和7月份开始萌发,生长期为8月、9月、10月、11月、12月五个月;8月份为生长高峰期,占其全年总生长量的31.5%;生长量从8—12月份呈线性下降趋势,至元月份停止生长,5月份开始脱绒,呈慢-快-慢生长模式。公羊IGF-Ⅰ浓度(340.74 ng/mL±56.41 ng/mL)四季均极显著大于母羊(204.38 ng/mL±62.31 ng/mL)(P<0.01);无论公羊还是母羊在绒毛萌发期(6月份)和停止生长期(3月份)IGF-Ⅰ浓度均极显著高于绒毛生长旺盛期(9月份)(P<0.01);经相关性分析IGF-Ⅰ浓度与绒毛生长速度呈极显著负相关(r=-0.93,P=0.004)。本试验结果表明IGF-Ⅰ浓度呈现明显的季节性变化模式,性别对血清IGF-Ⅰ浓度有极显著的影响,高浓度的IGF-Ⅰ可能对绒毛的萌发和休止起调节作用、低浓度的IGF-Ⅰ可能有利于生绒或长绒。     

母羊胎次与配种日期对内蒙古白绒山羊产羔数的影响

文章通过分析母羊胎次与配种日期对内蒙古白绒山羊产羔数的影响,确定内蒙古白绒山羊的最佳配种时间,以提高其繁殖效率.试验数据来自于内蒙古白绒山羊种羊场1998-2013年的繁殖记录.利用SAS 9.0软件的GLM程序确定母羊胎次、配种日期对产羔数的显著性影响.结果表明,母羊胎次和配种日期对产羔数影响极显著(P< 0.01).母羊第1胎产羔数最低(1.37),随着母羊胎次的增加,产羔数显著增加,第6胎之后产羔数开始下降;配种周期为9月29日-10月16日的产羔数最高(1.76),且母羊发情月份和发情高峰主要集中在10月份,所以在生产中此阶段可以作为内蒙古白绒山羊的配种期.     

不同能量水平和采精频率对绒山羊种公羊精液品质的影响

为研究日粮不同能量水平对陕北白绒山羊种公羊体重、血清睾酮水平和精液品质的影响,选择12只健康的种公羊按随机区组设计分为4组,每组3个重复,每个重复1只羊。日粮按NRC(1981,2007)标准推荐量的85%、100%、115%和130%设置4个能量梯度。结果表明,各个试验阶段日粮能量水平对试验公羊的平均日增重影响极显著(P< 0.01)。Ⅰ组和Ⅱ组公羊在整个试验期体重呈现先减后增的趋势,Ⅲ组和Ⅳ组公羊体重呈现先增后减再增的趋势;5 d 2次频率下公羊的睾酮和射精量高于5 d 4次的频率。日粮能量水平对试验公羊的血清睾酮水平和有效精子数影响极显著(P< 0.01),对射精量和精子密度影响显著(P< 0.05)。射精量、精子密度和有效精子数均以Ⅲ组最好。采精频率和能量浓度只对睾酮水平有极显著的互作效应(P< 0.01)。综上所述,陕北白绒山羊种公羊代谢能(ME)需要以12.08 MJ/d为宜。     

舍饲陕北白绒山羊血液生理生化指标的测定与分析

试验测定了舍饲陕北白绒山羊多项血液生理生化指标,分析不同年龄、不同性别陕北白绒山羊的血液生理生化指标,旨在为陕北白绒山羊疾病诊断和基础研究提供数据。结果表明,陕北白绒山羊公母之间的血液生理生化测定值在不同的年龄阶段有一定的变化,公羔的血红蛋白、总蛋白和球蛋白显著高于母羔(P<0.05),而单核细胞、嗜酸性粒细胞、白蛋白、尿素和无机磷含量显著(P<0.05)或极显著低于母羔(P<0.01);育成羊母羊血液中白细胞数、中性粒细胞数、血红蛋白、胆固醇和钙含量显著高于育成公羊(P<0.05),育成母羊无机磷极显著低于育成公羊(P<0.01);成年母羊的白细胞、中性粒细胞数、谷丙转氨酶显著高于成年公羊,而白蛋白、肌酸激酶和无机磷显著低于成年公羊(P<0.05)。研究结果提示,舍饲陕北白绒山羊血液生理生化指标中测定值的变化范围主要因不同年龄和性别间的差异引起的,未发现明显的异常值。     

非产绒期控制光照和埋植褪黑激素对藏西北绒山羊增绒效果的影响

研究旨在探讨非生绒期控制光照和埋植褪黑激素对藏西北绒山羊增绒效果的影响,为藏西北绒山羊非产绒期选择一种有效的增绒技术。选择体重和产绒量基本一致、年龄2~3岁的藏西北绒山羊母羊60只,随机分为3组,试验为期1年。结果表明:控制光照组产绒量最高,显著高于对照组36.3%(P0.01),但与皮下埋植褪黑激素组无差异(P0.05);皮下埋植褪黑激素组羊绒长度极显著提高(P0.01),但与控制光照组无差异(P0.05);在羊绒细度指标上,各组间差异均不显著(P0.05)。表明皮下埋植褪黑激素是藏西北绒山羊生产上方便有效的增绒技术。     

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 -