中国小型鹅种的遗传多样性分析

采用微卫星标记技术对我国13个小型家鹅群体(莲花白鹅、永康灰鹅、太湖鹅、闽北白鹅、长乐鹅、乌棕鹅、阳江鹅、酃县白鹅、右江鹅、籽鹅、百子鹅、豁眼鹅、伊犁鹅)的遗传多样性进行了分析。结果表明:13个品种的平均杂合度都较高,平均杂合度最高的为太湖鹅,最低的为豁眼鹅,杂合度范围为0.5041~0.7145,13个鹅种资源群体平的均杂合度为0.6132,反映了各鹅种的杂合度都较高,遗传多样性丰富;通过计算DA遗传距离发现各群体的遗传距离较远,分化时间较长;NJ聚类结果将13个中型鹅种聚为三大类,NJ的聚类结果分析与几个鹅品种的地域分布和经济用途的关系并不密切。     

我国地方鹅品种资源遗传多样性保护等级分析

研究旨在分析我国地方鹅品种资源遗传多样性保护等级,为更好地制定我国地方鹅品种资源保护方案提供理论依据。采用25个微卫星标记计算我国14个地方鹅品种(太湖鹅TH、永康灰鹅YK、百子鹅BZ、酃县白鹅LX、闽北白鹅MB、长乐鹅CL、兴国灰鹅XG、豁眼鹅HY、雁鹅YE、浙东白鹅ZD、广丰白翎鹅GF、丰城灰鹅FC、莲花白鹅LH、皖西白鹅WX)间DA遗传距离、基因流(Nm)、有效等位基因数(Ne)、杂合度(Ho)和多态信息含量(PIC),并采用Weitzman和Caballero两种遗传多样性保护理论,分析了各品种在遗传多样性最大化保护中的相对重要性。25个微卫星座位平均有效等位基因数为8.12,平均多态信息含量为0.581。14个地方鹅种的平均观察杂合度为0.6808,雁鹅观察杂合度最低(0.5662),百子鹅观察杂合度最高(0.7748);丰城灰鹅与浙东白鹅之间的遗传距离最小(0.2188),太湖鹅与永康灰鹅之间的遗传距离最大(0.7388)。Weitzman保护理论分析结果表明永康灰鹅、酃县白鹅、太湖鹅、百子鹅和雁鹅的品种贡献率较高(10.0%),Caballero保护理论分析认为太湖鹅、永康灰鹅、百子鹅、酃县白鹅和闽北白鹅具有较高的贡献率(0.5%),与Weitzman保护理论确定的等级顺序存在一定差异,主要原因是Weitzman保护理论没有考虑到品种内遗传多样性。我国地方鹅品种资源不仅具有丰富的品种间遗传多样性,品种内遗传多样性也较为丰富,在分析保护等级时,应两者兼顾。     

5个白鹅群体的遗传结构和进化分析

应用微卫星标记对我国5个白鹅品种资源群体(太湖鹅、四川白鹅、织金白鹅、伊犁鹅、皖西白鹅)的遗传结构和进化进行了研究。结果表明:(1)5个白鹅群体的平均杂合度都较高,反映了各鹅种群体内的遗传变异较大,各鹅种的适应性较强;(2)通过计算DS遗传距离和UPG-MA聚类,发现5个白鹅群体间的遗传距离较远,分化时间较长,5个白鹅群体分别独自为一类,聚类结果反映了5个鹅品种的进化与它们的选育历史及地理分布关系密切。应加强对我国现有鹅种资源的保护力度和开发力度。     

中国华东区地方鹅种群体遗传多样性及遗传分化研究

利用25对微卫星引物对我国华东14个地方鹅种进行群体遗传多样性及遗传分化分析。通过计算多态信息含量、平均杂合度、有效等位基因数、遗传距离、基因流和F-统计量等参数,评估各品种遗传多样性和品种间遗传分化。结果表明：各座位的等位基因数为4～16。所有群体均显示较高水平的杂合度,其中,雁鹅最低,为0．5662,百子鹅最高,为0．7748。鹅品种间存在较大的遗传分化,27．5％的遗传变异来自于品种间的差异。基于DA遗传距离的NJ聚类法将14个群体划分为4类。分析遗传分化与地理距离的相关关系发现,华东地方鹅种的遗传分化与地理距离不存在显著相关。     

广东省四个家鹅群体的遗传变异研究

通过筛选31个多态性较好的微卫星标记检测了广东省狮头鹅、乌棕鹅、阳江鹅、马岗鹅4个家鹅的遗传变异。利用等位基因频率计算了各群体的遗传参数、群体间的Nei氏标准遗传距离DS和DA遗传距离,并采用邻近法(NJ)和类平均法(UMPGA)进行聚类。结果表明广东省4个家鹅群体的平均杂合度为0.652,遗传一致性较好,各品种间的遗传距离远近顺序在两种遗传距离DS和DA的结果中是完全一致的,以DA为基础得到的UPGMA和NJ的聚类结果都表明这4种鹅聚为两类,狮头鹅和乌棕鹅聚为一类,阳江鹅和马岗鹅聚为一类。同时表明以DA为基础得到的结果NJ的聚类结果更加准确。表明在应用微卫星标记分析品种的遗传多样性时,使用更多的微卫星位点,才可以获得更准确更具普遍性的结论。     

利用微卫星标记分析中国地方鹅品种遗传变异及分化

通过25个多态性较好的微卫星标记,检测我国26个地方鹅品种1 560个个体,共检测到198个等位基因,每个位点平均为7.92个。有效等位基因数为1.307 0～5.795 5,平均3.066 2个。就全群而言,平均观察杂合度、期望杂合度、多态信息含量分别为0.668 6、0.457 7和0.564 0。对各个群体而言,观察杂合度、期望杂合度和多态信息含量变异范围分别是0.535 1～0.754 7、0.383 1～0.604 9、0.324 0～0.538 0。群体间存在明显的遗传分化,约有28%的遗传分化来自于群体间的变异。右江鹅与永康灰鹅之间的Reynolds遗传距离最大（0.522）,基因流值最小（0.365）,武冈铜鹅与豁眼鹅之间的Reynolds遗传距离最小（0.133）,基因流值最大（1.763）。在Reynolds遗传距离的基础上做品种的NJ聚类图,26个地方鹅资源群体分为5个类群。研究结果为我国地方鹅种种质特性研究提供基础数据,为我国地方鹅品种资源的合理保护和利用提供科学依据。     

我国十个鹅品种的遗传结构及遗传分化研究

利用多态性丰富的15个微卫星标记对列入国家级畜禽保护名录的10个鹅品种群体遗传结构、遗传分化及基因流进行研究.结果表明:10个鹅群体总近交系数(Fit)为-0.044,群体内近交系数(Fis)为-0.408,群体间基因分化系数(Fst)为0.257,3个固定指数只有Fst 达到极显著水平(P<0.01).鹅群体内近交系数(Fis)均为负值.各个鹅群体间,豁眼鹅与伊犁鹅的基因流值最小(Nm=0.416),四川白鹅与伊犁鹅间基因流值最大(Nm=1.430).结合基因流和STRUCTURE分析结果,10个地方鹅品种可划分为四类:兴国灰鹅、豁眼鹅和太湖鹅为一类,四川白鹅、狮头鹅和乌鬃鹅为一类,酃县白鹅和皖西白鹅为一类,雁鹅和伊犁鹅为一类,这种聚类结果与各个品种的选育历史和地理分布等一致.     

我国十个鹅品种的遗传结构及遗传分化研究

利用多态性丰富的15个微卫星标记对列入国家级畜禽保护名录的10个鹅品种群体遗传结构、遗传分化及基因流进行研究。结果表明:10个鹅群体总近交系数(Fit)为-0.044,群体内近交系数(Fis)为-0.408,群体间基因分化系数(Fst)为0.257,3个固定指数只有Fst达到极显著水平(P<0.01)。鹅群体内近交系数(Fis)均为负值。各个鹅群体间,豁眼鹅与伊犁鹅的基因流值最小(Nm=0.416),四川白鹅与伊犁鹅间基因流值最大(Nm=1.430)。结合基因流和STRUCTURE分析结果,10个地方鹅品种可划分为四类:兴国灰鹅、豁眼鹅和太湖鹅为一类,四川白鹅、狮头鹅和乌鬃鹅为一类,酃县白鹅和皖西白鹅为一类,雁鹅和伊犁鹅为一类,这种聚类结果与各个品种的选育历史和地理分布等一致。     

华中地区家鸭种质资源的遗传结构研究

利用28个微卫星标记对华中地区6个家鸭资源（淮南麻鸭、攸县麻鸭、临武鸭、荆江麻鸭、沔阳麻鸭和恩施麻鸭）的遗传结构进行了评估。结果表明：6个群体的平均杂合度都较高,最低的为攸县麻鸭（0．5512）,最高的为荆江麻鸭（0．6035）,群体平均杂合度为0．5801,反映了各鸭种的杂合度都较高,遗传多样性丰富;华中地区各鸭种间存在较大的遗传分化,22．5％的遗传变异来源于群体间的差异,进一步反映了各品种具有本品种特性的多样性;通过计算DA遗传距离发现各品种间的遗传距离较远,分化时间较长;NJ聚类结果将华中地区家鸭资源聚为3类,湖北省的荆江麻鸭、沔阳麻鸭和恩施麻鸭聚为一类;湖南省的攸县麻鸭和临武鸭聚为一类;河南省的淮南麻鸭独聚为一类。本研究结果为华中地区家鸭品种种质特性研究提供了基础,也为中国家鸭资源的合理保护和开发利用提供了科学依据。     

新疆13个绵羊群体遗传多样性及遗传分化的研究

利用10个微卫星标记对新疆13个绵羊群体的遗传多样性和遗传分化进行了分析。通过计算多态信息含量（PIC）、平均杂合度（H）、群体内近交系数（Fis）、遗传分化系数（Fst）、总群体近交系数（Fit）和基因流（Nm）等参数,评估各品种遗传多样性和品种间遗传分化。结果表明：13个绵羊群体10个微卫星标记的平均多态信息含量为0.6803;平均杂合度为0.7192,其中中国美利奴羊平均杂合度最高为0.7530,山区和田羊最低为0.6754;13个绵羊群体总近交系数为0.1066,群体内近交系数为0.0565,群体间基因分化系数为0.0531,说明5.65%的遗传变异来自群体间,94.35%的遗传变异来自群体内个体间的差异;基因流Nm平均值为4.4621（3.0808~7.4589）,说明各种群间存在或者在过去某个时期发生基因交流;各种群间平均遗传距离较低,为0.1702,平均遗传一致度数值较高,为0.8448,也再次证明了新疆13个绵羊群体间分化程度不高。基于Nei′s标准遗传距离运用UPGMA聚类法获得的新疆13个绵羊群体的聚类图与其品种育成史和地理分布基本相一致。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

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.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

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.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.