云南绵羊染色体比较研究

本文研究了云南昭通、德钦、腾冲绵羊染色体的核型，Ｇ带Ｃ带、Ａｇ－ＮＯＲ，结果表明：云南绵羊染色体众数２ｎ＝５４；染色体Ｇ带基本相似；Ｃ带显示三个绵羊品种染色体亚中着丝粒区均为淡染，近端着丝粒区均为深染，Ｘ和Ｙ性染色体整个都为淡染，产在三个地区的棉羊其染色体异染色质的大小，强弱个地区的绵羊其染色体异染色质的大小、强弱存在差异；Ａｇ－ＮＯＲｓ的数目分布在２￣１０之间，众数为７，腾冲绵羊Ａｇ－ＮＯＲｓ较     

西镇牛的染色体研究

对２１头西镇牛的染色体核型、Ｇ带、Ｃ带及Ａｇ－ＮＯＲｓ进行了研究。结果表明，西镇牛公牛的核型为６０，ｘｙ，，母牛为６０，ｘｘ。Ｙ染色体近端着丝点染色体。     

丹麦红牛的染色体分析

分析了７头（３公４母）丹麦红牛的染色体核型、Ｃ带和Ａｇ—ＮｏＲｓ。结果表明，丹麦红牛二倍体为２ｎ＝６０，公平核型为６０，ｘｙ，母牛为６０，ｘｘ，ｘ染色体为一大的亚中着丝粒染色体，ｙ染色体为一小的亚中着丝粒染色体，其臂比为１．７２２。丹麦红牛的核型和Ｃ带带型与普通牛（Ｂｏｓｔａｕｒｕｓ）相同。观察统计了３４３个细胞的Ａｇ—ＮｏＲｓ数，平均每细胞为５．３１４±０．１８１，变化范围为２～９个。分析了正常半体细胞多倍体的出现率，平均为３．４±１．２％。     

通过银染核仁组织区（Ag—NORs）对黄牛品种间遗传关系的探讨

用银染技术对中国４个地方黄牛品种（蒙古牛，泰川牛，岭南牛和西镇牛）４０头牛的Ａｇ－ＮＯＲｓ作了比较研究，并根据不同Ａｇ－ＮＯＲｓ的个体频率用数学方法估计了４个品种间的遗传距离，以此对４个品种作了聚类分析。结果表明，在４个品种中，西镇牛与岭南牛关系最近，西人扣与蒙古牛关系最远。这与从Ｙ染色体多态性，外形，历史，地理分布及生态类型的研究结果一致。     

青海细毛羊染色体研究

采用外周血淋巴细胞培养及常规染色体标本制备技术，研究了青海细毛羊染色体的核型和畸变，并以ＧＴＧ，ＣＢＧ，硝酸银等方法对染色体标本进行分带处理，分别显示了青海细毛羊染色体的Ｇ－带，Ｃ－带和Ａｇ－ＮＯＲｓ带型，结果表明；（１）青海细毛羊二倍体细胞的染色体数目为２ｎ＝５４，公羊核型式为５４，ＸＹ，ＮＦ＝６２。母羊核型式为５４，ＸＸ；ＮＦ＝６２。（２）染色体畸变类型主要为断裂和四倍体，频率分别为１．５３０     

转基因猪银染核仁组织区的初步研究

采用外周血淋巴细胞培养技术，硝酸银银染法研究转基因猪的染色体银染核仁组织区（Ａｇ－ＮＯＲ）。结果表明：由湖北白猪Ｖ系经基因转移形成的转基因猪（以后简称转基因猪）与湖北自猪ＩＶ系普通猪（以后简称普通猪）银染点的数目和大小在个体、细胞、染色体水平上具有多态性，Ａｇ－ＮＯＲ位于第８号和第１０号染色体的次缢痕区；不同个体的Ａｇ－ＮＯＲ数不同，转基因猪平均每个细胞有二个银染点，普通猪平均每个细胞有三个银染点     

藏羊和引入青海的新疆细毛羊染色体显带研究

采用外周血淋巴细胞培养及染色体显带技术，对藏羊和引入青海的新疆细毛羊染色体进行卫显带研究。结果表明：两品种绵羊Ｇ－带带型基本一致；Ａｇ－ＮＯＲｓ分布位点相同；Ｃ－带着色区域相同，但异染色质区域大小和染色深浅上存在差异。     

鸡MD肿瘤细胞NOR的研究

利用石蜡切片一步银染法对１４例马立克氏病鸡肿瘤细胞核仁组成区相关嗜银蛋白的数目、形态及分布进行研究。结果表明，ＭＤ肿瘤细胞中有２种形态的Ａｇ－ＮＯＲｓ，一种为团块状较大的Ａｇ－ＮＯＲｓ，生个肿瘤细胞平均为１．５８个／细胞；一种为较小的散在分布的Ａｇ－ＮＯＲｓ，平均为５．８１个／细胞。每人肿瘤细胞拥有７．３７个Ａｇ＝ＮＯＲｓ，ＭＤ鸡肿瘤细胞中Ａｇ－ＮＯＲｓ的数量、形态特征一其分化程序和ＤＮＡ含量有关     

牛轮状病毒重组株的血清学和基因型特性

从母牛接种过Ａ组ＢＲＶ株ＮＣＤＶ－Ｌｉｎｃｏｌｎ（Ｐ１：Ｇ６）苗的两个吡邻牛场分离到两株牛轮状病毒（ＢＲＶ），编号为ＮＳ－１和ＮＳ－２，Ｎｏｒｔｈｅｒｎ－ｂｌｏｔｔｉｎｇ试验表明，ＮＳ－１和ＮＳ－２有相的的Ａ组ＲＮＡ电泳模式，而且全部基因片段同源，体外中和试验表明，ＮＳ－１株病毒能被Ｇ６特异性单克隆抗体（ＭｃＡｓ）和抗ＢＲＶＢ６４１株（Ｐ５：Ｇ６）豚鼠高免血清（ＧＰＡＳ）中和，但不被Ｇ１０特异性Ｍ     

山羊外周全血中性粒细胞化学发光检测条件

应用全血细胞化学发光（ＣＬ）技术，测定了山羊外周全血中性粒细胞（ＰＭＮ）活性氧自由基（ＯＦＲ）的化学发光，对试验要素包括鲁米诺浓度、酵母多糖浓度、测定时间，以及化学发光测定仪的额定电压、工作温度作了试验筛选，比较了其对山羊ＰＭＮ－ＣＬ的发光本底、峰值及峰时变化的影响。结果表明，测定山羊全血ＰＭＮ－ＣＬ的最优条件：鲁米诺浓度为２×１０－３ｍｏｌ／Ｌ，酵母多糖浓度为５ｇ／Ｌ，测量时间为２ｓ；ＳＨＧ－Ⅰ型生物化学发光测定仪额定电压及工作温度设置分别为４．０Ｖ和（３３±１．５）℃。     

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 -