中国美利奴羊多胎品系选育中多胎性状分离与BMPR-IB基因型的相关性分析

以绵羊BMPR-IB基因为主效基因.以中国美利奴羊(新疆军垦型)多胎品系为研究对象,应用Genopro软件绘制多胎品系绵羊的系谱.记录母羊产羔数.采用PCR-RFLP方法对BMPR-IB基因进行基因型分型.分析多胎性状的分离规律,研究BMPR-IB基因型分布与以多胎性能为目标的品系培育的相关性.结果表明,在品系培育中,BMPR-IB基因的表型符合孟德尔遗传分离模式,增加绵羊产羔数由常染色体突变所致,BMPR-IB基因可以用于对绵羊产羔数的选择.     

BMPR-IB基因对绵羊外周血生殖激素水平的影响

为研究不同BMPR-IB基因型多胎萨福克羊外周血中生殖激素水平的差异,以培育的发情期多胎萨福克母羊为实验对象,应用PCR-RFLP技术检测个体的BMPR-IB基因型,ELISA方法检测绵羊外周血中E2、FSH、LH、PRL和P4的含量,分析BMPR-IB基因型与5种生殖激素水平的相关性.结果表明：多胎萨福克羊群体中存在BMPR-IB基因的BB、B＋和＋＋三种基因型.＋＋基因型个体的平均E2含量和P4含量显著低于B＋基因型和BB基因型个体（P＜0.05）,3种基因型个体间平均FSH含量、LH含量和PRL含量差异均不显著（P＞0.05）.BMPR-IB基因突变导致发情期母羊的雌二醇和孕酮的分泌量增加.研究结果可为合理利用BMPR-IB基因培育多胎肉羊提供依据.     

BMPR-IB基因作为影响蒙古羊双羔性状候选基因的研究

为了探索多胎候选基因BMPR-IB与蒙古羊双羔群体繁殖性状之间的关系,试验采用聚合酶链式反应-限制性片段长度多态性分子标记技术(PCR-RFLP),以蒙古羊单羔群体(18只)、多胎类型小尾寒羊(30只)为对照组对蒙古羊双羔群体(50只)进行了BMPR-IB基因的遗传多态性分析。结果表明:蒙古羊双羔群体和蒙古羊单羔群体中都不存在BMPR-IB基因的FecB(A746G)突变,说明BMPR-IB基因不是影响蒙古羊双羔性状的主效基因;而在多胎品种小尾寒羊中检测到了相应的突变,发现了3种基因型,其突变纯合子(BB)、杂合子(B+)和野生型(++)的基因型频率分别是0.100,0.733,0.167,将其与产羔数进行关联分析,结果BB基因型母羊和B+基因型母羊平均产羔数差异极显著(P0.01);经x2适合性检验,小尾寒羊该基因位点显著偏离Hardy-Weinberg平衡(P0.05),由此推断BMPR-IB基因是控制小尾寒羊多胎性能的主效基因。     

BMPR-IB基因对羔羊初情期及血清褪黑激素分泌水平的影响

为分析多胎萨福克新品系肉羊的繁殖特点,以及BMPR-IB基因对初情期多胎萨福克羔羊褪黑激素分泌的影响,应用PCR-RFLP方法检测多胎萨福克羔羊BMPR-IB基因的多态性,应用公羊试情和外阴外观变化确定母羔初情期,用ELISA方法测定初情期前后母羔血清中褪黑激素的含量,分析BMPR-IB基因不同基因型母羔初情前期、初情期、初情后期褪黑激素分泌水平的变化。结果表明:多胎萨福克羊群体中BMPR-IB基因存在++、B+和BB三种基因型,平均初情期179 d,不同基因型母羔初情期时间差异不显著(P0.05);褪黑激素在初情期分泌水平较高,初情前后的4个时间点分泌出现波动,但没有达到显著性水平(P0.05),BMPR-IB基因不同基因型羔羊血清中的褪黑激素含量差异不显著(P0.05)。说明BMPR-IB基因的突变没有引起初情期多胎萨福克羔羊褪黑激素分泌水平的显著变化。     

绵羊PRLR基因内含子9和外显子10多态性与产羔数的关系研究

本研究采用PCR-SSCP技术对绵羊催乳素受体(PRLR)基因内含子9和外显子10部分核苷酸多态性及其与小尾寒羊、中国美利奴(新疆型)绵羊多胎品系、肉用品系、体大品系、萨福克、无角陶赛特、中国美利奴(新疆型)和德国肉用美利奴产羔数间的关系进行了分析。结果发现:①在绵羊PRLR基因内含子9的第259 bp处,存在C→T转换,BB基因型的小尾寒羊平均产羔数分别较AA和AB基因型提高0.81和0.87只(P0.05);②在绵羊PRLR基因外显子10的第304 bp处存在一个G→A转换,该突变导致PRLR基因第387位氨基酸残基由Glu突变为Lys,并使中国美利奴(新疆型)多胎品系中AB基因型的平均产羔数较AA和BB基因型增加0.58和0.80只(P0.05);③在绵羊PRLR基因外显子10第571、585和606bp处分别存在G→A、C→G和C→T突变;其中前2处突变分别导致PRLR基因的第476位氨基酸由Ala突变为Thr,第480位氨基酸由Ser突变为Arg。其中第571 bp处突变导致小尾寒羊AB基因型的平均窝产羔数显著高于AA基因型的窝产羔数,增加0.8只(P0.05)。以上结果提示,PRLR基因可能是控制小尾寒羊和中国美利奴(新疆型)绵羊多胎品系产羔数的主效基因或与之存在紧密的遗传连锁。     

小尾寒羊和新疆多浪羊群体BMPR-IB基因多态性研究

以影响Booroola Merino高产性能的BMPR-IB基因为候选基因，对小尾寒羊和新疆多浪羊群体进行BMPR-IB基因多胎性分析.结果表明：小尾寒羊和新疆多浪羊群体内均存在BMPR-IB基因（A746G）的突变个体.小尾寒羊群体内存在3种基因型（BB、B＋、＋＋），BB和B＋基因型在群体内为优势基因型，其基因型频率分别为0.548和0.397，表明BMPR-IB基因突变位点的B等位基因对小尾寒羊的高繁殖力具有显著的影响.新疆多浪羊群体内存在两种基因型（B＋、＋＋），＋＋基因型在群体内为优势基因，而B＋基因型频率为0.039.通过对群体产羔率的调查分析发现：新疆多浪羊并非是一个多胎绵羊品种，其高产性能主要体现在地方品种绵羊出现四季发情，因而群体内出现一年四季产羔.     

BMPR-IB基因在寒泊羊群体中的增羔效应、遗传规律及育种应用分析

旨在揭示BMPR-IB基因在寒泊羊种群中的多态性及遗传学规律,探讨将BMPR-IB基因第746位碱基发生的A→G突变(FecB突变)作为分子标记进行绵羊多胎品种选育的科学性。本研究对寒泊羊育种核心群的健康种公羊、繁殖母羊、羔羊共计1 267只绵羊个体进行采血,利用PCR-RFLP方法判定个体BMPR-IB基因位点的基因型并进行群体遗传学分析。对繁殖母羊共计980胎次的产羔记录进行统计,分析FecB突变、胎次及产羔季节对胎产羔数性状的影响。统计所设计杂交组合后代共计167只健康羔羊的基因型比例。结果表明,BMPR-IB基因在寒泊羊种群中有BB、B+和++3种基因型,其基因型频率分别为1.97%、73.40%和24.63%,等位基因B和+的频率分别为38.67%、61.33%;BB、B+和++基因型繁殖母羊的平均胎产羔数分别为2.69、1.91、1.57只,目前寒泊羊种群的胎产羔数平均为1.85只;若经过品种选育使寒泊羊个体中增加一个B基因拷贝,胎产羔数预期增加0.44只;父母本杂交组合为B+×++的后代中B+和++基因型的比例为1.11∶1,父母本杂交组合为B+×BB的后代中BB和B+基因型的比例为0.82∶1,均符合孟德尔分离定律;预测经过6个世代的选育,可使寒泊羊种群母羊基本实现胎产羔数2只的育种目标。本研究结果为绵羊育种实践中制定选种和选配方案提供了理论基础。     

BMPR-IB基因多态性与河北肉用绵羊产羔数及羔羊生长发育的相关性研究

为了研究BMPR-IB基因单核苷酸多态性及其对绵羊产羔数和羔羊生长发育的影响,试验采用PCR-RFLP方法对小尾寒羊、杜泊、德克赛尔及河北肉用绵羊的BMPR-IB基因单核苷酸多态性进行了测定,并对BMPR-IB基因多态性与河北肉用绵羊产羔数和生长发育的关系进行了研究。结果表明:基因型频率在各品种间分布极不平衡,BB基因型河北肉用绵羊群体的总体平均产羔数显著高于B+基因型(P<0.05),极显著高于++基因型群体(P<0.01);90日龄时,++基因型河北肉用绵羊的胸宽和腰角宽显著高于B+基因型群体(P<0.05)。说明BMPR-IB基因的基因型对河北肉用绵羊羔羊的生长发育有一定影响。     

绵羊PRLR基因内含子9和外显子10多态性与产羔数的关系研究

本研究采用PCR-SSCP技术对绵羊催乳素受体（PRLR）基因内含子9和外显子10部分核苷酸多态性及其与小尾寒羊、中国美利奴（新疆型）绵羊多胎品系、肉用品系、体大品系、萨福克、无角陶赛特、中国美利奴（新疆型）和德国肉用美利奴产羔数间的关系进行了分析。结果发现：①在绵羊PRLR基因内含子9的第259 bp处,存在C→T转换,BB基因型的小尾寒羊平均产羔数分别较AA和AB基因型提高0.81和0.87只（P<0.05）;②在绵羊PRLR基因外显子10的第304 bp处存在一个G→A转换,该突变导致PRLR基因第387位氨基酸残基由Glu突变为Lys,并使中国美利奴（新疆型）多胎品系中AB基因型的平均产羔数较AA和BB基因型增加0.58和0.80只（P<0.05）;③在绵羊PRLR基因外显子10第571、585和606 bp处分别存在G→A、C→G和C→T突变;其中前2处突变分别导致PRLR基因的第476位氨基酸由Ala突变为Thr,第480位氨基酸由Ser突变为Arg。其中第571 bp处突变导致小尾寒羊AB基因型的平均窝产羔数显著高于AA基因型的窝产羔数,增加0.8 只（P<0.05）。以上结果提示,PRLR基因可能是控制小尾寒羊和中国美利奴（新疆型）绵羊多胎品系产羔数的主效基因或与之存在紧密的遗传连锁。     

中国美利奴多胎肉用细毛羊

中国美利奴多胎肉用品系是利用中国美利奴多胎品系母羊(带有FecB基因)和产肉性能好、羊毛细度在66支纱的南非肉用美利奴杂交选育于2005年育成,是将分子标记辅助选择技术应用于绵羊多胎性状的选择,在杂交一代中选择杂合子公羊 (3只)与杂合子母羊(47只)配种,其后代基因型分布分别为纯合多胎基因25.5%,杂合48.9%,野生型25.5%,然后对纯合子所产后代进行肉用性能的逐代选育而成.中国美利奴多胎肉用品系羊毛长度 周岁公羊(5只)平均自然长度12.60 cm±1.47 cm,1岁母羊(31只)平均自然长度11.47 cm±1.18 cm,细度实验室测定羊毛纤维直径,周岁公羊平均21.67 μm±3.70 μm,不匀系数17.06%,周岁母羊平均20.36 μm±3.23 μm,不匀系数为15.86%.净毛率周岁公羊体侧部净毛率为64.60%,母羊共测净毛率为65.64%.污毛产量育成母羊平均4.12 kg±0.73 kg,周岁公羊,平均6.3 kg,成年母羊平均3.47 kg±0.65 kg.测定6月龄公羔8只,屠宰前平均活重38.3 kg,屠宰率平均为48.5%,胴体重18.58 kg.母羊第一胎繁殖率纯合(BB)和杂合(B+)190.24%(156/82) ,不带多胎基因(++)105.71%(37/35).     

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 -