枫泾和长白青年母猪首次发情周期内血清中5种生殖激素含量变化

放射免疫法测定枫泾(FJ)和长白(L)青年母猪(各4头)首次发情周期内外周血清中促卵泡素(FSH)、促黄体素(LH)、17β-雌二醇(E_2)、孕酮(P_4)、和睾酮(T)的含量。测定结果,初情期开始日龄FJ猪平均为104.3±11.50天,L猪为235.0±1.95天。两猪种首次发情周期内外周血清中同种生殖激素有相似的变化趋势。在首次情期内,FJ和L猪的FSH平均含量分别波动在28.6±8.6～49.4±6.0ng/ml和16.8±2.5～38.9±0ng/ml之间;FSH总平均含量FJ猪组(37.8±2.7)显著高于L猪(27.0±3.1ng/ml)P<0.05;FJ猪发情0～2小时的FSH平均含量(34.4±2.1ng/ml)极显著地高于L猪(22.2±1.7ng/ml)P<0.001。排卵前LH峰均值FJ猪组(5.31±0.75ng/ml)显著高于L猪组(1.83±0.75ng/ml)P<0.05。发情当天(0天)E_2达峰值,FJ和L猪组分别是30.5±3.9和20.4±5.3pg/ml,两者无显著差异(P>0.05)。FJ和L猪组各自的P_4(ng/ml)和T(pg/ml)分泌呈显著正相关,相关系数依次为γ_F=0.71,P<0.05,γ_L=0.95,P<0.01。LH、FSH的含量高很可能是FJ猪高排卵率的重要因素之一。     

枫泾和长白母猪对初情期前注射黄体素释放激素类似物(LRH-A_2)的反应

进行两个试验,研究了初情期前不同日龄的枫泾和长白母猪LRH-A_2诱导的LH水平和不同剂量的LRH-A_2对LH水平的影响。结果表明,77日龄枫泾猪,85和202日龄长白猪在诱导前血清中LH含量分别为1.70±0.17、0.74±0.10和1.40±0.14ng/ml,前二者和后二者间的差异极为明显(P<0.001)。除枫泾猪的5μg和10μg剂量外,其余各剂量在注射5分钟后血清中LH含量均显著高于注射前的LH值(P<0.005～0.001)。枫泾猪诱导的LH峰值与LRH-A_2的剂量无关,而长白猪的峰值出现时间和峰值高低均因剂量而异。诱导的LH值随初情期前的小母猪日龄而变化。枫泾猪和长白猪诱导的LH峰值出现的日龄分别为30和60天,峰值分别为5.55±0.63和16.14±2.74ng/ml,差异极明显(P<0.005)。枫泾猪在30～60和75～90日龄时诱导的LH值分别显著低于长白猪在60和95日龄的诱导值,但接近初情期时,两猪种间的差异则变得不明显。可结论如下:甾体激素的负反馈机制,枫泾和长白猪分别在30和60日龄开始建立,并在初情期时达到完善。     

枫泾小猪生殖机能的发展和孕酮含量的测定

在枫泾小公猎生殖机能发展的试验中,用小公猪4头,从3月龄开始至7月龄,每个月龄都与6～8月龄母猪配种,共配22头,受胎率分别为40%(2/5)、100%(5/5)、50%(1/2)、66.7%(2/3)和85.7%(6/7),妊娠28天胚胎数量、重量和分娩仔猪数、初生重都达成年公猪所配的效果。表现枫泾小公猪3月龄已属发身期,配种后可使母猪受胎,4.5月龄已属性成熟期,具有充分的受精能力。在枫泾小母猪生殖机能发展试验中,用小母猪25头,分成5组,分别在初情期到第五情期,各用成年公猪精液配种,受胎率分别为20%(1/5)、100%(5/5)、100%(5/5)、100%(5/5)和60%(3/5);排卵数分别为13.0、12.2、14.8、14.8、和16.6。小母猪妊娠28日龄胚胎的大小与大母猪28日龄胚胎的相似。小母猪各情期孕酮含量高水平之间,各情期妊娠早期孕酮含量高水平之间,差异均不显著(P>0.05)。情期第9天和第12天孕酮水平为27.4ng/ml 和29.6ng/ml,妊娠第9天和第12天为21ng/ml 和26.8ng/ml,与8～10月龄大母猪的孕酮水平相似。上述受胎率和孕酮水平均表明枫泾小母猪113.2日龄(体重18.9公斤)已属初情期,可以配种受胎;135.8日龄(体重23.2公斤)已属性成熟期,具有充分的受胎能力。     

宁夏滩羊发情周期血液中促黄体素(LH)、孕酮、雌二醇——17β含量的测定

用放射免疫测定法测定了宁夏滩羊母羊(13只)外周血清中促黄体素(LH)、孕酮及雌二醇—17β的含量及其变化。血清LH的含量,在黄体期,其值很低,为5.0±0.41ng/ml,到发情开始后约6—12小时增至75.13±17.64ng/ml。孕酮含量的变化,在周期的黄体期,其值最高为2.84±0.10ng/ml;而在发情开始到发情后第二天最低0.52±0.06ng/ml。雌二醇—17β的含量是在发情开始前6—24小时时上升的;其值的变化范围是从黄体期的14.86±1.24Pg/ml到发情开始时的38.7±5.8Pg/ml。     

东北梅花鹿发情期血浆中LH,雌二醇含量变化

本文用放射免疫测定法测定了5头发情期东北梅花鹿血浆中促黄体素(LH)和17β-雌二醇的含量。所得结果:LH在发情前(0.288～0.321ng/ml血浆)与发情后(0.364～0.841ng/ml血浆)都处于低稳水平(P>0.05),但发情时出现非常显著的高峰(2.742ng/ml)(P<0.01);雌二醇在整个发情前后没有出现显著的高峰(P>0.05),仅在发情前约24小时发现一小峰(16.4±4.4pg/ml血浆),发情后12小时发现一小峰(24.9±6.1pg/ml血浆)。结果表明,东北梅花鹿发情期血浆LH、雌二醇含量的时相变化与其他已研究过的鹿种及一些反刍家畜基本一致。     

双峰驼排卵机制的研究——Ⅲ输精诱导排卵前后外周血浆促黄体素、孕酮和17β-雌二醇的变化

为了研究双峰驼精液诱导排卵的机制,本文用放射免疫测定法对双峰母驼人工输精诱导排卵前后外周血浆促黄体素(LH)孕酮(P)和17β一雌二醇(E_2)的含量进行了测定。母驼在卵泡发育周期中,LH的基础水平为2.7±1.2ng/ml。输精后4小时LH达到高峰,峰值为6.9±1.0ng/ml,约为基础水平的2.6倍。输精后30～48小时内排卵。在卵泡自然萎缩前一天也出现一个LH小峰(5.3±2.5ng/ml)。 在卵泡发育周期中,血浆孕酮处于低水平(0.36±0.28ng/ml)。诱导排卵后第3天增加到1.73±0.74ng/ml,第8天可达2.40±0.86ng/ml。血浆雌二醇在卵泡发育周期中平均为26.8±9.0Pg/ml,到卵泡成熟时可达30.8±5.1pg/ml,排卵后立即下降到19.0±4.1Pg/ml。但在排卵后3天又上升到29.8±6.5Pg/ml,在其它家畜中未见这种情况。 实验中设置7种对照组,证明双峰驼的排卵仅仅是由具有生殖能力的公驼精液诱导产生的,表明在这样的精液中可能存在着与排卵有密切关系的诱导排卵因子。     

屡配不孕母牛发情开始后八天内血清促黄体素（LH）含量的变化

本实验采用放射免疫测定技术(RIA)分析了9头屡配不孕母牛和6头正常母牛于发情开始后8天内的血清促黄体素(LH)的含量变化。测定结果表明:屡配不孕母牛的LH排卵峰值低于正常母牛,其峰值分别为2.71±1.00ng/ml和4.70±1.71ng/ml,差异显著(P<0.025)。为了初步验证LH峰值与屡配不孕之间的关系,对20头屡配不孕母牛在发情开始至配种前肌肉注射外源性LH180IU,其配种后60天的受胎率为70％(14/20),而未用LH处理的11头屡配不孕母牛的受胎率为18％(2/11),两者差异极显著(P<0.01)。上述实验结果提示:体内LH排卵峰值降低可能是导致乳牛屡配不孕的重要原因之一。     

关中驴公驴血浆睾酮、17β-雌二醇和皮质醇水平的季节性变化

本试验采用放射免疫分析法首次对关中驴公驴(n=13)血浆睾酮(T)、17β—雌二醇(17β—E_2)和皮质醇(F)的季节性变化特征进行了研究。T水平的变化与光照时数和温度正相关(r=0.67,P<0.05和r=0.61,P<0.05),繁殖季节(3—9月)平均水平(2.18±0.27ng/ml)极显著地高于非繁殖季节(10—2月,1.50±0.18ng/ml,P<0.001)。T水平的季节性变化与公驴全年性活动的变化和精液品质的改善基本一致。6月份高温能抑制公驴T的分泌,情期受胎率下降。17β—E_2水平的季节性变化趋势与T不同,4—9月平均水平(25.43±12.08pg/ml)显著高于10—3月(10.56±2.76pg/ml,P<0.05)。全年17β—E_2水平与温度正相关(r=0.59,P<0.05)。T/17β—E_2比值在一定范围的变化是调节公驴生殖功能的重要因素。F平均水平无明显季节性变化,但与T水平呈正相关(r=0.62,P<0.05)。     

枫泾公猪性成熟前、后外周血液睾酮含量变化初步研究

<正> 公猪外周血液中睾酮(T)含量的研究,国外Kattesh氏等(1)在研究不同发育阶段(150—250日龄)约克夏公猪外周血液中T含量及24小时T分泌模式中,认为T分泌模式在5月龄时建立。Ellendorff氏等(2)报导小型公猪性成熟时血浆T在晚上、夜间较早上低。而Brock氏(3)报导约克夏公猪性成熟时,白天和黑夜的T水平无明显差异。Liptrap等(4)指出成年公猪在与发情母猪交配时,随皮质类固醇激素升高,T水平立即升高。我国太湖猪性成熟早,产仔率高。我们以前的试验已证明,枫泾公猪3月龄就有     

卵巢囊肿奶牛外周血浆中促黄体素、孕酮、睾酮、雌二醇水平的研究

本试验采用放射免疫法测定了卵巢囊肿奶牛外周血浆中促黄体素、孕酮、雌二醇和睾酮水平。测定结果,促黄体素水平卵泡囊肿为0.84±0.25ng/ml(n=12),黄体囊肿为0.83±0.23ng/ml(n=5);孕酮水平卵泡囊肿为0.56±0.30ng/ml(n=12),黄体囊肿为2.85±0.64ng/ml(n=5);雌二醇水平卵泡囊肿为28.44±22.47pg/ml(n=12),黄体囊肿为8.14±0.88pg/ml(n=5);睾酮水平卵泡囊肿为84.67±40.40pg/ml(n=12),黄体囊肿为51.98±7.77pg/ml(n=5)。认为卵巢囊肿奶牛外周血浆中促黄体素水平低于正常期奶牛的水平;卵泡囊肿奶牛血浆中孕酮水平低于1ng/ml,黄体囊肿奶牛血浆中孕酮水平高于1ng/ml;卵泡囊肿奶牛血浆中雌二醇水平较高;卵泡囊肿奶牛公牛相与体内高水平睾酮有关。     

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.     

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 -