奶牛细管冻精解冻后低温保存可提高受胎率

奶牛细管冻精输精具有污染少、使用简便、受胎率高的优点，正取代奶牛颗粒冻精及低温精液成为奶牛人工授精用精液的主要剂型。但由于细管冻精的甘油含量高，解冻后在常温下不易保存。据我们实验观察，甘油在低温下对精子有一定的保护作用，但随着温度的升高，甘油对精子产生明显的危害作用。细管冻精和颗粒冻精解冻后不同温度保存的保存效果就能说明不同甘油浓度与温度对精子的危害程度，见表1。注：冷冻精液为我站生产，细管冻精为03ml剂型，颗粒冻精解冻液为葡萄糖50g、柠檬酸钠03g、乙二胺四乙酸二钠01g、双蒸馏水100ml。从表1可…     

黄牛细管冻精和颗粒冻精受胎率对比试验

随着黄牛改良工作的进展,对冷冻精液的制作剂型和质量的要求越来越高。目前,国外比较流行的剂型是细管冻精,而国内则多是颗粒冻精,但近年采用细管冻精也日益增多。为了探讨细管和颗粒2种不同剂型冷冻精液对受胎率有无差异,我站于1990年5月～11月在本县娄庄、渔沟、尹集、杨疃和夏楼5个家畜改良站,对2种不同剂型冷冻精液的受胎率进行了对比试验。 1 材料与方法 1.1 试牛对来站授配的黄母牛,通过     

浅析颗粒冻精与细管冻精在人工授精中的应用

随着畜牧业的迅速发展,大规模高度集约化的现代畜牧业的出现,促进了人工授精的进一步发展和应用.对冷冻精液的选择、会直接影响母牛受胎率的高低.现从三个方面来阐述颗粒冻精与细管冻精在人工授精方面的应用.     

黄牛细管冷冻精液配种技术在基层推广中的应用

黄牛细管冷冻精液配种技术是继黄牛颗粒冻精之后牛冻改工作的一大进步,细管冻精是用直径小、管壁薄的无毒塑料管盛装精液后冷冻而成,由法式凯苏输精枪输精,与颗粒冻精比较,黄牛细管冷冻精液在冷冻时受冻均匀、解冻时受热一致、解冻方便、输精时不易污染、避免精液和液氮的直接接触、精子活力好,极大提高了黄牛冻精改良的受胎率,扩大了黄牛改良的覆盖面,可根据群众要求上门服务,比较方便基层养殖户。     

波尔山羊细管冻精技术及应用

细管冻精技术是20世纪60年代法国研究开发出的一项新型人工授精技术.羊细管冻精在我国1999年才开始研目生产,目前仅有几家能生产且使用普及率很低.我站现有成套法国凯苏公司细管冻精生产设备,1999年初批量生产波尔山羊细管冷冻精液,检测冻后活力明显优于颗粒冻精.经人工授精后统计,羊细管冻精受胎率比颗粒冻精高5～15个百分点.目前我站已向省内外推广应用.     

牛细管冻精生产及使用技术

目前,我国牛的冷冻精液剂型除颗粒冻精外,还有细管冻精。细管冻精有很多优点,冷冻时受温比较均匀,冷冻效果好,精液利用率高,特别值得推广的是细管在输精时非常方便,大大提高了受胎率,可以培育出体格健壮、遗传性能优越的犊牛。牛的细管冻精生产与使用技术要点如下。1．采精：用于采集细管冻精的种公牛体型外貌和生产性能都应台乎本品种种公牛的特等或一等标准。种公牛必须体格健壮,新引进的公牛要经过严格检疫．没有传染疾病才允许使用。经过严格检疫挑选的成年种公牛每周可采精两次,每次可根据具体情况和需要连续排精两次。采精…     

细管冻精与颗粒冻精配种的对比试验

本试验对１１６ 头繁殖力正常的黄母牛进行了细管冻精和颗粒冻精配种。细管冻精配种第一情期受胎率６０２７ ％ ，总受胎率８２１９ ％ ，比颗粒冻精分别提高１８４１ 和１０１ 个百分点。     

细管冻精与颗粒冻精输配母牛受胎效果对比试验

应用西门塔尔牛细管冻精与颗粒冻精进行输配母牛受胎效果对比试验。对690头参试母牛配种资料结果统计分析表明,情期受胎率细管冻精平均为69.1％(260/376),颗粒冻精平均为55.7％(175/314),细管冻精较颗粒冻精平均提高13.4个百分点(P<0.01)提高幅度范围为11.8～15.3个百分点。     

黄牛改良中细管冷冻精液技术的应用效果

采用颗粒冷冻精液技术和细管冷冻精液技术．在10年内先后对当地母牛进行了人工授精10037头(次)．经过研究对照．结果发现：①细管冷冻精液技术受胎率比颗粒冷冻精受胎率提高了13．64个百分点。②经过几年的推广应用．细管冷冻精液技术省时、省力．节约了设施资金，扩大了授配范围．服务体系发生质变．更适合于农区基层改良工作。     

多层次细管冻精工艺的可行性探讨

随着牛精液冷冻工艺的迅速提高,细管冻精必将取代颗粒冻精。当今世界上已有38个国家细管精冻的普及率达90％以上。我国尚未普及,如何尽快创造条件,加快细管冻精生产,赶上世界先进水平,是畜牧工作者的当务之急。应用MVE—500型冷冻罐生产细管冻精,目前只限于一层,多层次生产尚未见报道。本试验目的在于找出罐内温度变化规律,从而探讨多层冻精的可行性。     

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.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

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.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

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