荷斯坦青年牛超排影响因素分析及效果比较

对105头荷斯坦奶牛进行超数排卵处理,对超排取得2个以上黄体的89头母牛进行采卵,其中12~14月龄青年牛39头和成母牛50头。超排结果表明,15月龄以下青年奶牛经FSH-PG方案超排可以取得良好的胚胎生产效果,可用胚率达到51.2%,头次超排获得可用胚5.33±3.90枚。试验还表明,超排时月龄、体重、FSH注射剂量、超排前黄体质量等因素能影响超排结果。16头供体奶牛采卵后经回移胚胎,受胎率较低;PG处理了51头供体奶牛,返情率为68.6%。     

不同超排方式对奶牛排卵效果的影响

本试验结合我公司胚胎移植现状，用18头纯种荷斯坦奶牛随机分成四组，进行不同的超排处理，共获得胚胎243枚，其中可用胚为145枚，对四组超排方式进行比较，结果表明：胚胎总数和可用胚数较多，胚胎质量好，退化胚和未受精卵较少；其中可用胚比率分别为83．1％和79．1％。未受精卵分别为5．63％和20．9％，经t检验胚胎总数、可用胚比率、未受精卵比率Ⅳ组与Ⅰ组和Ⅲ组比较差异显著（P〈0．05）。     

重复应用CIDR进行超排的效果分析

2002年11月至2003年1月，在新疆金牛生物股份有限公司牛场开展了澳大利亚进口荷斯坦牛超数排卵工作。供体牛埋植CIDR进行超排。CIDR用过一次超排后，经过处理供第二次使用(第二次为旧CIDR)。经过对184头澳大利亚供体牛进行超数排卵，其中：14月龄供体牛埋植新CIDR平均每头获可用胚7．6枚，埋植旧CIDR平均每头获可用胚6．1枚；15月龄供体牛埋植新CIDR平均每头获可用胚胎6．9枚，埋植旧CIDR平均每头获可用胚胎6.6枚。对同一批次不同月龄供体牛平均每头获可用胚胎数进行对比分析，结果差异不显著。     

奶牛胚胎远距离运输移植黄牛技术研究

超数排卵处理黑白花奶牛１１头，有效８头，超排有效率７２．７％，获总卵数４０枚，头均获卵５枚（４／８），可用胚２６枚，头均可用胚３．３枚（２６／８），胚胎可用率６５％。移植受体牛２３头，妊娠１０头，移植成功率４３．５％（２３／１０）。     

牛胚胎移植产业化超数排卵的系统研究

为了提高供体牛的利用率,加速胚胎移植技术的产业化,试验系统地研究了超排方案、青年奶牛的月龄及发情周期不同阶段、重复超排次数、超排间隔时间、卵巢状态、胎次与产后间隔时间对超排效果的影响,共超排供体奶牛1 127头次,回收胚胎共10 900枚,可用胚胎数量为6 942枚,平均每头次获得胚胎数量为6.73枚.结果表明:①应用PSO1、PSO2和 PSO3三种方案进行超排处理,PSO3方案的超排成功率和平均回收可用胚胎数均高于其他两个方案;②利用发情周期9～11 d的自然发情奶牛直接超排效果最好;③对青年奶牛进行超排处理,应限制超排起始时间,15月龄以上的青年奶牛超排效果较好;④供体牛连续重复超排控制在3次以内,连续4次超排处理后极大降低胚胎可用率;⑤超排处理的间隔最短时间应该选择46～60 d;⑥经产牛1～3胎次超排效果较好,7胎次以上较差;⑦产后间隔时间选取80～90 d.     

转基因奶牛与普通奶牛超数排卵效果的比较分析

本文对20头转基因母牛与20头普通母牛超数排卵效果进行了比较分析。在20头超排转基因奶牛中,16头有超排反应,4头无超排反应,超排成功率为80%(16/20),平均获胚/卵总数为6.15±4.43枚,可用胚数为3.94±2.62枚,未受精卵数为1.50±2.19枚,退化胚胎数为0.69±0.78枚;20头对照组普通奶牛中,17头有超排反应,3头无超排反应,超排成功率为85%(17/20),平均获胚/卵总数为8.65±5.70枚,可用胚数为4.18±3.11枚,未受精卵数为1.47±1.12枚,退化胚胎数为3.00±4.24枚。统计分析表明,转基因奶牛的获胚/卵总数、可用胚数、未受精卵数与普通奶牛均无显著差异(P>0.05),转基因奶牛的退化胚胎数显著低于普通奶牛(P<0.05)。本试验结果说明转入改变乳成分的外源基因不影响奶牛的超数排卵效果。     

牛胚胎移植技术的开发与应用研究阶段总结报告

１９９５～１９９７年共计超排供体牛１４６头次，有效１４０头次，有效９５．８９％，采卵１４０头次，获卵１２２８枚，头均获卵８．７７枚，其中可用胚８２７枚，头均可用胚５．９１枚。共计移植奶牛冷冻胚胎２３１头次，受胎１０２次，受胎率达４４．２％，移植性鉴别胚５９头次，产犊２１头（♂１１，♀１０），性鉴别符合率达１００％。     

高产奶牛超数排卵移植黄牛技术研究

2002-2004年,从饲养的812头奶牛群中,选择69头高产奶牛作供体进行超数排卵处理,63头供体牛共获胚胎495枚,超排成功率达91．3％(63／69),平均获胚胎7．17枚／头,可用胚胎402枚,平均可用胚胎5．82枚。其中采用加拿大生产的促卵泡素超排处理奶牛供体10头,获卵106枚,可用胚胎87枚,平均获可用胚胎8．7枚/头;采用鲜胚移植奶牛受体8l头,妊娠44头,妊娠率为54．3％,产犊28头,待产16头;采用冷冻胚胎移植黄牛受体278头,妊娠114头,妊娠率为41．0％。产犊22头,待产92头。     

牛超排专用FSH的超排效果分析

2004年4～6月,用3种不同剂量的FSH进行超排试验。青年母牛采用420单位,成年母牛采用500单位和560单位。共处理55头荷斯坦奶牛,超排有效50头,有效率91%,头均获胚7.58枚,其中可用胚头均4.36枚。结果表明,500单位超排剂量较适宜,560单位超排剂量会导致卵巢囊肿增加。     

青年荷斯坦奶牛初次超数排卵试验

对影响荷斯坦青年奶牛超数排卵的因素进行了对比分析，并探索了青年奶牛超排的可行性方案。卵巢上有黄体存在的供体牛可以用于超排。青年奶牛在不同性周期阶段进行超排的结果不同，但差异不显著。用FSH联合氯前列烯醇，采用常规逐日递减法肌肉注射进行超排，平均获得胚胎7．07枚，可用胚胎5．98枚；在人工授精的同时注射促排卵素3号(LRH—A3)，平均回收胚胎8．64枚，可用胚胎为5．5枚。促排卵素3号能提高胚胎的回收率，但可用胚胎率急剧下降。     

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 -