应用X精子冷冻精液生产体内性控胚胎的试验

采用CIDR FSH PG法对206头优秀荷斯坦供体母牛进行超数排卵,其中实验组73头超排后用X性控冷冻精液输精(每头3支),获可用胚310枚,头均可用胚4.25枚;对照组133头,采用常规冷冻精液输精(每头3支),获得可用胚787枚,头均可用胚5.92枚,差异不显著。结果表明,用已分离的X精子冷冻精液对超排母牛进行人工授精生产体内性控胚胎是可行的。     

常规精液与性控精液的超数排卵效果比较

采用常规精液输精和性控精液输精对580头15～18月龄荷斯坦母牛(其中常规组521头,性控组59头)进行了超排试验。超排后,采用常规精液输精供体母牛521头,共回收卵5311枚,平均每头10.19枚,其中可用胚胎2804枚,平均可用胚胎5.38枚,可用率52.28%,未受精卵697枚,未受精卵率13.12%,退化胚胎1725枚,退化胚率32.48%。采用性控精液输精供体母牛59头,共回收卵600枚,平均每头10.16枚,其中可用胚胎250枚,平均可用胚胎4.24枚,可用率41.67%,未受精卵170枚,未受精卵率28.33%,退化胚胎169枚,退化胚率28.17%。结果表明,性控精液组的未受精率大大高于常规精液组,而可用胚胎数和可用率明显低于常规精液组。其主要原因是性控精子在分离过程中受到不同程度的损伤,使精子的存活时间缩短,从而增加了未受精率和降低了可用胚胎率。     

常规精液与性控精液生产胚胎的效果比较

分别采用常规精液和性控精液输精,对580头15～18月龄荷斯坦母牛(其中常规组521头,性控组59头)进行了超排效果试验。超排后,521头采用常规精液输精供体母牛,共回收卵5311枚,头均10.19枚,其中可用胚胎2804枚,平均可用胚胎5.38枚,可用率52.28%,未受精卵697枚,未受精卵率13.12%,退化胚胎1725枚,退化胚率32.48%。59头采用性控精液输精供体母牛,共回收卵600枚,平均每头10.16枚,其中可用胚胎250枚,平均可用胚胎4.24枚,可用率41.67%,未受精卵170枚,未受精卵率28.33%,退化胚胎169枚,退化胚率28.17%。结果表明,性控组的未受精率大大高于常规精液组,而有效胚胎数和比例明显低于常规精液组。其主要原因是性控精子在分离过程中,受到不同程度的损伤,使精子的存活时间缩短,从而增加了未受精率和降低了有效胚胎率。     

应用性控冷冻精液生产性控胚胎试验

在供体奶牛超排时,应用X性控冷冻精液进行输精,生产体内性控胚胎.超排处理72头供体母牛(每头输4支精液),获可用胚335枚,平均每头供体牛获可用胚4.65枚.对照组共处理供体牛68头,采用常规冷冻精液输精(每头牛输精2支),获可用胚415枚,头均获可用胚6.1枚.     

应用X精子冷冻精液生产体内性控胚胎的试验研究进展

应用X精子冷冻精液对75头超排供体母牛进行2～3次（3～4支细管）输精，共采集胚胎633枚，其中可用胚339枚，退化胚135枚，未受精卵159枚。胚胎的受精率为74.9％（474/633），可用率为53.6％（339/633），发育率为71.5％（339/474），头均获得可用胚胎4.5枚。输2次精3支细管，与输3次精4支细管，均可获得同样的胚胎采集效果。应用LAMP法对61枚胚胎进行性别鉴定后，确定雌性胚胎比例为100％（61/61）。11枚X精子冷冻精液生产的体内性控冷冻胚胎移植后，怀孕率为63.6％（7/11）。因此，应用X精子冷冻精液对供体母牛进行输精，不仅可获得与未分离冷冻精液输精后相接近的胚胎的数量和质量，而且移植后可得到较高的怀孕率。应用X精子冷冻精液生产体内性控胚胎，可在我国胚胎移植技术中大量推广应用。     

奶牛胚胎性别控制技术的试验研究进展

应用LAMP法进行了613枚胚胎的性别鉴定结果，雌性胚胎302枚(49．3％)，雄性胚胎311枚(50．7％)，移植成功率平均为40．9％(122／298)，出生后代中与性别鉴定结果一致的121头，性别鉴定准确率为96．0％(121／126)。应用奶牛性腔胶囊后输精的14头供体母牛，共采集69枚可用胚胎，对其中64枚胚胎进行性别鉴定，确定雌性胚胎的比例为71．9％(46／64)，头均获4．9枚可用胚胎。应用奶牛性控液对3头供体母牛宫注后输精，共采集26枚可用胚胎，经性别鉴定后确定雌性胚胎比例为73．1％(19／26)，头均获可用胚胎8．7枚。应用分离X精子冷冻精液对12头供体母牛进行输精，对采集到的61枚胚胎进行性别鉴定后，确定雌性胚胎比例为100％(61／61)，头均获得可用胚胎5．5枚。11枚性控冷冻胚胎移植后，40d以上未返情率为63．6％(7／11)。用分离的X精子冷冻精液对供体母牛输精后，可获得与未分离冷冻精液输精后相接近的超排供体母牛采集胚胎的数量和质量。     

肉羊X、Y精子分离及其对超排羊腹腔镜输精卵子受精率的研究

采用电刺激采精方法收集1.5～3周岁的10只陶赛特种公羊精液,19℃水浴保存,经过1h运输后,利用流式细胞仪进行X、Y精子分离.共生产性控冷冻精液182支(X型98支,Y型84支).分离前精液活率为76％,分离后X、Y型冻精活率分别为39％和2％,有效精子数约为230万和10万,4h存活指数分别为10％和1％,畸形率分别为12％和26％.另外,结合腹腔内窥镜输精技术对19只超排母羊开展了输精,在输精后第6天采用子宫角采胚法共回收卵子104枚,其中受精胚胎53枚,受精率51％.结果表明:①分离所得X精子能够满足腹腔内窥镜低剂量输精要求;②Y精子活率检验仅为2％,失去了输精价值;③性控冷冻精液结合腹腔内窥镜输精技术应用于性控胚胎生产具有可行性.     

常规冻精与性控冻精的授精效果分析

试验对常规冻精和性控冻精在荷斯坦牛超排后的授精效果作了分析.对29头做性控(X-精子)冻精的授精,获得111枚可用胚胎,头均可用胚为3.83枚;受精率:青年牛卵子受精率为90.60%,经产牛卵子受精率为86.15%.对34头做常规冻精的授精,获得212枚可用胚胎,头均可用胚为6.24枚;受精率:青年牛卵子受精率为92.17%,经产牛卵子受精率为88.50%.     

牛性控精液及其应用

近年来．牛性控精液的商业化进程发展很快。然而，与常规精液比较，性控精液分离技术成本高，操作复杂，且受胎率低。虽然分离精液的公牛头数有限．但是许多国家仍在进行牛性控冷冻精液的商业化生产。目前，性控精液主要应用于青年母牛配种和超数排卵生产性控胚胎，以生产母犊。由于精子分离速度慢，与传统精液比较，性控精液精子数量少．使用性控精液输精常常会导致受胎率略有下降，获得可用胚胎数量减少。为确保使用性控精液成功．必须对牛加强饲养管理。处理精液小心谨慎，而且输精人员技术要熟练。随着成本的降低，性控精液将不断扩大应用于牛、马以及其他物种的繁殖中。     

分离后精子输精对超排奶牛卵子受精和胚胎质量的影响

研究应用性控精液对超排育成牛和成母牛输精,生产性控胚胎。结果表明:非性控精液组受精卵数同性控精液组相比差异不显著(P>0.05),但可用胚胎比例高于性控精液组(90.17%对89.73%,66.03%对63.57%)。育成牛群组受精卵比例高于成母牛群组(92.74%对84.93%)差异不显著(P>0.05);但可用胚胎比例显著高于成母牛群组(68.77%对55.28%)(P<0.05)。1次输2支性控精液组中,育成牛群组受精卵数、可用胚胎比例都显著高于成母牛群组(90.83%对79.69%,67.89%对53.13%)(P<0.05)。2次人工授精,每次输1支性控精液组中,育成牛群组受精卵及可用胚胎比例都显著高于成母牛群组(93.75%对87.41%,69.23%对56.30%)(P<0.05)。     

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 -