6月龄和成年牦牛卵巢及卵泡发育状况研究

为了研究6月龄牦牛和成年牦牛卵巢及表面卵泡发育状况,试验比较了6月龄和成年牦牛卵巢长度、宽度、厚度、重量、卵泡数量以及卵母细胞体外成熟培养效果。结果表明:成年牦牛卵巢长度(2.29±0.43)cm、宽度(1.91±1.31)cm和厚度(1.60±1.90)cm均显著大于6月龄牦牛[(1.65±0.30)cm、(1.14±0.25)cm、(0.79±0.26)cm](P<0.05),成年牦牛卵巢体积(6.92±7.00)cm3和重量(3.19±1.58)g极显著大于6月龄牦牛体积(1.63±0.93)cm3和重量(0.87±0.44)g(P<0.01)。6月龄牦牛Ⅰ级卵泡数(14.47±8.74)枚和平均总卵泡数(15.17±8.87)枚极显著高于成年牦牛Ⅰ级卵泡数(7.97±3.72)枚和平均总卵泡数(8.98±3.87)枚(P<0.01),Ⅱ级卵泡数差异不显著(P>0.05),成年牦牛平均每头含(0.02±0.15)枚Ⅲ级卵泡,而6月龄牦牛无Ⅲ级卵泡。成年牦牛有黄体卵巢重量显著大于无黄体卵巢重量(P<0.05),有黄体卵巢含(0.06±0.24)枚Ⅲ级卵泡,而无黄体卵巢不含Ⅲ级卵泡。6月龄和成年牦牛A、B级卵母细胞体外培养成熟率分别为(81.39±3.53)%、(80.44±4.50)%,差异不显著(P>0.05),而6月龄牦牛卵巢的平均卵母细胞数和平均A、B级卵母细胞数均显著高于成年牦牛(P<0.05)。     

牛有腔卵泡卵母细胞体外成熟的研究

试验从屠宰场收集了 4 8头青年黄牛、34头青年水牛的卵巢共 16 4个 ,共回收可用卵母细胞 86 4枚。水牛平均每个卵巢可回收 3.2 2枚可用卵母细胞 ,相当于黄牛 (6 .72枚 )的一半。试验结果表明 :水牛卵巢生长卵泡少 ,卵母细胞产量少、质量差 ;3种采集黄牛卵泡卵母细胞的方法 ,用抽吸加切割法平均从每个卵巢回收的可用卵数 (7.71枚 )都极显著高于抽吸法 (6 .19枚 )和切割法 (6 .4 4枚 ) (P <0 .0 1) ,但是该法手续繁杂 ,适于一次且只能收集少量卵巢时使用 ;在黄牛和水牛卵母细胞成熟培养液中用 0 .3%PVP代替 10 %FBS ,牛卵母细胞的体外成熟率无显著差异 (P >0 .0 5 )。     

牦牛卵母细胞的体外成熟

以屠宰场牦牛卵巢为材料,比较了抽吸加切割法和抽吸法2种卵母细胞离体采集方法的效率和5种成熟培养液的培养效果,并研究了卵泡位置、形态对卵母细胞体外成熟的影响。结果表明:在牦牛乏情期,平均每个卵巢用抽吸加切割法回收卵数极显著高于抽吸法(9.33±4.30VS4.70±2.62,P<0.01),可用卵数也极显著高于抽吸法(5.63±4.19VS4.37±2.32,P<0.01)。将牦牛卵丘卵母细胞复合体(COCs)分别置于5种成熟培养液中培养,其中M199(缓冲体系为Earles盐) 10% FBS 5.0mg/LLH 1.0mg/LE2 双抗(青霉素100IU/mL和链霉素100mg/L)的成熟液效果最好,成熟率为81.33%,卵裂率为49.33%。来自卵巢表面卵泡的COCs的成熟率和卵裂率均高于来自卵巢内卵泡的COCs(分别为81.33%VS69.33%,P>0.05;49.33%VS34.67%,P<0.05)。来自明亮卵泡的COCs的成熟率和卵裂率均极显著高于来自浑浊卵泡的COCs(分别为81.33%VS33.33%,P<0.01;49.33%VS3.33%,P<0.01)。     

牦牛卵巢卵母细胞体外培养成熟条件的建立

研究了不同采集方法和不同培养液对牦牛卵母细胞体外成熟的培养效果。结果:在牦牛乏情期,每个卵巢平均回收卵数为(9.33±4.30),可用卵数为(5.63±4.19)。将牦牛卵丘卵母细胞复合体分别置于5种成熟培养液中培养,成熟率分别为75.56%、71.11%、81.33%、77.33%和77.78%,卵裂率分别为42.22%、33.33%、49.33%、46.67%和42.22%,其中C的成熟液效果最好。来自卵巢表面卵泡的COCs的成熟率(81.33(vs69.33(,P>0.05)高于来自卵巢内卵泡的COCs,卵裂率(49.33%vs34.67%,P<0.05)显著高于来自卵巢内卵泡的COCs。来自明亮卵泡的COCs的成熟率(81.33%vs33.33%,P<0.01)和卵裂率(49.33%vs3.33%,P<0.01)极显著高于来自混浊卵泡的COCs。     

屠宰牛卵母细胞体外成熟和体外受精研究

对采集到的卵巢采取抽吸法、割破法回收卵母细胞,割破法得到的A级卵母细胞显著高于抽吸法。把有黄体和无黄体的卵巢卵母细胞进行培养比较,无黄体的卵巢卵母细胞的成熟率为84．33％,显著高于有黄体卵巢卵母细胞的74．32％。本试验中卵泡卵母细胞和深层卵母细胞体外成熟率均能达到75％以上．卵巢表面卵泡卵母细胞的卵裂率为54．76％,高于深层卵母细胞的卵裂率,但二者无显著差异。IVM时添加卵丘细胞、IVC时添加输卵管上皮细胞是比较理想的培养系统。     

PVP和17β-E2对牛卵泡卵母细胞体外成熟和体外受精的影响

在黄牛和水牛卵母细胞成熟培养液中用0.3%PVP代替10%FBS,卵母细胞的体外成熟率和受精率无显著差异(P>0.05),结果表明,在成熟培养液中用0.3%PVP代替10%FBS是可行的;在黄牛(或水牛)卵母细胞成熟培养液中添加17β-E2时,卵母细胞的体外成熟率和受精率都显著(P<0.05)或极显著(P<0.01)的高于不添加17β-E2组,试验结果表明,17β-E2对牛卵母细胞的成熟和受精是必要的.同时,本试验对现行的黄牛和黑白花牛体外受精程序应用于水牛体外受精的可行性进行了探讨,结果显示,虽然水牛卵母细胞在体外培养可成熟和受精,但是在同一处理下,水牛卵母细胞的成熟率和受精率都显著(P<0.05)或极显著(P< 0.01)低于黄牛和黑白花牛,这表明,利用现行的黄牛体外受精程序进行水牛的体外受精是有效、可行的,但可能所用的精液或受精过程的某些步骤不太适合水牛卵母细胞,还需进一步改进.     

山羊活体采卵及卵母细胞体外受精研究

选择健康空怀山羊母羊,随机分组,分别用PMSG1000u和FSH325~375u超数排卵处理,研究利用外源激素进行超排对山羊活体采卵效果的影响,比较活体采集与屠宰场采集的卵母细胞体外受精效果。结果表明,经超排处理后,卵巢明显增大,同时提高了采集卵母细胞的数量和质量。用FSH超排,≥2mm的卵泡数为23.00个±5.69个,采集卵母细胞数为12.67枚±4.06枚,极显著大于对照组(P<0.01)。活体采集的卵母细胞的体外成熟率及受精率分别为44.44%和33.33%,均略高于从屠宰场获取卵巢采集的可用卵泡卵母细胞,但差异不显著(P>0.05)。     

季节对延边黄牛卵母细胞质量及体细胞核移植胚胎发育的影响

研究季节对延边黄牛卵巢质量和卵母细胞的数量、质量、体外成熟以及核移植重组胚发育的影响。持续1年采集延边黄牛卵巢,分级卵巢,抽取卵巢表面直径2～8mm的卵泡内的卵母细胞,收集后进行体外成熟和重组胚的体外培养。结果表明,1级卵巢的比例在春冬季时明显高于秋季（P〈0．05）,2级卵巢的比例在春夏季高于冬季（P〈0．05）,秋季的3级卵巢比例最高,与其他季节有显著差异（P〈0．05）;在秋冬季,平均每个卵巢拣出卵母细胞数高于春夏季（P〈0．05）,成熟率上,秋季显著高于春夏季（P〈0．05）,但与冬季并无差异且其他各组间无显著差异（P〉0．05）;卵裂率上,秋季与春季有差异（P〈0．05）,但与其他季节无显著差异（P〉0．05）,囊胚率上,各组之间均无显著差异（P〉0．05）。通过研究发现,季节对延边黄牛卵母细胞的可用回收数量及其质量都会产生影响且秋季为延边黄牛体细胞核移植实验最适合季节。     

卵泡数量对陕北白绒山羊卵母细胞体外成熟与孤雌发育的影响

为了进一步探索陕北白绒山羊卵母细胞体外成熟的方法,试验以屠宰场陕北绒山羊卵巢为材料,采用抽吸法收集直径大于2 mm卵泡的卵母细胞,研究卵泡数量对卵母细胞体外成熟和孤雌发育的影响。根据卵泡数目的差异分为3组,其中卵泡数目大于15个的设为Ⅰ组,卵泡数目在8~14个之间的和卵泡数目在1~7个之间的分别设为Ⅱ组和Ⅲ组。对山羊卵母细胞及孤雌激活后胚胎进行体外培养后,进而根据山羊卵母细胞体外成熟率、孤雌激活胚卵裂率和囊胚发育率来分析卵泡数量对其发育的影响。结果显示卵泡数目在8~14个之间的Ⅱ组山羊卵母细胞体外成熟率显著高于其他两组(P0.05),而这3组间的卵裂率和囊胚率差异不显著(P0.05)。表明山羊卵泡数目的过多或过少降低了卵母细胞体外成熟效率,且对孤雌激活胚的发育能力无影响。     

不同周龄酉州乌羊幼羔超排及卵母细胞体外发育研究

选择4~8、8~12、12~16周龄羔羊进行超排处理,研究羔羊卵巢与卵泡的发育情况、卵母细胞活体采集效果及其体外发育能力。结果表明:羔羊超排处理后卵巢大小随着周龄的增加明显下降;4~8周龄组可用卵泡数、回收卵母细胞数极显著高于8~12周龄组和12~16周龄组(P0.01),但卵母细胞的回收率随着周龄的增加而升高;12~16周龄的A、B级卵母细胞所占比率较高,A、B级与C级卵母细胞的成熟率差异极显著(P0.01);对成熟卵母细胞进行体外受精,C级卵母细胞卵裂率显著低于A级与B级卵母细胞(P0.05);酉州乌羊幼羔体外胚胎移植妊娠率为27.03%,生产羔羊14只。结果提示,4~8周龄酉州乌羊羔羊超排效果优于8~12、12~16周龄段羔羊,活体采集的羔羊卵母细胞可经体外成熟、体外受精和胚胎移植获得后代。     

Sanguinarine metabolism and pharmacokinetics study in vitro and in vivo

Sanguinarine (SA) is a benzo[c] phenanthridine alkaloid which has a variety of pharmacological properties. However, very little was known about the pharmacokinetics of SA and its metabolite dihydrosanguinarine (DHSA) in pigs. The purpose of this work was to study the intestinal metabolism of SA in vitro and in vivo. Reductive metabolite DHSA was detected during incubation of SA with intestinal mucosa microsomes, cytosol, and gut flora. After oral (p.o.) administration of SA, the result showed SA might be reduced to DHSA in pig intestine. After i.m. administration, SA and DHSA rapidly increased to reach their peak concentrations (C_max, 30.16 ± 5.85, 5.61 ± 0.73 ng/ml, respectively) at 0.25 hr. Both compounds were completely eliminated from the plasma after 24 hr. After single oral administration, SA and DHSA rapidly increased to reach their C_max (3.41 ± 0.36, 2.41 ± 0.24 ng/ml, respectively) at 2.75 ± 0.27 hr. The half-life (T_1/2) values were 2.33 ± 0.11 hr and 2.20 ± 0.12 hr for SA and DHSA, respectively. After multiple oral administration, the average steady-state concentrations (C_ss) of SA and DHSA were 3.03 ± 0.39 and 1.42 ± 0.20 ng/ml. The accumulation indexes for SA and DHSA were 1.21 and 1.11. The work reported here provides important information on the metabolism sites and pharmacokinetic character of SA. It explains the reasons for low toxicity of SA, which is useful for the evaluation of its performance.     

Salmonella in pork cuttings in supermarkets and butchers' shops in Denmark in 2002 and 2006

The prevalence of Salmonella in fresh pork cuttings in Denmark in the years 2002 and 2006 was investigated at retail and compared with the retail supply pattern. A total of 1025 and 3473 samples were taken in 2002 from butcher's shops and supermarkets, respectively. The corresponding numbers in 2006 were 259 from butchers' shops and 628 from supermarkets. In 2002, 1.2% of all samples were positive for Salmonella; butchers' shops and supermarkets had 1.8% and 1.0% positive samples, respectively. The overall prevalence in 2006 was 4.2%, with prevalence of 8.1% and 2.6% for butchers' shops and supermarkets, respectively. Hence, increases around 3- to 5-fold were found. There was neither observed any parallel increase in Salmonella positive carcasses in Danish slaughterhouses during the study period, nor were any changes in supply routes towards slaughterhouses with higher prevalence observed, which could explain the apparent increase. We hypothesize that hygiene levels and ability to avoid cross-contamination and prevent growth of the organism, in the meat processing chain after slaughter were the most likely responsible factors. Results from this study indicate that the hygiene performance, particularly at retail, has a significant impact on the occurrence of Salmonella. This implies that there is no direct link between slaughterhouse Salmonella surveillance data and the level of Salmonella contamination at retail. To improve risk assessment of Salmonella in fresh pork meat, this study underlines the need for comprehensive retail data.     

Salmonellae and Campylobacters in Household and Stray Dogs in Northern Taiwan

Rectal swabs were collected from 437 household and 491 stray dogs in northern Taiwan from May 2003 to June 2005 to investigate the prevalence and antimicrobial susceptibilities of salmonellae and campylobacters. The results revealed that 2.1% of household dogs and 6.3% of stray dogs were positive for salmonellae, with Salmonella Duesseldorf being the most dominant serotype in both. Additionally, 2.7% of the household dogs and 23.8% of the stray dogs were positive for campylobacters. Campylobacter jejuni was the most prevalent species (86.8%), followed by C. upsaliensis (9.3%) and C. coli (3.9%). Both salmonella and campylobacter isolation rates from the stray dogs were significantly higher than those from the household dogs (p < 0.01). The susceptibility of 33 C. jejuni isolates to eight antimicrobials was studied by the E-test. A high rate of resistance was observed to azithromycin (93.9%), clindamycin (87.9%), erythromycin (81.8%), tetracycline (78.8%), chloramphenicol (69.7%), nalidixic acid (51.5%), gentamicin (33.3%), and ciprofloxacin (18.2%). The susceptibility of 40 Salmonella isolates to 15 antimicrobials was also studied by the disc-diffusion method. All the Salmonella isolates were susceptible to ciprofloxacin and ceftriaxone. Resistance was observed most frequently to tetracycline (77.5%), chloramphenicol (52.5%), and ampicillin (50%).     

Bartonella and Babesia infections in cattle and their ticks in Taiwan

Bartonella and Babesia infections and the association with cattle breed and age as well as tick species infesting selected cattle herds in Taiwan were investigated. Blood samples were collected from 518 dairy cows and 59 beef cattle on 14 farms and 415 ticks were collected from these animals or in a field. Bartonella and Babesia species were isolated and/or detected in the cattle blood samples and from a selected subset (n = 254) of the ticks either by culture or DNA extraction, PCR testing and DNA sequence analysis. Bartonella bovis was isolated from a dairy cow and was detected in 25 (42.4%) beef cattle and 40 (15.7%) tick DNA samples. This is the first isolation of B. bovis from cattle in Asia and detection of a wide variety of Bartonella species in Rhipicephalus microplus. Babesia spp. were detected only on one farm from dairy cows either infected by Babesia bovis (n = 10, 1.9%) or B. bigemina (n = 3, 0.6%).     

Mycobiota and aflatoxins in raw materials and pet food in Brazil

Commercial feedstuffs are a basic element in modern pet husbandry in the world. In dogs, the effect of mycotoxins is severe and can lead to death. Few reports on the influence of dietary mycotoxins were found in the scientific literature. The aims of this work were to isolate and identify the mycoflora and to determine the aflatoxins (AFs) natural occurrence in raw materials and ready dry pet food. Therefore, the aflatoxigenic capacity of Aspergillus flavus species was investigated. Aspergillus was the prevalent genera (65-89%) followed by Penicillium and Fusarium spp. Aspergillus flavus was the most prevalent species, followed by Aspergillus sydowii, Aspergillus fumigatus and Aspergillus versicolor. Aspergillus flavus frequencies ranged from 58% to 86% except in sorghum meal. All samples assayed (except corn grains and ready pet food) showed Fusarium spp. contamination. Corn meal and corn meal and gluten samples had 100% Fusarium verticillioides. Fusarium graminearum was isolated from sorghum meal. Aspergillus flavus strains (75%) isolated from raw materials and 57% from pet food were able to produce AFs. All samples showed AFs contamination percentages over 70%; corn and sorghum meal obtained the highest AFs levels. Ready pet food did not show quantitative levels of the tested toxins. This is the first report of the aflatoxigenic capacity by A. flavus from Brazilian pet food.     

Helminth and protozoan parasites in dogs and cats in Belgium

This study investigates the level of helminthic and protozoal infestation over the last 10 years in strays, well-cared-for dogs and cats. Determination of the prevalence of infections was based either on faecal examination or on worm counts at necropsy. Of 2324 faecal flotations (NaCl sp.gr. 1.20) of stray dogs, 34.2% had eggs or proglottids of one or more worm species consisting of Toxocara canis (17.4%), Toxascaris leonina (10.1%), Uncinaria stenocephala (11.4%), Trichuris vulpis (7.0%) and cestodes (2.1%). Isospora oocysts were observed in 5.2% of the dogs. The data on the distribution of the various worm species in the positive dogs indicate that T. canis eggs were by far the most common (50.9%). Necropsy data from 212 infected dogs indicate that 38.9% were infected with T. canis and 33.7% with T. leonina. The overall prevalence of worm infestation of 246 well-cared-for kennel dogs, based on worm egg counts by the McMaster technique, was 36.1%. Of 30 feline faecal samples examined by flotation, 83.3% were positive for parasites, including Toxocara cati (60%), Ancylostoma tubaeformae (36.6%), Taenia (Hydatigera) taeniaeformis (20%) and coccidia (30%). Toxocara cati was the most frequently found worm species at the necropsy of 25 cats (52%). Toxoplasma was not observed.     

Chlortetracycline in swine-bioavailability and pharmacokinetics in fasted and fed pigs

Chlortetracycline hydrochloride was administered intra-arterially (11 mg/kg) and as an oral drench (33 mg/kg) to ten 21.0-31.5-kg pigs. Five of the pigs were fasted 18 h prior to dosing and five of the pigs were fed ad libitum prior to dosing. The mean volume of distribution determined by area-under-the-curve calculations for the fasted pigs (0.967 +/- 0.210 l/kg) was significantly less (P less than 0.05) than the mean volume of distribution for the fed pigs (1.39 +/- 0.31 l/kg). Mean total body clearance of the drug was also significantly less (P less than 0.05) in the fasted pigs (0.165 +/- 0.055 l/kg/h) as compared to the fed pigs (0.307 +/- 0.053 l/kg/h). The elimination constants (beta) were not found to be statistically different (P less than 0.05): 0.1811 +/- 0.0057 for the fasted pigs; 0.2260 +/- 0.0461 for the fed pigs. The bioavailability for both groups was similar; 19.12 +/- 8.3% for the fasted pigs and 17.88 +/- 5.3% for the fed pigs. In a second experiment three groups of six pigs which weighed 34.5-44.1 kg were fed a corn-soy diet ad libitum. The rations were fortified with chlortetracycline at 100, 400 or 1000 mg chlortetracycline hydrochloride/kg feed. Chlortetracycline concentrations were determined in plasma samples collected over a 6-day period. Plasma chlortetracycline concentrations reach a plateau within 24 h after initial access to the trial diets and were highly correlated with the dose of the drug consumed (r2 = 0.97).