保护性赖氨酸对荷斯坦奶牛瘤胃发酵参数的影响

选用3头装有永久性瘤胃瘘管和十二指肠瘘管的荷斯坦奶牛,试验分4个阶段。每个阶段分别饲喂日粮I[基础日粮+保护性赖氨酸Ⅰ30g(/头·d)]、日粮Ⅱ[基础日粮+保护性赖氨酸Ⅱ30g/(头·d)]、日粮Ⅲ[基础日粮+保护性赖氨酸Ⅲ30g(/头·d)]和日粮Ⅳ(基础日粮),研究脂肪包被赖氨酸对瘤胃发酵参数的影响。结果表明,日粮中添加保护性赖氨酸对瘤胃pH值和NH3-N浓度影响不显著(P>0.05)。     

不同水平铜日粮对仔猪生长发育及肝铜沉积的影响

40头杜×长×赣白三元杂交仔猪随机分成4组 ,分别在基础日粮中(含铜9.897mg/kg)加入0mg/kg、150mg/kg、250mg/kg 和500mg/kg的铜(以CuSO4·5H2O折算) ,饲喂试验30d。结果表明 :150mg/kg 和250mg/kg 铜组有促进仔猪生长 ,降低料肉比的功能。而500mg/kg 铜组影响猪的生长发育 ,且250mg/kg 和500mg/kg 组均能使肝铜大量的蓄积。     

莫能菌素对肉牛育肥期瘤胃发酵和日粮主要成分消化率的影响

采用单因子试验设计,以青贮和大麦为基础日粮,在基础日粮中分别添加莫能菌素0、1000和1400mg(20%预混料),研究肉牛育肥期日粮中添加莫能菌素对瘤胃pH值、NH3-N、VFA和日粮主要成分消化率的影响。研究结果表明:各组牛瘤胃液pH值差异不显著(P>0.05);添加莫能菌素1000mg组NH3-N浓度显著低于添加莫能菌素1400mg组和对照组(P<0.05);添加莫能菌素1000mg显著提高了TVFA和丙酸浓度(P<0.05),降低乙酸/丙酸比值(P<0.05);添加莫能菌素1000mg显著提高日粮粗蛋白的消化率(P<0.05),但对其它主要成分消化率有降低趋势,且差异不显著(P>0.05)。根据试验结果推断肉牛育肥期日粮莫能菌素的添加水平为1000mg(20%预混料)为佳。     

大豆黄酮和染料木素对奶牛瘤胃液内主要养分相关酶活性的影响

采用3×3拉丁方试验设计,每组奶牛分别饲喂不同日粮,(基础日粮)为Ⅰ组、(基础日粮+200mg大豆黄酮/(d·头-1))为Ⅱ组、(基础日粮+200mg染料木素/(d·头-1))为Ⅲ组,测定大豆黄酮和染料木素对奶牛采食后2h瘤胃内与粗纤维、淀粉及蛋白质降解相关酶活性的影响。结果表明:二者在一定程度上均显著提高了瘤胃内微晶纤维素酶、羧甲基纤维素酶、水杨苷酶、木聚糖酶的活性(P<0.05);淀粉酶和蛋白水解酶活性方面,大豆黄酮和染料木素均没有对各组活性产生显著影响(P>0.05)。     

高铜对断奶应激仔猪血清生化指标及激素水平的动态影响

选用30头(28±2)日龄“长大定”三元杂交断奶仔猪,按体质量和性别随机分成3组,每组10头。组(对照组)仔猪饲喂基础日粮;组仔猪在断奶后14d内饲喂基础日粮+250mg/kg铜(CuSO4·5H2O),然后改喂基础日粮;组仔猪饲喂基础日粮+250mg/kg铜(CuSO4·5H2O)。试验期28d。所有试验猪均于断奶后0、7、14、28d,经前腔静脉采血,测定部分血清生化指标及血清激素水平。结果表明,与断奶前相比,3组仔猪断奶后血清总蛋白、白蛋白、球蛋白、总胆固醇和碱性磷酸酶水平均显著下降或极显著下降(P<0.05或P<0.01);组仔猪血清尿素氮含量在断奶后7d极显著升高(P<0.01),而血清生长激素、胰岛素和三碘甲状腺原氨酸在断奶后7d显著下降(P<0.05);组仔猪血清生长激素、胰岛素和三碘甲状腺原氨酸在断奶后14d极显著升高(P<0.01);组仔猪血清生长激素、胰岛素和三碘甲状腺原氨酸及甲状腺素在断奶后14、28d显著升高或极显著升高(P<0.05或P<0.01)。试验显示,高铜日粮可显著提高断奶应激仔猪血清生长激素、胰岛素和三碘甲状腺原氨酸及甲状腺素的水平。     

泌乳奶牛在低乳脂综合症下瘤胃微生物群落结构的变化

本试验利用18头安装瘤胃瘘管的奶牛饲喂一系列能导致低乳脂综合症(MFD)的日粮(每批日粮饲喂时间为28d)来检测因MFD引起的瘤胃微生物菌群的变化。奶牛首先饲喂含25%淀粉(DM基础)的TMR日粮,日粮中通过添加玉米青贮和慢速发酵的玉米(SFS处理,第1期)使日粮中淀粉含量达25%。第1期饲喂完后日粮更换为含27%淀粉的TMR日粮,日粮中添加一种快速发酵的高水分脱粒玉米使日粮中淀粉含量达27%(RFS处理,第2期)。第3期,RFS处理日粮中添加13.6mg莫能菌素/kg日粮(RFS/Mon处理组),第4期,奶牛饲喂日粮转换为无莫能菌素的RFS日粮(RFS/Post处理组)。两种来源的淀粉日粮和莫能菌素对奶牛乳脂含量的影响不同,聚簇分析证实4组奶牛的乳脂结构差异较大。采集4组奶牛的瘤胃固相和液相食糜,提取DNA进行全自动核糖体基因间隔区序列分析,并与已知细菌组分(BCC)对比。饲喂RFS日粮的1组奶牛(S-responsive)出现MFD,但饲喂莫能菌素未加重MFD症状,回撤莫能菌素后乳脂出现反弹。第2组奶牛(M-responsive)日粮由SFS更换为RFS日粮后,未出现MFD症状,但添加莫能菌素后出现MFD...     

丁酸钠对母猪繁殖力的调控研究

为了研究妊娠期和哺乳期基础日粮中添加丁酸钠对母猪繁殖力的影响,试验选择健康、体况一致、配种期相近的荣昌猪×大白猪杂交母猪24头,随机分为4组,每组6头,Ⅰ组饲喂基础日粮+300 mg/kg丁酸钠,Ⅱ组饲喂基础日粮+500 mg/kg丁酸钠,Ⅲ组饲喂基础日粮+800 mg/kg丁酸钠,Ⅳ组为对照组,饲喂基础日粮。结果表明:与对照组比较,Ⅰ组、Ⅱ组、Ⅲ组母猪产后采食量均明显提高,仔猪断奶体重及仔猪成活率均高于对照组。说明在基础日粮中添加丁酸钠可有效提高母猪的繁殖力,其中500 mg/kg的添加量效果较优。     

莫能菌素对育成水牛生长性能、肉用性能及血液生化指标的影响

为了研究饲料中添加莫能菌素对育成水牛生长性能、肉用性能、血液生化指标的影响，探讨莫能菌素添加对水牛养殖在禁抗的大环境中是否有其必要性，为替抗研究提供数据支撑。试验采用年龄、体重相近，体况良好的育成水牛24头，随机分成4组，每组6头。对照组饲喂基础日粮，3个试验组每头分别在基础日粮中添加100 mg、200 mg、300 mg莫能菌素，试验预试期7 d,正试期90 d。结果表明：3个试验组的生长性能指标和肉用性能指标与对照组差异不显著(P>0.05);血液生化指标中，3个试验组的尿素氮(BUN)浓度显著低于对照组(P<0.05),其余指标试验组和对照组差异不显著(P>0.05)。说明饲料中添加莫能菌素可以降低育成水牛血液中尿素氮的浓度，对其他性能影响不大。     

饲粮添加海南霉素和莫能菌素对奶牛瘤胃发酵特性和氮平衡的影响

本研究旨在探究饲粮添加海南霉素和莫能菌素对奶牛瘤胃发酵特性和氮平衡的影响.选用3头体重为(460.0±20.6)kg、装有永久性瘤胃瘘管的成年荷斯坦奶牛,采用3×3拉丁方试验设计,对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮添加20 mg/d海南霉素和350 mg/d莫能菌素的试验饲粮.结果表明:饲粮添加海南霉素和莫能菌素没有显著影响瘤胃液pH和丁酸含量(P＞0.05),但显著降低了瘤胃液总挥发性脂肪酸浓度、乙酸含量、乙酸/丙酸和氨态氮浓度(P＜0.05).与对照组相比,海南霉素组和莫能菌素组丙酸含量分别提高了16.26％和15.79％(P ＜0.01).饲粮添加海南霉素和莫能菌素显著降低了尿囊素排出量、尿嘌呤衍生物排出量和微生物氮产量(P＜0.05).饲粮添加海南霉素和莫能菌素也降低了粪氮量和尿氮量(P＜0.05),提高了沉积氮量(P＜0.01).与对照组相比,海南霉素组和莫能菌素组的表观氮消化率分别提高了5.61％和7.05％(P =0.03).总之,与莫能菌素相似,饲粮添加海南霉素可以改变瘤胃发酵模式,使其更趋向于丙酸型发酵,并且能够提高氮利用效率.     

胡麻油和苹果酸对延边黄牛瘤胃脂肪酸代谢及饲料降解率的影响

试验旨在研究基础日粮中添加胡麻油和苹果酸对延边黄牛瘤胃脂肪酸代谢及日粮养分降解率的影响。选用4头平均体重为（350±15）kg、安装永久性瘤胃瘘管的延边黄牛,釆用4×4拉丁方设计,设1个对照组、3个试验组：对照组（CON组）饲喂基础日粮,LO组饲喂基础日粮+475 g/d胡麻油;LOM组饲喂基础日粮+475 g/d胡麻油+160 g/d苹果酸;LOMS组饲喂基础日粮+475 g/d胡麻油+160 g/d苹果酸+47.5 g/d小苏打（NaHCO3）。在正试期第3、4天采集瘤胃液测定其脂肪酸含量,在正试期第5、6天采用尼龙袋法测定饲料在瘤胃内的降解率。结果显示：除了饲喂后6 h瘤胃t11-C18：1含量外,3个试验组在各个时间点的瘤胃各脂肪酸含量均显著高于CON组（P<0.05）,且3个试验组间无显著差异（P>0.05）;与CON组相比,LO组瘤胃DM、OM、CP及NDF的降解率均有所降低,但LOM和LOMS组瘤胃DM、OM、CP及NDF的降解率均有一定程度提高。综合以上结果,日粮中单独或同时添加胡麻油、苹果酸均有利于提高延边黄牛瘤胃液中的脂肪酸含量;日粮中单独添加胡麻油会降低日粮养分在瘤胃中的降解率,而同时添加胡麻油和苹果酸在一定程度上可提高日粮养分在瘤胃中的降解率。     

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