烟酸对高温环境中奶牛生产性能和血清生化指标的影响

本试验旨在研究烟酸对高温环境中奶牛生产性能和血清生化指标的影响。试验选用3头泌乳早期的中国荷斯坦牛,采用3×3拉丁方设计。在基础日粮中分别添加0、6、12 g/d烟酸,试验期为75 d。结果表明:(1)添加烟酸对热应激奶牛直肠温度和呼吸频率无显著影响(P>0.05)。(2)添加6、12 g/d烟酸可使产奶量分别提高13.20%(P<0.05)、9.39%(P<0.05),而4%标准乳量无显著差异(P>0.05);添加烟酸不影响乳蛋白和乳脂率(P<0.05)。(3)添加烟酸使血清胆固醇含量降低,但未达显著水平(P>0.05);添加烟酸6、12 g/d使血糖含量提高37.89%(P<0.05)、51.93%(P<0.05),但两添加组之间无显著差异(P>0.05);添加烟酸12 g/d可显著降低奶牛血清尿素氮含量(P<0.05);添加6、12 g/d烟酸使游离脂肪酸含量降低23.89%(P<0.01)、10.39%(P<0.01)。综合分析试验奶牛的生产性能和血清生化指标变化,夏季给奶牛补饲烟酸有助于缓解热应激,适宜的添加量为6 g/d。     

壳聚糖对乳房炎奶牛血清胆固醇、尿酸和肌酐的影响

试验分组:为确定壳聚糖对奶牛乳房炎的治疗效果,选择产奶量、胎次和泌乳期相近,营养中等,乳房炎阴性6头,阳性30头,总计36头奶牛,组成A(阴性对照组)、B(阳性对照组)和C、D、E、F组(试验组),每组6头.各组基础日粮和饲养管理相同,分别在试验各组基础日粮中添加壳聚糖0、0、10、20、40和80g/d/头.连续喂养2周,分别与试验前0天(0d)、7天(7d)、14天(14d)采取血样,分离血清,测定血清中胆固醇、尿酸和肌酐的含量.结果:应用壳聚糖7-14d后,2、3、4、5组奶牛血清胆固醇含量均数随壳聚糖用量的增加而降低的趋势,其中4、5组在14d时显著降低(p﹤0.05);血清尿酸和肌酐水平显著(p﹤0.05)或极显著(p﹤0.01)地降低.结论:壳聚糖具有降低乳房炎奶牛血请胆固醇,降低其血清尿酸和肌酐含量的功能.     

不同水平互花米草提取物对泌乳奶牛生产性能和血清生化指标的影响

文章旨在研究饲粮中添加互花米草提取物对奶牛产奶性能及血清生化指标的影响。试验选取体重(550±25) kg、胎次2～3胎、泌乳期(110±24) d及泌乳(24.2±4.2) kg/d的泌乳期荷斯坦奶牛90头,采用完全随机区组设计分为6组,每组15头,进行为期60 d的饲养试验,其中预试期10 d,正试期50 d。对照组饲喂基础饲粮,处理组分别在基础饲粮中每天添加5、10、25、50 g/d和100 g/d的互花米草提取物。结果表明:整个试验期间,处理组的采食量、产奶量、乳脂率、乳蛋白率、总固形物含量、乳尿素氮含量以及血清谷丙转氨酶、谷草转氨酶、碱性磷酸酶、谷氨酰胺基转移酶、α-羟丁酸脱氢酶、乳酸脱氢酶、总蛋白、球蛋白和肌酐含量与对照组相比均无显著差异(P>0.05);5～50 g/d组乳糖率和白蛋白含量显著高于100 g/d组(P<0.05)。互花米草提取物添加量5～50 g/d组体细胞数显著低于对照组和100 g/d组(P<0.05)。50 g/d组尿素氮浓度显著高于100 g/d组(P<0.05);而该组尿酸浓度显著低于5 g/d组(P<0.05)。50 g/d组葡萄糖浓度显著高于对照组、5 g/d和10 g/d组(P<0.05)。试验条件下,饲粮中添加100 g/d范围内的互花米草提取物对奶牛产奶性能没有明显影响,但50 g/d组可以提高乳糖率和血糖浓度,降低体细胞数,是适宜的添加剂量。     

壳聚糖对奶牛血清钙、磷和羟脯氨酸含量的影响

选择40头中国荷斯坦奶牛，随机分为对照组和试验1、2、3四个组。每头每天分别在各组日粮中加入0g、2g、4g和6g壳聚糖，连续饲喂35d。每周测定一次血清钙、磷和羟脯氨酸的含量。结果奶牛血清钙和羟脯氨酸的含量差异不显著(P＞0．05)，添加6g/d壳聚糖，血清磷在4周后显著升高(P＜0．05)。表明：壳聚糖不影响奶牛血清钙和血清羟脯氨酸的含量。在日粮中添加6g/d壳聚糖4周以后，有利于促进机体对磷的吸收。     

日粮不同精粗比例对中产奶牛血清生化指标的影响

本课题应用随机分组试验设计,将40头中等产奶量的荷斯坦奶牛随机分为四组,Ⅰ组为对照组,Ⅱ、Ⅲ和Ⅳ组为试验组,四组日粮的精粗比例依次为50%:50%、40%:60%、35%:65%和30%:70%,用以研究日粮不同精粗比例对奶牛血清生化指标的影响.结果表明:随着粗饲料比例的增加,血清总蛋白、白蛋白含量呈现增加趋势;血清尿素氮含量总体上呈现降低趋势;血清谷草转氨酶活性、谷丙转氨酶活性呈现增加趋势.血清葡萄糖含量总体上呈现降低趋势,但各组之间均差异不显著(P>0.05),血清乳酸脱氢酶的活性呈现不明显的降低趋势,其中血糖(y,mmol/L)与血清乳酸脱氢酶(x,IU/L)存在显著的线性相关关系:y=0.0035x-1.48,r2=0.68,n=40,P<0.05.试验Ⅳ组血清总胆固醇含量极显著(P<0.01)高于对照Ⅰ组,显著(P<0.05)高于试验Ⅱ组.血清胰岛素水平呈现增加趋势,其中试验Ⅳ组显著(P<0.05)高于对照Ⅰ组和试验Ⅱ组、Ⅲ组,而其它各组之间差异不显著(P>0.05).而通过对血清胰岛素和胆固醇水平进一步统计分析发现,血清总胆固醇(y,mmol/L)水平与血清胰岛素(x,μIU/ml)水平存在着显著的线性相关:y=0.13x+1.84,r2=0.65,n=40,P<0.05.生长激素总体上均呈现增加趋势,其中各试验组的血清生长激素水平显著(P<0.05)高于对照Ⅰ组,其他各组之间差异不显著(P>0.05),进一步统计得出,血清生长激素(y,ng/ml)与粗饲料采食量(x,kg/d)之间存在显著(P<0.05)的线性相关关系:y=0.18x-3.26,r2=0.68,n=40,P<0.05.     

海带水解物对泌乳奶牛生产性能及血清生化、抗氧化与免疫指标的影响

本试验旨在研究补饲海带水解物（LPH）对奶牛生产性能及血清指标的影响。试验采用随机分组设计,选用90头胎次、体况相近,产奶量为（41.2±6.6） kg/d,泌乳天数为（125±16） d的高产荷斯坦奶牛,随机分为3组,每组30头。3组奶牛在饲喂相同的基础饲粮的基础上分别补饲0（对照组）、15(L组)、30 g/（头·d）LPH(H组)。试验期为60 d。结果显示：1）补饲15 g/（头·d）LPH对干物质采食量和产奶量没有显著影响（P>0.05）,而补饲30 g/（头·d）LPH则能在不影响产奶量的同时显著降低干物质采食量（P <0.05）。2）补饲15或30 g/（头·d）LPH可以显著提高乳蛋白含量（P <0.05）,并且有降低体细胞数的趋势（P=0.07）,而对乳脂、乳糖、总固形物、乳尿素氮含量均没有显著影响（P> 0.05）。3）补饲15或30 g/（头·d）LPH可以显著降低血清总胆固醇含量（P<0.05）。与对照组相比,H组血清葡萄糖和高密度脂蛋白胆固醇含量极显著提升（P <0.05）,L组血清总蛋白含量有上升趋势（P=0.06）,H组...     

复合植物提取物对奶牛产奶量、乳成分和血液指标的影响

本试验旨在研究日粮中添加复合植物提取物对奶牛产奶量、乳成分和血液生理生化指标的影响。选择25～27月龄、1胎、泌乳天数(67±1) d、产奶量(32±5) kg/d且健康的泌乳高峰期荷斯坦奶牛40头,随机分为对照组和试验组,每组20个重复,每个重复1头牛。对照组饲喂基础日粮,试验组饲喂基础日粮+1g/(d·头)复合植物提取物(每克含辣椒油树脂3.5%、肉桂醛5.5%、丁香酚9.5%)。试验预试期3d,正试期60 d。结果表明:与对照组相比,试验组奶牛产奶量提高2.37%(P>0.05);日粮添加复合植物提取物有降低牛奶体细胞数、尿素氮含量的趋势(P>0.05);与对照组相比,试验组奶牛血常规指标、血清生理生化指标差异均不显著(P>0.05)。在本试验条件下,日粮添加1 g/(d·头)复合植物提取物能够在一定程度上提高奶牛产奶量、降低牛奶体细胞数和尿素氮含量,但不影响血液生理状态。     

不同化学形式微量元素对热应激奶牛生产性能和血清指标的影响

本试验旨在探讨不同化学形式微量元素对奶牛生产性能和血清指标的影响。选择年龄、胎次、泌乳天数和产奶量相近的健康荷斯坦奶牛32头,随机分为4组,即在基础饲粮中添加120 g/d干酒糟及其可溶物(DDGS)的对照组、120 g/d无机微量元素的试验Ⅰ组、15 g/d有机微量元素+105 g/d DDGS的试验Ⅱ组和10 g/d有机微量元素+110 g/d DDGS的试验Ⅲ组,每组8头。试验期90 d。结果表明,1)与对照组相比,试验Ⅰ组产奶量有下降的趋势,试验Ⅱ组和Ⅲ组产奶量有提高的趋势,试验组乳成分、干物质采食量和呼吸频率差异均不显著(P0.05);2)第30天,试验Ⅲ组血清谷胱甘肽过氧化物酶(GSH-Px)活性显著高于其他各组(P0.05);3)第30天,试验Ⅲ组血清铜含量显著高于对照组、试验Ⅰ组(P0.05),硒含量显著高于试验Ⅱ组(P0.05),第60天钙含量显著高于试验Ⅰ组(P0.05);4)各组间奶牛血清激素、免疫球蛋白G(Ig G)含量差异均不显著(P0.05)。本试验条件下,热应激奶牛饲粮添加有机微量元素能够改善奶牛生产性能,提高奶牛血清抗氧化能力,血清Ig G和锌、硒含量,并且呈剂量依赖。     

日粮中添加生物素对奶牛生产性能及血液生化指标的影响

本试验旨在研究生物素对泌乳早期中国荷斯坦奶牛生产性能和血液生化指标的影响.选择8头泌乳早期的初产中国荷斯坦奶牛随机分为4组,每组2头,采用4×4重复拉丁方设计.4组中,A组为对照组,仅饲喂基础日粮;B、C和D组在饲喂基础日粮的基础上分别添加20、30和40 mg/d生物素.研究结果表明:1)添加生物素组显著提高奶牛的产奶量,其中B、C和D组奶牛的产奶量比分别比A组高1.69、2.19和1.56 kg/d(P<0.05);2)日粮中生物素的添加提高了乳的乳蛋白率,A、B、C和D组乳蛋白率分别为2.77%、2.96%、2.89%和2.86%,其中,B组较对照组显著提高(P0.05).综合分析得出,本试验条件下,奶牛日粮中添加生物素可提高生产性能和乳品质,以30 mg/d的添加量为宜.     

不同益生菌添加剂对水貂生长性能及血清生化指标的影响

采用在饲料中添加貂源植物乳杆菌和饲用活性干酵母,研究这2种益生菌添加剂对水貂生长性能及其血清生化指标的影响。结果表明:添加植物乳杆菌组平均日增重极显著高于对照组和添加酵母菌组(P<0.01);对照组显著高于酵母菌组(P<0.05);对照组和添加植物乳杆菌组的采食量分别高于添加酵母菌组8.5g/d和8.9 g/d;添加益生菌的2个试验组在脂肪消化率上高于对照组(P<0.01);3组干物质消化率和蛋白质消化率差异不显著(P>0.05);添加植物乳杆菌组和酵母菌组的尿氮含量显著低于对照组(P<0.05),净蛋白质利用率均高于对照组7%。添加植物乳杆菌组血清胆固醇含量低于对照组1.27 mol/L(P<0.05),添加酵母菌组血清胆固醇含量与对照组差异不显著(P>0.05)。研究结果还表明:饲料中添加植物乳杆菌能有效提高水貂日增重,降低尿氮含量,提高净蛋白质利用率,降低血清胆固醇含量。酵母菌在提高脂肪消化率和降低胆固醇方面同样具有一定的作用。     

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 -