不同来源肽对培养液中瘤胃细菌蛋白产量的影响

试验研究了大豆肽、玉米肽和瘤胃液肽对培养液中瘤胃细菌蛋白产量的影响。结果表明:培养液中氨基氮含量越高,细菌生长速度越快,菌体蛋白氮产量显著增加(P<0 01或P<0 05)。培养初期(0～6h),细菌生长快,菌体蛋白氮产量也显著增加(P<0 01或P<0 05);培养后期(6～24h),细菌生长缓慢,菌体蛋白氮产量处于平稳期(P>0 05)。对于不同来源肽来说,瘤胃液肽和大豆肽对细菌生长的促进作用要明显好于玉米肽(P<0 05)。结果表明:瘤胃细菌生长需要肽营养,肽可能是细菌生长的限制性因素之一。     

添加不同种类二糖对奶牛体外瘤胃发酵与微生物蛋白合成的影响

本试验旨在研究不同种类二糖对苜蓿瘤胃发酵与微生物蛋白合成的影响。试验选用3头健康的,装有永久性瘤胃瘘管的中国荷斯坦奶牛作为瘤胃液供体动物(600 kg左右),利用体外批次培养方法,以苜蓿和玉米为饲料源做体外发酵基质,然后添加蔗糖、乳糖以及异麦芽糖(添加水平分别为0%、0. 5%、1. 5%、3. 0%)。结果表明:随着三种二糖添加水平的提高,瘤胃体外潜在产气量显著增加(P0. 05)、慢速降解部分极显著增加(P0. 01);瘤胃总挥发性脂肪酸浓度、乙酸/丙酸值极显著增加(P0. 01)、氨态氮浓度极显著降低(P0. 01);乳酸有降低的趋势;瘤胃微生物蛋白极显著增加(P0. 01),微生物蛋白合成效率极显著提高(P0. 01)。二糖种类与添加水平对潜在产气量、慢速降解部分、总挥发酸浓度、氨态氮浓度存在显著互作影响(P0. 05),对瘤胃微生物蛋白合成、乳酸浓度不存在显著互作影响(P0. 05)。综上,添加乳糖对瘤胃发酵功能的微生物蛋白质合成影响最显著。     

4种谷物加工副产物的体外发酵特性及细胞壁多糖降解规律

试验旨在研究米糠、小麦麸、大豆皮和玉米皮4种谷物副产物的体外发酵动态、发酵产物组成以及发酵前后非淀粉多糖(NSP)的降解。试验以脱除脂肪、蛋白质和低聚糖的谷物副产物为发酵底物，以新鲜猪粪为发酵菌源，利用ANKOM RFS体外产气系统37℃恒温培养30 h,记录发酵过程中的累计产气量，测定发酵液pH值和短链脂肪酸(SCFA)组成，发酵前后非淀粉多糖含量和组成。结果显示：米糠、小麦麸和玉米皮的发酵动力学基本相似，而大豆皮的干物质降解率、累积产气量、理论最大产气量、产气速率和延滞时间均显著高于前三者(P<0.05)。总体而言，总短链脂肪酸产量与总非淀粉多糖降解量极显著正相关(P<0.01);SCFA中乙酸摩尔比与消失底物中葡萄糖和糖醛酸的摩尔比呈极显著正相关与阿拉伯糖和木糖的摩尔比呈极显著负相关(P<0.01);丙酸摩尔比与消失底物中阿拉伯糖和木糖的摩尔比呈极显著正相关(P<0.01),与葡萄糖和糖醛酸摩尔比呈极显著负相关(P<0.01);丁酸摩尔比与消失阿拉伯糖的摩尔比呈显著正相关(P<0.05),与糖醛酸摩尔比呈极显著负相关(P<0.01)。研究...     

饲料中添加大豆糖蜜对肉羊瘤胃发酵的影响

试验选用安装永久性瘤胃瘘管的德国美利奴与东北细毛羊杂交羯羊12只,按体重相近的原则将其分为4组,每组3个重复。在基础日粮中分别添加占风干饲料重0、2%、5%和8%的大豆糖蜜进行饲喂,研究其对肉羊瘤胃发酵的影响。在饲喂后0、2、4、6h和8h采集瘤胃液样本,测定瘤胃液pH值、NH3-N、菌体蛋白和VFA浓度。结果表明:饲喂2h后5%组NH3-N浓度分别比0、2%和8%提高26.91%、24.67%、23.11%(P<0.05);在2h时间点5%组和8%组瘤胃菌体蛋白浓度显著高于0组(P<0.05);随着大豆糖蜜添加量的增加瘤胃菌体蛋白浓度也有不同程度的升高,其中5%组瘤胃菌体蛋白浓度最高;大豆糖蜜可提高瘤胃液丙酸浓度,其中5%组和8%组显著高于对照组(P<0.05)。     

饲喂燕麦-箭筈豌豆捆裹青贮对绵羊瘤胃pH与氮代谢参数的影响

选用6只装有永久瘤胃瘘管的羯羊作为试验动物,采用3×3拉丁方设计,研究了A(100%燕麦—箭筈豌豆捆裹青贮料,简称青贮料),B(80%青贮料+20%玉米)和C(63%青贮料+37%玉米)3种饲粮处理对绵羊瘤胃内环境的影响。结果表明,瘤胃液pH值为A>B>C,但A的瘤胃液总氮含量平均值显著低于处理C(P<0.05);除食前1 h处理间NH3-N浓度差异接近显著(P=0.085)外,其他时段A,B和C差异显著或不显著(P<0.05或P>0.05);瘤胃液中尿素氮仅B和C食后8 h的测值和平均值显著(P<0.01或P<0.05)高于A;C的瘤胃液蛋白氮含量平均值显著高于A(P<0.05),但3种处理差异不显著。因此,3种饲粮试羊的瘤胃液pH值和微生物蛋白合成状况间没有显著差异。     

不同厚度蒸汽压片处理对玉米活体外瘤胃发酵的影响

试验以未处理的玉米及两种不同厚度蒸汽压片玉米(压片厚度为1.5mm,SFC 1.5;压片厚度为2.0mm,SFC 2.0)为材料,采用营养成分分析、活体外人工瘤胃产气量试验,研究不同厚度蒸汽压片处理对玉米营养成分、淀粉糊化度和活体外发酵特性的影响。结果表明,不同厚度蒸汽压片处理显著降低玉米粗蛋白质和粗脂肪含量(P0.05),显著提高了玉米的淀粉糊化度(P0.05);并且显著提高了玉米在瘤胃液内的淀粉降解率和体外产气速度(P0.05),显著降低了瘤胃液中氨态氮(NH3-N)浓度(P0.05);降低压片厚度(1.5和2.0mm),蒸汽压片玉米淀粉糊化度增加约17%(88.76%和71.60%),SFC 1.5的体外产气速度、4h干物质和淀粉产气率显著高于SFC 2.0(P0.05)。不同厚度蒸汽压片处理对玉米瘤胃48h产气量、12和24h瘤胃液pH、总挥发性脂肪酸产量及乙酸、丙酸、乙酸/丙酸、异丁酸、异戊酸、戊酸摩尔比影响均不显著(P0.05)。综上所述,不同厚度蒸汽压片处理可显著提高玉米在瘤胃内淀粉降解率和降解速度,降低瘤胃液中氨态氮浓度,而对48h产气量及其他发酵参数没有明显影响。     

PEG和CrEDTA作为绵羊瘤胃液相标记物的比较研究

对4只4×4拉丁方设计中的绵羊，分别用PEG（聚乙二醇）和CrEDTA（乙二胺四乙酸铬）两种液相标记物同时测定了瘤胃液稀释率和瘤胃液体积。结果表明，两种方法测得的瘤胃液稀释率之间或瘤胃液体积之间存在极显著（P＜0．01）或显著（P＜0.05）相关关系。但用两种方法测得的瘤胃液稀释率或瘤胃液体积之间差异极显著（P＜0．01）或显著（P＜0．05）。用PEG法测得的两指标均高于用CrEDTA法测得的结果。     

嗜热毛壳菌纤维素酶对小尾寒羊瘤胃代谢的影响

本试验研究不同水平嗜热毛壳菌纤维素酶对小尾寒羊瘤胃代谢的影响。试验动物为4只安装有永久性瘤胃瘘管的成年小尾寒羊公羊(平均体重为45 kg),采用4×4拉丁方试验设计,在基础日粮中分别添加0％、0．3％、0．6％和0．9％4个水平酶制剂,采集瘤胃液测pH值、氨氮浓度和挥发性脂肪酸(VFA)浓度。试验结果表明:各组试羊瘤胃液平均氨氮浓度的变化范围为10．01-12．80 mg/dL,各组之间相同时间点差异不显著(P>0．05)。瘤胃液平均pH值在6．50-6．80范围内变动,试验组pH值低于对照组(P<0．05),以0．6％水平较好。各组试羊瘤胃乙酸、丙酸及总 VFA浓度的变化规律基本相同,即喂料后逐渐上升,其中乙酸和总VFA浓度在2 h后达到最高点,丙酸浓度在4 h 达到最高点,随后平稳下降于饲喂前降至最低点,再次采食后又重复出现此规律。试验组瘤胃乙酸和总VFA浓度显著或极显著高于对照组(P<0．05或P<0．01),以0．6％水平组最高。     

不同纤维含量日粮中添加不同水平酵母培养物 对牦牛瘤胃消化率的影响

试验以不同纤维含量的日粮(40%、50%、60%)和不同酵母培养物添加剂量(0%、0.75%、1.5%、3%)为两因素,采用3×4交叉设计;以牦牛瘤胃液进行体外产气发酵48 h,测定瘤胃液发酵后产气量、干物质(Dry Matter,DM)降解率、发酵前后粗蛋白质(Crude Protein,CP)降解率、中性洗涤纤维(Neutral Detergent Fiber,NDF)以及酸性洗涤纤维(Acid Detergent Fiber,ADF)降解率、瘤胃液的pH值、氨态氮(NH_3-N)的含量、微生物蛋白的(Microbial Protein,MCP)含量。结果表明:①随日粮中纤维含量的降低,产气量和DM降解率、NDF降解率、ADF降解率及CP降解率均显著提高(P0.05),而不同水平酵母培养物添加剂量对上述指标并无显著影响(P0.05),同时纤维含量与酵母培养物添加量不存在显著互作效应(P0.05)。②纤维含量添加水平对瘤胃液pH值影响显著(P0.05),但酵母培养物添加水平对瘤胃液pH值无显著影响(P0.05),同时纤维含量与酵母培养物添加量不存在显著互作效应(P0.05)。③随纤维含量降低,发酵后瘤胃液中MCP显著提高至6.23 g/l(P0.05),NH_3-H含量显著降低至16.89 mg/100 ml(P0.05);随酵母培养物添加量的提高,发酵后瘤胃液中MCP显著提高至6.15 g/l(P0.05);在纤维含量与酵母培养物添加量互作条件下,瘤胃液中MCP含量显著提高至6.65 g/l(P0.05),并且纤维含量为40%时的酵母培养物添加组效果更好。     

醋酸棉酚对绵羊瘤胃微生物数量及消化代谢的影响

本试验旨在研究添加醋酸棉酚后绵羊瘤胃微生物数量、瘤胃液代谢指标、水解酶活性的变化,探究醋酸棉酚对绵羊瘤胃微生物数量及消化代谢的影响。试验选用8只3岁左右、平均体重为(49.13±4.70)kg的健康哈萨克羊,安装永久性瘤胃瘘管后随机分为2组(每组4只),分别为对照组和试验组,试验分为2期,每期25 d。所有羊只饲喂同一营养水平粉状精料,每只羊每天粉状精料饲喂量为体重的1.50%,小麦秸秆及苜蓿为体重的1.00%,玉米青贮为体重的0.05%(干物质基础),混合饲喂,自由饮水;在此基础上,试验Ⅰ期试验组饲粮每天每只添加600 mg醋酸棉酚,试验Ⅱ期饲粮每天每只添加1 200 mg醋酸棉酚。结果表明:添加醋酸棉酚对绵羊瘤胃液pH及细菌总数量无显著影响(P>0.05),饲喂前(即0h)试验组绵羊瘤胃液氨态氮浓度显著高于对照组(P<0.05),饲喂后6.0、9.0、12.0 h,试验组绵羊瘤胃液挥发性脂肪酸浓度显著低于对照组(P<0.05),试验Ⅰ期各时间点试验组绵羊瘤胃原虫总数量极显著低于对照组(P<0.01),饲喂后3.0h,试验组绵羊瘤胃液纤维素酶活性显著高于对照组(P<0.05),饲喂后9.0、12.0 h,试验组绵羊瘤胃液蛋白酶活性极显著低于对照组(P<0.01);试验Ⅱ期,饲喂后6.0 h,试验组绵羊瘤胃液蛋白酶活性显著低于对照组(P<0.05),饲喂后12.0h极显著低于对照组(P<0.01);添加醋酸棉酚后瘤胃液中棉酚的浓度在饲喂后1.5、3.0 h最高。综上,醋酸棉酚在初期摄入后显著降低绵羊瘤胃原虫数量;醋酸棉酚通过抑制绵羊瘤胃液蛋白酶活性,降低瘤胃液中戊酸、异戊酸及异丁酸的浓度而对瘤胃内蛋白质消化代谢产生影响,这种作用主要发生在摄入醋酸棉酚6.0 h后;醋酸棉酚对绵羊瘤胃液中的纤维素酶、淀粉酶的活性整体没有显著影响。     

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.     

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.     

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.     

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 -