不同贮藏温度对王草青贮发酵品质的影响

本试验旨在研究不同贮藏温度对王草青贮品质的影响,选用热带牧草王草为青贮原料,用塑料瓶青贮并在25、30和35℃条件下贮藏30 d,测定王草青贮品质。结果表明,不同贮藏温度对王草青贮饲料的干物质(DM)、粗蛋白质(CP)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)及水溶性碳水化合物(WSC)含量均无显著影响(P>0.05);30℃处理能显著降低王草青贮饲料的pH及氨态氮/总氮(P<0.05),V-Score评分等级为优,具有较好的青贮发酵品质;25和35℃处理下pH及氨态氮/总氮、丁酸含量较高(P<0.05),V-Score评分等级为差,青贮发酵品质较差。综上所述,不同贮藏温度可影响王草青贮品质,其中30℃较25和35℃更有利于王草青贮。     

青贮饲料管理中的一些常见问题

1优良的发酵类型 最好的发酵类型是纯乳酸发酵，这是因为干物质和能量的回收利用率是最高的。青贮饲料中高的乳酸/乙酸比值优于低的乳酸/乙酸比值。好的青贮饲料中，丁酸含量要低于0.1%（以干物质计）。在青贮饲料中，发酵能够得以迅速进行且保存养分。微生物接种可改善微生物发酵，这种改善是通过提高干物质的回收利用率和产奶量提高来体现的。     

温度和添加剂对象草青贮发酵品质、α-生育酚和β-胡萝卜素的影响

为提高青贮饲料的发酵品质,降低α-生育酚和β-胡萝卜素的损失,研究了温度(45,30和15℃)和添加剂(无添加:CK;纤维素酶:E;植物乳杆菌:LP)对象草青贮饲料的影响。试验结果表明,在所有温度水平,象草青贮饲料的发酵品质良好,但30℃时产生了少量丁酸,发酵品质略有下降;添加LP和E降低了pH(P0.05),增加了乳酸含量和乳酸乙酸比(P0.05),提高了发酵品质。象草青贮饲料贮藏在45和15℃时的α-生育酚含量显著高于30℃(P0.05),β-胡萝卜素含量显著低于30℃(P0.05)。LP和E添加组在所有温度水平的α-生育酚和β-胡萝卜素含量均较低(P0.05)。E组在45℃的α-生育酚含量显著高于LP组,E组在30和15℃的β-胡萝卜素含量显著高于LP组。     

青贮饲料中乳酸菌的作用

正青贮饲料中的微生物,除土壤污染和添加水分外,还有附着在植物原料上的如乳酸菌、肠道杆菌、丁酸菌、酵母菌、霉菌及其他微生物。但仅有乳酸菌是有益的,乳酸菌是制作优良青贮饲料的主要微生物,能分解青贮饲料中的碳水化合物并形成乳酸引起乳酸发酵,因乳酸菌的活动青贮饲料得以保存。肠道杆菌在青贮饲料中是兼性厌     

温度和乳酸菌添加剂对燕麦青贮发酵品质及有氧稳定性的影响

以乳熟期刈割的燕麦为材料,研究温度和乳酸菌添加剂对其青贮发酵品质及有氧稳定性的影响,设置无添加(对照,CK)、商业青贮添加剂Synlac I(SLI处理)和人工筛选菌株Lactobacillus rhamnosus HT1(HT1处理)3个处理,分别置于25℃、35℃和45℃下青贮60 d后,取样测定青贮燕麦的发酵品质和有氧稳定性。结果表明:随着贮藏温度的升高,燕麦青贮饲料中水溶性碳水化合物和乳酸含量降低,pH和氨氮含量显著升高(P0.05)。乳酸菌添加剂能够改善燕麦青贮饲料的发酵品质和有氧稳定性。25℃下,添加剂处理的青贮饲料霉菌和酵母菌数量低于1.00 log_(10 )cfu/g,丙酸和丁酸均未检出。与HT1处理相比较,SLI处理在25℃下效果更好,水溶性碳水化合物、乳酸和挥发性脂肪酸含量更高(P0.05),氨态氮和好气性细菌含量较低(P0.05)。45℃下则相反,HT1处理效果更优,其水溶性碳水化合物、乳酸和乙酸含量更高,氨态氮、酵母菌和好气性细菌数量较低。且35℃和45℃下HT1处理青贮饲料在有氧发酵阶段pH均小于4.20,有氧稳定性更好。综上所述,HT1处理可以提高燕麦青贮饲料的发酵质量和有氧稳定性,适合用于黄土高原夏季和初秋燕麦青贮饲料调制。     

切碎长度对不同牧草青贮饲料发酵品质的影响

本试验以羊草、无芒雀麦、黄花草木樨和沙打旺为青贮原料,按照长短两种切碎长度处理后分别青贮,研究牧草种类和切碎长度对青贮发酵品质的影响。结果表明,牧草种类对青贮饲料的pH值、氨态氮含量及乳酸、乙酸和丁酸含量有极显著影响(P0.01),无芒雀麦的发酵品质不如另外3种牧草;切短处理能极显著降低青贮饲料的丁酸含量(P0.01),同时显著提高乙酸含量(P0.05),对pH值也有显著影响(P0.05);牧草种类和切碎长度对青贮饲料的干物质含量、粗蛋白含量及乳酸和丁酸含量有交互作用(P0.01)。综上所述,青贮原料切短处理可以提高牧草青贮发酵品质。     

植物乳杆菌和布氏乳杆菌对全株玉米青贮发酵品质影响

本研究旨在分析植物乳杆菌和布氏乳杆菌混合添加后对青贮饲料发酵品质的影响,设计为2个发酵处理,T同型发酵菌处理(植物乳杆菌),TY同型和异型发酵处理(植物乳杆菌和布氏乳杆菌)的全株玉米青贮发酵实验.在第100天时感官评定青贮饲料的优劣等级;用酸度离子计测定青贮饲料的pH值;用高效液相色谱仪分析乳酸、乙酸、丁酸的含量;平板...     

青贮饲料发酵品质评定体系及其新进展

牧草青贮发酵品质评定体系的建立是对青贮饲料质量好坏更好的监督与评价,是提高青贮饲料质量、减少资源浪费的重要途径与方法,同时对提高家畜饲草料营养价值以及生产性能有着重要的意义.牧草青贮发酵品质评定体系中常规的实验室评定指标一般以有机酸(乳酸、乙酸和丁酸)和氨态氮含量为基准,但目前的研究结果表明,青贮料中乳酸含量增多就容易发生二次发酵,而且牧草青贮的pH值和氨态氮含量与牧草本身化学成份不同有关,因此在青贮饲料发酵品质评定体系中不宜将这些指标用作青贮料发酵品质评定的统一标准.     

种植时间对西藏地区青贮玉米发酵品质和微生物多样性的影响

本文旨在研究西藏地区不同种植时间对青贮玉米发酵品质和微生物多样性的影响,为西藏地区玉米青贮饲料制作提供理论依据。以西藏地区春玉米（3月种植,10月刈割）和夏玉米（6月种植,10月刈割）为材料,进行青贮饲料制作,青贮后的第7,14,30和60 d开窖取样,测定青贮饲料的发酵品质和微生物多样性。结果表明：种植时间会影响玉米的营养成分和发酵品质,相比于春玉米,夏玉米青贮饲料中干物质含量、pH值、丁酸含量和氨态氮/总氮更低,但乳酸和水溶性碳水化合物含量更高。微生物多样性结果显示,与春玉米相比,夏玉米青贮饲料中变形菌门丰度更低,厚壁菌门、拟杆菌门和LAB菌种的丰度更高。因此,夏玉米青贮饲料的发酵品质更好。     

棉花秸秆青贮加工及其对绵羊饲喂效果的影响研究

本试验旨在探讨纤维素酶和秸秆青贮剂对棉花秸秆青贮饲料发酵品质及对绵羊饲喂效果的影响,进而为改善棉花秸秆青贮饲料的营养品质和科学利用提供理论依据。试验结果表明,青贮处理可有效降低棉花猜秆中的游离棉酚含量;添加纤维素酶可显著降低棉花秸秆青贮饲料的乙酸、丁酸和氨态氮含量;添加秸秆青贮剂可显著增加棉花秸秆青贮饲料中的乙酸和V-score。纤维素酶和秸秆青贮剂的互作效应可显著影响棉花秸秆青贮饲料的乙酸、丁酸、可溶性碳水化合物和V-score。经90 d饲喂后,育肥5组的经济效益为290.4元/只,显著高于其他4个处理。     

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 -