奶牛生化增奶剂研究进展

本文阐述了以微生物制剂为主的奶牛生物增奶剂和化学增奶剂的研究概况。报道了当前酵母茵、乳酸茵、米曲霉、复合茵制剂等国内外研究进展，并对微生物增奶剂的作用机制进行了概述。同时指出化学增奶剂的应用效果取决于所试奶牛日粮营养成分的盈缺，选择适宜时机和剂量才能取得良好效果。     

奶牛增奶剂研究进展

阐述了奶牛营养性添加剂、中药增奶剂、微生物增奶剂的研究进展。同时对其作用机理和注意事项作了述评。     

奶牛增奶剂的应用

(接上期)3微生物增奶剂微生物增奶剂指的是奶牛专用微生态制剂或益生菌制剂。目的是通过微生物提供营养、调控菌群、抑制疾病、增强抵抗力、促进营养物质的转化和利用。3.1酵母菌酵母菌是最先开发应用的生物增奶剂,早在1925年Eckles和Williams就报道了用酵母菌作为泌乳牛的补充     

奶牛中药增奶剂应用概况及述评

本文提示奶牛中药增奶剂对反刍动物的利用有其特殊性，中药需经瘤胃微生物和肠道菌群两道关的微生物降解过程，分解为单体而呈现药理作用。同时根据中药有效化学成份对生物作用的共性，阐述了当前中药增奶剂的应用情况，提出可以用生物转化技术提取某些中药活性成份的设想。     

肉牛快速育肥试验报告

在喂养肉牛的过程中,为了补充传统饲料中维生素等微量元素不足的缺点,满足饲养户对肉牛快速育肥的需求,我们采用无公害新一代"促长增奶剂"快速育肥肉牛,经过与对比组的对照实验,证明了传统饲料与"促长增奶剂"配合使用对肉牛的快速育肥、提高肉质都有显著的作用。     

增奶剂提高奶牛产奶量的试验报告

1998年4～5月,凤台奶牛场对奶牛试用了牛羊增奶剂进行了增加产奶量的试验,结果表明,增产效果明显。试验方法和试验材料试验动物试验在凤台奶牛场进行,选20头股次相近,泌乳期相似,产奶水平接近的荷斯坦泌乳牛分两组进行试验,具体情况见表l。表1试验牛情况日常管理两组牛的饲养管理和口粮饲喂相同,环境一致,采食位置不变,每天饲喂3次,挤奶3次,自由饮水。试验方法两组牛均按照同一饲养水平进行饲喂,试验组另外每天每头扑饲120g增奶剂,分平。中、晚3次拌入糖料中（混合精料配方见表2）。使用增奶剂前3d逐头称产奶量作为基数。试验…     

奶牛增奶剂的应用

微生物增奶剂指的是奶牛专用微生态制剂或益生菌制剂。目的是通过微生物提供营养、调控菌群、抑制疾病、增强抵抗力、促进营养物质的转化和利用。     

氨基酸复合微肥增奶试验

氨基酸复合微肥在农作物增产上取得了理想的效果,但在畜牧业生产上,特别是饲喂奶牛增奶方面尚未见报道。本试验旨在研究和探索氨基酸复合微肥饲喂奶牛增奶效果,试验结果表明,氨基酸复合微肥对奶牛有增奶作用。关于氨基酸复合微肥对奶牛增奶作用还有待于进一步实验研究。     

奶牛增奶饲料投入生产

一种以内蒙古大草原天然植物为主要原料的绿色新产品———奶牛天然植物增奶饲料，日前由位于平谷县内的北京天域绿洲饲料有限公司批量投入生产。经在北京和内蒙古两地进行的大量测试数据表明，奶牛食用增奶饲料７～１０d就有明显效果，１个月后每天增奶１．５～２kg，效益则为投入的３～４倍。奶牛天然植物增奶饲料是国家自然科学基金委员会资助的科研项目，由于增奶饲料中含有良好的植物性免疫促进成分，可使奶牛通过其特殊的内调控原理增强非特疫性免疫功能，促进乳腺发育，从而有效地达到奶牛增奶的目的。（引自《江西日报》２００１年…     

三种干奶药对奶牛乳房炎在干奶期的治疗、预防效果比较

奶牛生产中往往通过干奶期治疗消除乳房在上个泌乳期已存在的感染、预防产后新发感染。干奶期的治疗能使乳房有机会在下一个泌乳期到来之前修复受损的乳腺组织,降低产后临床型乳房炎的发病率。本试验旨在比较三种不同成分的干奶药——盐酸头孢噻呋乳房注入剂(干奶期)(RC)、复方普鲁卡因青霉素-萘夫西林钠-硫酸双氢链霉素乳房注入剂(干奶期)(NF)、邻氯青霉素乳房注入剂(干奶期)(AB)的安全性、对干奶期隐性乳房炎治疗效果和产后新发临床乳房炎预防效果、弃奶期以及经济效益,以期为临床干奶药选择提供依据。结果表明,(1)RC的安全性较好;(2)三种干奶药对干奶期隐性乳房炎治疗和细菌清除效果无显著差异;(3)AB预防产后新发感染效果最好;(4)NF弃奶期最短;(5)AB经济效益最好,对各项综合评分,RC为4分,AB为6分,NF为5分,因此在临床干奶期治疗中首选邻氯青霉素乳房注入剂(干奶期),针对提高新产牛产奶的商品率,可选用复方普鲁卡因青霉素-萘夫西林钠-硫酸双氢链霉素乳房注入剂(干奶期),针对干奶环境略差的牧场可考虑选用盐酸头孢噻呋乳房注入剂(干奶期)。     

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.     

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