苜蓿干草提取叶蛋白最佳工艺的研究

采用酸化加热加盐的综合方法提取苜蓿干草中的叶蛋白。分别进行了草粉预浸时间、絮凝时间、絮凝温度、料水比、加盐量和提取液pH值等6个因素对叶蛋白粗蛋白质提取率影响的单因素试验研究,得到各单因素最佳工艺参数分别为:预浸时间24h,絮凝时间10min,料水比1∶30,絮凝温度60℃,pH值3,加盐量2%。对料水比、加盐量、絮凝时间和pH值的4因素3水平正交试验结果表明,影响粗蛋白质提取率的因素依次为料水比>加盐量>pH值>絮凝时间,最佳工艺条件组合为料水比1∶20,加盐量1%,絮凝时间5min和pH值为2.5。     

“青大1号”紫花苜蓿叶蛋白提取条件优化

为了开发新的食用蛋白质资源,本试验以“青大1号”紫花苜蓿新品系青干草为原料,采用酸化加热法配合加盐法提取叶蛋白.单因素试验设计,分别考察料水比、加盐量、絮凝时间、pH、预浸时间、絮凝温度6个因素对粗蛋白质提取率的影响,并以单因素试验结果为依据,采用四因素（料水比、加盐量、絮凝时间、pH）三水平L9（34）正交试验设计进行提取工艺优化.试验结果表明：影响粗蛋白质提取率的因素,从大到小依次为料液比、絮凝时间、pH、加盐量.当絮凝温度为70℃、料液比为1∶10、加盐量1％、絮凝时间5min、pH为4时是叶蛋白提取的最优提取条件.     

正交优化苜蓿叶蛋白提取工艺条件研究

文章在单因素试验的基础上,采用L9(33)正交试验对苜蓿叶蛋白提取工艺进行研究。结果表明,最佳工艺条件组合为:料液比1∶20、加盐量4%、pH为5,在此条件下可溶性蛋白的提取率可以达到19.62%。影响可溶性蛋白提取率的因素依次为:料液比加盐量pH,絮凝温度在60℃、时间为15min时效果最好。     

正交优化法提取苜蓿中叶蛋白的工艺研究

以苜蓿为原料,采用盐析法提取苜蓿中的叶蛋白。在单因素实验基础上,通过正交试验优化了工艺条件。结果表明,最佳提取条件为：pH为5,加盐量为4%,加热温度70℃,加热时间10min,离心时间8min,在此条件下提取率可达11.32%。     

三叶草叶蛋白提取工艺优化研究

作者选用三叶草为试验材料,通过正交试验L9(3⁴)分别对料水比、加盐比、不同pH和絮凝温度4个因素进行优化。以叶蛋白提取率、蛋白质量分数为指标,以期获得三叶草叶蛋白提取的最佳优化工艺参数。正交试验表明,提取三叶草叶蛋白的最佳提取工艺为A₃B₃C₁D₂,即料水比为1∶3、加盐量为5%、pH为3.0、絮凝温度为70 ℃为最佳的提取工艺组合。本研究初步用正交试验的方法对三叶草叶蛋白的最佳提取工艺进行了优化研究,为三叶草叶蛋白的开发应用提供了理论依据。     

菊芋叶蛋白提取工艺研究及氨基酸分析

以新鲜菊芋(Helianthus tuberosus)叶片为材料,研究叶蛋白的提取工艺。比较了4种提取剂对菊芋叶蛋白的提取效果,通过对叶蛋白得率、粗蛋白含量和粗蛋白提取率的比较,以焦亚硫酸钠溶液的提取效果最佳;在单因素试验的基础上,采用料液比、加盐量、絮凝温度、p H值多因素正交处理,对菊芋叶蛋白的提取工艺进行优化。结果表明,其最佳提取工艺条件为:料液比1∶7,加盐量0.5%,絮凝温度90℃,p H 2.0;对提取叶蛋白进行氨基酸分析的结果表明,菊芋叶蛋白氨基酸种类齐全,配比协调,总氨基酸含量为42.07%,必需氨基酸占总氨基酸的比值(E/T)为40.55%,必需氨基酸与非必需氨基酸的比值(E/N)为0.68。     

葡萄籽仁蛋白质混合酶提取工艺的优化

以酿酒葡萄籽为原料,将籽仁分离后,用干燥籽仁,在料液比1∶30条件下,对菠萝蛋白酶与木瓜蛋白酶等量混用量、酶解温度、时间、pH值4个因素,采用正交试验法对籽仁中蛋白质提取最佳工艺参数进行探讨。结果表明:各因素对蛋白质提取率的影响次序为酶量温度pH值时间;最佳工艺参数:混合酶量为0.24 g/mL,提取温度为55℃,pH值为7.5,提取时间为50 min。在最佳工艺下酿酒葡萄籽仁蛋白提取率达92.7%。     

聚合草鲜草叶蛋白提取条件研究

以紫花聚合草为材料,研究固液比、盐浓度、凝絮方法对叶蛋白提取率和蛋白质提取率的影响.结果表明:各单因素最佳条件分别为:固液比为1:6、加盐浓度0.6%、乙醇浓度65%、pH值1.5、三氯乙酸沉淀法叶蛋白提取率和蛋白质提取率均较高.对固液比、盐浓度、凝絮方法3因素3水平正交试验结果表明,影响聚合草叶蛋白提取率的因素依次为凝絮方法固液比加盐量,最佳条件组合为固液比1:7、盐浓度0.3%、乙醇法沉淀.     

不同处理条件对苜蓿叶蛋白凝聚效果的研究

以现蕾期新鲜苜蓿Medicago sativa为材料,采用温度、pH值单因素处理及温度、加热时间、pH值和NaCl质量分数多因素处理,探讨不同方法对苜蓿叶蛋白凝聚效果的影响。结果表明,在单因素条件下,温度以75℃为宜,pH值4.0对苜蓿叶蛋白产量、叶蛋白纯度和粗蛋白提取率有显著影响。而在多因素条件下,叶蛋白的最适凝聚组合条件为温度85℃,时间2min,pH值4.0,以及NaCl质量分数0.4%。     

苜蓿鲜草中提取叶蛋白最佳工艺研究

该研究以北方寒冷地区龙牧801苜蓿鲜草为原料,用酸化加热法提取苜蓿叶蛋白。研究提取温度、提取液pH值、提取时间三因素对苜蓿叶蛋白提取率的影响。在单因素实验基础上,采用三因素三水平正交试验确定酸热法提取苜蓿叶蛋白的最佳工艺条件为:提取温度为60℃、pH值为4.0、提取时间为12min,在此工艺条件下,粗蛋白提取率为45.32%。     

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 -