菌酶固态发酵豆粕去除抗营养因子的差异化研究

本文旨在研究不同微生物和酶发酵豆粕对去除豆粕中抗营养因子的影响。将豆粕、不同的微生物或酶均匀混合,同时控制适当的水分,转入发酵呼吸袋内,密封,37℃培养箱内培养3 d,结束后60℃烘干,粉碎过60目取样,检测豆粕中水苏糖、棉籽糖、大豆球蛋白、β-伴球蛋白、胰蛋白酶抑制因子、脲酶等抗营养因子的含量变化。结果表明：酿酒酵母对水苏糖、棉籽糖的去除作用最大,去除率达90%,乳酸菌对水苏糖、棉籽糖的去除效率次之,达60%;蛋白酶对大豆抗原蛋白和β-伴球蛋白的消除作用最佳,去除率分别达70%和50%;菌酶协同发酵对单种抗营养因子的消除并无提高,但可以同时有效去除多种抗营养因子。从结果可以看出,不同的微生物或酶对豆粕中不同的抗营养因子去除效率存在差异,通过菌酶协同发酵,可以实现大部分抗营养因子的同时去除。     

发酵豆粕产品质量的综合评价

发酵豆粕是断奶仔猪日粮中应用比较广泛的蛋白原料之一,然而其质量评估体系还不完善,关键指标的检测方法还有改进的空间。通过评估发酵豆粕中抗营养因子含量的降解程度,蛋白质量受热处理的影响程度,同时改善相关指标的检测方法,才能够真实有效的综合评估发酵豆粕的品质。我们建议发酵豆粕的质量控制指标如下:蛋白溶解度≥70%、酸溶蛋白(占蛋白比)≥20%、大豆球蛋白+β-伴大豆球蛋白≤10%、水苏糖+棉籽糖≤1%、赖氨酸/粗蛋白≥6.0%。     

角蛋白酶水解豆粕参数优化对营养价值的提升

研究旨在通过优化嗜热厌氧杆菌(Keratinibaculum paraultunense) KD-1角蛋白酶酶解豆粕条件来达到提高豆粕营养价值,改善其功能的目的。以酸溶蛋白含量为指标,采用单因素试验和正交试验优化豆粕酶解条件。结果表明,酶解豆粕的最佳条件为:酶解温度85℃,底物浓度10%,酶解时间3 h。经KD-1粗酶液酶解后,豆粕中的粗蛋白质、酸溶蛋白、游离氨基酸等营养物质含量显著增加(P0.05);脲酶、棉籽糖、水苏糖、大豆球蛋白、β-伴大豆球蛋白、胰蛋白酶抑制因子等6种抗营养因子含量显著下降(P0.05)。结果显示,豆粕经角蛋白酶酶解后,其营养价值显著增加,功能得到了改善。     

产β-甘露聚糖酶菌株HTGC-10对豆粕抗营养因子改性的实时监测分析

试验旨在实时监测豆粕发酵过程中抗营养因子的降解效果。以β-甘露聚糖酶高产菌株HTGC-10为发酵菌株,降解甘露聚糖,使用薄层层析及实时电泳检测菌株HTGC-10的降解效果。结果显示,菌株HTGC-10可将甘露聚糖降解为小分子的甘露寡糖;使用HTGC-10发酵10%的豆粕,在发酵的0～24 h内,菌株HTGC-10可以很好地降解豆粕中的大分子蛋白。在发酵的0～24 h内,菌株HTGC-10可以很好地降解抗营养因子,将豆粕中的大豆球蛋白、β-伴大豆球蛋白和KTI抗营养因子分别降解至原含量的11.9%、18.5%和2.0%,继续发酵24～48 h对豆粕抗营养因子的降解作用不大。研究表明,豆粕发酵以24 h为宜,可以更好地利用豆粕资源。     

不同来源及微粉化豆粕对断奶仔猪营养物质消化率和生产性能的影响(二)

<正>(上接2015年7期《新饲料》第29页)3结论3.1实验室分析不同大豆产品的氨基酸和粗蛋白含量与期待值接近(见表1)。因为干物质的含量较高,两种微粉化的高蛋白豆粕的蛋白含量均高于粗粉的高蛋白豆粕。普通豆粕粗纤维和中性洗涤纤维含量远高于两种高蛋白豆粕或大豆浓缩蛋白。大豆浓缩蛋白的蔗糖和寡糖的比例最低,其他大豆产品的含量比较接近。大豆浓缩蛋白的胰蛋白酶抑制因子(TIA)含量为1.1mg/g,远低于所有豆粕样品的2.7mg/g。大豆浓缩蛋白的蛋白质分散指数(PDI)和蛋白质溶解度值低于豆粕样品。微粉的豆粕样品PDI值     

发酵豆粕技术及其在单胃动物和水产动物上应用的研究进展

豆粕是一种重要的饲料原料,但因其含有胰蛋白酶抑制因子、大豆抗原蛋白、寡糖等营养抑制因子,从而限制了豆粕的应用。通过微生物发酵技术可以缓解这一问题。细菌和真菌均可通过发酵降低豆粕中的抗营养因子,提高小肽含量,改善必需氨基酸和非必需氨基酸的含量。发酵豆粕品质与添加的菌株种类密切相关,菌株种类不同,则发酵豆粕营养成分含量也有所差异。饲喂发酵豆粕可以提高单胃动物的日增重,改善生产性能,对提高蛋白利用率等具有明显的改善作用;可降低水产动物的饲料成本。发酵豆粕在未来的动物生产上具有较好的应用前景。     

不同蛋白酶对豆粕抗原蛋白降解程度的比较分析

为提高豆粕蛋白质利用率和动物生产性能,分析了不同来源的蛋白酶对豆粕中抗原蛋白(大豆球蛋白和β-伴大豆球蛋白)含量的影响,将经过蛋白酶处理的豆粕进行聚丙烯酰胺凝胶电泳(SDS-PAGE)检测分析。结果表明,同等酶活的不同蛋白酶对豆粕中的抗原蛋白降解程度有较大差别。经过发酵条件的优化,最终选择酸性蛋白酶、中性蛋白酶、乳酸菌和枯草芽孢杆菌混合发酵方式,最终使得发酵豆粕乳酸含量达到2.76%,酸溶蛋白含量14.76%,大豆球蛋白含量降低至25.3 mg/g。     

β-伴大豆球蛋白对仔猪抗营养阈值的研究进展

β-伴大豆球蛋白等抗原蛋白热稳定性较强,其抗原活性难以完全去除,可导致仔猪等幼龄动物产生过敏反应,从而影响其生理健康、日粮养分消化利用和生产性能。目前针对不同大豆制品在畜禽生产中的应用已有大量研究,但大豆抗原蛋白在幼龄畜禽日粮中的安全剂量尚不明确。本文对β-伴大豆球蛋白的理化性质及对仔猪的致敏机制、大豆制品中β-伴大豆球蛋白含量及大豆制品在仔猪生产中的应用进行综述,并对β-伴大豆球蛋白在仔猪日粮中的安全剂量进行探讨。     

大豆低聚糖的生理特性及应用

大豆低聚糖(Soybean oligosac-charides)是大豆籽粒中可溶性寡糖的总称,主要成分是水苏糖(stachyose)、棉子糖(raffinose)和蔗糖(sucrose)     

多种益生菌固态湿发酵豆粕营养品质变化研究

为探究不同益生菌固态湿发酵对豆粕营养品质的影响，选择地衣芽孢杆菌（Bac-l）、凝结芽孢杆菌（Bac-c）、罗伊氏乳杆菌(Lac)、米曲霉(Asp)、酿酒酵母(Sac)、沼泽红假单胞菌(Pho) 6种益生菌，固态发酵48 h，以粗蛋白、酸溶蛋白、蛋白酶、抗营养因子等为指标，从发酵豆粕营养指标、酶活性、抗营养因子含量等方面进行评定。结果表明：沼泽红假单胞菌发酵豆粕粗蛋白含量增加至31.55%(P<0.05)；酿酒酵母和沼泽红假单胞菌发酵豆粕后酸溶蛋白含量提升至12.98%(P<0.05)；罗伊氏乳杆菌能够有效降低pH(P<0.05)，提高干物质回收率达到94%(P<0.05)；发酵豆粕时，沼泽红假单胞菌的酸性蛋白酶活性最高，酿酒酵母的中性蛋白酶活性最高，地衣芽孢杆菌的碱性蛋白酶活性最高（P<0.05），酿酒酵母的植酸酶和纤维素酶活性最优；米曲霉分解大分子蛋白质的能力最强，对3种抗营养因子（大豆球蛋白、β-伴大豆球蛋白、胰蛋白酶抑制因子）的降解率也最高，分别达到64.71%、78.94%和98.07%(P<0.05)。说明益生菌发酵可以改善豆粕营养品质，...     

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