不同粉碎粒度对大豆分离蛋白(SPI)及棉粕分离蛋白(CPI)提取率的影响

采用传统的碱溶酸沉法提取了大豆粕及棉籽粕中大豆分离蛋白(SPI)及棉粕分离蛋白(CPI),并分别测定了棉籽粕,60目棉粕分离蛋白和80目棉粕分离蛋白中游离棉酚的含量,结果显示,60目及80目大豆粕中大豆分离蛋白的提取率分别为39.82%和44.95%(P<0.05),粗蛋白含量分别为81.07%和71.35%;60目及80目棉籽粕中棉粕分离蛋白的提取率分别为23.22%和35.39%(P<0.05),粗蛋白含量分别为76.03%和82.44%;棉籽粕、60目棉粕分离蛋白及80目棉粕分离蛋白中游离棉酚的含量分别为2182.54、522.79和503.87mg/kg(P<0.01)。综上所述,不同的粉碎粒度对大豆分离蛋白和棉粕分离蛋白的提取率有显著的影响,碱溶酸沉法显著降低了棉粕分离蛋白中游离棉酚的含量。     

不同处理对大豆浓缩蛋白（SPC）粗蛋白含量及提取率的影响

分别用超声波处理不同粉碎粒度的高温脱脂豆粕,然后采用醇法浸提工艺提取其中的大豆浓缩蛋白（SPC）。结果显示：40目、60目及80目豆粕提取的大豆浓缩蛋白中粗蛋白含量分别为51．85％、55．50％和54．32％（P〈0．05）。提取率分别为97．65％、97．51％和95．80％（P〈0．05）;超声波处理之后提取的大豆浓缩蛋白中粗蛋白含量分别为55．44％、55．11％和58．77％（P〈0．05）,提取率分别为97．50％、96．78％和95．65％（P〈0．05）。不同的粉碎粒度对大豆浓缩蛋白中粗蛋白的含量及提取率有显著影响,粒度越小,粗蛋白含量越高,提取率越低;在相同的粉碎粒度下,超声波处理能提高大豆浓缩蛋白中粗蛋白的含量,但是对其提取率无显著影响。     

棉籽粕脱毒方法的研究进展

我国年产棉籽粕600万t,其中新疆地区是棉籽粕主产地,占总产量60%以上,资源丰富且蛋白质含量较高,棉籽蛋白的生物效价与豆类蛋白相近,是畜牧业、水产业中物美价廉的蛋白来源,且棉籽糖也是优质的食用功能性糖类,但棉酚的存在在很大程度上限制了棉籽粕的利用,因为动物食用过量棉酚物质后,会出现中毒症状.20世纪80年代,国内棉花主产区棉籽浸出粕抽样检测游离棉酚518 mg/kg,20世纪90年代在新疆建设兵团主产棉区所测样品中游离棉酚平均含量为608 mg/kg;2001年棉粕中游离棉酚含量为760 mg/kg;2009年,王安平收集的中国5个不同主产区棉粕样品游离棉酚平均含量为1021 mg/kg.主要原因是随着油脂提取工艺的改进,降低了棉油中FG含量,将更多棉酚保留于棉粕副产物中,因而棉粕中棉酚含量呈上升趋势.因此进一步研究我国棉籽蛋白的营养价值及棉酚特性,开发具有经济效益的棉酚降解技术,对于促进棉籽粕及棉籽蛋白的合理利用具有重要意义.     

一例犊牛棉籽饼粕饲料中毒的分析研究

棉籽饼粕是一种富合营养物质的蛋白质饲料,含蛋白质40％以上,赖氨酸1．59％,蛋氨酸0．52％,可作为一种蛋白质资源用于动物饲料中,在一定程度上弥补了蛋白资源的不足,但是由于棉籽饼粕中含有大量的游离棉酚,棉酚有一定的毒性,就限制了它的有效利用。笔者为了确定安阳某奶牛养殖场的14头病牛的中毒原因,对该养殖场的饲料、棉籽饼1、棉籽饼2、棉籽4种待测饲料样品中的游离棉酚和钙的含量进行了检测,结果显示：其中游离棉酚的含量分别为2223．9mg／kg、2224．9mg／kg、2223．8mg／kg、2368．0mg／kg,远远超过了《中华人民共和国饲料卫生标准》中规定的允许含量1200mg／kg,且饲料样品中的钙含量均较低〈0．01％,通过综合分析确定：安阳某奶牛场的14头中毒病牛为棉籽饼粕饲料中毒。     

棉籽蛋白营养价值及其在仔猪饲粮中的应用前景北大核心CSCD

我国大豆每年进口量1亿t左右,其中约90%用于畜牧业,大豆高度依赖进口严重制约着我国畜牧业可持续发展,寻求高效的大豆替代饲料原料是降低大豆进口依存度的有效手段之一。棉籽饼粕是世界上除大豆粕和菜籽粕外第三大贸易类蛋白质饲料原料,棉籽饼粕中游离棉酚含量较高和氨基酸组成不平衡是限制其应用的主要因素。提升棉籽加工副产品的营养价值对于实现大豆蛋白的高效替代具有十分重要的意义。随着棉籽加工工艺的发展,采用脱糖法和脱毒法萃取棉酚和棉子糖生产棉籽蛋白的技术逐渐成熟。棉籽蛋白的粗蛋白质含量高于50%,且具有氨基酸平衡好、营养价值高和适口性好等优点。本文通过综述棉籽蛋白营养成分及其在加工过程中产生的棉子糖和小肽等功能性物质,探讨了棉籽蛋白在仔猪饲粮中应用潜力,旨在为提高仔猪生产中棉籽蛋白利用效率和降低我国大豆进口量提供参考。     

固体联合发酵对棉粕发酵产物富肽蛋白产量及脱毒效果的影响

利用枯草芽孢菌（Bacillus subtilis NDX6）和植物乳杆菌（Lactobacillus plantarum BLLP）对棉粕、豆粕不同比例混合样品进行有氧和无氧联合发酵试验,并用纯棉粕进行联合发酵生长曲线研究,探讨固体联合发酵对棉粕发酵产物中富肽蛋白含量及脱毒效果的影响.结果表明,6个配方中纯棉粕发酵降解有毒物质游离棉酚含量最高约81％,游离氨基酸及小肽的含量提高约6.5倍（P＜0.05）,饲料pH由原来的6.20以上降低到5.12以下,有益菌活菌数提高约10倍;纯棉籽粕有氧发酵时间为38 h,无氧发酵时间60～66 h,游离氨基酸含量提高约7.54倍,游离棉酚降低约89％.用棉粕固体联合发酵可以脱毒,降解蛋白提高饲料吸收利用率.     

脱酚棉籽蛋白及其在奶牛中的应用

脱酚棉籽蛋白是采用北京中棉紫光生物科技有限公司专利技术（ZL00134520．6）生产的一种新型的优质饲用蛋白，它是棉籽经过去油、脱酚等新工艺加工而成的一种金黄色粉末状蛋白质饲料。与普通棉粕相比，脱酚棉籽蛋白的粗蛋白含量高，氨基酸含量丰富，结构平衡，游离棉酚含量低，营养价值较高。用“奶牛专用脱酚棉籽蛋白”分别在新疆、北京、天津、宁夏等地进行大面积奶牛饲喂试验，试验组奶牛产奶量明显提高，同时改善了奶牛体质，降低了发病率，经济效益十分明显。由于其来源广泛，以及与豆粕的相对性价比，可长期作为奶牛精饲料中稳定的组分之一而固定下来。现在北京三元、内蒙古伊利以及宁夏、天津、新疆等地的奶牛养殖企业正在推广使用这种棉籽蛋白产品。     

脱酚棉籽蛋白（植物萃取物）

脱酚棉籽蛋白是一种新型的优质饲料蛋白。脱酚棉籽蛋白蛋白质含量在50％以上,游离棉酚含量小于400毫克／千克。且其氨基酸组成与理想蛋白平衡模式接近。通过大量饲养试验和生产应用证明。棉籽蛋白可替代豆粕,玉米蛋白粉、鱼粉等动、植物蛋白。广泛应用于牛,鸡、猪和鱼等畜禽及水产饲料的生产之中。     

棉籽蛋白如何脱毒

<正> 我国年产棉仁饼粕五十多亿斤,含粗蛋白二十多亿斤,是一项重要的植物蛋白资源。普通棉籽中含棉酚1.6～2.8％,游离状态的棉酚对单胃动物有毒性。因此,要使棉籽蛋白充分发挥利用价值,必须消除棉籽中的棉酚毒素。解决的途径:一是培育不含棉酚(或含量极少)的“无毒棉”;二是从棉籽加工工艺方面采取消除或降低棉酚毒素的措施,使其含量降低到适于食用或饲用的安全标准以下。对含有棉酚的普通棉饼,除可以直接限量     

脱酚棉籽蛋白的营养特性及应用

1加工工艺及特点脱酚棉籽蛋白是一种新型优质饲用蛋白。普通棉粕含有较多的游离棉酚,其不仅降低了日粮中赖氨酸的利用率,同时对畜禽的毒害主要表现为影响造血功能,造成贫血致使动物生长受阻,同时还影响动物的繁殖机能,造成动物不育。脱酚棉籽蛋白的游离棉酚含量通常在400mgkg以     

Beta2-agonists and cAMP inhibit protein degradation in isolated chick (Gallus domesticus) skeletal muscle

1. The role of beta2-agonist and of cAMP in chick skeletal muscle proteolytic pathways and protein synthesis was investigated using an in vitro preparation that maintains tissue glycogen stores and metabolic activity for several hours. 2. In extensor digitorum longus (EDL) muscle total proteolysis decreased by 15 to 20% in the presence of equimolar concentrations of epinephrine, clenbuterol, a selective hbetaagonist, or dibutyryl-cAMP. Rates of protein synthesis were not altered by clenbuterol or dibutyryl-cAMP. 3. The decrease in the rate of total protein degradation induced by 10(-5)M clenbuterol was paralleled by a 44% reduction in Ca2+-dependent proteolysis, which was prevented by 10(-5)M ICI 118.551, a selective fbeta2antagonist. 4. No change was observed in the activity of the lysosomal, ATP-dependent, and ATP-independent proteolytic systems. Ca2+-dependent proteolytic activity was also reduced by 58% in the presence of 10(-4)M dibutyryl-cAMP or isobutylmethylxanthine. 5. The data suggest that catecholamines exert an inhibitory control of Ca2+-dependent proteolysis in chick skeletal muscle, probably mediated by fbeta2adrenoceptors, with the participation of a cAMP-dependent pathway.     

Distribution of capsular types and production of muramidase-released protein (MRP) and extracellular factor (EF) of Streptococcus suis strains isolated from diseased pigs in seven European countries

Streptococcus suis strains (n=411), isolated from diseased pigs in seven European countries were serotyped using specific antisera against serotype 1 to 28, and were phenotyped on the basis of their muramidase-released-protein (MRP) and extracellular-factor protein (EF) production. Overall, S. suis serotype 2 appeared to be most prevalent (32%), followed by serotype 9 (20%) and serotype 1 (12%). Serotype 2 was most frequently isolated in France, Italy and Spain, whereas serotype 9 was most frequently isolated in Belgium, The Netherlands and Germany. In the United Kingdom serotypes 1 and 14 were most frequently isolated. High percentages of S. suis serotype 1, 2, 1/2 and 14 strains, isolated from tissues associated with S. suis infections such as brain, serosa, joint, heart and organs expressed the EF-protein, indicating that in these serotypes expression of EF is likely to be associated with virulence. In contrast, strains belonging to serotype 7 and 9, isolated from tissues associated with S. suis infections did not produce EF. These results strongly suggest that in the serotypes 7 and 9 EF expression is not related to virulence. More than 80% of the S. suis serotype 9 strains produced an MRP* protein, a high molecular variant of the 136kDa MRP. Expression of MRP* in serotype 9 strains is possibly associated with virulence.     

Comparative sequence analysis of major envelope protein gene (B2L) of Indian orf viruses isolated from sheep and goats

Orf virus (ORFV), the type species of Parapoxvirus, is responsible for contagious ecthyma in sheep and goats. In the present report, sequence analysis of major envelope gene (B2L) of four Indian orf virus isolates originating two each from sheep and goats was carried out. These recent isolates belonged to different outbreaks that occurred in Kumaon hills and adjoining plains during 2004-2005. Preliminary screening of the scab samples was carried out by diagnostic PCR. Full-length B2L gene encoding for immunogenic major envelope protein from all the four ORFV isolates was amplified by PCR and the amplicons (1206 bp) were cloned and sequenced. Comparative sequence analysis revealed an open reading frame of 1137 nucleotides (nt) encoding a polypeptide of 378 amino acids (aa). Indian isolates were highly related amongst themselves with sequence identity of over 97% at the nt and aa level. Further, they showed 97-98% sequence identity with sequences of other ORFV isolates from around the world; while 94-95 and 82.7-83.8% sequence identity was observed, respectively, with pseudocowpox and bovine papular stomatitis viruses--the other members of the genus. Phylogenetic analysis also showed that these Parapoxviruses from sheep and goats are closely related to other orf viruses reported worldwide.     

Characterization of Streptococcus equi subsp. ruminatorum isolated from spotted hyenas (Crocuta crocuta) and plains zebras (Equus burchelli), and identification of a M-like protein (SrM) encoding gene

Thirteen strains of Streptococcus equi subsp. ruminatorum from free-ranging spotted hyenas (Crocuta crocuta) and plains zebras (Equus burchelli) in Tanzania were characterized by biochemical and molecular-biological methods. Although the colony appearance of the S.e. ruminatorum wildlife strains differed from that of the S.e. ruminatorum type strain CECT 5772(T), all biochemical reactions of the wildlife strains were similar to those of the type strain. In addition, all wildlife strains produced hyaluronidase and were capable of hydrolysing arginine, three strains (23%) synthesized acetoin, but only eight strains (62%) produced acid from ribose. rep-PCR indicated that different clones of S.e. ruminatorum were distributed among the hyena and zebra populations in the study area. Identical rep-PCR patterns in hyena and zebra strains suggest that a direct transmission of S.e. ruminatorum between these species may occur. The presence of a M-like protein (SrM) gene was demonstrated in all S.e. ruminatorum strains including the type strain. Sequencing of the M-like protein gene revealed a hypervariable region within the deduced amino acid sequence. Most of the strains clustered with previously described strains based on the hypervariable region of the S.e. zooepidemicus SzP protein. Sequencing also demonstrated that identical SrM protein sequences were shared among S.e. ruminatorum strains from different host species.     

Substitution of milk protein with isolated soy protein in calf milk replacers

The influence of replacement of milk protein by isolated soy protein on digestion and pancreatic enzyme secretion was determined in nine Holstein male calves. Calves (average weight 47 kg) were fitted with permanent re-entrant pancreatic and a T-type cannula in the distal ileum at 6 to 10 d of age. Following a 2-wk recuperation period, the calves were fed three milk replacers in a triplicated 3 x 3 latin square. Experimental diets consisted of a control, in which 100% of the CP originated from spray-dried skim milk powder (SM), and the test diets, in which 50% (SM/ISP) or 100% (ISP) of the skim milk protein was replaced by isolated soy protein. Each experimental period lasted 2 wk. Replacement of SM protein by ISP decreased (P less than .05) the digestibilities of protein and most amino acids. Ileal digestibilities of total indispensable amino acids for SM, SM/ISP and ISP diets were 82.1, 75.8 and 61.8%, respectively, and total tract digestibilities of total indispensable amino acids were 90.0, 82.6 and 74.0%, respectively. Including ISP did not affect (P greater than .05) the volume of secretion of pancreatic juice, protein or chymotrypsin; however, the secretion of trypsin decreased (P less than .05). Reduction in trypsin secretion may be responsible, in part, for the lower amino acid digestibilities in milk replacers containing isolated soy protein.     

Comparison of glycoprotein B (gB) variants of the elephant endotheliotropic herpesvirus (EEHV) isolated from Asian elephants (Elephas maximus)

The recently described elephant endotheliotropic herpesviruses (EEHV) have been associated with the deaths of numerous captive elephants. A proposed tool for the detection of EEHV infection in elephants is the PCR-based screening for EEHV-DNA in whole blood samples. Unfortunately, this detection method has only been successful in post-mortem analyses or in animals already displaying clinical signs of EEHV disease, thus rendering this method unsuitable for identification of carrier elephants. Here, we focus on glycoprotein B (gB) for serologic assay development, since gB is an envelope protein known to induce a neutralising antibody response in other herpesvirus infections. We sequenced the entire gB gene from five Asian elephants with EEHV, representing four different gB variants. Computer-aided methods were used to predict functionally important regions within EEHVgB. An extra-cytoplasmic region of 153 amino acids was predicted to be under positive selection and may potentially contain antigenic determinants that will be useful for future serologic assay development.     

猪轮状病毒中国分离株JL94 VP7基因的克隆与序列分析

用MA104细胞培养增殖了轮状病毒地方分离株JL94,利用一对根据Genebank中已发表的轮状病毒VP7基因cDNA序列而设计并合成的引物，通过反转录-聚合酶链反应(RT—PCR)从JL94毒株扩增出VP7基因全长cDNA。将其插人pMD18-T载体中，构建了重组质粒pMD18-T—JL94／VP7，并对其进行了Hind Ⅲ，HindⅡ和BamH I的单、双酶切初步鉴定及其核苷酸序列测定，证明克隆的pMD18-T—JL94／VP7为轮状病毒的VP7基因。通过核苷酸序列比较，JL94／VP7与A群猪轮状病毒C134／VP7、OSU／VP7、ICB2185／VP7、YM／VP7核苷酸序列同源性分别为87％、99％、74％和83％。     

反刍动物蛋白质的营养及研究进展(续)

4　反刍动物氨基酸的营养与研究进展4 .1　反刍动物氨基酸的代谢氨基酸是组成蛋白质的基本单位 ,从很大程度上说 ,蛋白质的营养就是氨基酸的营养 ,对于反刍动物来说也不例外。反刍动物体内氮的来源有 4个途径 ,即通过瘤胃壁吸收的氮、小肠吸收的瘤胃微生物氮、瘤胃非降解蛋白质