水解羽毛粉与蒸制羽毛粉营养价值的比较研究

用饲养试验与氨基酸真可消化率测定相结合研究水解羽毛粉和蒸制羽毛粉对蛋鸡的饲养效果。结果表明:水解羽毛粉的TAAD为77.58%,蒸制羽毛粉的TAAD为71.84%,二者差异显著;以2%～4%的水解羽毛粉或2%蒸制羽毛粉等氮取代蛋鸡日粮中的豆粕,并维持适宜的赖氨酸、蛋氨酸水平,可提高蛋鸡生产水平,降低饲料成本2.21%～2.58%。     

水解羽毛粉加工技术的研究进展

水解羽毛粉加工技术的研究进展中国农业科学院饲料所沈银书，霍启光经估算，我国每年有近２８万吨的羽毛及其下脚料，这是相当可观的蛋白质饲料资源。目前国内已有不少小型生产厂家将这一资源加工成饲用羽毛粉产品，但由于多数厂家加工条件简陋，产品质量得不到可靠的保证...     

膨化羽毛粉在鸡日粮中的应用

膨化羽毛粉是利用家禽羽毛通过膨化机膨化后粉碎而成，粗蛋白含量在82％左右，含有多种易消化吸收的氧基酸。     

羽毛粉蛋白饲料的开发利用

禽类羽毛主要由角蛋白质构成，因其本身受氨基酸不平衡的影响，人们经常认为畜禽对其消化率低。其实羽毛蛋白并不低于一般的蛋白饲料，尤其是鱼粉。实践证明：只要经过特殊的加工工艺，再合理搭配饲料原料（肉骨粉、血粉等）是可以取得良好效果的。羽毛蛋白饲料属营养类蛋白质饲料，主要用于动物的日粮配合，补充蛋白质饲料的不足，替代鱼粉，克服鱼粉含盐量高、脱脂率低的弊端。具有提高毛皮质量、维持畜禽毛被正常生长、促进畜禽生长发育的功能，并有增进禽肝功能的作用。对严重啄羽、啄肛、食毛等现象的家禽，长期使用能够防止此类癖症的…     

用微生物改善羽毛粉的营养价值

在美国由肉鸡和火鸡加工业产生的羽毛每年约80万吨,由于羽毛体积大,处理成本较高,因而寻找利用羽毛的方法显得十分重要。然而由于羽毛的化学成分主要是角蛋白,单胃动物对这种蛋白的消化很有限,因此,羽毛粉在添加到动物日粮中之前必须水解,为使羽毛蛋白暴露于消化酶之中,水解解开角蛋白分子中的化学键是必需的。羽毛粉通常用蒸汽和压力水解,以增加其营养成分的利用率,水解设施和能源开支会增加羽毛粉的价格,同时有些养分有可能在水解过程中被破坏。Steineretal(1983)发现用氢氧化钠     

高压处理羽毛粉适宜时间的探讨

禽类加工业中一种廉价的下脚料——羽毛粉的角朊蛋白含量一般在85%以上,但极难被家畜消化吸收,需通过处理使角朊蛋白分解成(月示)、胨、肽和氨基酸.借助酸、碱、酶及其它物质的综合作用可以达到这一目的.但有许多不足之处,如长时间水解使氨基酸遭受破坏,且成品中常有脂肪残余,使之带有难闻的气味,影响适口性,用碱、酸水解后,中和生成大量的盐,使产品易吸湿变质,添加这种产品往往使日粮含盐量过高,产生不良后果.为此,本研究欲采用高压处理法,在适宜的高温高压下,探讨不同处理时间对羽毛粉的粗蛋白质含量及其体外消化率、和氨基酸含量的影响,为寻找合理的加工工艺提供依据.     

羽毛粉的加工利用

羽毛粉以其高蛋白具有很大的潜力。据统计,我国每年可收集利用的羽毛下脚料约20万～30万吨,而加工后用于饲料的不足2万吨,且有下降的趋势。大部分羽毛未被合理利用,不仅是巨大的资源浪费,而且污染环境。其原因是羽毛粉加工技术不过关,加工成本太高,产品消化吸收率低,质量参差不齐,饲养效果不佳。因此,若能采用合理的加工技术,提高其产品质量,为市场提供合格的饲用羽毛粉,对养殖业将是一个巨大的贡献。     

水解羽毛粉替代豆粕饲喂生长猪的效果研究

选用20kg左右的DLY生长猪64头,随机分为4个处理,每个处理4个重复,每个重复4头,分别饲喂基础日粮、添加2%、4%、6%水解羽毛粉（等蛋白替代豆粕）的日粮。结果表明,随着试验日粮中水解羽毛粉添加量的提高,试验猪的日采食量和日增重降低,而料肉比上升,并且6%处理组差异达到显著（P〈0.05）;各处理组的干物质表观消化率、蛋白质表观消化率和有机物表观消化率均差异不显著（P〉0.05）,而氮的表观生物学价值和净蛋白利用率随着水解羽毛粉添加量的提高明显降低,并且6%处理组的净蛋白利用率显著低于对照组（P〈0.05）和2%处理组（P〈0.05）;2%处理组的单位增重饲料成本较对照组降低0.20元/kg。     

饲用羽毛肽粉营养成分分析

采用国标及通用的方法,对饲用羽毛肽粉中各营养成分进行分析,并与其它饲料蛋白源进行比较。结果表明,饲用羽毛肽粉粗蛋白、粗脂肪、糖分和粗灰分、盐分含量分别为85.05%、7.9%、1%7、.76%、0.9%。饲用羽毛肽粉含有18种氨基酸,总氨基酸、必需氨基酸和呈味氨基酸分别占总量的70.47%、27.78%、38.70%,总氨基酸占蛋白质的82.86%,必需氨基酸和呈味氨基酸分别占氨基酸总量的39.42%和54.92%。饲用羽毛肽粉作为鱼粉替代品的限制性氨基酸为赖氨酸(Lys)、组氨酸(His)、色氨酸(Trp)、蛋氨酸+胱氨酸(Met+Cys)。饲用羽毛肽粉含14种脂肪酸,不饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸、ω-3不饱和脂肪酸分别占脂肪酸总量的25%、15%、10%、2%,EPA占脂肪酸含量的2%,未发现含有DHA。饲用羽毛肽粉含有丰富的营养成分,但其作为水产动物饲料蛋白源在氨基酸平衡及不饱和脂肪酸含量较鱼粉差,可通过调整营养配方,改善其应用价值。     

Functional role of type VI collagen during early feather development of the chicken embryo in vitro

The regulatory function of type VI collagen during early feather development in embryonic chickens was investigated at the cellular and organ levels. Immunohistochemical studies of embryonic chicken skin showed that type VI collagen was distributed in spatial‐specific and temporal‐specific manners related to early feather development. To clarify the role of type VI collagen, we studied the feather development in intact, reconstituted and reconstituted gel skin cultures. When ethyl‐3,4‐dihydroxybenzoate (EDHB) was added to the medium of intact skin as an inhibitor of type VI collagen synthesis, the feather buds did not elongate and the number of neural cell adhesion molecule (NCAM)‐positive cells was reduced. However, the magnitudes of both suppressive effects of EDHB were reduced by the addition of liquid type VI collagen. Similar improvement was also observed in the reconstituted skin with liquid type VI collagen and in the reconstituted gel skin with solid type VI collagen at a low concentration. Moreover, type VI collagen promoted feather bud development in the absence of EDHB. However, a high concentration of solid type VI collagen in the reconstituted gel skin arrested the feather bud elongation, and antitype VI collagen antibodies caused feather buds to become longer and smaller in the reconstituted skin. At the cellular level, type VI collagen affected the proliferation, migration and NCAM expression of mesenchymal cells. These results suggest that type VI collagen regulates early feather development by controlling mesenchymal cell behavior.     

感染MDV鸡羽髓组织中CyP、LASP1和PCBP1蛋白的表达分析

本实验室前期的蛋白质组学研究显示,鸡羽髓组织中亲环素蛋白(CyP)、LIM和SH3蛋白1(LASP1)和多聚胞嘧啶结合蛋白1(PCBP1)3种蛋白为马立克氏病病毒(MDV)感染过程中差异表达蛋白。为进一步检测这3种蛋白在病毒感染过程中的表达水平,本研究以MDV GA强毒株感染SPF鸡,应用荧光定量PCR和westernblot检测病毒感染14 d和21 d后这3种蛋白在羽髓组织中的表达水平。检测结果表明,病毒感染14 d后,羽髓组织中这3种蛋白的mRNA和蛋白表达水平均有不同程度的下调,其中LASP1 mRNA和PCBP1蛋白分别下调62%和48%(p<0.05);在21 d,除CyP蛋白表达基本不变外,其他mRNA和蛋白均不同程度下调,其中LASP1蛋白下调达到46%(p<0.05)。结果表明在两个不同的MDV感染时期,MDV均可以不同程度的抑制羽髓组织中这3种蛋白的表达,本研究为进一步阐释MDV与羽髓组织的相互作用机理提供有价值的参考。     

A gene co‐expression network analysis of the candidate genes and molecular pathways associated with feather follicle traits of chicken skin

Back and thigh skin of chickens showed significant differences in the thickness and the feather follicle density and size, which are important traits for slaughtered chickens' appearance. In the present study, global gene expression profiling was conducted in the back and thigh skin of chickens using Microarray technology. The results showed that 676 genes were differentially expressed between back and thigh skin. The expression of the differentially expressed genes (DEGs), including PPP1R3C, IGF1, PTCHD1, HOXB6, FGF9, CAMK4, SHH, BMP8B, FOXN1 and PTGER2, was validated by real‐time quantitative polymerase chain reaction (RT‐qPCR), and the results were consistent with microarray results. Functional analysis revealed that the DEGs were significantly involved in cell proliferation, differentiation, apoptosis, adhesion and transport process, and the pathways were significantly mapped into the ECM‐receptor interaction, peroxisome, focal adhesion, Hedgehog and PPAR signalling pathways. Protein–protein interaction network analysis suggested that signalling pathways related to feathers morphogenesis and development, such as Wnt, FGF, MAPK, SHH and BMP signalling pathways, occupied important positions in the network. Genes involved in these signalling pathways and adhesion molecules might play a vital role in skin and feather follicle development. Further single nucleotide polymorphism (SNP) association analysis of Wnt3A showed that the AC genotype of SNP g.255361 C>A significantly increased the feather follicle density of thigh skin. Our findings may provide new insights on candidate genes and pathways related to skin and feather follicle formation of chickens.     

Properties of alkaline‐hydrolyzed waterfowl feather keratin

The properties of hydrolyzed feather keratin (HFK) were compared to those of hydrolyzed wool keratin (HWK) with the aim of developing better ways to utilize feather keratin waste. Amino acid analysis showed that HFK contained more hydrophobic amino acids did than HWK. Although gel permeation chromatography indicated that HFK and HWK had more low‐molecular weight peptides than their intact sources, Fourier transform infrared spectroscopy indicated that both hydrolyzed keratins retained their original secondary structure. The physical properties of HFK were evaluated by treating HFK to human hair fibers. HFK treatment enhanced significantly the surface hydrophobicity and strength of fibers, and HFK was more permeable into hair fibers. These results suggest that HFK is suitable for industrial applications to improve fibers. In addition, HFK may be suitable for raw material of products requiring both flexibility and hydrophobicity, such as films and biodegradable plastics.     

氨基酸对水禽羽毛发育的影响

羽毛是水禽重要的外貌特征,其形态发生、结构组成及换羽模式等与羽毛品质高度相关。随着水禽出栏日龄的不断缩短,水禽羽毛的早期发育和及时成熟显得尤为重要,试验研究表明,含硫氨基酸和支链氨基酸缺乏能够显著影响早期水禽羽毛的发育。     

酶解法制备饲用羽毛肽粉

本研究以普通市售羽毛粉为原料,通过正交试验设计,分别研究胰蛋白酶、木瓜蛋白酶、菠萝蛋白酶降解制备饲用羽毛肽粉的条件。综合分析实验结果,建立了3种混合酶降解制备饲用羽毛肽粉的最优工艺:在温度55℃,pH 8,混合酶浓度1/50 g/mL条件下反应24 h,终产品中小分子蛋白含量较无酶组约提高了200%。     

羽毛蛋白饲料添加剂的制备工艺研究

实验以鸡羽毛为原料采用化学水解法制备动物饲料添加剂可溶性羽毛蛋白水解物,通过L93(4)正交实验设计以羽毛溶解率为考察指标,确定羽毛蛋白饲料添加剂的最佳制备工艺条件:Ca(OH)2为羽毛质量的13%、固液比1:9、反应温度126℃和反应时间180min。羽毛蛋白水解物的粗蛋白质含量84.70%、胃蛋白酶消化率为90.60%和粗灰分含量11.01%。     

Performance and Egg Characteristics of Laying Hens Fed Diets Incorporated with Poultry By-Product and Feather Meals

The effects of poultry by-product meal (PBPM) and feather meal (FM) incorporated separately and in combination in the diet on laying hen performance and egg characteristics during postpeak production were determined. Bovans White strain laying hens, 42 wk of age, were fed diets with 0% PBPM and FM, 5% FM, 5% PBPM, or 4% FM + 4% PBPM. Egg production, feed intake, and egg mass were not significantly affected by dietary treatments, whereas egg weight and feed conversion ratio (FCR) were significantly affected. Egg weights of hens receiving 4% FM + 4% PBPM were significantly lower than those fed the control diet, whereas those fed 5% FM or 5% PBPM were intermediate. FCR was significantly improved by the diets containing 5% FM or 5% PBPM compared with the diet containing 4% FM + 4% PBPM. Dietary PBPM decreased Haugh units, but FM did not. Egg breaking strength, shell weight, and weights of albumen and yolk were not affected by treatments. The results suggested that FM or PBPM could be incorporated up to 5% singly or up to 8% in combination in layer diets but with possible detrimental effects on Haugh units, egg weight, and FCR.