嗜麦芽窄食单胞菌YJ-1角蛋白酶底物特性及酶活测定方法研究

从羽毛加工厂污泥中分离到一株嗜麦芽窄食单胞菌(Stenotrophomonas maltophilia)YHYJ-1,对羽毛、羊毛和毛发底物均具有降解作用。菌株YHYJ-1对不同底物的降解能力存在差异,培养36 h羽毛完全降解,羊毛降解时间是72 h,毛发则在84 h有部分降解作用。分别以可溶性羽毛角蛋白、羽毛粉和偶氮角蛋白为底物进行酶活测定,以最高酶活值设定为100%,3种底物的相对酶活分别为100%、65.1%和23.2%,表明菌株YHYJ-1角蛋白酶的最适底物为可溶性角蛋白。菌株YHYJ-1接种于羽毛粉培养基,培养20 h后角蛋白酶活性急剧升高,28 h酶活达最大值,之后快速下降。     

5种禽类羽毛的氨基酸组分和含量分析

本文研究５种禽类羽毛氨基酸组分和含量分析的差异．新浦东鸡的副羽含量最高达９０．１％；居古拉火鸡最低在７１％。１４种羽毛的氨基酸平均含量为８０％。从氨基酸组分看，丝氨酸，谷氨酸和亮氨酸较高。而赖氨酸，组氨酸和甲硫氨酸均较低，这与已发表的文献一致［３］。     

羽毛粉的氨基酸真消化率及其与体外理化指标间相关性的研究

依据蒸汽压力（３００dＰa、４００kＰa和５００kＰa七蒸煮时间（３０min、６０min和９０min）设置９个组合,将白色肉仔鸡鸡毛制成９种羽毛粉。对这些羽毛制成９种羽毛粉。 对这些羽毛粉进行容重（ＢＤ）、蛋白质胃蛋白酶消化率（ＰＤＰ）、氨基酸真消化率（ＴＡＡＤ）等指标的测定。结果表明,不同加工参数对羽毛粉的ＴＡＡＤ测值有显著的影响。在本试验的设备条件下,羽毛粉适宜的加工参数为３０min/４００dＰa。经回归分析表明,     

HVT免疫鸡羽毛根中病毒抗原的检测

１日龄非免疫鸡,ＨＶＴ常规剂量免疫后,于第３周起,每周采集一次羽毛根,分别作常规ＭＤＶ琼扩抗原的检测,结果显示：在免疫后第３～８周检测,均未观察到特异性ＡＧＰ沉淀线;若取较多数量的富含羽髓的羽毛根,经２ｍｌ磷酸缓冲液（ＰＢＳ）浸提、浓缩胶浓缩约４０倍后,再作上述检测,则分别于免疫接种后的第３～５周都有特异性的ＡＧＰ沉淀线出现,且与感染细胞上清中浓缩的ＨＶＴ及ＭＤＶ琼扩抗原所形成的沉淀线基本吻合,而第６周检测时,仅与ＨＶＴ阳性血清呈微弱阳性,用同样方法对免疫后第６周后的检测结果均表明为阴性。由此推断,免疫鸡羽毛根中含有较低水平的、并与致病性ＭＤＶ抗原具有交叉反应性的ＨＶＴ琼扩抗原,但采用常规ＡＧＰ法不能直接检测到。     

白介素21在42日龄中国黄羽鹌鹑盲肠扁桃体中的定位

为探明白介素21(IL-21)在鹌鹑机体免疫调节的作用机制,观察IL-21的分布特点,取42日龄中国黄羽鹌鹑盲肠扁桃体,运用免疫组织化学法对白介素21进行组织学定位,观察阳性细胞的形态及分布情况。结果显示,IL-21阳性反应细胞多呈圆形或椭圆形,少数呈梭形,有的呈团块状,阳性反应细胞主要分布于黏膜上皮下固有层中,少数位于肠腺周围,生发中心周围也有少量阳性细胞分布。证实IL-21在鹌鹑盲肠扁桃体中广泛存在,分布数量及反应强度与局部免疫细胞及机体免疫状态有关。     

角蛋白酶的研究现状及发展前景

综述了角蛋白酶在基因工程和生理生化性质方面的研究,介绍了角蛋白酶的具体应用领域。     

High dietary incorporation levels of rendered animal protein ingredients on performance of rainbow trout Oncorhynchus mykiss (Walbaum, 1972)

Two growth trials were conducted using spray-dried blood meal (BM), feather meal (FEM), meat and bone meal (MBM) and poultry by-product meal (PBM) as major protein sources in the diet of rainbow trout. In the first trial, five diets were formulated to examine the nutritive value of spray-dried BM and PBM. Increasing levels of BM (6, 12%) or PBM (10, 20, and 30%) replaced fish meal and corn gluten meal in the diet. For the second trial, eight diets were formulated to contain the following combinations: FEM + MBM, FEM + PBM or MBM + PBM. The diets containing FEM + MBM and FEM + PBM were supplemented with either L-lysine or DL-methionine, the amino acids predicted to be the two most limiting in these diets. Each experimental diet was allocated to three tanks of fish and fed for 20 weeks in the first trial or 16 weeks in the second trial. All the experimental diets were readily consumed by the fish and high growth and good feed efficiency ratio (FER) were achieved for all diets. In the first trial, there were no significant differences (P > 0.05) in weight gain or FER of fish fed the five experimental diets, suggesting that BM and PBM had high nutritive values for rainbow trout. In the second trial, growth of the fish fed the diet containing the FEM + PBM combination was not statistically different from growth of fish fed the control diet. Growth of fish fed diets with FEM + MBM or PBM + MBM combinations were slightly lower than that of fish fed the control diet. Supplementation of diets with either L-lysine or DL-methionine had no effect on the performance of the fish. The results from this study show that feather meal, poultry by-product meal, blood meal and meat and bone meal have good potential for use in rainbow trout diets at high levels of incorporation.     

强化羽毛粉饲喂肉鸡试验

用强化羽毛粉取代肉鸡饲料配方中的鱼粉进行了肉鸡饲养试验。结果表明:膨化确是加工羽毛的有效方法,用一些天然蛋白质强化后的“强化羽毛粉”可以取代原配方中的鱼粉,其体重与对照无明显差异,达到了相同的经济效益,并且能减少鱼粉进口及环境污染。     

饲用羽毛肽粉与常规饲料蛋白源中肽的分子量分布比较

通过比较自主研发的饲用羽毛肽粉与常规饲料蛋白源鱼粉、羽毛粉、棉籽粕、脱酚棉籽粕、味精生产残渣、豆粕、寡肽鱼溶粉、菜籽粕中不同分子量肽的含量,评估饲用羽毛肽粉在水产养殖饲料中的应用前景。结果表明,不同饲料蛋白源肽分布差异明显,其中饲用羽毛肽粉除寡肽含量低于味精生产残渣外,其他各类肽含量显著高于其他饲料蛋白源。     

断喙对肉鸭啄羽及其生产性能的影响

选择200只1日龄樱桃谷肉鸭,随机分成试验和对照两组,每组100只。试验组于14日龄断喙,对照组正常饲养,观察肉鸭在饲养过程中啄羽情况,测量试验鸭增重、料肉比、死亡率等指标,结果表明肉鸭断喙能有效防止啄羽,提高生产性能,减少死亡率,试验组比对照组每只多增重175g,料肉比低0.3,死亡率降低6%,经济效益显著。