狸獭染色体型研究初报

采用秋水仙素－低渗－空气干燥法制作了狸獭的染色体标本，并对其染色体核型进行了初步的分析研究。结果表明，狸獭染色体除Ｙ为端着丝粒染色体外，其余均为中部或亚中部着丝粒染色体，２ｎ＝４２，无随体存在。     

利用狸獭小肠提取肝素

1 前言 人们养殖狸獭的最终目的是为了获得终产品—毛皮、肉等,并使之为人们所消费,人们对终产品的需求、消费反过来又可刺激狸獭养殖业的更大发展。这种养殖→终产品开发生产→产品消耗→促进养殖的模式是狸獭养殖业在我国健康发展的必由之路。因此,笔者认为狸獭屠宰取皮后的胴体及其内脏器官大有开发利用的价值。现将利用狸獭小肠粘膜提取肝素的试验总结如下。     

红烧狸獭肉罐头加工工艺

狸獭肉，肉质细嫩，营养价值很高，是制作肉制品很好的原料，但一直未被人们所重视。本文介绍了利用狸獭肉为原料制作红烧狸獭肉罐头的加工工艺，研究制定了各加工阶段的工艺参数，为广泛而充分地利用狸獭资源开辟了新的途径。     

狸獭养殖

(一)狸獭的生物学特性 狸獭又称海狸鼠、沼狸,属于啮齿目,硬毛鼠科,海狸鼠属动物。狸獭原产于南美洲的智利、阿根廷、巴西等国家。中国无野生狸獭,现国内所饲养的狸獭是从国外引进的原种繁殖的后代。     

草原红牛染色体核型与C带分析

采用外周血淋巴细胞短期培养及常规染色体标本制备技术,研究了草原红牛染色体核型及C显带,并着重分析了Y染色体的形态。结果表明:草原红牛二倍体细胞的染色体数目为2n=60,公牛为XY,母牛为XX,常染色体为端着丝粒染色体,X染色体为亚中部着丝粒染色体,Y染色体为中部着丝粒染色体。草原红牛C带带型特征与已报道的普通牛C带特征相一致:所有常染色体着丝粒区深染,常染色体臂和整个X染色体为浅染,Y染色体为半深染。     

泽蛙的染色体组型研究

本文用骨髓细胞制片法，分析了福建产泽蛙的染色体组型。其二倍体染色体数目为２６，臂数为肥，配成１３对，分为二个组：大型染色体组（ＮＯ１－５），小型染色体组（ＮＯ６－１３）。大型染色体组中除ＮＯ３为亚中部着丝粒染色体外，其余为中部着丝粒染色体；小型染色体组中ＮＯ６、７对的短臂上有明显次缢痕，除ＮＯ８、１１对为亚中部着丝粒染色体外，其余均为中部着丝粒染色体。福建产泽蛙中期分裂相中见有Ｂ染色体一条，其形态为端着丝粒染色体。通过福建产的泽蛙与安徽、广东、四川及日本和菲律宾等地区泽蛙染色体组型的比较，结果是差异明显，显示出泽蛙核型多样性。     

串叶松香草染色体核型分析

对串叶松香草根尖细胞进行染色体常规制片,并进行核型分析。结果表明,串叶松香草染色体数为2n=14,,核型公式为K（2n）=2x=14=4m＋6sm＋4st,其中中部着丝粒染色体（m）为2对,近中部着丝粒染色体（sm）为3对,近端部着丝粒染色体（st）为2对。核型类型为3B。     

狸獭的配种技术

１　发情狸獭的繁殖能力很强，幼龄狸獭到５～６月龄时性成熟，便可参加配种，同时不受季节限制，一年四季均可发情、交配，受胎、产仔。母狸獭每隔２５天左右为一个发情周期，如未受胎可反复发情，每次发情持续１～３天。母狸獭发情可从外阴门的变化来判定：没有发情的母狸獭外阴门紧闭。发情的母狸獭外阴门先肿胀，后潮红、隆起，而后张开外翻，并流有粘液性的分泌物。从表情上观察，表现不安，排尿次数增多，来回在舍内徘徊，愿接触雄性狸獭，当接近雄狸獭便排出一种恶臭的尿液。２　配种时间配种的时间应选择在凉爽的时间进行，最适宜是…     

狸獭的配种技术

１发情狸獭的繁殖能力很强，幼龄狸獭到５－６个月龄时性成熟，便可参加配种，同时不受季节限制，一年四季均可发情、交配，受胎、产仔。母狸獭每隔２５天左右为一个发情周期，如未受胎可反复发情，每次发情持续１－３天。母狸獭发情可从外阴门的变化来判定：没有发情的母狸獭外阴门紧闭。发情的母狸獭外阴门先肿胀，后潮红、隆起，而后张开外翻，并流有粘液性的分泌物。从表情上观察，表现不安，排尿次数增多，来回在舍内徘徊，愿接触雄性狸獭，当接近雄狸獭时排出一种恶臭的尿液。２配种时间配种的时间应选择在凉爽的时间进行，最适宜在日…     

关于狸獭种兽场及幼龄种兽标准暂行规定

<正>为加强国内狸獭选种、育种、提纯复壮工作和克服种兽混乱现象,特制定本暂行规定.旨在为行业管理、科学饲养管理提供依据;在不断提高狸獭种兽品质的同时,促进其商品性生产的发展.1 幼龄狸獭选种要求规定1）幼龄狸獭种兽必须从 1.5～2.5周岁龄种母鼠所繁殖的后裔中选择.2）幼龄狸獭种兽生长发育迅速,5月龄雄鼠体重3.5kg以上;母鼠体重3.0kg以上.     

饲料中添加壳寡糖和/或霉菌毒素吸附剂对凡纳滨对虾生长性能、非特异性免疫力及抗病力的影响

本试验旨在研究在饲料中单独或联合添加壳寡糖(COS)和霉菌毒素吸附剂(MA)对凡纳滨对虾(Litopenaeus vannamei)生长性能、非特异性免疫力及抗病力的影响。首先配制基础饲料(C0组,作为对照组),然后在基础饲料中分别添加100 mg/kg COS(C0.1组)、250 mg/kg COS(C0.25组)、2 500 mg/kg M A(M 2.5组)、100 mg/kg COS+2 500 mg/kg M A(C0.1+M 2.5组)、250 mg/kg COS+2 500 mg/kg MA(C0.25+M2.5组),共制成6种等氮等脂的试验饲料,投喂初重为(0.23±0.02)g的凡纳滨对虾8周。每组设3个重复,每个重复放养40尾对虾。结果表明:1)C0.1+M2.5组的特定生长率、增重率显著高于M2.5组(P0.05),C0.1+M2.5组的饲料系数最优,显著低于其他各组(P0.05),C0.1+M2.5组的蛋白质效率最高并显著高于除C0.25+M 2.5组外的其他各组(P0.05);C0.1+M 2.5组的虾体粗蛋白质含量较C0.1组显著升高(P0.05),虾体粗脂肪含量较C0.1组显著降低(P0.05)。2)C0.1+M 2.5、C0.25+M 2.5组血清中碱性磷酸酶(AKP)活性均显著低于C0.1和C0.25组(P0.05),C0.1+M2.5组血清中超氧化物歧化酶(SOD)、酚氧化酶(PO)活性均显著高于M2.5和C0.1组(P0.05),C0.1+M2.5组血清中丙二醛(MDA)含量显著低于C0.1组(P0.05);C0.1+M2.5组肝胰腺中MDA含量显著低于C0.1组(P0.05),C0.25+M 2.5组肝胰腺中AKP、PO、SOD、溶菌酶(LZM)活性比C0.1+M 2.5组均有降低,相反肝胰腺中MDA含量则有所升高。3)以哈维氏弧菌攻毒7 d后,C0.1+M2.5及C0.25+M 2.5组的累积死亡率均显著低于C0和M 2.5组(P0.05)。由结果可知:本试验条件下,饲料中添加一定量的COS和/或MA均能促进凡纳滨对虾的生长,联合添加COS与MA的促生长、提高免疫力和抗病力的效果优于单独添加COS和MA,综合来看,以100 mg/kg COS和2 500 mg/kg M A联合添加时作用效果较佳。     

Conventional freezing of in vitro-produced and biopsied bovine blastocysts in the presence of a low concentration of glycerol and sucrose

The purpose of this study was to develop a practical cryopreservation method for in vitro-produced (IVP) and sex-predetermined bovine blastocysts that will be applicable to direct transfer of the post-thaw embryos. Blastocysts were harvested 7 days after IVF and allocated to either an intact or biopsy group. The cryoprotective solution contained 0.7 M glycerol and 0, 0.05 or 0.1 M sucrose. Slow cooling at a rate of -0.5 C/min was terminated at -25, -30, or -35 C, and rapid cooling in liquid nitrogen was followed. After one-step thawing and dilution, the IVP blastocysts were cultured for 3 days to assess their survival. The post-thaw survival rate of intact blastocysts after termination of slow cooling at -30 C in 0.7 M glycerol plus 0.1 M sucrose (96.2%) was significantly higher than that at -25 C in 0.7 M glycerol alone (44.4%). The post-thaw survival rate of biopsied bovine blastocysts after termination of slow cooling at -25 C in 0.7 M glycerol alone (53.8%) tended to be lower than that at -25 C in 0.7 M glycerol plus 0.05 M sucrose (91.3%) or -30 C in 0.7 M glycerol plus 0.1 M sucrose (92.3%). Thus, addition of a small amount of sucrose to 0.7 M glycerol cryoprotective solution shortened the process of slow cooling for both the intact and biopsied bovine embryos. Judged from the survival levels in vitro after thawing and one-step dilution of embryos (>80%), this is an improved method of cryopreservation for subsequent direct transfer of IVP and biopsied bovine blastocysts.     

含紫花苜蓿饵料对鲤鱼生长性能、肉品质及消化酶活性的影响

通过在日粮中添加不同水平的紫花苜蓿草粉和鲜草,研究苜蓿草粉及鲜草对禾花鲤生长性能、鱼肉品质、消化酶活性及经济效益的影响。选取整齐一致的2龄禾花鲤1440尾,随机分为6个处理,每处理3个重复,每重复80尾,分置于18个试验池中饲养。各处理饲粮中苜蓿草粉的添加量分别为0,4%,8%,12%,16%和0 鲜草,正试期50 d。研究结果显示:1)添加苜蓿草粉后,试验Ⅱ组的尾均日增重和增重率显著高于对照组。试验Ⅰ、Ⅲ组的上述2项指标高于对照组,试验Ⅳ组低于对照组,苜蓿鲜草组低于对照组,但差异均不显著。2)和对照组相比,添加苜蓿草粉显著(试验Ⅳ组)或极显著(试验Ⅰ、Ⅱ、Ⅲ组)提高了禾花鲤肌肉中粗蛋白质含量,随着苜蓿草粉添加水平的增加,肌肉中粗脂肪和胆固醇水平显著下降,肌肉中水分含量呈先降后升的二次变化趋势,苜蓿鲜草组的肌肉中粗蛋白质、粗脂肪含量和胆固醇水平无显著变化。3)添加苜蓿草粉后对消化道各部位蛋白酶活性及淀粉酶活性有促进作用,均呈先升后降的变化趋势,其中试验II组的酶活性最高。添加苜蓿鲜草对消化道各部位酶活性无显著影响。4)与对照组相比,试验Ⅰ、Ⅱ、Ⅲ组经济效益均有所提高,但以试验Ⅱ组最好。以上结果表明,在鲤鱼饲粮中添加8%紫花苜蓿草粉对鲤鱼生产性能、鱼肉品质及消化酶活性指标有较显著的改善,但紫花苜蓿鲜草不适宜直接投喂鲤鱼。结合生产实际,建议在鲤鱼饲粮中添加8%紫花苜蓿草粉。     

Evaluation of the anaerobic method for the analysis of fecal microflora of beagle dogs.

The plate-in-bottle method of Mitsuoka et al. (1969) for the counting of fecal bacteria in beagle dogs was superior to an anaerobic jar method. Comparisons of three nonselective media, such as medium 10 supplemented with 10% cecal extract of dogs (designated as M10C), M10 with 10% fecal extract of dogs (M10F), and M10, by the plate-in-bottle method indicated that the visible bacterial counts for M10C were higher than those for M10 and M10F. The high percentage (18.4%) of numbers of the extremely oxygen-sensitive anaerobes to the fecal total counts by using the plate-in-bottle method with M10C was also observed.     

人工诱发鸡新城疫的攻毒条件的比较研究

将4周龄淮南麻黄鸡80羽随机平均分成4组：口鼻接种组、皮下接种组、肌肉接种组和空白对照组，分别用不同稀释度的NDV攻毒，观察攻毒结果并统计死亡情况。结果不同攻毒途径的致病性有差异，肌肉注射致病性最强，皮下注射次之，滴鼻滴口最弱。不同攻毒途径所需的攻毒剂量各不相同，滴鼻滴口所需的剂量最大，皮下注射次之，肌肉注射量最小。本文对造成不同攻毒途径致病性差异的原因进行了深入探讨。人工诱发新城疫，建议采用注射途径。     

Comparative studies of the persistence of animal mycoplasmas under different environmental conditions

A comparison of the persistence of mycoplasmas in animals was carried out. When inoculated into liquid media, strains of Mycoplasma bovis, M. arginini, Acholeplasma laidlawii, and A. axanthum persisted for 59-185 days post-inoculation. The survival periods were not significantly influenced by temperature (4, 30, 37 degrees C, and room temperature). The survival periods for M. bovigenitalium, M. gallisepticum, M. bovirhinis, and M. gateae ranged from <7 to 185 days depending on medium components and temperature. Further, it was determined that strains of M. bovigenitalium, M. bovis, M. bovirhinis, M. arginini, and A. laidlawii persisted in a dry paper disc for at most 28, 126, 154, 56 and over >168 days at 4 degrees C, respectively. At 4 degrees C, strains of M. gallisepticum, M. columborale, M. edwardii, M. felis, and M. gateae survived for at most 28, 21, 42, 28, 28 and 70 days, respectively. At 30 degrees C, strains of M. bovis, M. bovirhinis, M. arginini, A. laidlawii, and M. gallisepticum persisted for at most 28, 84, 56, >168 and 14 days, respectively, but strains of M. gallisepticum, M. columborale, M. edwardii, M. felis, M. gateae, and U. diversum did not survive for more than 14 days. In an outdoor environment, strains of M. bovirhinis and A. laidlawii survived for at most 28 and 14 days, respectively. Finally, it was found that 14 isolates of M. gallisepticum persisted for periods similar to those of the reference strains. The results under dry conditions at a variety of temperatures presented contribute to understanding the epizootiology of mycoplasmal infections in the field.     

The putative penicillin-binding proteins 1 and 2 are important for viability, growth and cell morphology of Brucella melitensis

The penicillin-binding proteins (PBPs) are enzymes that regulate the assembly of the peptidoglycan layer of the bacterial cell wall. The genome of Brucella melitensis strain 16M possesses seven pbp genes: three in pbp-1 family (designated as 1A, 1B, and 1C); one in pbp-2 family; and three in pbp-6 family (designated as 6A, 6B, and 6C). We investigated the importance of pbp-1 and pbp-2 genes to viability, cell morphology and infectivity of B. melitensis. A recombinant B. melitensis strain (designated 16MDeltapbp1C) was generated by disrupting the pbp-1C of strain 16M by allelic exchange. This strain produced nearly 20% smaller colonies on trypticase soy agar plates, and grew slower in trypticase soy broth compared to the strain 16M. Electron microscopy revealed that strain 16M exhibited native cocco-bacillus morphology, while 16MDeltapbp1C possessed a spherical morphology. Strain 16MDeltapbp1C did not differ from strain 16M in terms of recovery from infected mouse macrophage cell line J774.1, or recovery from spleens of infected BALB/c mice, suggesting that pbp-1C is dispensable for intracellular persistence of B. melitensis. Expression of mRNA of fixR, the gene downstream of pbp-1C was similar between the strains 16M and 16MDeltapbp1C suggesting that disruption of pbp-1C did not induce any polar effects. Multiple attempts to mutate pbp-1A, pbp-1B, or pbp-2 genes failed, most probably because these genes are indispensable for viability of B. melitensis. Our findings suggest that pbp-1C regulates in vitro growth and cell morphology, whereas pbp-1A, pbp-1B, and pbp-2 are essential for viability of B. melitensis.     

Improvement of whole crop rice silage nutritive value and rumen degradability by molasses and urea supplementation

Whole crop rice was harvested 120 days after planting and chopped to 2–3-cm length for silage making. The whole crop rice silage (WCRS) was supplemented with different levels of molasses and urea to study nutritive value and in situ rumen degradability. The ensiling study was randomly assigned according to a 6?×?5 factorial arrangement, in which the first factor was molasses (M) supplementation at M0, M1, M2, M3, M4, and M5 %, and the second was urea (U) supplementation at U0, U0.5, U1.0, U1.5, and U2.0 % of the crop dry mater (DM), respectively. After 45 days of ensiling, temperature, pH, chemical composition, and fermentation end products of the silages were measured. Ten U and M treatment combinations of WCRS were subsequently selected to study rumen degradability by nylon bag technique. The results showed that temperature and pH of the silages linearly increased with U supplementation level, while total volatile fatty acid (TVFA), acetic acid (C2) and propionic acid (C3) decreased. In contrast, increasing level of M supplementation decreased WCRS temperature and pH, whereas TVFA, C2, and C3 concentrations increased dramatically. Both M and U supplementation increased concentration of butyric acid (C4). Dry matter, organic matter (OM), and acid detergent fiber (ADF) contents of the silages were not influenced by either M or U supplementation. Increasing U supplementation increased crude protein (CP) content, while M level did not show any effect. Furthermore, neutral detergent fiber (NDF) content in silage was decreased by both M and U supplementation. The results of the in situ study showed that M and U supplementation increased both ruminal DM and OM degradation. The water-soluble fraction (a) was the highest in WCRS U1.5M3 and lowest in U0M0. Increasing M and U supplementation levels increased the potentially degradable fraction (b) of both DM and OM. Total rumen degradable fraction (a?+?b) was highest in WCRS U1.5M3, whereas OM degradability was highest in U0M3. However, effective degradation of both DM and OM were the highest in WCRS U1.5M3 and the lowest in U0M0. We conclude that supplementation of U and M increases WCRS quality and rumen degradability. Supplementation of U at 1.5 and M at 3–4 % of the crop DM is recommended for lactating dairy cows and fattening beef cattle.     

添加乳酸菌和发酵底物对桑叶青贮发酵品质的影响

为开发桑叶作为非常规饲料资源,本试验探讨了添加乳酸菌、葡萄糖或糖蜜对桑叶青贮发酵品质的影响,试验设对照组(C)、乳酸菌组(P)、葡萄糖组(G)、糖蜜组(M)、乳酸菌+葡萄糖组(P+G)、乳酸菌+糖蜜组(P+M),青贮后第7,14,30和60天开窖取样分析桑叶青贮饲料发酵品质。结果表明,添加乳酸菌加速了桑叶青贮过程中乳酸发酵,青贮第7天P,P+G和P+M组乳酸含量已达到C组的6倍以上,pH值降至4.30以下,其中P+G和P+M在青贮结束时降至4.0左右。补充发酵底物并未有效改善桑叶青贮发酵品质,C、G和M组pH值在青贮前30 d始终保持在5.85以上,青贮60 d时C组为5.96,G和M组分别下降至5.35和5.24,显著(P<0.05)高于P组。整个青贮过程中P组显示最高的乙酸含量,始终显著(P<0.05)高于C、G和M组,青贮7 d后开始显著(P<0.05)高于P+G和P+M组。青贮第7天P组氨态氮/总氮显著(P<0.05)低于对照组,之后各组氨态氮/总氮均随青贮时间的延长逐渐上升,其中P、P+G和P+M组氨态氮/总氮显著(P<0.05)低于C、G或M组直至青贮结束。本试验结论认为单独添加乳酸菌明显提高了桑叶青贮发酵品质,而组合添加并未进一步得到大的改善。     

小肠可吸收氨基酸模式对内蒙古白绒山羊组织蛋白质周转的影响

选用9只体况良好,体重25～30 kg的2周岁内蒙古白绒山羊半同胞羯羊,安装永久性十二指肠近端瘘管和两侧颈静脉血插管进行试验,试验采用随机区组试验设计,3个试验处理为在基础日粮条件下的3种十二指肠氨基酸灌注模式,分别为M、M90 C10和M80 C20.本试验采用稳定性同位素d5-Phe大剂量一次灌注法,测定不同组织的蛋白质合成率(FSR).结果表明,小肠可吸收氨基酸模式对皮肤蛋白质的FSR有显著影响.其中,M90 C10组和M80 C20组皮肤蛋白质的FSR极显著高于M组(P＜0.01).小肠可吸收氨基酸模式对空肠、肝脏和肌肉组织的FSR无显著影响(P＞0.05).同时表明小肠可吸收氨基酸模式对氨基酸在外周组织,尤其是皮肤和肌肉组织间的分配具有显著影响(P＜0.05).