星星草群落地上生产结构、现存量季节动态和净初级生产力的研究

对星星草（Ｐｕｃｃｉｎｃｅｌｌｉａｔｅｎｕｉｆｌｏｒａ）群落的生产结构、现存量季节动态和地上净初级生产力（ＡＮＰＰ）的研究结果表明：同化系统（ＡＳ）和非同化系统（ＵＡＳ）的现存量分别集中分布于地上０～２０ｃｍ和０～３０ｃｍ的范围内，属典型的下繁型草地群落。其ＡＳ．ＵＡＳ和地上总现存量（Ｙ）在空间不同层次（ｘ）的积累规律表现为变型双曲线函数Ｙ＝ａ＋ｂ／ｘ形式。星星草种群及其群落地上生物量增长规律符合Ｌｏｇｉｓｔｉｃ增长模型；其地上现存量季节动态呈二次抛物线方程Ｙ＝ａ＋ｂｘ＋ｃｘ２形式。该群落的ＡＮＰＰ为２００．９８／ｍ２·ａ。     

生物统计讲座(Ⅳ)

四、样本均数可靠性及总体均数可信限的测定§4.1样本均数的可靠性测定(标准误) 观察事物,若有可能最好是从事物的总体来研究,那么在这种情况下所得的统计数值可以认为是完全可靠的。但事实上不可能搜集得总体的全部资料,因此,一般是采取抽样的方法来进行研究的。而从样本所得的结果(统计数)来推论和估计总体(参数)。但即使是严格遵守随机化     

泌乳母猪支链氨基酸营养

支链氨基酸（ｂｒａｎｃｈｅｄ ｃｈａｉｎ ａｍｉｎｏ ａｃｉｄ，ＢＣＡＡ）是一组在碳链上具有支链结构的脂肪族中性氨基酸，包括亮氨酸（Ｌｅｕ）、异亮氨酸（Ｉｌｅ）和缬氨酸（Ｖａｌ），均为必需氨基酸。在泌乳母猪的营养研究中，ＢＣＡＡ的营养作用越来越受到重视。本文就此对目前的研究现状作一简要概述。     

生物统计的几个概念

抽样为了估计总体的参数（如均数、率、标准差等）而从其中抽出一部分个体组成供分析的样本称为抽样。抽样方法应能防止主、客观因素造成偏性（即系统误差）,保证样本对总体的代表性。简单随机抽样是以抽签或相当于抽签的方式从总体中抽取个体组成样本。其要点是总体中每个个体被抽中的机会必须均等。标准误     

阿拉善荒漠草地牧草氨基酸组成特点与营养价值研究

对阿拉善荒漠草地３８种优势牧草氨基酸总量、必需氨基酸、含硫氨基酸、限制性氨基酸含量及必需氨基酸指数（ＥＡＡＩ）的组成特点进行了研究。结果表明,氨基酸总含量为２．４７％～２２．５０％;各科牧草氨基酸总含量顺序为：百合科＞豆科＞蒺藜科＞菊科＞禾本科＞藜科＞蔷薇科＞柽柳科＞蓼科;必需氨基酸含量为０．９７％～８．９２％,同时满足ＥＡＡ／ＮＥＡＡ＞６０％,ＥＡＡ／ＴＡＡ＞４０％ 的牧草有２３种;各科牧草必需氨基酸含量占氨基酸总量比值依次为：蔷薇科＞菊科＞藜科＞豆科＞蓼科＞禾本科＞百合科＞柽柳科＞蒺藜科;含硫氨基酸含量为０．２８％～１．４０％,含硫氨基酸占氨基酸总量比值从高到低依次为柽柳科、藜科、蓼科、豆科、蔷薇科、蒺藜科、禾本科、菊科、百合科;内蒙古白绒山羊限制性氨基酸总含量为０．７０％～３．２２％;３８种牧草的ＥＡＡＩ值,对羊肉为０．９１４～１．０１０,对山羊绒为０．９７６～１．２５０,对山羊毛为０．９５１～１．２１９。阿拉善荒漠草地牧草是当地白绒山羊和绵羊优良的饲料来源,对山羊毛和羊绒的产量和品质有重要的作用。     

流感病毒血凝素基因在昆虫细胞中的表达

应用ＲＴ－ＰＣＲ方法扩增了禽流感病毒Ａ／Ｇｏｏｓｅ／Ｇｕａｎｇｄｏｎｇ／１／９６（Ｈ５Ｎ１）１．７ｋｂ的ＨＡ基因,将其克隆到ｐＵＣ１９的ＢａｍＨＩ位点,筛选到阳性重组子 ｐＵＣＨ５。然后将 ＨＡ基因亚克隆到杆状病毒转移载体 ｐＢｌｕｅＢａｃＨｉｓＢ,筛选到重组转移载体ｐＢａｃＨ５。经过序列分析证明阅读框架正确后,在脂质体转染试剂介导下,ｐＢａｃＨ５与线性化的杆状病毒 ＤＮＡ（Ｂａｃ－Ｎ－Ｂｌｕｅ ＤＮＡ）共转染Ｓｆ９昆虫细胞。重组杆状病毒经三轮蚀斑纯化,获得纯化的重组杆状病毒ｒＢａｃＨ５。提取重组杆状病毒ＤＮＡ经ＰＣＲ扩增证明目的基因片段插入到杆状病毒基因组中。间接免疫荧光染色试验、血凝试验和 Ｗｅｓｔｅｒｎ ｂｌｏｔ试验结果表明 ＨＡ基因在重组杆状病毒感染的Ｓｆ９细胞表面获得表达。重组杆状病毒表达的ＨＡ蛋白能够凝集公鸡红细胞,血凝价１２８０－２５６０ＨＡＵ／ｍｌ。ＨＡ蛋白在杆状病毒表达系统的成功表达,为禽流感亚单位疫苗的研制奠定了基础。     

草原蝗虫密度的抽样技术研究

在蝗虫密度为０．０５～８．５０头／ｍ２的不同类型草地，以投环方式统计不同大小（０．０２、０．０５、０．１０、０．２０、０．３５ｍ２）的铁环击中或套入蝗虫数，计算调查地蝗虫平均数，以笼罩法作为“真值”对照，对不同大小铁环调查数进行统计检验。结果表明，在调查密度范围内，以０．０５、０．１０、０．２０ｍ２铁环的调查数较接近“真值”，其精确性随蝗虫密度的高低略有变动。根据草地蝗虫为Ｐｏｉｓｓｏｎ分布的特点，采用Ｐｏｉｓｓｏｎ置信域和二项式抽样法，建立以０．１０ｍ２环中蝗虫的出现率估测平均密度和反估计的二项式抽样模型，并进行统计检验。最后，以Ｐｏｉｓｓｏｎ置信值为概率保证，提出了理论抽样数计算模型。     

禽传染性支气管炎病毒分离毒株的血清型鉴定与免疫防制研究

应用基于单克隆抗体的间接免疫荧光实验和病毒血清中和实验，分别对１１个禽传 性支气管为为病毒分离毒株进行血清型鉴定。其中３株为Ｍａｓｓ型，２株为Ａｒｋ型，２株为Ａｒｋ／Ｍａｓｓ混合弄其余４株为不可分类型或未知型。     

肉鸭氨基酸需要量的研究

提出了估计肉鸭氨基酸需要的数学模型，用生长鸭的比较屠宰试验和成年鸭的氮平衡试验对模型的某些参数者了估计，并用该模型对生长肉鸭各生长阶段的氨基酸需要量进行了估计，结果表明该模型估计的肉鸭的前期氨基酸需要量和文献报道值很吻合（ｒ＝０．９４）后期折估计值普遍低于文献报道值。     

首乌蜜精营养素分析研究

定量分析首乌蜜精所含的氨基酸、粗蛋白、还原糖、蔗糖，Ｖｃ、ＶＢ１、ＶＢ２、ＶＥ、ＶＤ、ＶＡ、灰份和矿物质。结果表明，首乌蜜精含有１６种氨基酸，其总含量为２９８．１９ｍｇ／１００ｍ１；粗蛋白含量为３６６．００ｍｇ／１００ｍ１；还原糖、蔗糖、灰份含量为５５．９７％、８．５９％、０．２２％；Ｖｃ、ＶＢ１ＶＢ２、ＶＥ、ＶＤ、ＶＡ含量（每１００ｍｌ）分别为０．０６ｍｇ、１７．４６ｍｇ、０．２１ｍｇ、２．３５ｍｇ、４１．０６μｇ、１８，６２μｇ；含有民民Ｚｎ、Ｃｏ、Ｆｅ、Ｍｎ、Ｍｇ、Ｎａ、Ａｌ、Ｃａ、Ｃｕ、Ｓｒ’Ｔｉ、Ｋ１４种矿物质，其总含量为１１４７．７５ｍｇ／Ｌ，不含对人体有害的矿物质。首乌蜜精所含的各种营养素是其多种食疗保健作用的物质基础。     

Relation between selenium content and glutathion‐peroxidase activity in blood of cattle

Summary

To identify a simple method for assessing the selenium demand in cattle, the relationship between selenium content in whole blood and the concentration of the selenium containing enzyme glutathion peroxidase (EC 1.11. 1.9; GSH‐Px) in red blood cells was studied. On six farms with suspected low soil selenium content, blood samples were collected from groups of calves, yearlings and adults at the end of the housing period and of the grazing period.

The data obtained showed a highly significant correlation between the parameters mentioned: GSH‐Px (U/g Hb) = 3.261 * Se (μg/kg) ‐ 40.553. In growing animals there was a decline in Se supply with age, followed by a gradual recovery in heifers. This was most pronounced on some sandy soils and on peat soil.

Seasonal effects could not be demonstrated.     

Molecular characterization of unusual bovine rotavirus A strains having high genetic relatedness with human rotavirus: evidence for zooanthroponotic transmission

We report here the genomic characterization of two rare rotavirus A (RVAs) G1P[11] and G9P[X] strains detected in cattle calves from two different geographical locations in India during routine rotavirus surveillance. These strains possessed unusual G types (VP7 gene) on a bovine/artiodactyl genotype constellation, G1‐P[11]‐I2‐Rx‐Cx‐Mx‐Ax‐N2‐T6‐E2‐H3 (HR‐B91) and G9‐P[X]‐I2‐Rx‐Cx‐Mx‐Ax‐N2‐T6‐E2‐H3 (WB‐H2). This is the first report on molecular characterization of G9 in cattle, and second report on G1 in cattle. The VP7 gene of HR‐B91 occupied lineage IIc within G1 while that of WB‐H2 occupied IIIb within G9 genotype. The latter was found to be very diverse from other RVA strains of G9 genotype, and this may emerge as a new genotype in due course. The study provides evidence of zooanthroponotic transmission of human G1 and G9 RVA genes to calves. Of note, the G9 genotype was found to serve as the ancestral genotype for G1. Phylogenetic analysis of remaining gene segments revealed close relatedness to artiodactyl or artiodactyl‐like human RVA strains. The findings of this study highlight the potential role of interspecies transmission and reassortment events in generating the rare rotavirus strains.     

Use of a modified skin slice with subcutaneous fat and carcase weight without this slice for prediction of meatiness and fatness in young slaughter geese

1. White Italian geese (40 males and 40 females) were reared until 12 weeks of age and fed standard diets ad libitum. After rearing ended, the geese were weighed (males-5216 g, females-4945 g) and killed. Carcases were chilled and skin slices with subcutaneous fat removed. The remaining part of the carcase was dissected into meat, intermuscular fat and bones. 2. The weight of a skin slice with subcutaneous fat, taken from the carcase surface excluding the forewings and wing tips (X2), and the weight of a carcase excluding this slice, the forewings and wing tips (X1) were very good indicators of the content of skin with fat (r > 0.99) and meat (r > 0.98) in a whole carcase. 3. The above traits provided a basis for deriving regression equations to estimate the content of meat (Y) or skin with subcutaneous and intermuscular fat (U) in whole carcases of White Italian geese. The following equations are recommended for practical application: Y = 0.755X1 - 27.8 (Sy = 26.3 g); U = 1.070X2 + 19.5 (Su = 11.4 g).     

Effect of Pregnancy and Foetal Number on Diameter of Corpus Luteum,Maternal Progesterone Concentration and Oxidant/Antioxidant Balance in Ewes

The aim of this study was to determine the changes in diameter of corpus luteum (CL), maternal progesterone (P) concentration, lipid peroxidation and non‐enzymatic antioxidant levels along with enzymatic antioxidant activities in pregnant ewes bearing single and twin foetuses. The ewes were selected from healthy animals that were brought to the abattoir for slaughtering. The ewes were divided into three groups: Group 1 (non‐pregnant, non‐oestrous, n = 30), Group 2 (pregnant bearing a single foetus, n = 30) and Group 3 (pregnant bearing twin foetuses, n = 12) after they were slaughtered. Pregnant ewes were in the first half of the pregnancy. The diameter of CL and P concentration of pregnant ewes bearing a single foetus or twin foetuses were found higher than that found in non‐pregnant ewes. Similarly, the P concentration of pregnant ewes bearing twin foetuses was higher than that found in pregnant ewes bearing a single foetus. Malondialdehyde (MDA) level in pregnant ewes bearing twin foetuses was higher than that found in both non‐pregnant and pregnant ewes bearing a single foetus. The serum glutathione (GSH) level and glutathione‐peroxidase (GSH‐Px) activity of pregnant ewes bearing twin foetuses were found lower than that found in non‐pregnant ewes. Additionally, the GSH‐Px activity of pregnant ewes bearing twin foetuses was found lower than that found in pregnant ewes bearing a single foetus. No significant difference was found between pregnant ewes bearing female and male foetus with respect to diameter of CL, P concentration and oxidative stress parameters. There were significant positive correlations between foetal number (0, 1, 2) and diameter of CL, P concentration, MDA level, and between P concentration and diameter of CL, MDA level. However, significant negative correlations were found between foetal number (0, 1, 2) and GSH level, GSH‐Px activity, and between P concentration and GSH‐Px activity. In conclusion, the diameter of CL enlarges, P production increases and oxidant/antioxidant balance impairs because of the gestation stress in ewes during pregnancy.     

实验肝片吸虫感染对大鼠机体自由基代谢影响的研究

通过大鼠感染肝片吸虫复制感染模型 ,研究肝片吸虫感染后血清抗氧化功能的变化。 60只大鼠随机分成感染组和对照组 ,每组 30只。感染组大鼠一次口服 2 5个囊蚴 ,对照组不感染。于感染前 (0周 )和感染后 (1 ,3,5,7,9周 )采集血样 ,检测感染后谷胱甘肽过氧化物酶(GSH Px)、超氧化物歧化酶 (SOD)、过氧化物酶 (CAT)活性和丙二醛 (MDA)含量的变化。结果表明大鼠感染肝片吸虫后 ,感染组血清中GSH Px先升高后下降 ,SOD活性无明显变化 ,CAT活性在感染后下降 ,MDA含量在前 5周变化不明显 ;说明自由基参与了肝片吸虫病的发病过程     

Effect of dietary antioxidant supplementation on the oxidative status of plasma in broilers

In this study, the effect of dietary antioxidants on the plasma oxidative status of growing birds fed a diet rich in polyunsaturated fatty acids was investigated. One‐day‐old broilers were fed for 42 days a diet containing 4% linseed oil and supplemented with single plant extracts rich in antioxidants (natural tocopherols, rosemary, grape seed, green tea, tomato) or a combination of some of these plant extracts, in two different total doses (100 and 200 mg product/kg feed). A diet with synthetic antioxidants with and without α‐tocopheryl acetate (200 mg/kg feed) were also included. The plasma oxidative status was evaluated measuring the ferric reducing ability of plasma (FRAP), the superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) activity. Lipid peroxidation was measured by thiobarbituric acid‐reactive substances (TBARS). No significant effect of the dietary treatments was observed for FRAP as well as for TBARS. However, diet affected GSH‐Px activity (p = 0.002) and a trend for an effect on SOD activity was observed (p = 0.084). A higher GSH‐Px activity was found for 200 mg/kg tomato extract and natural α‐tocopherol in relation to the corresponding 100 mg/kg treatment, and the lowest GSH‐Px activity was measured for the synthetic antioxidants treatment. The lowest and highest SOD activity were found for the 200. and 100 mg/kg treatment with tomato extract respectively. In conclusion, the oxidative status and lipid oxidation of plasma in broilers was not affected by feeding natural antioxidant extracts at the doses in the present study, but some changes in antioxidant enzyme activities were observed, of which the implication remains to be elucidated.     

硒蛋白x基因沉默和过氧化氢处理对人正常肝脏细胞中硒蛋白基因表达和抗氧化酶活性的影响

本试验旨在探讨硒蛋白x(Selx)基因沉默和过氧化氢(H2O2)处理对人正常肝脏细胞(LO2)中硒蛋白基因表达和抗氧化酶活性的影响,为探索Selx与其他硒蛋白之间的调控关系及Selx的功能奠定基础。对本实验室保存的Selx基因稳定沉默LO2细胞株(si Selx)和对照细胞株(CK),利用噻唑兰(MTT)法比较其生长速率;si Selx和CK用200μmol/L H2O2处理2.5 h后,采用荧光定量PCR技术考察25个硒蛋白基因的表达量;同时比较Selx基因沉默以及H2O2处理对LO2细胞株中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活性及总抗氧化能力(T-AOC)的影响。结果显示:1)Selx基因沉默显著降低了LO2细胞株的生长速率(P0.05);2)Selx基因沉默显著上调了G px6、Txnrd2、Seli基因的表达量(P0.05),显著下调了Dio2、Dio3、Selm、Sepw1基因的表达量(P0.05);H2O2处理显著上调了Dio1基因的表达量(P0.05),显著下调了G px2基因的表达量(P0.05);Selx基因沉默后H2O2处理显著上调了G px6、Txnrd2、Dio1基因的表达量(P0.05),显著下调了Txnrd3、Dio2、Selm、Sepw1、Selv基因的表达量(P0.05);3)Selx基因沉默显著提高了LO2细胞株GSH-Px活性(P0.05),显著提高了SOD的活性(P0.05);Selx基因沉默后H2O2处理显著提高了GSH-Px活性(P0.05)。由此可见,Selx基因沉默降低了LO2细胞株的生长速率,Selx基因沉默后H2O2处理影响部分硒蛋白基因在细胞中的表达量,同时也影响了GSH-Px、SOD活性。     

皖南花母猪昼夜行为规律的研究

从250头皖南花猪群中抽选出健康的6月龄后备母猪、发情母猪、妊娠母猪和哺乳母猪分别为4、4、4和5头,连续120小时观测皖南花母猪的行为规律。结果表明,4种母猪每天采食消化能分别为15.94、9.05、35.57和44.61兆焦耳;后备母猪平均每天饮水、排粪和排尿分别为4、2和1次,发情母猪分别为6、1和4次,妊娠母猪为4.8、2.8和5次以及哺乳母猪分别为6.3、2.3和2.6次。4种母猪全天站立活动时间分别占18.83、33.44、16.01和22.43％,其中白夭站立活动时间比夜晚长(P<0.01)。在每天的6～20时中,各类母猪每2小时的站立活动时间占全天的百分比(y)可用y=sum from 0 to 4(a_iX~i)来表达,其中X为6～20时中每2小时的上限值,a_i为参数。将发情、妊娠和哺乳母猪的参数分别与后备母猪相比,得到的对应参数比值分别为1.06～1.16、0.24～0.19和9.54～0.62。仔猪平均每次拱奶时间为76.5秒,母猪每次放乳时间33.3秒,白天拱奶时间比夜晚长(P<0.01)。白天和夜晚分别每隔1.26和1.45小时哺乳1次。     

Induced non-enzymatic browning of soybean meal. II. Ruminal escape and net portal absorption of soybean protein treated with xylose

Non-enzymatic browning was tested as a means of increasing ruminal escape of soybean meal N. Soybean meal was treated with xylose (3 mol/mol SBM-lysine), sodium hydroxide (pH 8.5) and enough water to achieve an 83% dry matter mixture and then heated at 150 C for 30 min (XTS-30). Trial 1 evaluated ruminal escape of N from XTS-30 compared with commercial soybean meal (CS) or urea (U) in a replicated 3 X 3 Latin square design using six duodenally cannulated Angus X Hereford steers (24.7 kg). Duodenal flow of dietary N was higher (P less than for steers fed XTS-30 (47.9 g/d) than for steers fed CS (39.5 g/d). The ruminal escape estimate for XTS-30 (33.7%) was higher (P less than .10) than CS (13.1%), whereas total tract apparent N digestibility was not different among treatments. In trial 2, net portal absorption of alpha-amino N was measured in Finnsheep X Suffolk ram lambs (24.7 kg) fed U, CS or XTS-30 in a 3 X 3 Latin square design. Portal blood flow was measured by primed, continuous infusion of para-aminohippuric acid. Portal blood flow was lower (P less than .05) for U.fed lambs than for lambs fed CS or XTS-30, and tended to be lower for lambs fed CS than those fed XTS-30. Net portal absorption of alpha-amino N tended to be lowest for lambs fed U (281 mmol/d) and highest for lambs fed XTS-30 (578 mmol/d). The results are interpreted to show that non-enzymatic browning increased flow of soybean meal N to the intestine.     

The effect of vitamin A on trypsin inhibition activity of the blood and cervical mucus after the effects of hormones on the ovaries of sheep in the estrus period

Vitamin A (50,000 I. U.), administered after oestrus synchronization by PGF2 alpha (2 X 125 micrograms; 1st and 11th day) together with PMSG (750 and 1000 I. U.), had a stronger influence on the changes in the trypsin-inhibition activities (TIA) of the blood plasma, as compared with the effect of PMSG. The changes in the average TIA values within 120 hours after the administration of the stimulating dose were also observed more frequently to depend on vitamin A. After administration of 1000 I. U. PMSG, an increase was recorded only in the values of the fraction of low-molecular TIA, whereas the administration of the combinations of PMSG + vitamin A resulted in an increase of all the TIA's under study. This increase was directly correlated with an increased number of non-atretic tertiary follicles, with an increased number of ovulations (at the same dose of PMSG), and with a reduced ratio of changes in the concentration of progesterone (P) and 17-beta oestradiol (E): P/E = 1.1 after the administration of 1000 I. U. PMSG, P/E = 0.81 after I. U. PMSG + vitamin A, and P/E = 0.90 after 1000 I. U. PMSG + vitamin A. The increase in the average TIA of the cervical mucus is due to the increased secretory activity of the cervical glands rather than to the multiplication of these glands after ovary stimulation.