Milk productivity of breeding sheep of the Altai finewool breed

During development of energy and protein feeding standards of high-productivity breeding sheep of the Altai breed in the pregnant and suckling periods, it was established that a 15–20% increase of the energy or protein level in winter rations promotes an increase of their milk productivity by 21.7 and 32.3% in ewes with twin offspring and by 3.2–11.0% with one.     

Water resources are the limiting favor in growing soybeans in rice crop rotations

It is shown that under conditions of Kalmykia when growing soybean in rice crop rotations, it is possible to form a stable yield of this crops up to 1.65 t/ha with consideration of the regularities of its growth and development along with the dynamics of saving resources.     

Genetic diversity of ruminant <Emphasis Type="Italic">Pestivirus</Emphasis> strains collected in Northern Ireland between 1999 and 2011 and the role of live ruminant imports

Background

The genus pestivirus within the family Flaviviridae includes bovine viral diarrhoea virus (BVDV) types 1 and 2, border disease virus (BDV) and classical swine fever virus. The two recognised genotypes of BVDV are divided into subtypes based on phylogenetic analysis, namely a-p for BVDV-1 and a-c for BVDV-2.

Methods

Three studies were conducted to investigate the phylogenetic diversity of pestiviruses present in Northern Ireland. Firstly, pestiviruses in 152 serum samples that had previously tested positive for BVDV between 1999 and 2008 were genotyped with a RT-PCR assay. Secondly, the genetic heterogeneity of pestiviruses from 91 serum samples collected between 2008 and 2011 was investigated by phylogenetic analysis of a 288 base pair portion of the 5’ untranslated region (UTR). Finally, blood samples from 839 bovine and 4,437 ovine animals imported in 2010 and 2011 were tested for pestiviral RNA. Analysis of animal movement data alongside the phylogenetic analysis of the strains was carried out to identify any links between isolates and animal movement.

Results

No BVDV-2 strains were detected. All of the 152 samples in the first study were genotyped as BVDV-1. Phylogenetic analysis indicated that the predominant subtype circulating was BVDV-1a (86 samples out of 91). The remaining five samples clustered close to reference strains in subtype BVDV-1b. Out of the imported animals, 18 bovine samples tested positive and 8 inconclusive (Ct ≥36), while all ovine samples were negative. Eight sequences were obtained and were defined as BVDV-1b. Analysis of movement data between herds failed to find links between herds where BVDV-1b was detected.

Conclusion

Given that only BVDV-1a was detected in samples collected between 1968 and 1999, this study suggests that at least one new subtype has been introduced to Northern Ireland between 1999 and 2011 and highlights the potential for importation of cattle to introduce new strains.

     

猪细小病毒X株在不同细胞上增殖效果比较

为选择猪细小病毒X株增殖的细胞系,对猪细小病毒X株在ST、PK-15、CEF、Vero细胞系上增殖情况进行比较,观察病变时间和病变情况,并分别测定其TCID50和血凝价。结果表明,猪细小病毒X株在这4种细胞上都能产生细胞病变,在ST、PK-15、CEF、Vero细胞上最先开始出现病变的时间分别为24、36、72和48 h,测其在以上4种细胞上的TCID50分别为10-6.4/0.1 mL、10-5.8/0.1 mL、10-2.1/0.1 mL和10-3.2/0.1 mL,HA分别为1 210、1 28、1 23、1 25,因此,建议选用ST细胞作为猪细小病毒X株的增殖细胞系。     

Humus and nitrogen in soddy-podzolic soils of different agricultural lands in Perm region

Heavy loamy soddy-podzolic soils (Eutric Albic Retisols (Abruptic, Loamic, Cutanic)) under a mixed forest, a grass–herb meadow, a perennial legume crop (fodder galega, Galéga orientalis), and an eightcourse crop rotation (treatment without fertilization) have been characterized by the main fertility parameters. Differences have been revealed in the contents of humus and essential nutrients in the 0- to 20- and 20- to 40-cm layers of soils of the studied agricultural lands. The medium acid reaction and the high content of ash elements and nitrogen in stubble–root residues of legume grasses favor the accumulation of humic acids in the humus of soil under fodder galega; the C_HA/C_FA ratio is 0.95 in the 0- to 20-cm layer and 0.81 in the 20- to 40-cm layer (under forest, 0.61 and 0.41, respectively). The nitrogen pool in the upper horizon of the studied soddy-podzolic soil includes 61–76% nonhydrolyzable nitrogen and 17–25% difficultly hydrolyzable nitrogen. The content of easily hydrolyzable nitrogen varies depending on the type of agricultural land from 6% in the soil under mixed forest to 10% under crop rotation; the content of mineral nitrogen varies from 0.9 to 1.9%, respectively. The long-term use of plowland in crop rotation and the cultivation of perennial legume crop have increased the content of hydrolyzable nitrogen forms but have not changed the proportions of nitrogen fractions characteristic of this soil type.     

生物絮团系统中不同低盐度条件对水质及凡纳滨对虾生理指标的影响

为探讨生物絮团养殖系统在低盐度条件下对凡纳滨对虾生理健康的影响,本研究以凡纳滨对虾为养殖对象,在生物絮团养殖系统中设置5‰（S5组）、10‰（S10组）和15‰（S15组）3个不同的低盐度组,进行为期4周的养殖实验。结果表明,各处理组间的水质指标没有明显区别(P>0.05),均在适合对虾养殖的范围内。凡纳滨对虾的生长、肌肉水分、粗蛋白和粗脂肪含量在各组间没有明显区别(P>0.05),但S10组的灰分含量显著高于S5组和S15组(P<0.05)。在S5组的盐度条件下,凡纳滨对虾肠道的淀粉酶和胰蛋白酶活性显著提高(P<0.05),S15组的盐度条件下对虾的血清抗氧化水平显著提高(P<0.05)。由此可见,凡纳滨对虾在低盐度生物絮团养殖系统中的生长不受显著影响,但抗氧化水平和消化酶活会受到显著影响。本研究可为对虾生物絮团养殖系统的盐度调控提供参考。     

吴旗县水土保持生态建设调查报告

吴旗县确立“封山退耕、植树种草、舍饲养羊、林牧主导、强农富民”的开发思路 ,将全县 10 3万hm2 坡耕地全部退耕 ,只保留 2万hm2 耕地发展高效农业 ,农村经济呈现出蓬勃发展的势头。该县在全国率先实施了“封山禁牧、舍饲养羊” ,走出了西部开发的新路子 ,是黄土高原水土保持生态建设的创举。建议总结推广其典型经验 ,加大黄土高原水土保持生态建设力度等     

Soils of paleocryogenic hummocky-hollow landscapes in the southern Baikal region

The features of ancient periglacial phenomena are widespread in landscapes lying beyond the modern permafrost zone. The specificity of the paleogeographic conditions in the south of the Baikal region resulted in the formation of paleocryogenic landscapes with hummocky-hollow landforms. The paleocryogenic mounds (hummocks) are of rounded or elongated shape, their height is up to 2–3 m, and their width is up to 20–25 m. They are separated by microlows (hollows). This paleocryogenic microtopography favors the differentiation of the pedogenesis on the mounds and in the hollows, so the soil cover pattern becomes more complicated. It is composed of polychronous soils organized in complexes with cyclic patterns. Light gray and gray forest soils and leached and ordinary chernozems are developed on the mounds; gray and dark gray forest soils and chernozems with buried horizons are developed in the hollows. The soils of the paleocryogenic complexes differ from one another in their morphology, physical and chemical properties, elemental composition, and humus composition. For the first time, radiocarbon dates have been obtained for the surface and buried humus horizons in the hollows. The results prove the heterochronous nature of the soils of the paleocryogenic landscapes in the south of the Baikal region.     

柚新品种‘老哥贡柚’的选育

‘老哥贡柚’是从‘冰糖柚’优良芽变中选育出的新品种。‘老哥贡柚’树势较强,枝梢较密,坐果率高。果实圆锥形,果皮浅黄色,果面光滑,油胞密集,果肉白色。纯甜无酸,食后无麻苦味,平均单果质量712 g,少核或无核,可溶性固形物含量(w,后同)为12.3%,总糖含量11.32%,总酸含量0.35%,可滴定酸含量0.22%,维生素C含量0.469 mg·g^-1。10月中下旬成熟,丰产、稳产,抗逆性强。     

黄鳝温和气单胞菌病病原的分离鉴定及免疫应答

从患病黄鳝苗种的肝脏、消化道、血液中分离到2株细菌,经腹腔人工注射及浸浴感染试验均出现与自然病例相似的症状,并从病鳝体内重新分离到生理生化特性与原菌株相同的细菌.经多项形态、生理生化测试,此2株细菌均鉴定为温和气单胞菌(Aeromionas sobria).该菌对先锋霉素Ⅵ、复达欣、头孢呋肟、菌必治、氟嗪酸等药物高度敏感,可选用这些药物拌饵投喂黄鳝苗种,来防治黄鳝苗种的温和气单胞菌病.免疫试验表明,黄鳝在免疫后7 d可以检测到抗体,滴度为25(32),以后逐渐上升,21 d达最大值212,随后下降,免疫保护率较对照组有明显提高.