Effects of Compound Plant Nutrients on Rumen Fermentation Parameters,Rumen Microbiota and Fatty Acid Composition of Longissimus dorsi Muscle in Finishing Small Tail Han Sheep北大核心CSCD

This study was conducted to investigate the effects of compound p1ant nutrients (CPN) on rumen fermentation parameters, rumen microbiota and fatty acid composition of longissimus dorsi musc1e in finishing sma11 tai1 Han sheep. Sixteen 4-month-o1d finishing sma11 tai1 Han sheep with an initia1 body weight (BW) of (24.18±0.31) kg were random1y divided into two groups, name1y, with 8 rep1icates per group and 1 sheep per rep1icate. The sheep in the contro1 group were fed a basa1 diet, whereas the sheep of the contro1 group (CPN group) was fed the basa1 diet supp1ementation with 3‰ CPN. The experiment 1asted for 97 days after 7 days adaption. The resu1ts showed as fo11ows: compared with the contro1 group, 1) adding CPN decreased the concentration of ammonia nitrogen (NH3-N) (P<0.05); 2) CPN supp1ementation affected beta diversity of rumen microbiota; 3) the re1ative abundance of Acidobacteriota, Erysipe1otrichaceae_UCG-002, Lactobacillus, and Megasphaera were enhanced by adding CPN (P<0.05), whereas, the re1ative abundance of Bacteroidetes and Prevotella was 1ower (P<0.05); 4) the supp1ementation of CPN had no significant effect on fatty acid composition of longissimus dorsi musc1e of fattening sma11-tai1ed Han sheep (P>0.05); 5) the contents of tota1 MUFA, C18:1n9c, C14:1, C16:1, C18:2n6c, C18:3n3 and n-3PUFA in the longissimus dorsi musc1e were corre1ated with the re1ative abundance of Megasphaera, Erysipe1otrichaceae_UCG-002, Succiniclasticum and Ruminococcus (P<0.05). In conc1usion, CPN can regu1ate the rumen microbiota structure and reduce the rumen NH3-N concentration of fattening sma11-tai1ed Han sheep. In production practice, CPN can be used as a rumen eco1ogica1 regu1ator. © 2023 Authors. All rights reserved.     

Isolation, expansion, and differentiation of goat adipose-derived stem cells

A goat adipose-derived stem cell (ADSC) line was established and compared to a rat line. Goat ADSC cells had normal diploidy after subculture. Proliferation of goat ADSCs was faster than rat cells in the same conditions. Both rat and goat ADSCs stained positively for vimentin, CD49d, CD44 and CD13, but stained negatively for CD34 and CD106. Bone nodules were apparent, and alizarin staining was positive after osteogenic induction. Cells expressing osteocalcin were positive by alkaline phosphatase (ALP) staining. After osteogenic induction, ossification nodules of goat ADSCs were larger than in rats, with dense ALP staining. Adipogenic induction resulting in lipid droplets and peroxisome proliferator-activated receptor (PPARγ2) expression were observed. Cartilage lacunae were formed and COL2A1 was expressed. More cartilage lacunae with better morphology were seen following differentiation of goat ADSC's using the hang-drop method. For goat ADSCs, results with both adherent-induced and hanging-drop induced cultures were better than for three-dimensional cultures.     

黑龙江省和谐自然保护区理论体系的构建

随着黑龙江省自然保护区数量及占地面积的迅速增长,自然保护区质量提升滞后以及建设与管理过程中诸多矛盾冲突的不和谐现状也随之显现,解决这些问题的关键在于推进自然保护区和谐发展.自然保护区的和谐是和谐社会内容的一部分,有关这方面的研究有利于促进我国社会主义和谐社会目标的最终实现.但目前我国关于构建和谐自然保护区的相关研究还处于初级阶段.本文在研究国内外自然保护区建设和管理相关理论的基础上,从法律保障体系建设、社区共管体系建设、生态补偿机制建设和区域发展援助基金成立,以及生态旅游开展等方面,提出了黑龙江省构建和谐自然保护区管理建议,为黑龙江省的生态文明和和谐社会建设提供了参考.     

人工饲养条件下扬子鳄两种越冬方式的比较

华北地区引进扬子鳄后 ,在室内安全越冬问题急需妥善解决 ,1996～ 1999年 ,采用人工控温使扬子鳄冬眠和不冬眠两种方式越冬。结果表明 ,在华北地区 ,在无法模拟自然条件使扬子鳄冬眠越冬的环境改变时 ,在人工控温下不冬眠是扬子鳄越冬的首选方式     

Productivity,Respiration, and Light-Response Parameters of World Grassland and Agroecosystems Derived From Flux-Tower Measurements

Grasslands and agroecosystems occupy one-third of the terrestrial area, but their contribution to the global carbon cycle remains uncertain. We used a set of 316 site-years of CO₂ exchange measurements to quantify gross primary productivity, respiration, and light-response parameters of grasslands, shrublands/savanna, wetlands, and cropland ecosystems worldwide. We analyzed data from 72 global flux-tower sites partitioned into gross photosynthesis and ecosystem respiration with the use of the light-response method (Gilmanov, T. G., D. A. Johnson, and N. Z. Saliendra. 2003. Growing season CO₂ fluxes in a sagebrush-steppe ecosystem in Idaho: Bowen ratio/energy balance measurements and modeling. Basic and Applied Ecology 4:167–183) from the RANGEFLUX and WORLDGRASSAGRIFLUX data sets supplemented by 46 sites from the FLUXNET La Thuile data set partitioned with the use of the temperature-response method (Reichstein, M., E. Falge, D. Baldocchi, D. Papale, R. Valentini, M. Aubinet, P. Berbigier, C. Bernhofer, N. Buchmann, M. Falk, T. Gilmanov, A. Granier, T. Grünwald, K. Havránková, D. Janous, A. Knohl, T. Laurela, A. Lohila, D. Loustau, G. Matteucci, T. Meyers, F. Miglietta, J. M. Ourcival, D. Perrin, J. Pumpanen, S. Rambal, E. Rotenberg, M. Sanz, J. Tenhunen, G. Seufert, F. Vaccari, T. Vesala, and D. Yakir. 2005. On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm. Global Change Biology 11:1424–1439). Maximum values of the quantum yield (α=75 mmol · mol^?1), photosynthetic capacity (A_max=3.4 mg CO₂ · m^?2 · s^?1), gross photosynthesis (P_g,max=116 g CO₂ · m^?2 · d^?1), and ecological light-use efficiency (ε_ecol=59 mmol · mol^?1) of managed grasslands and high-production croplands exceeded those of most forest ecosystems, indicating the potential of nonforest ecosystems for uptake of atmospheric CO₂. Maximum values of gross primary production (8 600 g CO₂ · m^?2 · yr^?1), total ecosystem respiration (7 900 g CO₂ · m^?2 · yr^?1), and net CO₂ exchange (2 400 g CO₂ · m^?2 · yr^?1) were observed for intensively managed grasslands and high-yield crops, and are comparable to or higher than those for forest ecosystems, excluding some tropical forests. On average, 80% of the nonforest sites were apparent sinks for atmospheric CO₂, with mean net uptake of 700 g CO₂ · m^?2 · yr^?1 for intensive grasslands and 933 g CO₂ · m^?2 · d^?1 for croplands. However, part of these apparent sinks is accumulated in crops and forage, which are carbon pools that are harvested, transported, and decomposed off site. Therefore, although agricultural fields may be predominantly sinks for atmospheric CO₂, this does not imply that they are necessarily increasing their carbon stock.     

非洲猪瘟形势下我国养猪业该何去何从

非洲猪瘟是由非洲猪瘟病毒感染家猪或野猪后引发的一种恶性传染病,该疫病在中国的暴发给整个养猪业造成了毁灭性的打击。然而,目前虽有报道称已经有科研单位研制出非洲猪瘟疫苗,但距离其实际应用于生产仍需要相当长的时间。中国是全球最大的猪肉生产和消费国,非洲猪瘟疫情在我国的快速传播使我国生猪产能遭受重创,直接导致猪肉供求失衡、猪肉价格翻番、猪肉市场异动。因此,文章从非洲猪瘟的传播方式、对非洲猪瘟相对有效的防控措施等方面探讨在非洲猪瘟形势下我国养猪业该如何维持产能、如何走好养殖之路。     

Chemical characteristics and relative bioavailability of supplemental organic copper sources for poultry

Five commercially available organic Cu products and reagent-grade CuSO4 x 5H2O (Cu Sulf) were evaluated by polarographic analysis and solubility in 0.1 M K2HPO4-KH2PO4 buffer (pH 5), 0.2 M HCl-KCl buffer (pH 2), or deionized water. Fractions from these solubility tests were evaluated by gel filtration chromatography for structural integrity. The organic sources were Cu lysine complex (Cu Lys), Cu amino acid chelate (Cu AA), Cu proteinate A (Cu ProA), Cu proteinate B (Cu ProB), and Cu proteinate C (Cu ProC). Separation of peaks in the chromatograms for the soluble Cu fraction from deionized water indicated that 77, 31, 69, 94, and 16% of the Cu remained chelated for the above sources, respectively. Two experiments were conducted to estimate the relative bioavailability of Cu from the organic Cu supplements for chicks when added at high dietary concentrations to practical corn-soybean meal diets. Liver Cu concentration increased (P < 0.0001) as dietary Cu increased in both experiments. When Cu Sulf was assigned a value of 100% as the standard, linear regression slope ratios of log10 liver Cu concentration regressed on added dietary Cu concentration gave estimated relative bioavailability values of 124 +/- 5.1, 122 +/- 5.3, and 111 +/- 6.0 for Cu Lys, Cu AA, and Cu ProC, respectively, in Exp. 1. The bioavailability estimates for Cu Lys and Cu AA were greater (P < 0.05) than that for Cu Sulf. Values in Exp. 2 were 111 +/- 7.6, 109 +/- 8.4, and 105 +/- 7.5 for Cu Lys, Cu ProA, and Cu ProB, respectively, and all sources were similar in value for chicks. Solubility of Cu in pH 2 buffer provided the best prediction of bioavailability (r2 = 0.924). Other indicators of chelation integrity and solubility had little value as predictors of bioavailability (r2 < or = 0.445).     

中国麇鹿朊蛋白核心片段的原核克隆表达与纯化

从采取的新鲜麋鹿血液中提取麋鹿基因组DNA,通过PCR的方法从麋鹿基因组中扩增麋鹿PrP蛋白核心片段的DNA,并分别在引物的5′和3′端引入EcoRⅠ和HindⅢ两个酶切位点,下游引物将原序列TATTAC突变为TAAT从变成两个终止密码子。通过两个酶切位点将麋鹿PrP蛋白核心片段DNA连接到pET-32a（＋）,转化DH5α,通过酶切鉴定和PCR鉴定,筛选出阳性克隆送菌液测序,从测序结果分析阳性克隆是否符合要求。测序正确后将核心片段基因连接到pET-32a（＋）,阳性质粒命名为MPrP-pET-32a（＋）,阳性质粒转化E.coli BL21（DE3）,进行诱导表达、蛋白质纯化鉴定。