不同供磷水平对柱花草和黑籽雀稗根际生理活性的影响

以热带柱花草和黑籽雀稗为材料，通过盆栽试验，研究不同磷水平对其根际酸性磷酸酶、微生物数量及根系活力的影响。结果表明：2种牧草根际酸性磷酸酶(ACP)活性随着磷浓度的增加而降低，在低磷(P0)处理时达最高，柱花草的ACP活性为603.24 mg/(kg·h)，黑籽雀稗为367.21 mg/(kg·h)。当高磷浓度处理时，柱花草根际ACP活性较黑籽雀稗低。各处理中，柱花草的根际微生物总量较黑籽雀稗高，柱花草根际真菌的数量随磷浓度的增加而减少，处理间差异达极显著水平，低磷处理时土壤真菌数量较多，这有利于根瘤菌的形成。2种牧草的根系活力随着施磷浓度的增加而递减。黑籽雀稗根系活力P0处理极显著高于P3和P4处理,显著高于P2处理。黑籽雀稗根系活力受供磷水平的影响大于柱花草。     

Are dual-purpose and male layer chickens more resilient against a low-protein-low-soybean diet than slow-growing broilers?

ABSTRACT

1. Although fattening dual-purpose types or male layer hybrid chickens appears more ethical than the common practice of culling day-old male layer chicks, the lower feed efficiency of these birds raises concerns. Replacing feed ingredients that compete with food production by those of lower value for human nutrition would be beneficial.

2. Lohmann Dual (LD), a modern dual-purpose type, Lohmann Brown (LB), a male layer hybrid, and Hubbard JA 957 (HU), a slow-growing broiler type, were fattened for nine weeks on two diets (control or ?20% crude protein; n = 6 × 12 birds). Growth, carcass and meat quality were analysed.

3. Growth performance of HU exceeded that of LD and especially of LB. The growth depression caused by the low-protein diet fed to LD (?7%) was only half of that found in HU (?13%). The LD fed the control diet had the same feed efficiency as the HU fed the low-protein diet. Even the LB had a lower performance and feed efficiency with the low-protein diet in growth. There was a gradient in carcass properties (weight, dressing percentage, breast meat yield, breast proportion and breast angle) from HU to LD to LB, with some additional adverse effects of the low-protein diet especially in HU. There were some breed differences in fatty acid profile in the intramuscular fat.

4. In conclusion, the dual-purpose type used complied with regulations for Swiss organic poultry systems in terms of growth rate and was found to respond less when fed a low-protein diet than the slow-growing broiler type. The LB males were inferior in all growth and carcass quality traits. Future studies need to determine the exact protein and amino acid requirements of dual-purpose and layer hybrid chickens and the economic feasibility of the systems, especially for organic farming.     

Ovarian mixed germ-cell tumor comprising mature teratoma and embryonal carcinoma in a four-toed hedgehog (Atelerix albiventris)

This report describes the clinical and histopathological characteristics of a rare mixed germ-cell tumor comprising teratoma and embryonal carcinoma in the left ovary of a 10-month-old four-toed hedgehog, with chief complaints of loss of appetite and lethargy. Laparotomy revealed a swollen left ovary with small disseminated peritoneal nodules, and bilateral ovariohysterectomy was performed. The left ovary had a mature teratoma with well-differentiated fat, bone, cartilage, salivary gland, trachea, keratin cyst, and nervous tissues, and an embryonal carcinoma consisting of poorly-differentiated epithelial cells arranged in tubular, alveolar, or solid patterns. Immunohistochemically, the embryonal carcinoma cells were positive for placental alkaline phosphatase and c-KIT. This is the first case of mature teratoma with embryonal carcinoma in the ovary of a hedgehog.     

酸与碱处理对海带多糖提取及其抗氧化活性的影响

本试验采用柠檬酸提取法和碱提取法从海带中提取多糖组分,以总抗氧化能力和羟自由基（·OH）为衡量抗氧化活性指标,比较这两种提取方法得到海带粗多糖产率和抗氧化活性。试验结果表明：柠檬酸提取法和碱提取法的提取率分别为15.92%和6.05%,所提取的海带粗多糖具有良好的抗氧化活性,且柠檬酸提取法抗氧化活性更高。 [关键词] 柠檬酸提取法|碱提取法|海带多糖|抗氧化活性     

不同供磷水平小麦苗期根系特征与其相对产量的关系

研究了缺磷条件下不同基因型小麦苗期根系形态学及生理学适应特征 ,结果表明 :在缺磷环境中 ,小麦根轴数量和侧根长度明显减小 ,同化物向根部的分配比例增加 ,根轴长度、侧根数量和根系长度等均是显著提高。供试基因型小麦的根轴数量及其长度的差异在每个供磷水平及不同供磷水平之间均是显著的 ,说明这两种性状的差异是由基因型和环境因素共同决定的 ;而侧根特征的差异只在不同供磷水平之间是显著的 ,表明侧根性状主要是受环境因素控制的。对 6种基因型小麦的研究表明 ,高磷水平的小麦种子根的生长角度明显低于低磷处理的小麦 ,根角之间存在着显著的基因型差异。在缺磷条件下 ,6种基因型小麦完整根系分泌的酸性磷酸酶活性、根轴数量、根轴长度、根生长角度和根系长度之间均存在着显著的基因型差异。相关分析表明 ,缺磷条件下的小麦苗期根系形态指标和根系分泌的酸性磷酸酶活性的交互作用与小麦的相对产量之间具有显著的线性关系 ,这种关系说明以上 5种性状均可作为早期有效地筛选磷高效小麦品种的指标     

碱法草浆造纸蒸煮黑液厌氧生物降解及其主要微生物类群研究

采用中温(35±1℃)UASB AF相结合的反应器处理碱法草浆造纸蒸煮黑液,设计了两种试验方案。试验方案Ⅰ-碱法草浆黑液酸化后进行厌氧发酵,Ⅰ号反应器内装陶粒。试验方案Ⅱ-黑液用化学法(HCl)去除木质素后进行厌氧发酵,Ⅱ号反应器内装软填料。进行HRT、有机负荷和有机污染物(COD_(cr)、BOD_5)去除效率、沼气产气率相关性试验。在厌氧发酵稳态运行条件下,采用Hungate厌氧操作技术,MPN计数法对UASB AF反应器内厌氧污泥中的主要微生物类群区系组成进行了生态分析研究。     

Study on Soil Improvement Measure of Plant Landscape Construction in Saline and Alkaline Area in Tianjin

Tianjin is located in North China, which is semi- arid climate, next to east of Bohai, but being influ- enced little by internal bay. The urban district and strand area locates in a crossing area between the al- luvial plain of Hai River and the land form…     

芒果中性/碱性转化酶MiNI基因的克隆与表达分析

采用RT-PCR技术克隆了1个编码NI基因的cDNA序列,命名为MiNI基因,并对不同来源的中性/碱性转化酶的分子特征及系统进化进行比较分析。结果表明：MiNI基因开放阅读框为2034 bp,编码677个氨基酸,相对分子量为76.6 kDa,理论等电点为6.24;生物信息学分析结果显示,NI二级结构α螺旋占38.85%,无规则卷曲占35.45%,伸展链占18.91%,β折叠占6.79%;MiNI具有glycoside hydrolase family 100结构保守域,与克里曼丁桔、龙眼、巴西橡胶树和番木瓜都具有一致的motif位点;MiNI基因编码的氨基酸序列与克里曼丁桔、龙眼氨基酸序列同源性最高;构建NI系统进化树分析表明,与芒果遗传距离最近的是克里曼丁桔,最远的是玉米和枸杞。qRT-PCR分析显示,果皮MiNI基因表达量远高于果肉;花后10~40 d,果皮MiNI基因表达量显著下降;花后40~100 d,果皮MiNI基因表达量维持在一个相对稳定水平;花后100~130 d,随着果实成熟,果皮MiNI基因表达量又显著上升;而花后10~40 d,果肉MiNI基因表达量显著下降,至果实发育后期果肉MiNI基因表达量始终处于极低水平。该研究为进一步了解MiNI基因在芒果果实蔗糖代谢过程中的作用以及从分子角度阐明芒果糖代谢机理奠定理论和技术基础。