超声波对鱿鱼墨黑色素成分和物理结构的影响

为了提高鱿鱼综合利用价值,以加工废弃物中的鱿鱼墨黑色素为原料,研究超声波处理对黑色素成分和物理结构的影响。采用超声功率15 W/mL、超声时间2 s、间歇时间1 s、总工作时间20 min的工作条件对黑色素进行处理。结果表明：鱿鱼墨黑色素在超声波处理后,波长为224 nm和267 nm附近的两个峰吸光值显著增加,黑色素在环己烷中的溶解性显著增加,样品中没有新的具有紫外可见吸收特性物质生成;黑色素中蛋白质在超声波处理后的没有发生显著变化,而脂质含量显著减少;超声波后Ca、Mg、Na、K、Fe、Cu、Cd和Pb等8种金属元素含量均显著降低;电镜图片显示黑色素微球颗粒在超声过程中发生了爆炸,产生更为细小的碎片和碎末。     

诃子抗氧化活性物质提取工艺与抗氧化活性研究

对诃子抗氧化活性物质提取工艺、抗氧化活性及其初步物质基础进行了研究。结果表明,最佳提取工艺为：乙醇体积分数50%、液料比20、提取温度60℃、提取次数4次、提取时间7min;总还原力、FRAP法抗氧化能力和DPPH自由基清除能力的结果均显示诃子粗提物具有很强的抗氧化活性。生物活性追踪结果发现,诃子抗氧化活性物质主要由存在于乙酸乙酯相的弱极性化合物组成,该相质量浓度为25、50μg/mL样品的总还原力OD700值分别为0.197±0.002和0.380±0.006,FRAP法抗氧化能力OD593分别为0.272±0.023和0.631±0.002,DPPH自由基清除率分别为(86.838±0.600)%和(90.318±0.917)%。相关关系表明,诃子抗氧化活性的主要物质基础为总黄酮和总多酚。     

Soil aggregation and water holding capacity of soil amended with agro-industrial byproducts and poultry litter

Journal of Soils and Sediments - Soil organic matter (SOM) addition has been shown to be effective for improving physicochemical and hydrological properties, but its effectiveness may be improved...     

Epidemiology of nematode parasites of sheep around Jimma,southwestern Ethiopia

An investigation was made into the epidemiology of nematode infections of sheep in two districts of Jimma zone, southwestern Ethiopia. We used two approaches—long-term monitoring of identified sheep for nematode infection and abattoir or market survey for analysis. In the first monitoring regime, we used 80 lambs [40 sheep (20 per sex) from each district (Dedo and Yebu)] averaging 4–5 months of age. Faecal egg counts (FEC), packed cell volume (PCV) and body weight changes were monitored over a period of 1 year. Additionally, faecal samples were collected (on a weekly basis) from sheep brought to abattoir/market for 1 year to monitor faecal egg counts. The nematode parasite burden, as judged by FEC and PCV, was generally low indicating that the climatic conditions are not conducive to the development and survival of nematode eggs and the free-living stages; hence, little transmission occurred. In the experimental flocks, the highest FEC and lower PCV were recorded during the long rainy season (June to September) with peak in August and September. Faecal samples collected from abattoir/market also followed the same trend. Results from experimental sheep indicated that location had a significant (P < 0.01) effect on FEC, PCV and average daily body weight gain. The FEC and PCV for sheep in Yebu (mid-altitude) district were 126 ± 3.33 and 30.6 ± 0.26, whereas the values for Dedo (highland) were 93 ± 4.35 and 32.0 ± 0.21, respectively. The results indicate that the highland areas are comparatively less favourable to the survival and development of nematodes. Female lambs had lower FEC and higher PCV compared to male lambs (P < 0.05). The overall nematode parasite challenge in the area, however, is low. We, therefore, recommend rotational grazing management combined with monitoring parasite load and selective treatment to reduce productivity loses and pasture contamination.     

Induced resistance to foliar diseases by soil solarization and Trichoderma harzianum

The effect of soil solarization and Trichoderma harzianum on induced resistance to grey mould (Botrytis cinerea) and powdery mildew (Podosphaera xanthii) was studied. Plants were grown in soils pretreated by solarization, T. harzianum T39 amendment or both, and then their leaves were inoculated with the pathogens. There was a significant reduction in grey mould in cucumber, strawberry, bean and tomato, and of powdery mildew in cucumber, with a stronger reduction when treatments were combined. Bacillus, pseudomonad and actinobacterial communities in the strawberry rhizosphere were affected by the treatments, as revealed by denaturing gradient gel electrophoresis fingerprinting. In tomato, treatments affected the expression of salicylic acid (SA)‐, ethylene (ET)‐ and jasmonic acid (JA)‐responsive genes. With both soil treatments, genes related to SA and ET – PR1a, GluB, CHI9 and Erf1 – were downregulated whereas the JA marker PI2 was upregulated. Following soil treatments and B. cinerea infection, SA‐, ET‐, and JA‐related genes were globally upregulated, except for the LOX genes which were downregulated. Upregulation of the PR genes PR1a, GluB and CHI9 in plants grown in solarized soil revealed a priming effect of this treatment on these genes' expression. The present study demonstrates the capacity of solarization and T. harzianum to systemically induce resistance to foliar diseases in various plants. This may be due to either a direct effect on the plant or an indirect one, via stimulation of beneficial microorganisms in the rhizosphere.     

丁香有效部位对低密度脂蛋白弱氧化修饰的抑制效果

低密度脂蛋白(LDL)弱氧化修饰是形成动脉粥样硬化(AS)的关键因素。为了研究丁香有效部位(EFC)对LDL弱氧化修饰的抑制效果,采用Fe~(2+)体外诱导LDL弱氧化,通过测定脂质过氧化产物共轭二烯(CD)、硫代巴比妥酸反应物(TBARS)的产生、LDL紫外可见光谱及载脂蛋白B-100(apo B-100)中赖氨酸(Lys)游离氨基、色氨酸(Trp)活性的衰减程度反映抑制效果。结果表明,在LDL弱氧化过程中,对脂质过氧化保护方面,EFC(2.5μg/m L)能有效延缓增殖阶段CD产生,其延缓效果强于0.5μg/m L阳性对照。EFC(50μg/m L)能延缓LDL降解阶段TBARS生成,延缓效果强于10μg/m L BHT;相应质量浓度(1.25μg/m L、1.5μg/m L)的EFC能减缓LDL因为氧化而改变的紫外可见光谱。对蛋白(apo B-100)氧化保护方面,EFC(5μg/m L)能显著抑制Lys中游离氨基活性衰减(P0.05),其抑制效果与1.25μg/m L BHT无显著性差异;EFC(1μg/m L)能保护apo B-100中Trp免受破坏。结果表明EFC能有效抑制LDL弱氧化,为后续相关功能食品研发提供了参考。     

Genetic and phenotypic parameter estimates for reproduction traits in indigenous Arsi-Bale goats

The study was conducted to evaluate reproductive performances and estimate genetic parameters for reproduction traits in Arsi-Bale goats. A total of 792 kidding records collected from 2001 to 2007 were used. Parity of dam, year, season and type of kidding were investigated as fixed effects by PROC GLM of SAS. Derivative-Free Restricted Maximum Likelihood (DFREML) method was used to estimate genetic parameters by fitting four animal models. Parity of dam and year of kidding influenced (P < 0.05) all the traits. The overall means for age at first kidding (AFK), kidding interval (KI), litter size at birth (LSB), litter size at weaning (LSW), litter weight at birth (LWB), litter weight at weaning (LWW), abortion and dystocia were 574.9 ± 8.3 days, 280.0 ± 13.7 days, 1.6 ± 0.03, 1.37 ± 0.03, 3.7 ± 0.08 kg, 9.11 ± 0.38 kg, 3.8% and 0.13%, respectively. The estimates of direct additive heritability for the traits, except for abortion and dystocia, under the best model (direct animal for AFK and repeatability model for other traits) were 0.245 ± 0.19, 0.060 ± 0.08, 0.074 ± 0.05, 0.006 ± 0.05, 0.125 ± 0.05, 0.053 ± 0.07, respectively, while the corresponding permanent environmental effects were 0.00 ± 0.00, 0.07 ± 0.07, 0.08 ± 0.05, 0.172 ± 0.06, 0.03 ± 0.04 and 0.07 ± 0.05, respectively. Repeatability estimates for KI, LSB, LSW, LWB and LWW were 0.13, 0.15, 0.18, 0.16 and 0.12, respectively. Genetic correlations between reproductive traits vary from medium to high. Arsi-Bale goats have good reproductive performance with low incidence of reproductive disorder. Except for AFK, other traits have low estimates of heritabilities with high genetic correlation among the traits. Repeated measures of the traits are needed before deciding to keep or cull the animal.     

Smallholder goat breeding and flock management practices in the central rift valley of Ethiopia

The study was conducted in the central rift valley of Ethiopia to define Arsi-Bale goat keepers’ breeding objectives and breeding practices and to describe flock management practices and rate of inbreeding in Arsi-Bale goat population. Two-stage sampling techniques were employed to select study sites and 202 respondents. Semistructured questionnaire and group discussion were used to collect the required information. Data were analyzed using statistical package for social science. Rate of inbreeding in the population and indices were also calculated. On average, each respondent holds around 12 goats in which 30.7, 66.6 and 2.7% were males, females and castrates, respectively. The most important purpose of goat production in the study area was for milk utilization. Farmers have multiple breeding objectives and they considered both subjective and objective selection criteria with slightly more emphasis on morphological characteristics for buck selection than replacement doe selection. Only 39.1% (n = 79) of respondents have their own breeding bucks. None of the respondents practiced controlled mating. Average rate of inbreeding in the population was around 0.20. Arsi-Bale goats are found to be adaptive to the prevailing condition. Therefore, any breed improvement strategy to be designed or implemented in the study area and other similar areas should consider important traditional breeding practices.