Comparison of effects of high-pressure processing and heat treatment on immunoactivity of bovine milk immunoglobulin G in enriched soymilk under equivalent microbial inactivation levels

Immunoglobulin-rich foods may provide health benefits to consumers. To extend the refrigerated shelf life of functional foods enriched with bovine immunoglobulin G (IgG), nonthermal alternatives such as high-pressure processing (HPP) may offer advantages to thermal processing for microbial reduction. To evaluate the effects of HPP on the immunoactivity of bovine IgG, a soymilk product enriched with milk protein concentrates, derived from dairy cows that were hyperimmunized with 26 human pathogens, was subjected to HPP or heat treatment. To achieve a 5 log reduction in inoculated Escherichia coli 8739, the HPP or heat treatment requirements were 345 MPa for 4 min at 30 degrees C or for 20 s at 70 degrees C, respectively. To achieve a 5 log reduction in natural flora in the enriched soymilk, the HPP or heat treatments needed were 552 MPa for 4 min at 30 degrees C or for 120 s at 78.2 degrees C, respectively. At equivalent levels for a 5 log reduction in E. coli, HPP and heat treatment caused 25% and no detectable loss in bovine IgG activity, respectively. However, at equivalent levels for a 5 log reduction in natural flora, HPP and heat resulted in 65 and 85% loss of bovine IgG activity, respectively. Results of combined pressure-thermal kinetic studies of bovine milk IgG activity were provided to determine the optimal process conditions to preserve product function.     

Establishment of Chinese soybean Glycine max core collections with agronomic traits and SSR markers

It is very important to efficiently study and use genetic diversity resources in crop breeding and sustainable agriculture. In this study, different sampling methods and sample sizes were compared in order to optimize the strategies for building a rationally sized core collection of Chinese soybean (Glycine max). The diversity in the core collection captured more than 70% of that in the pre-core collection, no matter what sampling methods were used, at a sampling proportion of 1%. Core collections established with both simple sequence repeat (SSR) marker data and agronomic traits were more representative than those chosen on an independent basis. An optimal sampling method for a soybean core collection was determined, in which strategy ‘S’ (allocating accessions to clusters according to the proportion of square root of the original sample size within each ecotype) was used based on SSR and agronomic data. Curve estimation was used to estimate the allelic richness of the entire Chinese soybean germplasm and a minimum sample size for a core collection, on which a sampling proportion of about 2% was determined to be optimal for a core collection. Further analysis on the core collection with fourteen agronomic traits and allelic constitution at 60 SSR loci suggested that it highly represented the entire collections both on genetic structure and diversity distribution. This core collection would provide an effective platform in proper exploitation of soybean germplasm resources for the study of complex traits and discovering important novel traits for crop genetic development.     

恢复承德玉米制种基地的可行性分析

承德具有自然隔离条件好、气候类型丰富等独特的自然条件,曾是我国高粱和玉米“两杂”作物种子的主要生产基地之一.但由于受多种因素的影响,到20世纪中后期,种子生产基地面积逐步减少.分析了承德作为玉米制种基地的有利条件以及制约制种基地建设的主要因素,提出了适宜的基地建设规模.认为恢复承德玉米制种基地对于推动种子生产基地建设和管理、确保农业生产用种安全和种子业持续健康发展是十分必要和可行的.     

The genetic relationship between popping expansion volume and two yield components in popcorn using unconditional and conditional QTL analysis

Popping expansion volume (PEV) is the most important quality trait in popcorn, while its germplasm is inferior to normal dent/flint corn in yield. In this study, 259 F_2:3 families, developed from the cross between a dent corn inbred Dan232 and a popcorn inbred N04, were evaluated for their PEV, grain weight per plant (GWP) and 100-grain weight (100 GW) in two environments. The genetic relationship between PEV and GWP, and 100 GW on individual gene loci were evaluated using unconditional and conditional QTL mapping methods. In total, five, one and three unconditional QTL were identified for PEV, GWP, and 100 GW, respectively. The positive alleles of all QTL for PEV were from N04, while positive alleles of all QTL for GWP and 100 GW were from Dan232. In conditional mapping, one and two QTL failed to be detected, and all four additional QTL were detected. Nevertheless, three QTL were identified, which controlled PEV independently from GWP/100 GW. They seemed to be potential candidates in popcorn breeding to increase PEV without decreasing GWP/100 GW. The results suggested that for significantly correlated traits, the conditional QTL mapping method could be used to dissect the genetic interrelationship between traits at the level of individual QTL, as well as reveal additional QTL that were undetectable by unconditional mapping.     

Reduced tillage in north-west Europe—A review

The main features of the climate and soils of the main crop production areas of different countries in north-west Europe are outlined, and the main crops grown are summarised. The need for tillage is considered; provided that suitable conditions exist for germination, root growth is most likely to be influenced by mechanical impedance and aeration. Traditional tillage may not always be necessary and may hinder timely sowing of crops. Shallow tillage can facilitate planting a larger area of crops closer to the optimum dates in autumn and in spring, which also saves energy and labour.Research experience with reduced tillage over the last 20–25 years is reviewed. Shallow tillage has been as good as mouldboard ploughing at the traditional depth in most countries on a wide range of soil types, if weed control was satisfactory. Direct drilling has often proved satisfactory in the absence of crop residues for autumn sown crops (wheat, barley, oil-seed rape and beans) where drainage (and therefore soil aeration) was not limiting. Direct drilling has not generally been successful for spring sown crops. Direct drilling is inappropriate for root crops, but strip tillage for sugar beet may become practicable. Some research on soil conditions associated with these experiments is considered.Crop residues are a major constraint to shallow tillage or direct drilling of autumn sown crops. The limitations of reduced tillage due to inadequate weed control, wheel-traffic damage and unsatisfactory drainage are reviewed. The need for occasional deep loosening is also discussed. Where the amount of residues is small, much tillage may be unnecessary, except to relieve compaction by wheels; bed systems or wide-span gantries to avoid wheel damage could become practical developments for some crops.     

Aggregates and gel network structure of globin hydrolysates

A gel with excellent functional properties was prepared successfully using the hydrolysates of globin. In the present study, the structures of intermediate aggregates and gel network were observed directly with an electronic microscope. It was shown clearly that the intermediate aggregates were in a thin rod shape with a length of 130--140 nm, which was in good accordance with the results of the light scattering obtained in a previous study. The diameter of intermediate aggregates was 4--5 nm. Each unit of the intermediate aggregate was composed of beta-chain and peptide beta-1 in a ratio of 1:1. Its molecular weight was 26922 Da, and it had a diameter of 4.1 nm. The thin rod-shaped aggregates were formed with units through the hydrophobic interaction. The length of intermediate aggregate was >30--33 times the diameter. Furthermore, the cross-linked structure formed by peptide alpha-1 and the thin rod-shaped aggregates was also confirmed by the photography of the electronic microscope. These results supported the model proposed in previous papers as proper to depict exactly the formation and structure of the gel network of globin hydrolysates.     

组合式分娩栏对母猪活动和躺卧的影响

为了研究不同型式分娩哺育栏对母猪行为的影响,该试验设计了组合式分娩哺育栏,并进行了饲养试验,同时与普通矩形分娩哺育栏进行了比较。分别记录母猪在哺乳期的采食量以及仔猪的日增质量。在母猪哺乳期的第9、11、14、18天,采用监控设备对8头母猪的行为进行了录像。试验结果表明：组合式和矩形分娩哺育栏内母猪的站立时间分别占各种行为发生时间的22.74%和6.73%,坐立时间分别占2.22%和7.72%,躺卧行为分别占72.50%和84.55%,组合式分娩哺育栏内母猪走动时间占1.13%,矩形分娩哺乳栏内母猪不发生走动行为。组合式分娩哺育栏组母猪的姿势转换次数高于矩形分娩哺育栏组,每天平均数分别为99次和53次。组合式分娩哺育栏组和矩形分娩哺育栏组每头母猪的采食量分别为5.92 kg/d和5.24 kg/d,仔猪日增质量分别为229.93 g/d和224.85 g/d。组合式分娩哺育栏增加了母猪的活动空间,减少了对母猪身体的限制,母猪可以自由的表达各种行为,母猪的活动量增加,提高了母猪的福利状况,母猪的采食量和仔猪的日增质量因此而得到提高,提高了母猪的生产性能。     

Short term soil priming effects and the mineralisation of biochar following its incorporation to soils of different pH

The aim of this work was to determine the magnitude of the priming effect, i.e. short-term changes in the rate (negative or positive) of mineralisation of native soil organic carbon (C), following addition of biochars. The biochars were made from Miscanthus giganteus, a C4 plant, naturally enriched with ¹³C. The biochars were produced at 350 °C (biochar350) and 700 °C (biochar700) and applied with and without ryegrass as a substrate to a clay-loam soil at pH 3.7 and 7.6. A secondary aim was to determine the effect of ryegrass addition on the mineralisation of the two biochars.After 87 days, biochar350 addition caused priming effects equivalent to 250 and 319 μg CO₂-C g⁻¹ soil, in the low and high pH soil, respectively. The largest priming effects occurred at the start of the incubations. The size of the priming effect was decreased at higher biochar pyrolysis temperatures, which may be a way of controlling priming effects following biochar incorporation to soil, if desired. The priming effect was probably induced by the water soluble components of the biochar. At 87 days of incubation, 0.14% and 0.18% of biochar700 and 0.61% and 0.84% of biochar350 were mineralized in the low and high pH soil, respectively. Ryegrass addition gave an increased biochar350 mineralisation of 33% and 40%, and increased biochar700 at 137% and 70%, in the low and high pH soils, respectively. Certainly, on the basis of our results, if biochar is used to sequester carbon a priming effect may occur, increasing CO₂-C evolved from soil and decreasing soil organic C. However, this will be more than compensated for by the increased soil C caused by biochar incorporation. A similar conclusion holds for accelerated mineralisation of biochar due to incorporation of fresh labile substrates. We consider that our results are the first to unequivocally demonstrate the initiation, progress and termination of a true positive priming effect by biochar on native soil organic C.     

延边黄牛与利延一代牛的短期育肥屠宰试验

经８５ ｄ 的育肥试验结果表明,在育肥期间利延Ｆ１ 牛的体高、体长、胸宽、胸深、胸围和髋宽等体尺的增长值均高于延边黄牛,其中利延Ｆ１ 牛髋宽的增长值显著高于延边黄牛（ｐ ＜ ０ ．０１） ．育肥期间延边黄牛与利延Ｆ１ 牛的日增重分别为０ ．８９ ｋｇ 和１ ．０６ ｋｇ,利延Ｆ１ 牛比延边黄牛高１９ ．１ ％ ,差异显著（ｐ＜ ０ ．０５） ;消化试验结果表明,延边黄牛与利延Ｆ１ 牛对日粮中的粗蛋白、粗脂肪、中性洗涤纤维和酸性洗涤纤维的消化率差异不显著（ｐ ＞ ０ ．０５） ;屠宰试验结果表明,延边黄牛与利延Ｆ１ 牛的屠宰率分别是５１ ．６ ％ 和５４．４ ％ ,净肉率分别是３９ ．２ ％ 和４３ ．９ ％ ,肉骨比分别是３ ．１５ 和４ ．１８ ,眼肌面积分别是７２ ．６ ｃｍ２ 和８８ ．６ ｃｍ２ ．经检验,差异均极显著（ｐ ＜ ０ ．０１） ;对牛肉的一般化学成分分析结果表明,延边黄牛与利延Ｆ１ 牛之间差异不显著（ｐ＞ ０ ．０５） ．