朝鲜鹌鹑体重与体尺的相关及回归分析

利用SPSS 13.0分析软件对9周龄朝鲜鹌鹑的体尺和体重进行了相关分析、通径分析并建立了最优回归方程。研究表明,朝鲜鹌鹑的胫长(X1)、胸宽(X2)、胸深(X3)、胸骨长(X4)和体斜长(X5)5个体尺性状与体重(Y)存在不同程度的相关性,而且相关的密切程度有性别差异。胸骨长和体斜长是影响公鹑体重的2个主要体尺指标,而胫长和胸深是影响母鹑体重的2个主要体尺指标,在选择朝鲜鹌鹑体重的同时对公鹑应加强胸骨长和体斜长的选择力度,而对母鹑应加强胫长和胸深的选择力度。最优回归方程公鹑为:Y=-90.395+19.690X2+20.667X4+8.899X5;母鹑为:Y=-16.678+48.269X1。     

冷冻对椰肉质构特性以及榨汁后流变学和脂肪球粒度分布特性的影响

冷冻贮藏保鲜是目前普遍公认的最为安全的食品保鲜方法之一,已被工业化广泛应用。本研究采用冷冻贮藏食品中常用的4种温度（-80、-40、-18、-10 ℃）对椰肉进行冷冻处理,经过自然解冻后对椰肉质构、榨汁后椰浆流变学和脂肪球粒度特性进行研究与分析。结果表明,冷冻后椰肉硬度明显减小,且随着冷冻温度的升高而减小;椰浆表现出假塑性流体的特征,冷冻使椰肉榨汁后的椰浆黏度、剪切应力和脂肪球粒度都增加,且随着冷冻温度的升高而增加,脂肪球颗粒均匀度下降。     

马铃薯种薯生产技术标准参数研究──Ⅰ．不同种植密度对种薯产量和块茎大小的影响

本研究以马铃薯极早熟品种“东农３０３”脱毒种薯为试验材料，将种薯分成（２０±５）ｇ和（３０±５）ｇ两组，分别按５个密度进行种植（行距均为７０ｃｍ，株距分别为１２．５、１５．０、１７．５、２０，０和２２．５ｃｍ）．试验结果表明，在哈尔滨的自然条件下，马铃薯块茎产量和单位面积块茎数目随着种植密度的增大而增加，单个块茎重量则随着密度的增加而减少．大种薯（３０±５）ｇ播种可以获得较高的块茎产量．在本试验中，种薯重量为（３０±５）ｇ、株１２．５和１５．０ｃｍ时，获得了较高的块茎产量和较多的块茎数．通过对植株地上部鲜重和叶面积指数变化的分析，表明高密度群体具有发育快、生长旺盛的特点。     

Quality Improvement in Oat

Abstract

Oats (Avena sauva L.) are a nutritious, high protein grain crop with important food, feed and value-added applications. For commercial purposes, oat quality is frequently expressed as a grade, based on test weight, foreign matter, and the physical appearance of the grain. More detailed quality analyses may include evaluations for percent groat, kernel size and uniformity, and groat composition. Compositional components of economic importance include protein, fat, β-glucan and antioxidant concentrations. Exact quality specification for quality requirements can vary widely among applications. Feed applications favor higher protein and fat concentrations, and lower fiber. Food applications favor lower fat concentrations, and higher β-glucan. Production of high quality oat grain is dependent on the planting of high quality seed with current local adaptation, sound cultural practices, and favorable weather conditions. It is particularly important that seed planted produce plants resistant to current races of pathogens. Disease infestation is a common source of quality loss. Whereas, unfavorable environmental conditions can frequently result in quality loss, breeders continue to strive for environmental stability of quality traits through genetic improvement of oats.     

Study of the impact of wheat flour type,flour particle size and protein content in a cake-like dough: Proton mobility and rheological properties assessment

The study of food products is always a challenge due to the number of components involved and the interactions that may occur between them. Water is a particular ingredient which interacts with all hydrophilic compounds, although affinities may differ for limiting water amount. During this study, results obtained using ¹H NMR on cake dough were compared in terms of the effects of flour type (soft or medium hard), the addition of gluten (5%–20%) and the use of soft flour fractions (flour particle fractions smaller or larger than 50 μm). T₂ values and the signal intensities of different proton populations were studied as a function of the wheat protein contents of dough samples. Physicochemical characterization methods were used to better understand how the origin and particle size of flour might impact the hydration properties and mobility of a model system. Increasing the protein content in dough samples was related to an increase of the mobility of fat protons and of the least mobile proton population (relaxation times ranging from 175 to 180 ms and from 5 to 7 ms, respectively).     

Particle size heterogeneity in milled barley and sorghum grains: Effects on physico-chemical properties and starch digestibility

The average particle size of ground grains is known to influence properties related to processing (e.g. water absorption and solubility) and nutritional value (e.g. starch digestion rate) of human foods and animal feeds. The purpose of this study was to identify the contributions made by individual size fractions of hammer-milled barley and sorghum grains to average bulk compositional, hydration, rheological, and enzyme susceptibility properties. Barley and sorghum grains were each hammer-milled through a 4 mm screen and subsequently fractionated on a set of eight sieves ranging from 0.125 mm to 2.8 mm. Individual fractions were characterised for (1) starch, aNDF, and water content, (2) water absorption index (WAI) and water solubility index (WSI), (3) viscosity profile during cooking and cooling in excess water, and (4) in vitro starch digestibility. Weighted average values based on fraction yields and property values for WAI, WSI, and starch digestibility were not significantly different from values obtained for non-fractionated ground grains of both barley and sorghum. Glucose yields from starch digestion varied about ten-fold between the smallest and largest particle fractions, and WAI and WSI had value ranges of 1.9–2.8 g/g (sorghum), 2.1–4.0 g/g (barley) and 1.3–4.5% (sorghum), 0.7–10.3% (barley), respectively. Viscosity profiles for milled sorghum grain fractions were dominated by starch swelling which became increasingly restricted as particle sizes increased. Viscosity profiles for milled barley grain fractions did not exhibit typical starch-based behaviour and were most likely dominated by soluble fibres. Taken together, the results show that there is considerable potential for designing combinations of hydration, rheological and digestibility properties of ground grains through informed selection of appropriate grains and particle size distributions.     

Durum wheat breadmaking quality: Effects of gluten strength,protein composition,semolina particle size and fermentation time

The effects of particle size of granulars (semolina and flour combined), gluten strength, protein composition and fermentation time on the breadmaking performance were compared for eleven durum wheat genotypes of diverse strength from North America and Italy grown in the same environment. All genotypes were γ-gliadin 45 types (low-molecular weight glutenin subunit 2 patterns) associated with superior pasta-making quality. Three cultivars with high-molecular weight glutenin subunit 20 exhibited relatively weak gluten, confirming that this subunit is associated with weakness in durum wheat. Gluten strength as measured by a range of technological tests was directly and strongly related to the proportion of insoluble glutenin (IG) in granulars protein as determined by a spectrophotometric procedure. Reducing the particle size of granulars by gradual reduction shortened development time in both the farinograph and mixograph. Reducing granulars also increased starch damage and, accordingly, farinograph water absorption, but remix-to-peak baking absorption was unaffected due to increased fermentation loss for finer granulars. Neither loaf volume, nor remix-to-peak mixing time were affected by the particle size of the granulars indicating that regrinding is not an asset for baking provided there is adequate gassing power. Loaf volume was directly related to gluten strength and IG content, and inversely related to residue protein, a non-gluten containing fraction. When fermentation time was reduced from the standard 165 to 90 min and 15 min, all genotypes exhibited a progressive increase in loaf volume. Therefore, regardless of strength, short fermentation time is preferred when high volume durum wheat bread is desired. Some of the stronger durum genotypes exhibited remix-to-peak bread volume comparable to that expected of good quality bread wheat, indicating that there is potential to select for genotypes with improved baking quality in conventional breeding programs by screening for high content of insoluble glutenin.     

规模化猪场妊娠母猪2种饲喂方式的比较研究

为研究一种更有利于提高妊娠母猪生产性能的饲喂方式,为临床生产提供参考信息。于2015年4月在临沂帛乘原种猪繁育有限公司进行试验,将56头3~6胎次配种期接近的妊娠母猪随机平均分为A、B两组,每组妊娠期114天,哺乳期21天。A组采用妊娠期每天1次、哺乳期每天4次和断奶后7天内每天2次的饲喂方式,B组进行传统的妊娠期每天2次、哺乳期每天4次和断奶后7天内每天2次的饲喂方式。结果表明,A组在总产仔数、产活仔数、仔猪出生重、21天断奶仔猪重和断奶后7天发情率等方面均优于B组,且优势明显。规模化猪场母猪在妊娠期内每天采用1次饲喂,其繁殖性能优于2次饲喂。     

Freezing tolerance of selected perennial ryegrass (<Emphasis Type="Italic">Lolium perenne</Emphasis> L.) accessions and its association with field winterhardiness and turf traits

Reproductive output and fertility variation in teak were evaluated in five study sites in Western Ghats region of southern India. In four seed production areas (SPA1-4)) and a natural population (NAT) plots with 100 trees were investigated. The 40-year-old seed production areas are located in high rainfall (>2,500 mm) sites in Kerala state and the natural stand is at a drier location in Tamil Nadu. Fruit production per tree was rather high in the natural stand (1500) and quite variable in the seed production areas. SPA 4, located far south from the other sites, had the highest fruit production (almost twice that in the other study sites), high relative population size (N _r = 0.5) and predicted low genetic drift in two consecutive years. Fecundity was very low in SPAs 2 & 3 (200 fruits per tree). Reproductive output was similar in successive years except SPA 1, where the fruit production in the first year was almost five times that in the second year. Fertility variation (computed as sibling coefficient, Ψ) was in general higher in NAT and hence the relative population size was lower than in SPAs. The variation in female fertility in the natural stand was, somewhat surprisingly, similar to that in the seed production areas, while the male fertility variation was higher. In the seed production areas the male fertility variation was lower or similar to the female fertility variation. The fertility variation, Ψ was on average around 3 and correspondingly the relative effective population size, N _r = 0.36 and the variance effective number around 60. Selection for tree diameter would improve predicted diversity of the seed crop as it was positively correlated with reproductive output and negatively correlated with fertility variation among trees.     

Cutting Wheel Structure Selection of EPB TBM and Its Adaptability Evaluation in Large Particle Size Gravel Strata

Large particle size gravel strata layer is very difficult for TBM construction which brings about a series of problems for EPB TBM advancing in Beijing Metro. Cutting wheel is an important component of EPB TBM and cutting wheel with reasonable structure is essential for EPB TBM to advance steadily and effectively in large particle size gravel strata. In-situ EPB TBM advancing tests are carried out in large two adjacent shield interval where the strata conditions make it possible to find out the most efficient cutting wheel structure by monitoring key parameters through Real-time Information Management System. Based on the analysis and comparison of advancing efficiency, strata adaptability of key parameters and tools wearing, the following conclusions can be obtained: 1) Spoke cutting wheel has better strata adaptability and higher efficiency than panel cutting wheel as well as more advantages in controlling tools wearing. 2) open ratio ranging from 55% to 65% is the reasonable for cutting wheel. 3) Advancing speed and earth pressure are very important for EPB TBM construction. Compared with panel cutting wheel, spoke cutting wheel can obtained higher advancing speed and more stable earth pressure in tests. However the change of earth pressure should also be paid attention when EPB TBM advancing in fast speed. The advancing speed should be controlled in the range of 20 to 60 mm/min.