不同牛场奶牛泌乳曲线拟合及参数分析

以3个牛场2009～2010年参与DHI测定的成年母牛的泌乳期数据为资料,用Wood模型通过SPSS的非线性参数和决定系数来拟合泌乳曲线并分析泌乳曲线参数在不同牛场和胎次的差异.结果表明,不同牛场估测的泌乳曲线模型参数存在显著的差异(P＜0.05),导致部分泌乳特性参数也有一定的差异.这些差异可能是牛群选育或饲养管理或二者共同的结果.因此,分析泌乳曲线应与牛场自身的饲养管理和选育程度相结合.     

日粮补充植物油籽对奶牛血液脂肪酸及生化指标的影响

试验选择40头生产性能、泌乳日龄相近的妊娠荷斯坦奶牛，采用单因素随机试验设计，研究添加不同植物油籽对其血液脂肪酸及生化指标的影响。试验结果表明，添加植物油籽对奶牛动脉血浆中顺-9，反-11CLA、C18：3。昭等大部分脂肪酸影响不显著。但膨化大豆fES）、混合油籽（MIX）、整粒全脂大豆组（WS）血浆中反-11C18：3，分别较对照组（CT）提高了132．75％、113．36％和41．01％，差异极显著（P〈0．01）。膨化大豆、混合油籽、整粒全脂大豆组动脉血中瘦素（leptin）较对照组分别显著提高219．67％、160．66％和85．25％。总的来看，膨化大豆对血浆中反-11C18：1含量和瘦素浓度影响强于其它处理：而处理之间血浆中CLA含量差异不显著，这也间接说明乳脂中的CLA含量在一定程度上取决于血液中的反-11C18：1。     

甘肃省中西部地区人工牧草产量与气候因子关系研究

根据试验观测资料,分析了气象因素和产量的动态,运用统计学原理分别建立了人工牧草产量与各环境因子及多因子回归模型,采用最优化原理期望值系数法对影响人工牧草的环境因子进行相关分析,并利用水-热指数建立人工牧草产量积累的农业气象模式。     

Extreme rainfall indices and its impact on rice productivity—A case study over sub-humid climatic environment

Frequent occurrences of extreme rainfall events create severe threat to agricultural production. This is one of the most significant consequences of global warming due to increase in greenhouse gases. A precise understanding of frequency and magnitude of these events and its influence on agricultural productivity can extensively help in policy decisions and planning agricultural as well as water management operations. This study has analyzed observed trends in extreme rainfall indices during monsoon months as well as seasonally at four stations located over different agro-ecological zones of Bihar, namely Samastipur (zone-I), Madhepura (zone-II), Sabour (zone-IIIA) and Patna (zone-IIIB). Mann-Kendall nonparametric test was employed for detection of trends and the slopes of the trend lines were determined using the method of least square linear fitting. Since rice is the important crop in this part of the region, the vulnerability of extreme rainfall indices on productivity also analysed using simple correlations. All the sites show an increasing trend of number of days with rainfall 10.0 cm or more (very heavy precipitation event) during monsoon season. Sabour shows a significant increasing trend of 0.4 and 0.6 day/decade, respectively during monsoon and annually. During September, occurrence of heavy precipitation events over Madhepura recorded a significant positive trend of 0.4 day/decade. Highly significant magnitudes of increasing trends were noticed for Madhepura (46.6 mm/decade) and Sabour (27.5 mm/decade) for occurrence of highest five-day total precipitation during monsoon season. The results show statistically significant positive trends of number of days with rainfall > R2.5 cm for all the study sites during August. All the sites, the magnitude of highest 1-day and 5-days maximum rainfall is showing increasing trend. Increasing trends of fraction of rainfall due to extremely wet days is also showing increasing trend in all the sites. The rice productivity showed 10th degree polynomial technological trend in all the sites and steady increase in all the sites except Samastipur. The correlation between extreme rainfall indices during monsoon season and productivity anomaly index indicate that almost all the extreme rainfall indices contribute positively to rice productivity except P95pTOT and R99pTOT over Sabour and R7.5 cm over Patna. If we assume the observed increasing trends in different extreme rainfall indices will continue, as estimated by the global circulation models, the chances of occurrence of intense rainfall events in near future will also increase proportionally and efforts should be made to prepare detailed site specific—at least at district level—disastrous management plan especially to reduce impact of extreme rainfall event on agricultural production system under changing climatic scenarios.     

烟酸铜对仔猪生产性能及血液生化指标的影响

选择体重20 kg左右的仔猪160头,分为5组:对照组饲喂添加150 mg.kg-1Cu(Cu来源于CuSO4)的基础日粮;试验Ⅰ、Ⅱ、Ⅲ和Ⅳ组饲喂分别添加150、135、120和105 mg.kg-1Cu(Cu来源于烟酸铜)的基础日粮,每组4个重复,每个重复8头,试验期28 d,研究烟酸铜对仔猪生产性能和血液生化指标的影响.结果表明:试验Ⅰ、Ⅱ、Ⅲ组的平均日增重(ADG)和平均日采食量(ADFI)均比对照组有所提高,而Ⅳ组则有降低的趋势;同时,前3组的料肉比(FCR)有不同程度的降低,但Ⅳ组则略有提高.与对照组比较,试验组血清的总蛋白(TP)、白蛋白(ALB)含量有提高的趋势,但差异不显著(P>0.05),而血清中的尿素氮(BUN)含量显著下降(P<0.05);Ⅲ组的总胆固醇(T-CHO)、甘油三酯(TG)含量较对照组显著下降(P<0.05),而Ⅳ组则极显著下降(P<0.01).试验组的血清铜蓝蛋白(CP)、总超氧化物歧化酶(T-SOD)水平有不同程度的提高,其中Ⅰ组差异显著(P<0.05),而铜锌超氧化物歧化酶(Cu/Zn-SOD)水平则升高不明显(P>0.05).这表明在猪饲料添加不同含量烟酸铜与添加CuSO4在促生长效果方面基本一致,血液生化指标的变化规律差别不大;有机铜的吸收利用率较无机铜高.     

Growth of Nodipecten subnodosus (Bivalvia: Pectinidae) in La Paz Bay, Mexico

Nodipecten (Lyropecten) subnodosus (Sowerby 1835), the largest pectinid in tropical waters, has been continuously exploited. In support of sustainable development for this species, we started basic growth studies to establish aquacultural practices. N. subnodosus was cultured using triangular plastic cages in La Paz Bay (1995–1996) to describe growth and survival; we determined relationships between quantity of available food and growth and behaviour of body component indices. This culture system allows an isometric shell growth of scallops over 13 months; 56.8±2.1 mm height, 54.5±2.1 mm length and 23.0±1.1 mm width. Allometric growth was found between weight and height, length and width (survival was 44.3%). Body component indices and growth increased progressively until the summer of 1996 when all indices decreased negatively, influenced by high water temperatures. Gonad tissue developed during the first year. Gametogenic activity was evident, presenting the first spawn in summer. Particulate organic and inorganic matter and chlorophyll concentrations were relatively constant during the study, and there was no evidence relating these values to growth and body component indices. Culture of N. subnodosus is feasible in La Paz Bay. However, high water temperatures in summer reduced growth and survival rates.     

维生素A水平对獭兔生产性能及血液生化指标的影响

选用45日龄Vc-Ⅱ新品系獭兔54只,研究维生素A水平对獭兔生产性能及血液生化指标的影响。结果表明,在基础日粮中添加10000IU/kg维生素A可显著提高獭兔的日增重(P<0.05)、降低料肉比(P>0.05)、降低血清BUN含量(P<0.01)。建议VC-Ⅱ生长獭兔日粮中维生素A的添加量为10000IU/kg。     

Pasta-Making Quality in Triticum durum. New Indices from the Ratio among Protein Components Separated by SDS-PAGE

Densitometric analysis of the gluten subunits as resolved by SDS-PAGE electrophoresis of 23 samples from seven varieties of durum wheat has provided further evidence for the positive effect on the quality of pasta made from durum wheat of low-molecular-weight glutenins (LMWG) and high-molecular-weight-glutenins (HMWG) and the negative influence of the intermediate-molecular-weight group (IMWG) (albumins, globulins, some glutenins, and omega gliadins). Differences in the expression of pasta quality were expected among the varieties investigated. However, high quality was invariably the result of a preferential accumulation of (LMWG) and (HMWG) in respect to IMWG. It appeared that such a biochemical feature could represent a general mechanism on which the pasta-making quality of durum wheat relies. The high correlation observed between the ratio (LMWG)/IMWG or (LMWG + HMWG)/IMWG and quality (r = 0.85^*** and 0.88^***, respectively) suggested that SDS-PAGE with densitometry of the gluten subunits could provide new quality indices useful in breeding durum wheats with improved pasta-making quality and for the grading of durum produce for industrial purposes.     

玉米杂交种及其亲本自交系的生化指纹鉴定

本试验以浙单9号等五个玉米杂交组合及其亲本自交系为材料,进行种子盐溶蛋白聚丙烯酰胺凝胶电泳等多种电泳鉴定方法的研究,以揭示玉米杂交种及其亲本自交系的“生化指纹”(biochenucal fingerprint),以及筛选出适合于玉米杂交种及其亲本自交系真实性和纯度鉴定的方法。结果表明,各供试玉米杂交种及其亲本自交系都具有相应的、唯一的种子盐溶蛋白聚丙烯酰胺凝胶电泳所显现的生化指纹。对于有些组合。玉米芽鞘和叶片绿色组织过氧化物酶同工酶电泳图谱存在阴极第4、第5酶带差异,因这两条酶带的差异稳定,并且重现性好,故能用过氧化物酶同工酶技术对其进行有效地鉴定。上述两种方法,尤其是前者,因技术要求不高,费用低,快速及重现性好等特点,能满足我国目前种子检验室日常玉米品种纯度快速测定工作的要求,具育良好的应用前景。     

Selection for bean and liquor qualities within related hybrids of Arabica coffee in multilocal field trials

The success of a new variety of Arabica coffee (Coffea arabica L.) depends to an important extent on its liquor and bean qualities. Selection for these traits is however constrained by the prevalence of large genotype-by-environment (G×E)interactions in conjunction with the low genetic variability characteristic of this species. The aim of this study was to assess the extent to which key bean and liquor traits are affected by the environments and could be combined in order to improve the efficiency of selection for coffee quality in a narrow genetic basis set of hybrids obtained from a set of related lines and collectively representing the Ruiru 11 cultivar. Twenty-one full-sib families representative of this hybrid cultivar grown in Kenya in five sites exhibiting strong edaphic and climatic differences were used for the study. Rainfall amounts during various phases of berry development were used to explain the differences observed in the discriminating abilities of the locations for bean and liquor traits. The results showed that these families were best differentiated for bean sizes in the site where moisture supply was optimal throughout berry expansion and filling stages, whereas discrimination on the basis of liquor traits were best observed in the site where moderate moisture stress occurred during bean filling stage. The overall precision in prediction of family values was low for liquor qualities; but a much more efficient selection for large bold beans, optimally based on the AA grade was shown to be possible. Selection indices for family selection were computed to realize a trade-off between genetic gains in bean size and liquor flavour. This revised version was published online in August 2006 with corrections to the Cover Date.