动物肠道正常菌群对黏膜免疫影响的研究进展

动物胃肠道内存在有大量的正常微生物，对动物的消化生理、营养物质的代谢及动物对外源有害微生物入侵的抵御起着重要的作用，是动物的自然生物屏障，正常菌群对机体的免疫系统功能特别是黏膜免疫功能的发挥具有重要意义。     

菜子饼对仔鸡饲粮氨基酸消化率和生产性能的影响

试验用29日龄肉用仔鸡、以Cr_2O_3作指示剂、回肠末端取样法测定了含不同菜子饼的饲粮的氨基酸表观消化率,并比较了不同饲粮对肉用仔鸡生产性能的影响.结果表明:(1)榨油工艺影响菜子饼中硫葡萄糖甙水解物的量,200型螺旋压榨菜子饼、95型螺旋压榨菜子饼和200型螺旋压榨浸出菜子饼分别含6.691、3.668和2.104mg/g饼肉用仔鸡的甲状腺重与饲粮中菜子饼种类和用量有关.(2)三种菜子饼均降低了饲粮的氨基酸消化率,这种效应以200型螺旋压榨菜子饼最大,200型螺旋压榨菜子饼最小,95型螺旋压榨菜子饼居中.肉用仔鸡的生产性能与饲粮的氨基酸消化率相关.     

不同剂型植酸酶对蛋鸡产蛋性能、蛋品质和骨骼质量的影响

本研究旨在探讨2种剂型(粉状和颗粒状)植酸酶对产蛋高峰期蛋鸡产蛋性能、蛋品质和骨骼质量的影响.选取1 440只30周龄产蛋高峰期罗曼粉壳蛋鸡随机分为4个处理,每个处理10个重复,每个重复36只.处理Ⅰ为正对照组,饲喂基础饲粮,处理Ⅱ为负对照组,在试验期的第1～5周在正对照组饲粮的基础上分别降低钙和有效磷水平至3.23%和0.24%,而在试验期的第6～10周则降至3.23%和0.19%.处理Ⅲ在处理Ⅱ的基础上添加粉状植酸酶(300 U/kg),处理Ⅳ在处理Ⅱ的基础上添加颗粒状植酸酶(300 U/kg).试验期10周.结果表明,低磷饲粮显著降低全期平均日采食量和胫骨灰分含量(P<0.05),提高后期破蛋率(P<0.05),对日产蛋率、平均蛋重、蛋品质等无显著影响(P>0.05).添加2种植酸酶均显著提高平均日采食量(P<0.05)和胫骨灰分含量(P<0.01),但2种植酸酶之间产蛋率、平均蛋重、蛋品质等无显著差异(P>0.05).添加粉状植酸酶能显著提高灰分中磷的含量(P<0.05),添加颗粒状植酸酶显著降低了后期破蛋率(P<0.05).由此可知,在低磷蛋鸡饲粮中添加植酸酶可显著提高蛋鸡平均日采食量和胫骨灰分含量,对蛋品质的影响不显著.2种剂型的植酸酶对产蛋性能、蛋品质和骨骼质量的影响无显著差异.     

确定钢筋混凝土独立柱基础的高度

本文通过公式的推导设计步骤的实例,提出用计算的方法直接确定基础的高度。     

Finite mixture model analysis of microarray expression data on samples of uncertain biological type with application to reproductive efficiency

Common goals of microarray experiments are the detection of genes that are differentially expressed between several biological types and the construction of classifiers that predict biological type of samples. Here we consider a situation where there is no training data. There is considerable interest in comparing expression profiles associated with successful pregnancies (SP) and unsuccessful pregnancies (UP) in model and farm animals. Successful pregnancy rate is known to be much higher in embryos generated by in vitro fertilization (IVF) than in nuclear transfer (NT) embryos, and higher under induced ovulation for large follicles (LF) than for small follicles (SF). The tasks of identifying genes differentially expressed between SP and UP, and predicting SP for future samples are not well accomplished by comparing IVF and NT, or LF and SF. A suitable method is finite mixture model analysis (FMMA), which models each observed class (IVF and NT, or LF and SF) as a mixture of two distributions, one for SP and one for UP, with different known or unknown proportions (here known to be 0.50 SP for IVF and 0.02 SP for NT). The means of the two distributions differ for the differentially expressed genes, which we identify via a likelihood ratio test. We confirm by simulation that FMMA strongly outperforms hierarchical clustering and linear discriminant analysis using the known class labels (NT, IVF). We apply FMMA to a real data set on IVF and NT embryos, and compute their posterior probabilities of SP, which confirm our prior knowledge of the SP proportions for IVF and NT.     

山东省城市旅游经济联系时空差异及其动力机制

利用山东省统计年鉴及社会统计公报数据,运用引力模型、旅游经济隶属度模型,对2004～2010年山东省17个地级市旅游经济联系的时空差异进行了定量研究,结果表明:2004～2010年山东省城市旅游经济联系,时空差异明显,鲁中和鲁东地区的城市旅游经济联系强于鲁西地区,城市旅游经济连系呈现不规则的"H"型空间结构模式;泰安的旅游地位和作用突出,济南和青岛的旅游影响力下降。经济发展水平、旅游区位、旅游基础设施、旅游资源、旅游政策等因素共同构成山东省时空差异的动力机制。     

饲粮策略对不同遗传品系二郎山山地鸡生产性能和屠宰性能的影响

本试验旨在研究饲粮策略对不同遗传品系和性别的二郎山山地鸡生产性能和屠宰性能的影响。试验采用4×2×2因子设计,4个二郎山山地鸡遗传品系[SD02、SD03、SD03×SD02(SD0302)、SD02×SD03(SD0203)]、2个饲粮策略[1~28 d、29~49 d、50~67 d的赖氨酸水平分别为1.15%~1.00%~0.85%(高赖氨酸)、1.00%~0.85%~0.70%(低赖氨酸)]、公母2个性别。每个处理公母各4个重复,每个重复30只鸡,共计1 920只。试验考察了山地鸡各阶段的生产性能、28 d血清生化指标及67 d屠宰性能。结果表明:饲粮策略对各阶段二郎山山地鸡采食量无显著影响(P>0.05),高赖氨酸饲粮显著提高了山地鸡1~67 d死淘率(P<0.05),极显著提高了山地鸡67 d体重、1~67 d体增重(P<0.01),显著降低了1~49 d(P<0.05)和1~67 d料重比(P<0.01),但对山地鸡屠宰率、半净膛率、全净膛率、左胸肌率、左腿肌率无显著影响(P>0.05),对67 d胸肌肉色及屠宰后45 min pH也无显著影响(P>0.05)。品系SD02的28、67 d体重和1~28 d、1~49 d和1~67 d体增重在各品系中均最高,且遗传品系均极显著影响以上指标(P<0.01);品系SD0302的49 d体重最高,品系SD02次之,均极显著高于品系SD0203(P<0.01);品系SD0302和SD02的1~28 d采食量显著高于其他2个品系(P<0.05);品系SD02的屠宰率、腹脂率均显著低于另外3个品系(P<0.05)。饲粮策略、性别和遗传品系之间在山地鸡67 d体重、1~67 d体增重上表现了极显著的交互效应(P<0.01)。综上所述,高赖氨酸饲粮策略可显著改善二郎山山地鸡67 d体重、1~67 d体增重、1~49 d和1~67 d料重比;对生产性能和屠宰性能综合评估可知,4个遗传品系优劣顺序为:品系SD0302、SD02>品系SD03>品系SD0203;各遗传品系公鸡的生产性能均优于母鸡;饲粮策略、性别和遗传品系之间在体增重上表现了显著的互作效应,应区别饲养。     

Effects of exogenous enzymes and dietary energy on performance and digestive physiology of broilers

The study was conducted to compare the effects of XG with AG and BM at different metabolizable energy diets on growth performance, digestive physiology and energy utilization of broilers fed with corn-SBM diet. A 2 × 4 factorial design was used with two basal diets (the positive control group, PC; negative control with ME reduction 100 kcal/kg, NC) and with or without the addition of three exogenous enzymes (0.02% BM; 0.01% AG; 0.05% XG) respectively. 1,200 one-day-old broilers were randomly allocated to 8 treatments with 10 pens of 15 broilers. There was no significant difference on BW, BWG, and FI at 0-21d, 21-42d or 0-42d for diet, enzymes or their interactions, but FI at 22-42d and 0-42d were tend to be decreased with the addition of enzymes. The F/G was significantly improved by the addition of enzymes especially in NC diet. The dietary AME and TME in PC or NC diet were significantly increased by XG or AG in NC diet. The villus length and V/C of ileum were significantly increased by the addition of BM or XG. XG improved the activities of trypsin, chymotrypsin and amylase, BM improved the activity of trypsin at 21d, and AG improved the activity of chymotrypsin at 21d. Comparing to PC diet, the addition of enzymes in PC or NC diet decreased feed cost per kg body weight gain especially in NC diet (except AG in PC diet) with the highest profits for XG in NC diet. In conclusion, supplementation of 0.02% BM or 0.01% AG or 0.05% XG could improve feed conversion of broilers in corn-soybean meal diet by improving energy utilization and digestive physiology, and also supplementation of 0.05% XG had a preferable efficacy in low energy diet.     

填饲能量相同时不同油脂对肉鸭肥肝质量的影响

本研究旨在探讨填饲能量相同条件下,大豆油和鱼油对樱桃谷肉鸭产肝性能和肥肝品质的影响.试验采用单因子设计,选用60只体重一致的8周龄樱桃谷肉公鸭,随机分成3个处理,每个处理20个重复,每个重复1只鸭.填饲期为21 d,第1～7天3个处理均填饲玉米饲粮,第8～21天处理1填饲玉米饲粮,处理2和处理3分别填饲在玉米饲粮中添加3%大豆油和3%鱼油的饲粮,各处理填饲能量相同.结果表明:产肝性能随填饲时间延长而提高(P<0.01);填饲3周后,鱼油组平均肝重301.89 g、料肝比37.25、肝体比5.15,均与玉米组和大豆油组差异极显著(P<0.01);鱼油组肥肝的粗脂肪含量极显著高于玉米组和大豆油组(P<0.01);肝脏组织切片表明,随着填饲时间增加,肝脏中脂肪滴增加,且鱼油组脂肪滴最多、最大,表现融合;鱼油组和大豆油组均可极显著降低肥肝中的饱和脂肪酸含量(P<0.01),提高不饱和脂肪酸含量(P<0.01),特别是鱼油能提高二十碳五烯酸和二十二碳六烯酸含量(P<0.01),大豆油可提高亚油酸和亚麻酸含量(P<0.01).以上结果可以看出,在填饲能量相同条件下,填饲第8～21天添加鱼油可提高樱桃谷肉鸭的产肝性能和肥肝品质;添加大豆油对产肝性能无显著影响,但可调控肝脏脂肪酸组成.