肉牛添加剂的研究与应用

用本课题组研制的肉牛添加剂育肥体重230kg、330kg、400kg和530kg的肉牛，可使日增重分别提高25．5％、7．3％、25．4％和16.7％，效果显著（P＜0．05），可使饲料报酬最多提高25．8％（P＜0.05）；投入产出比最大为1：8，用该添加剂育肥高档肉牛时屠宰率可达57.2％，眼肌面积43cm2、皮下脂肪覆盖面积为优级，大理石状评分为优级。     

RPLC法测定饲料添加剂中的B族维生素

本文提出了利用反相离子对色谱法,简单,快速,准确同时定量测定饲料添加剂中的烟酸,烟酰胺,盐酸吡哆辛,氰钴胺素,核黄素和硫胺素。样品前处理简单,六个维生素能在12min内获得满意的分离,各组份之间的分离度Rs大于1.60。各个维生素的回收率在87.0～101.0％,相对偏差为3.1～2.0％。色谱柱为LichrosorbRP-18 250×φ5mm,流动相为甲醇/水,0.25％TEA,1.25mmol/l PICB-5,3.75mmol/l PICB-7,pH3.00,紫外可变波长检测器采用MAXPL操作方式λ 1=254nm,λ_2=280nm,λ_3=354nm,流速1.1 nl/min。     

基于双列杂交的花生主要品质性状遗传效应分析

为了提高花生品质性状优势组合的选育效率,以5个花生材料为亲本,采用Griffing完全双列杂交配制20个组合,分析花生籽仁中粗脂肪含量、粗蛋白含量、蔗糖含量和脂肪酸组分等10个性状的配合力和遗传参数.配合力效应分析表明,豫花132(W191)的粗脂肪、硬脂酸、亚油酸、花生酸和山嵛酸含量等性状的一般配合力效应值最大,冀花...     

晚稻秸秆还田腐熟技术在油菜上的应用效果

研究了腐秆剂的作用效果.结果表明,在油菜作物上盖草施腐秆剂能提高油菜子产量,比不盖草不施腐秆荆每公顷增产49.5～124.5 kg,增产率达2.22%～5.61%;明显改善油菜的株高、分枝、角长、角果数及角粒数等农艺、经济性状,但降低了油菜的千粒重;促进了油菜的生长发育.     

喀斯特山区特征灌木 白刺花的青贮效果

为合理开发利用贵州喀斯特山区资源,促进其生态畜牧业可持续发展,以该区域特征灌木白刺花(Sophora davidii)为研究对象,开展单独青贮与添加剂青贮(乳酸菌、纤维素酶、乳酸菌+纤维素酶、甲酸、蔗糖和乳酸菌+纤维素酶+甲酸+蔗糖)研究,以探讨其可青贮性与最优青贮技术,为贵州岩溶山区粗饲料资源的开拓及贮存提供可借鉴的方法与技术支持。结果表明,白刺花青贮饲料感官品质较好,pH值(3.97～4.73)和氨态氮/总氮(3.76%～12.23%)较低,纤维和单宁总体下降,酸性洗涤纤维(30.70%～42.16%)、中性洗涤纤维(48.37%～61.84%)和单宁(0.63%～0.89%)较低,蛋白质下降幅度不大或略有上升,含量(16.83%～20.10%)较高,品质较好;添加剂处理可改善其感官品质,降低pH值、氨态氮/总氮(降幅8.26%～69.26%)与酸性洗涤纤维含量(降幅7.78%～27.18%),提高青贮品质;其中蔗糖(3% FM)处理感官品质最好,pH值(3.97)和氨态氮/总氮(5.67%)较低,蛋白质(19.89%)较高,青贮品质最好,是白刺花青贮的最适添加剂。     

食品添加剂磷酸氢二铵中砷含量的测定

运用原子荧光光谱法对进出口食品添加剂磷酸氢二铵中砷含量进行了测定,通过线性范围、检出限、精密度、回收率和实验室间比对测试,证明了原子荧光光谱法能快速、准确地检测出进出口食品添加剂中砷的含量。该方法线性关系良好,检出限低,准确度高,重复性和再现性好,可广泛用于进出口食品添加剂中砷含量的检测。     

Polymorphic mountain whitefish (Prosopium williamsoni) in a coastal riverscape: size class assemblages,distribution, and habitat associations

We compared the assemblage structure, spatial distributions, and habitat associations of mountain whitefish (Prosopium williamsoni) morphotypes and size classes. We hypothesised that morphotypes would have different spatial distributions and would be associated with different habitat features based on feeding behaviour and diet. Spatially continuous sampling was conducted over a broad extent (29 km) in the Calawah River, WA (USA). Whitefish were enumerated via snorkelling in three size classes: small (10–29 cm), medium (30–49 cm), and large (≥50 cm). We identified morphotypes based on head and snout morphology: a pinocchio form that had an elongated snout and a normal form with a blunted snout. Large size classes of both morphotypes were distributed downstream of small and medium size classes, and normal whitefish were distributed downstream of pinocchio whitefish. Ordination of whitefish assemblages with nonmetric multidimensional scaling revealed that normal whitefish size classes were associated with higher gradient and depth, whereas pinocchio whitefish size classes were positively associated with pool area, distance upstream, and depth. Reach‐scale generalised additive models indicated that normal whitefish relative density was associated with larger substrate size in downstream reaches (R² = 0.64), and pinocchio whitefish were associated with greater stream depth in the reaches farther upstream (R² = 0.87). These results suggest broad‐scale spatial segregation (1–10 km), particularly between larger and more phenotypically extreme individuals. These results provide the first perspective on spatial distributions and habitat relationships of polymorphic mountain whitefish.     

凝胶渗透色谱净化-气相色谱法同时测定饲料中4种抗氧化剂

本文建立了凝胶渗透色谱净化(GPC)-气相色谱法(GC)同时测定饲料中2,6-二叔丁基对甲酚(BHT)、叔丁基羟基茴香醚(BHA)、叔丁基对苯二酚(TBHQ)和乙氧喹(EQ)4种抗氧化剂方法。4种抗氧化剂在10～400mg/L时与峰面积有良好的线性关系(r2>0.9999),检出限(3S/N)为0.37～0.46 mg/kg,添加回收率为82.7%～98.8%,相对标准偏差(n=5)为1.7%～4.3%。     

Deoxynivalenol in chicken feed alters the vaccinal immune response and clinical biochemical serum parameters but not the intestinal and carcass characteristics

This study was conducted to investigate the impacts of deoxynivalenol (DON) feeding either alone or in combination with a microbial feed additive (MFA) on the immune response to a viral vaccine and serum clinical chemical parameters. Forty 1‐day‐old boiler chicks were weighed and randomly divided into four groups, 10 birds in each group: (i) control group fed with basal diet; (ii) DON group fed with basal diet artificially contaminated with 10 mg DON/kg feed; (iii) DON + MFA group fed with basal diet contaminated with 10 mg DON/kg feed and supplemented with 2.5 kg of MFA/ton feed; and (iv) MFA group fed with basal diet supplemented with 2.5 kg of MFA/ton feed. At 35 days of age, birds were slaughtered and blood was collected for investigating the antibody titre against infectious bronchitis virus (IBV) and clinical chemical parameters. The results showed that DON reduced (p = 0.032) the titre against IBV, decreased (p = 0.005) the level of alanine transaminase (ALT) (4.2 ± 0.5 U/l) compared with control birds (6.4 ± 0.5 U/l), increased (p = 0.002) the serum cholesterol concentration (144 ± 6 mg/dl) compared with their control counterparts (123 ± 5 mg/dl) and increased (p = 0.074) the amount of circulating triglycerides (62.25 ± 7.50 mg/dl) compared with controls (39.55 ± 4.74). These results indicate that dietary DON altered the humoral immune response to viral vaccine and affected the serum clinical biochemistry. However, DON in combination with MFA did not affect serum IBV titre. Taken together, DON in the feed of broilers produced an impairment of the success of IBV vaccine and affected the health of birds.     

Estimation of genetic variance components and heritabilities for cut-flower yield in gerbera using least squares and maximum likelihood methods

Summary Genetic variance components and heritability were estimated for cut-flower yield of gerbera in the Davis population using ordinary least squares and maximum likelihood methods. The overall estimate of narrow-sense heritability is 0.33 based on least squares (LS) and 0.31 based on maximum likelihood (ML). The results of the study indicate that (1) ML and LS provide very similar results if sample size is large enough, suggesting both are useful for plant breeding programs; (2) about one third of the variation in gerbera cut-flower yield is additive, implying selection in cut-flower will be successful; and (3) although additive variation gradually decreased, heritability remained near 0.27 suggesting there is still potential variation in the population for further selection.