Water Extractable Trace Elements in Poultry Litters and Granulated Products

Poultry litter contains many trace elements such as As, Cu, and Zn, and its land application may lead to the accumulation of these elements in soils, especially near the soil surface. The objectives of this study were to determine the total amount of trace elements and evaluate the effect of litter granulation and various litter to water extraction ratios on water extractable trace elements in 8 raw and granulated litter products. Granulated litters that contained urea, dicyandiamide, or hydrolyzed feathermeal had significantly lower contents of total As, B, Cu, Mn, and Zn than untreated litters because of the dilution of litters with additives. Trace element concentrations (mg/L) in the water extracts of the various poultry litters generally decreased when extraction ratios (litter to water) shifted from 1:10 to 1:250, or as the amount of poultry litter decreased with a constant water volume (200 mL). But, the water extractable content of trace metals (mg/kg) generally increased from an extraction ratio of 1:10 to 1:200, with values similar at 1:200 and 1:250 extraction ratios. Based on our results, we suggest using a 1:200 extraction ratio when evaluating water extractable As, Cu, and Zn in poultry litters. The estimated land application rates of trace metals, when poultry litter is applied on the basis of total P content, were considerably lower than the trace metal loadings allowable under the current environmental regulations governing biosolids and other materials with measurable amounts of trace metals. The laboratory water extractions of poultry litters and granulated products have increased our understanding of the potential risks to water quality posed by the land application of poultry litter and will contribute to the development of base knowledge needed to define land application practices that are protective of soil and water quality.     

林可霉素水溶性粉剂对由魏氏梭菌引起的鸡坏死性肠炎的药效研究

本文对新兽药制剂林可霉素水溶性剂，用人工感染发病的方法进行了药效学研究。     

产蛋鸡日粮中添加Vc的效果试验

选取海兰商品蛋鸡１０８只,分为对照和试验Ⅰ、Ⅱ３组,每组３６只,分别饲喂添加０、１００、２００ｍｇ／ｋｇＶｃ的蛋鸡日粮。４２天的试验结果：Ⅰ组提高蛋鸡产蛋数６．３６％,饲料转化效率提高６．７％,经济效益增加１７．０２％;Ⅱ组降低蛋鸡产蛋数１．４５％,降低饲料转化效率２．９４％,比对照组少收入６．３％。说明适宜的Ｖｃ添加量能显著提高产蛋鸡的生产性能。     

Reduced protein kinase C activity and endogenous protein phosphorylation in ethionine-induced fatty liver in cows

Protein kinase C (PKC) activity was evaluated and the phosphorylation of its endogenous substrates was explored in fatty liver induced by administration of ethionine (an analogue of methionine) to cows in order to assess the relevance of PKC-dependent phosphorylation in the development of fatty liver. PKC activity was decreased in both the cytosolic and the total particulate fractions from fatty livers, compared to the corresponding fractions from control liver. The mode of activation by the PKC cofactors (1-oleoyl-2-acetyl-sn-glycerol, 12-O-tetradecanoylphorbol-13-acetate, phosphatidylserine and Ca²⁺) was similar in both control and fatty livers, suggesting a quantitative but not a qualitative change in PKC in fatty liver. At least three substrate proteins (34 kDa, 26 kDa and 19 kDa) were found in the cytosolic fraction and their phosphorylation was reduced in fatty liver. These results suggest that impairment of the signal transduction pathway mediated by PKC is involved in the pathogenesis of fatty liver in cows.Abbreviations ATP adenosine triphosphate - EGTA ethylene glycol bis(-aminoethylether)-N,N,N,N-tetraacetic acid - NEFA non-esterified fatty acid - OAG 1-oleoyl-2-acetyl-sn-glycerol - PKC protein kinase C - PS phosphatidylserine - SDS-PAGE sodium dodecyl sulphate-polyacrylamide gel electrophoresis - TG triglyceride - TPA 12-O-tetradecanoylphorbol-13-acetate     

管理方式对华北驼绒藜生长及种子产量、质量的影响

研究施肥、浇水等不同管理措施对华北驼绒藜生长及种子产量、质量的影响。结果表明,适宜的田间管理可以提高华北驼绒藜的株高、枝条数、种子产量和质量。其中3次施肥+喷钾增产增质效果优于其它处理。3次施肥为最佳施肥方式。浇水及喷施钾肥对促进华北驼绒藜营养生长和提高种子产量、质量没有明显的作用。     

温度与饲粮维生素C水平对后备蛋鸭血清免疫和抗氧化指标的影响

本试验旨在研究温度与饲粮维生素C水平蛋鸭的血清免疫和抗氧化指标的影响.选取12周龄金定鸭216只,温度设低温(2±1)℃和适温(18±1)℃2个水平;饲粮中的维生素C添加水平分别为0、200和800 mg/kg.试验共6个处理,每个处理6个重复,每个重复6只试验鸭.试验期为6周.试验结果表明:1)低温使血清维生素C浓度显著降低了27.78%(P＜0.05),对氧化氢酶(CAT)、总抗氧化能力(T-AOC)、丙二醛(MDA)、白介素2(IL-2)、免疫球蛋白(IgG、IgA、IgM)、生长激素(GH)、胰岛素(Ins)、胰岛素样生长因子(IGF-I)、瘦素(Lep)、皮质醇(Cort)、三碘甲状腺原氨酸(T3)和甲状腺素(T4)的含量影响显著(P＜0.05);2)饲粮中添加200 mg/kg维生素C时,血清维生素C、IGF-I、Lep水平显著升高(P＜0.05),Cort浓度显著降低(P＜0.05);3)温度和维生素C的交互作用对Cort的含量的影响极显著(P＜0.01),对IGF-I、Lep、IgG和IgA的含量影响显著(P＜0.05),对GH、Ins、维生素C、L3、T4及各个抗氧化指标的影响没达到显著水平(P＞0.05).结果提示,低温影响后备蛋鸭血清维生素C的浓度,但饲粮中添加200 mg/kg维生素C时,可提高在低温条件下的后备蛋鸭血液维生素C的水平、提高血液中Lep和IGF-I的浓度、增强机体抗氧化和抗寒冷应激能力.     

两种免疫增强制剂对早期断乳仔猪红细胞免疫功能的影响

选取28日龄断奶的三元[杜×(大×长)]杂交仔猪15头,平均初始体重为(5.22±0.89)kg,随机分为3组:活性卵白组、活性酵母组和对照组,每组5头。对照组饲喂基础日粮,两个处理组在相同的基础日粮中分别口服卵白制剂及酵母制剂,剂量为10 mL/只,连续服用10 d。应用红细胞C3b受体花环(Erythrocyte C3bR,E-C3bR)试验和红细胞免疫复合物花环(ErythrocyteICR,E-ICR)试验,探讨两种免疫增强制剂在服药不同时间对断乳仔猪红细胞免疫功能的影响。结果显示,活性卵白组和活性酵母组的E-C3bRR和E-ICRR在服药后第1周、第2周都极显著的高于对照组(P<0.01),并于第2周达最高值。服药后第3周活性卵白组的E-C3bRR和E-ICRR均维持在较高水平,与对照组差异极显著(P<0.01);而活性酵母组呈现明显下降趋势,与对照组无明显差异。结果表明,活性卵白组较活性酵母组具有更加持续稳定的红细胞免疫促进功能。     

中国狗牙根染色体数变异研究初报

通过国内30份狗牙根种源当色体数目的观测分析.结果表明,①我国狗牙根种质资源染色体数目呈现非常高的异质性,不同种源具有不同染色体数,同一种源不同根尖存在不同染色体数,同一根尖不同细胞亦具备不同染色本数,不同倍性平均出现的频率依次为:4n(32.26%)>n(18.98%)>3n(10.7%)>6n(2.13%)>2n(0.41%).此外,非整倍体平均比率高达32.1%.②染色体数目与纬度、经度、海拔间均无显著回归关系.该项研究为我国狗牙根种质资源开发利用提供了初步的试验依据.     

嗜热毛壳菌纤维素酶对小尾寒羊瘤胃代谢的影响

本试验研究不同水平嗜热毛壳菌纤维素酶对小尾寒羊瘤胃代谢的影响。试验动物为4只安装有永久性瘤胃瘘管的成年小尾寒羊公羊(平均体重为45 kg),采用4×4拉丁方试验设计,在基础日粮中分别添加0％、0．3％、0．6％和0．9％4个水平酶制剂,采集瘤胃液测pH值、氨氮浓度和挥发性脂肪酸(VFA)浓度。试验结果表明:各组试羊瘤胃液平均氨氮浓度的变化范围为10．01-12．80 mg/dL,各组之间相同时间点差异不显著(P>0．05)。瘤胃液平均pH值在6．50-6．80范围内变动,试验组pH值低于对照组(P<0．05),以0．6％水平较好。各组试羊瘤胃乙酸、丙酸及总 VFA浓度的变化规律基本相同,即喂料后逐渐上升,其中乙酸和总VFA浓度在2 h后达到最高点,丙酸浓度在4 h 达到最高点,随后平稳下降于饲喂前降至最低点,再次采食后又重复出现此规律。试验组瘤胃乙酸和总VFA浓度显著或极显著高于对照组(P<0．05或P<0．01),以0．6％水平组最高。