Effect Of Replacing Fish Meal With Blood Meal On Chemical Composition Of Supplement For Nile Tilapia (Oreochromis Niloticus)

The objective of the work was to evaluate the effect on the nutrient content of replacing fish meal (FM) with blood meal (BM) in fish supplement. Three isonitrogenous diets (35% crude protein) were formulated using FM as the main source of animal protein (BM0); 50% replacement of FM with blood meal (BM50); or 100% replacement of FM with BM (BM100). The chemical composition (ash, crude protein, crude fat and crude fibre) and amino acid composition were determined. Replacement of FM with BM did not affect the proximate composition of the diet apart from ash content which decreased with the level of substitution. Substituting fish meal with blood meal reduced the levels of methionine, lysine, isoleucine, leucine, proline, valine and increased the levels of arginine, phenylanine and alanine in the diet. Amino acid indices revealed that BM0 had more amino acids with the highest chemical scores followed by BM50 and BM100. In all the diets, methionine was the most limiting amino acid. The essential amino acid index of the diets reduced with the level of replacement of FM (0.94, 0.88 and 0.77). The study showed substitution of up to 50% FM with BM gave a useful protein diet and 100% gave almost a poor protein diet.     

改装机械加工设备解决化工装置检修问题研究

随着我国经济水平不断提高，化工设备检修手段也在不断发展，以改装机械加工设备来解决化工装置检修问题成为了当下提高检修效率的热议话题之一。文章主要分析化工装置检修，阐述了以改装机械加工设备方式解决化工装置检修难题的过程，总结经验以供参考。     

青土湖水面形成区土壤颗粒组成与化学特性变化

青土湖输水作为石羊河流域治理的一项关键措施,对保护湖区水资源和生态环境具有重要意义。在距青土湖水面边缘东南方向0-450 m的10个样点中分3层取0-60 cm土样,测定土壤粒径的质量百分比与全氮、全磷、全钾和电导率,分析青土湖水面形成后土壤颗粒组成与化学特性变化。结果表明,随着离水面边缘距离的增加,土壤颗粒与化学特性呈有规律的增减变化,土壤粘粉粒组成与其全磷、全钾之间存在正线性相关。青土湖水面形成加剧了距水面边缘0-150 m处的土壤理化性质变化;土壤细粒及养分出现富集,分别在距水面边缘100-150 m和300 m处达到最大值。因此,土壤养分与土壤细物质的良好相关性表明,土壤粘粉粒变化可作为反映该区域土壤性状变化和评价衡量水面形成后土壤恢复程度的定量指标之一。     

氮、磷添加对青藏高寒草甸土壤碳氮磷化学计量特征影响的Meta分析

为了解青藏高原高寒草甸土壤碳(Carbon,C)、氮(Nitrogen,N)、磷(Phosphorus,P)化学计量特征对氮、磷添加的响应,提高养分管理水平及草地生态系统的养分平衡。本研究严格筛选出21篇文章(612项数据)进行Meta分析,通过亚组分析分析了不同施肥方式(氮添加、磷添加、氮磷添加)、不同施肥强度(轻度、中度、重度)对青藏高原草地土壤C,N,P化学计量特征的影响。研究结果表明：养分添加显著增加了青藏高原草地土壤C,N,P含量;氮添加对土壤的增加效应随施肥强度增加而增加,磷轻度施肥(20g·m^-2以下)处理、氮磷添加轻度施肥处理下的土壤C,N,P含量及化学计量比增加效果最好。本研究结果总体反映出氮、磷添加对青藏高原高寒草甸土壤产生积极影响,研究结果可为青藏高原草地生态系统的保护提供科学依据。     

Determination of the effective dosage of tiletamine–zolazepam–ketamine–xylazine,with or without methadone,in dogs

ObjectiveTo determine the effective dosage of the combination tiletamine–zolazepam–ketamine–xylazine (TKX), with or without methadone, in dogs.Study designProspective, randomized, experimental study.AnimalsA total of 29 dogs.MethodsDogs were randomly administered TKX (group TKX, n = 13) or combined with 0.3 mg kg^–1 of methadone (group TKXM, n = 16) intramuscularly. The TKX solution contained tiletamine (50 mg mL^–1), zolazepam (50 mg mL^–1), ketamine (80 mg mL^–1) and xylazine (20 mg mL^–1). The effective dosages for immobility in 50% and 95% of the population (ED₅₀ and ED₉₅) were estimated using the up-and-down method. Approximately 20 minutes after drug administration, a skin incision was performed and the response was judged as positive or negative if the dogs moved or did not move, respectively. The TKX volume for the subsequent dog in the same group was increased or decreased by 0.005 mL kg^–1 if the response of the previous dog was positive or negative, respectively. Heart and respiratory rates, and sedation/anesthesia scores (range 0–21) were recorded before and 15 minutes after drug administration.ResultsEstimated ED₅₀ and ED₉₅ (95% confidence intervals) were: TKX, 0.025 (0.020–0.029) and 0.026 (0.010–0.042) mL kg^–1; TKXM, 0.022 (0.018–0.025) and 0.033 (0.017–0.049) mL kg^–1. Median (interquartile range) scores for sedation/anesthesia were 17 (16–18) and 17 (15–20), and times until lateral recumbency were 5 (4–6) and 6 (4–10) minutes in TKX and TKXM, respectively (p > 0.05). In both groups heart and respiratory rates decreased, but values remained acceptable for anesthetized dogs.Conclusions and clinical relevanceThe results provide a guide for volumes of TKX and TKXM in dogs requiring restraint for minimally invasive procedures. Inclusion of methadone in the TKX combination did not influence ED₅₀.     

苏尼特绵羊肉理化品质的分析研究

苏尼特绵羊是内蒙古优良地方肉羊品种之一,以肉质嫩、口感好而名扬全国。以苏尼特绵羊和小尾寒羊背最长肌为原料肉,进行比较研究。结果表明,相对于小尾寒羊,苏尼特绵羊肉不仅具有高蛋白、低脂肪和低胆固醇等很高的营养品质,而且具有保水性好、嫩度高、熟肉率高等优良食用品质。对羊肉颜色的研究结果表明,与小尾寒羊相比,苏尼特绵羊肉的肉色更鲜红饱满。这些结果充分说明了苏尼特绵羊肉具有理想的化学成分和物理性状,也为苏尼特绵羊肉品质优良的主观印象提供了客观实验依据。     

Inheritance of fiber quality and lint yield in a chemically mutated population of cotton

The narrow germplasm base of the upland cotton (Gossypium hirsutum L.), grown on the Texas high plains historically, has limited improvement of fiber quality. Chemical mutagenesis and subsequent selection have helped the development of lines with improved fiber quality in cultivars adapted to this region. This study was conducted to determine the inheritance of improvements in fiber quality. M₃ lines with divergent fiber properties of micronaire, length, and strength were selected from a population of Paymaster HS 200 treated with 3% v/v ethyl methanesulfonate (EMS) for two hours. The 115 selected lines of M₄ and M₅ generation were evaluated for fiber quality and lint yield. Regression of the M₄ and M₅ on the M₃ generation, as well as the M₅ on the M₄ was used to generate narrow sense heritability coefficients. Significant variations were observed between the mutant lines in all generations except for lint yield in the M₅ (1997). The highest heritability estimates were found in fiber length (h ²= 0.29** to 0.46**). Micronaire and strength showed intermediate heritability estimates of h ²= 0.14 to 0.19, while lint yield had a very low heritability estimate of h ²= 0.03. Fiber length and strength were correlated (r= 0.58** to 0.46**) in all the three generations. The mutants identified in these studies have the potential to improve fiber quality of upland cotton without introducing alien genes that may reduce adaptation to short growing season production regions.     

涞水县设施蔬菜化肥与农药施用现状及对策

为进一步提高设施蔬菜生产技术水平,对涞水县设施蔬菜生产温室进行调查,通过调查设施设备、主栽作物、种植模式、销售渠道、经济效益等基本情况,发现存在基础配套设备落后、种植户管理水平差异较大等问题;通过调查涞水县温室蔬菜栽培中化肥、农药使用情况,发现存在过度依赖化学农药、施用方式粗放、缺乏合理施用方案、化肥农药安全使用意识差等问题;并提出依据需水规律合理灌溉、依据需肥规律合理施肥等栽培管理建议,以及加强农业防治(选择抗病品种、轮作倒茬等)、物理防治(高温闷棚、覆盖防虫网、黄板诱杀等)及生物防治(使用生物农药、性诱剂及有益生物等)建议。     

湖羊肌肉营养成分组成及风味物质研究

选取5、10、18月龄及4岁湖羊各10只,屠宰后取背最长肌和肱三头肌分析常规营养成分;取10月龄湖羊背最长肌分析氨基酸;取肱三头肌测风味物质。结果表明:湖羊肌肉水分含量随年龄增长而降低(P<0.05),粗蛋白含量、粗脂肪、粗灰分的含量随年龄增长而增加(P<0.05)。湖羊肌肉蛋白质中8种必需氨基酸组成全面,与FAO模式比较,各种氨基酸评分均接近或大于1。湖羊肌肉脂肪中检测到的70种挥发性风味化合物,包括14种酸、7种酮、9种醛、5种醇、10种酯类、13种烃、12种其他化合物(包括呋喃、吡嗪、吡啶、吲哚等含氮硫氧等杂环化合物)。其中酯类含量最高,占肉中总风味物24.1%~28.3%,其次为烃和酸,分别占20.5%~21.2%和19.0%~20.0%。     

环介导等温扩增技术快速检测猪细小病毒的试验

利用环介导等温核酸扩增技术(LAMP),建立了一种灵敏、特异、快速的猪细小病毒(PPV)检测方法.该方法针对猪细小病毒非结构蛋白(NS-1)基因保守区域设计6条特异引物,在63℃的等温条件下45 min即可完成反应.最低检测限量为10拷贝的PPV目的基因,比常规聚合酶链式反应(PCR)方法敏感100倍,并具有良好的特异性.以钙黄绿素和Mn2+作为荧光指示剂,可快速、直观判定反应结果.通过对149份临床样品进行检测比较,LAMP与PCR检出阳性样本数分别为33份和27份,表明LAMP方法阳性检出率高于PCR.