饲用油脂的营养价值及其在养殖业中的应用进展

油脂作为饲料中的能量来源已广泛应用于动物饲料中。在动物日粮中添加油脂不仅可以满足动物高生产性能的需要,还可以提高饲料利用率。文章主要概述了饲用油脂的来源、营养价值及其在养殖业中的应用现状。     

滚珠丝杠进给系统动态特性集中质量建模与仿真

为了研究高速滚珠丝杠进给系统的动态特性,提出一种改进的集中质量建模方法,该方法考虑了滚珠丝杠进给系统基座的质量、柔性及进给系统部件间反向间隙对系统动态特性的影响,并完善了滚珠丝杠进给系统集中质量模型等效参数的计算方法。以MAG某加工中心X轴滚珠丝杠进给系统为实验对象,对该集中质量模型建模方法进行实验验证,仿真结果与实测结果具有相同数量的特征频率,且特征频率的误差在5%以内。滚珠丝杠进给系统的仿真分析表明,螺母位置改变引起的进给系统固有频率变化将影响伺服系统的稳定性,滚珠丝杠进给系统中的反向间隙会激励部件产生高频振动,给进给系统带来不利影响。     

对偶模型在畜禽饲料配方优化设计上的应用

 在一般线性规划配方模型基础上通过引入其对偶线性规划问题 ,以求解参与优化计算的养分项目即资源的影子价格。在配方优化设计领域 ,养分资源的影子价格揭示了当增减参与计算并希望最终达到的养分指标时对最终饲粮成本的影响程度。某一资源影子价格的值越大 ,表明其对配方的最低成本影响越突出 ;而影子价格为“零”的养分指标是指其在特定取值范围内 ,该指标的达成对最低成本不构成影响 ,同时笔者还讨论了今后我国饲料配方技术研究的深层次发展方向     

提高商品猪瘦肉率技术的研究

本课题在小试、重复和中试筛选出“杜长乐”、“长大乐”较优组合基础上,在基本相同的饲料营养和管理条件下,于1986～1987年进行了生产示范试验.两年来共生产示范猪3591头(其中供港活大猪2807头),良种猪比例达55.1～68.15%.据892头有试验记载猪测定统计,育肥期平均日增重548克,料肉比3.57:1,胴体瘦肉率55.96～57.74%,并获得了明显的经济效益.达到了省科委下达本项目的主要技术经济指标.     

常用饲料添加剂载体的吸附性能及影响因素的研究

选取较常用的饲料添加剂载体碳酸钙、谷壳粉、海泡石粉作为研究对象 ,以乳酸乙酯为吸附质 ,分别得出了上述 3种载体的吸附等温式 :Q =6 .6 9× 1 0 0 C0 .2 92 2 、Q =1 .90×1 0 2 C0 .51 0 5和Q =1 .6 5× 1 0 2 C0 .1 2 59。谷壳粉的吸附能力随其水份含量的升高呈现倒“V”型变化 ;碳酸钙的吸附能力随水份含量升高而趋于增强 ;海泡石的吸附能力与水份含量成反比。并提出了水份影响载体吸附性能的“媒介作用”和“释放作用”两个概念。     

土壤类型对凉山烤烟品质的影响

以云烟87为材料,在盐源烟区选取5种不同类型土壤进行烤烟大田栽培,研究了四川凉山土壤类型对烤烟主要化学成分、中性致香物质及内在质量的影响。结果表明,参试土壤钙、镁含量较丰富,明显缺氯;紫色土、红壤、黄壤、沉积土等明显缺钾和氮;水稻土和沉积土缺磷。不同土壤烤后烟叶化学成分有差异,水稻土和紫色土上烤后烟叶烟碱、总氮含量较高,糖含量较低,基本符合优质烟叶质量标准;红壤、紫色土和黄壤上烤后烟叶钾含量相对较高,接近优质烟叶钾含量;沉积土、水稻土和红壤上烤后烟叶氯含量较高,接近优质烟叶氯含量。不同土壤烤后烟叶致香物质含量差异较大,黄壤和红壤上烤后烟叶苯丙氨酸类降解产物含量较高;黄壤、红壤和水稻土上烤后烟叶类西柏烷类产物含量较高;水稻土、紫色土和红壤上烤后烟叶质体色素降解产物含量及致香成分总量较高。不同土壤烤后烟叶内在质量存在一定的差异,由高到低对应的植烟土壤依次为:紫色土、红壤、黄壤、沉积土、水稻土。     

近红外光谱技术在家禽养殖领域应用现状

近红外光谱是一种快速光谱分析的新方法,伴随着光谱技术与化学计量法的发展,近红外光谱已广泛应用于农业、食品、医药、石油化工等行业,极大地提高了各行业信息化水平。基于近红外光谱在家禽养殖领域的应用现状,本文总结了近红外光谱技术的发展及其在饲料成分检测和禽肉检测中的应用。在饲料检测和家禽肉类检测方面,通过将禽肉样品的光谱信息与质量指标的参考值相关联,建立了预测饲料和待测肉类高精度、高稳定性的数学模型。与传统方法相比,近红外光谱技术具有信息量大、数据计算速度快等优点。本文还归纳了近红外光谱技术在饲料品质检测和肉类品质检测的应用现状,指出了近红外光谱在家禽养殖领域的大规模应用推广的可能性。同时指出近红外光谱技术存在的问题和未来发展方向,结果表明近红外光谱技术在饲料和畜产品检测领域具有良好的发展前景和应用价值。     

Effects of temperature and body weight on growth rate and feed conversion ratio in turbot (Scophthalmus maximus)

Six size groups of hatchery produced turbot (2–499 g) were reared at six constant temperatures (10–25 °C). The results were used to develop a mathematical model for growth rate and feed conversion in turbot. At each temperature there were linear relationships between logarithms of (a) specific growth rate (G%/day) and body weight (W g), and (b) feed conversion ratio (FCR) and W. The slopes of the regressions were linearly related to temperature and the intercepts of the regression changed with temperature according to a second order polynomial. The optimal temperature for growth (T_opt.G) is predicted to decline with increasing body weight: T_opt.G = 22.45 − 0.713lnW, i.e. 22.5, 20.8, 19.1 and 17.5 °C for 1, 10, 100 and 1000 g fish, respectively, and the growth rates of these fish sizes at their optimal temperature (G_max) were predicted to be 7.63, 2.73, 1.03 and 0.40%/day, respectively. The optimal temperature for feed conversion (T_opt.FCR) is also predicted to decline with increasing fish size: T_opt.FCR = 18.80 − 0.625lnW, i.e. 18.8, 17.4, 15.9 and 14.5 °C for 1, 10, 100 and 1000 g fish, respectively, and the predicted feed conversions of these fish sizes (FCR_min) were 0.44, 0.56, 0.68 and 0.82 for the present feed types. The growth model predicts that 2 g turbot can reach 743 and 619 g in 1 year when reared at T_opt.G and T_opt.FCR, respectively.     

浅析饲用甜菜的发展前景

从畜牧业的发展作为农民增收和经济发展的重要途径入手，阐述了饲料行业的重要性，论述了饲用甜菜在饲料行业的优势，说明了饲用甜菜在我国畜牧业中的关键性和发展前景．     

Gut ecology, feed digestion and performance in weaned piglets fed liquid diets

Gut environment and microflora, digestibility, and performance were studied in weaned piglets in Central Vietnam fed a dry control diet (CO), a naturally fermented liquid diet (FE), and a liquid diet with inclusion of rice distiller's residue (RDR). Digesta samples were collected at the start (day 0) and at the end of experiment (day 42). Diet FE had a lower pH than diet RDR, contained more organic acids, had the lowest counts of E. coli and total coliforms (P < 0.05), and the highest counts of lactic acid bacteria (LAB) (P < 0.05). Piglets fed diets FE and RDR had lower pH (P < 0.05), and higher concentrations of organic acids in the stomach, ileum and mid-colon (P < 0.05) than piglets fed diet CO. Counts of LAB in stomach and ileum were higher in animals fed diets FE and RDR than CO (P < 0.05), while the number of E. coli and total coliforms along the gastrointestinal tract was reduced. The ileal digestibility of crude protein and organic matter was improved in piglets fed diet RDR (P < 0.05) compared with piglets fed diet CO. Piglets fed diet RDR had a higher weight gain (P < 0.05) and a better feed utilization (P < 0.05) than piglets fed the other diets. The present findings support the contention that fermented diets and/or fermented feedstuffs can be used for dietary manipulation to improve gut health and animal performance.