产蛋鸡饲料的粉碎粒度研究

将玉米、豆粕分别粉碎通过8mm、7mm、5mm筛孔,配制成3种粉碎粒度的配合饲料,进行产蛋鸡的对比饲喂试验,结果表明,试验的3种粉碎粒度对蛋鸡的生产性能无显著影响。对于干物质、粗蛋白的消化吸收有一定的影响,但也不显著(P>0.05)。综合考虑,在本试验条件下,选择7mm直径的筛孔作为产蛋鸡饲料粉碎粒度的控制为佳。     

饲料粉碎粒度的研究

本文综述国内外对饲料粉碎粒度的研究结果，包括对饲料粒度的一般要求，筛孔大小的选择，饲料粒度对畜禽生产性能、营养素消化吸收以及胃肠形态学的影响等。     

饲料加工粉碎粒度与效率的控制方法

生产普通水产饲料时必须选择微粉碎机。而普通带筛片的微粉碎粒度达到95％通过0．15目的筛孔是困难的，否则效率将非常低，它们可以满足一般鱼类(如鲤鱼、草鱼等)或较大鱼的饲料粉碎要求。采用气流分级的有筛和无筛粉碎机可以满足鳗鱼、虾饲料等的加工要求，其粒度可以方便地无级调整(在一定范围内)。具有内置分级筛网或装置的气流分级微粉碎机有较大的优越性，可以简化设备的管理，节省投资。     

饲料粒度对母猪生产性能的影响

在饲料生产过程中 ,常需对谷物饲料及其他饲料原料进行粉碎加工 ,主要目的是增加饲料在胃肠道中与消化液接触的表面积 ,使饲料更容易被消化。但是 ,如果饲料粒度过细则会产生相反作用 ,主要表现在两个方面 :一是由于饲料加工机械磨损加快 ,使生产成本提高 ;二是容易引起猪的胃病 ,影响生产性能。因此 ,合理地选择饲料的粉碎粒度 ,使之既经济又有利于家畜的健康。美国堪萨斯州的专家研究了不同饲料粉碎粒度对母猪生产性能的影响。试验选用了玉米—豆饼型日粮 ,玉米的粉碎粒度分别为 12 0 0、90 0、6 0 0、4 0 0 μｍ4个规格。试验时把 10 0头…     

鳗鱼饲料加工技术探讨

<正> 1.粉碎方式的确定为了实现鳗鱼饲料通过60目的要求,在目前生产上采用先配料后粉碎的情况下存在两种粉碎方式:①开式粉碎。用一台微粉碎机来获得所要求的粒度。②闭式粉碎。用微粉碎机(或粉碎机)和分级器(或分级筛)来实现粒度要求。如采用开式粉碎,必须配备小筛孔(Φ1～1.2),于是在粉碎室内出现物料环流层,使符合粒度的细粉不能及时排出,造成物料反复粉碎,其后果是粉碎机产量低、电耗高、料温高。笔者曾对某厂微粉碎机作过测定,测得机壳温度50℃,卸料器出口料温     

猪饲料颗粒大小及其对猪生产性能的影响

猪饲料的颗粒大小有二种表示方法:包括饲料颗粒直径和饲料粉碎粒度(原料的粉碎程度)。饲料粉碎粒度是影响饲料品质的重要因素,进而会影响猪的生产性能。     

饲料加工质量评价指标及其控制技术

根据《饲料和饲料添加剂管理条例》第二条规定,我国的饲料产品包括单一饲料、饲料添加剂预混合饲料、浓缩饲料、配合饲料和精料补充料,除单一饲料外,其它都是将多种饲料原料(成分)按照规定的加工1粉碎粒度粉碎粒度的大小,直接影响到动物的消化吸收、粉碎成本、后续加工工序和产     

粉碎粒度对饲料加工生产性能的影响

讨论了饲料粉碎粒度与加工成本、混合均匀性、颗粒饲料的质量等加工生产性能的关系，同时提出了饲料粉碎粒度需要解决的一些问题。     

血凝法测定饲料中植物凝集素含量

通过研究植物凝集素(lectin)的血细胞凝集活性与其浓度的关系，提出了用血凝法测定饲料中lectin的新方法，并探讨了试样粉碎粒度、脱脂方法、脱脂时间、抽提时间、抽提次数等测定条件对测定结果的影响。结果表明，lectin的活力与浓度之间存在高度线性相关(R^2=0．99)。血凝法测定饲料中lectin的含量时，以样品粉碎过40目、样品与30～60℃石油醚或乙醚比例(W／V)1：8脱脂8h、样品与生理盐水(W／V)1：8抽提8h为宜。在上述条件下测定，回收率可达88％～102％。经过对8种不同的饲料及原料样品lectin含量的测定，平均相对偏差为0．9％～2．4％，变异系数为1．3％～3．3％。结果表明，利用血凝法可快速测定饲料中的lectin含量。     

松粉机和风筛提粉器在饲料微粉碎工艺中的应用

<正> 加工鱼虾饵料和特种饲料,其原料粒度一般要求为全通过40～60目筛。目前国内多数饲料厂采取的办法是,原料经第一台粉碎机(筛孔直径为φ1.5毫米以上)粉碎后到小方筛(筛孔为40～60目)进行筛理,筛上物再进入第二台微粉碎机(筛孔直径为φ0.5～φ0.6     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.