急性热应激条件下肉鸡骨骼肌谷氨酰胺代谢的变化

研究急性热应激对肉鸡骨骼肌（胸肌和腿肌）谷氨酰胺（Gln）代谢和血清相关指标的影响。选择常规饲养至35日龄（d）的公AA鸡50只,预饲至42 d时,选取30只随机分成5组（每组6只）,分别进行0（Ⅰ组,室温对照组）、4（Ⅱ组）、8（Ⅲ组）、12（Ⅳ组）、16（Ⅴ组）h的急性热应激处理,采血清和骨骼肌样分析。结果表明：与对照组相比,急性热应激显著（P<0.01或0.05）降低了血清的TP、ALB、GLOB、A/G、Gln、ALP,增加了血清Glu、GOT、GPT、CK,影响程度均随着时间的延长而增加。对照组中,腿肌的CP、Gln、Glu、GS高于胸肌（P<0.01或0.05）,Glnase低于胸肌（P<0.01）。急性热应激对骨骼肌CP、Gln、Glu和Glnase有降低作用,对GS有增加作用,在处理16 h时均有显著以上差异。试验说明,34℃急性热应激对肉鸡血清和骨骼肌中蛋白质和Gln代谢产生了显著的影响,且存在明显的组织特异性和时间依赖性。     

在不同营养水平日粮中添加益生菌对肉鸡抗氧化功能、黏膜免疫及回肠菌群的影响

采用2×2因素设计,研究在不同营养水平日粮中添加益生菌对肉鸡免疫器官指数、血清和肠黏膜抗氧化性能、肠黏膜IgG和SIgA及回肠菌群的影响,评价益生菌在宿主内的免疫效应及其机理。试验选用1日龄AA肉鸡320只,分成4组,每组10个重复,每个重复8只,饲喂以下4种日粮:(1)正对照组(NC):基础日粮;(2)负对照组(LC):低能低蛋白日粮,使基础日粮的代谢能降低320 kJ/kg,粗蛋白均降低0.85%;(3)试验1组(NP):基础日粮+0.01%益生菌;(4)试验2组(LP):低能低蛋白日粮+0.01%益生菌。结果表明,在不同营养水平下,益生菌能提高21 d肉鸡的胸腺指数(P<0.01)、脾脏指数和法氏囊指数(P<0.05),但不影响42 d免疫器官指数(P>0.05),可显著提高肉鸡21 d血清和肠黏膜总超氧化物歧化酶(T-SOD)的活性(P<0.05),降低肉鸡21 d血清丙二醛(MDA)的含量(P<0.01),对21 d肠黏膜MDA含量也有降低趋势(P=0.057),能极显著提高42 d血清T-SOD活性和总抗氧化能力(T-AOC)(P<0.01),显著降低42 d血清和肠黏膜MDA的含量(P<0.05);在不同营养水平日粮中添加益生菌对肠黏膜IgG的含量有提高趋势(P=0.077),显著提高42 d肠黏膜IgG和SIgA含量(P<0.05),能显著降低21 d、42 d回肠大肠杆菌数量(P<0.05),极显著提高21 d回肠乳酸杆菌的数量(P<0.01),对42 d回肠乳酸杆菌数量没有显著影响(P>0.05)。结果提示,在不同营养水平下添加益生菌能促进肉鸡前期的免疫器官生长和发育,增强血液和肠黏膜的抗氧化功能,促进肠黏膜免疫球蛋白分泌,并能促进回肠乳酸杆菌增殖,抑制大肠杆菌增殖。     

壳聚糖硒对肉仔鸡生产性能、肠道菌群的影响

试验共设5个组,对照组饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ和Ⅳ组在基础日粮中分别添加0.01％、0.05％、0.10％和0.20％壳聚糖硒,试验期42d.结果表明:与对照组相比,在1～42 d时,Ⅰ、Ⅱ、Ⅲ和Ⅳ组平均日增重分别提高了2.52％(P＞0.05)、9.88％ (P＜0.05)、11.82％ (P＜0.05)和9.30％ (P＜0.05),平均日采食量分别提高了2.28％(P＞0.05)、4.67％ (P＞0.05)、4.24％ (P＞0.05)和9.24％ (P＜0.05),料重比Ⅱ、Ⅲ组分别降低了4.49％ (P＞0.05)、6.74％ (P＜0.05);在22～42 d时,盲肠内双歧杆菌数量分别提高了0.59％ (P＞0.05)、3.79％ (P＞0.05)、7.23％(P＜0.05)和0.95％ (P＞0.05),乳酸杆菌数量分别提高了0.48％ (P＞0.05)、4.78％ (P＞0.05)、5.38％ (P＜0.05)和5.26％ (P＜0.05),大肠埃希菌数量分别降低了6.06％ (P＞0.05)、10.88％ (P＜0.05)、15.57％ (P＜0.05)和21.51％ (P＜0.01).壳聚糖硒适宜的添加水平为0.10％.     

Effects of freeze-dried Mitsuokella jalaludinii culture and Natuphos(®) phytase supplementation on the performance and nutrient utilisation of broiler chickens

BACKGROUND: Phytate‐bound phosphorus (P) in poultry diets is poorly available to chickens. Hence exogenous phytase is often added to their diets. Mitsuokella jalaludinii is a rumen bacterial species that produces high phytase activity. In this study the effects of freeze‐dried active M. jalaludinii culture (FD‐AMJC) and Natuphos^® phytase (phytase N) supplementations on the growth performance and nutrient utilisation of broiler chickens fed a low‐available P (aP) diet were evaluated. RESULTS: Supplementation of FD‐AMJC or phytase N to the low‐aP diet improved the feed intake, feed conversion rate, body weight gain, dry matter (DM) digestibility and P, Ca and Mn retention, increased the tibia bone ash content, Ca and P concentrations in tibia DM and P and Zn concentrations in plasma and reduced the P excretion of broiler chickens. However, the feed conversion rate, P and Ca retention, DM digestibility and reduction of P excretion were better with FD‐AMJC than phytase N supplementation. Supplementation of FD‐AMJC to the low‐aP diet also improved the apparent metabolisable energy value of the diet, Cu and Zn retention and crude protein digestibility, but phytase N supplementation did not. CONCLUSION: FD‐AMJC supplementation was more efficient in improving nutrient utilisation and reducing P excretion in chickens than phytase N supplementation. Copyright © 2011 Society of Chemical Industry     

膨润土制备猫砂研究

通过XRD、扫描电镜、粒度测试等性能分析手段,对阜新膨润土的性质进行了研究,在大量试验的基础上,确定了膨润土制备宠物猫砂中改性沸石的添加比例和粘结剂的添加量。在试验室中制备出了猫砂产品,其性能指标优于国内某猫砂产品,接近进口某猫砂的性能,其成本较低,具有市场竞争力。     

Field Interventions Against Colonization of Broilers by Campylobacter

Poultry accounts for a high proportion of human campylobacteriosis cases, and the problem of Campylobacter colonization of broiler flocks has proven to be intractable. Owing to their broad host range and genetic instability, Campylobacter organisms are ubiquitous and adaptable in the broiler farm environment, colonizing birds heavily and spreading rapidly after introduction into a flock. This review examines strategies to prevent or suppress such colonization, with a heavy emphasis on field investigations. Attempts to exclude Campylobacter via enhanced biosecurity and hygiene measures have met with mixed success. Reasons for this are becoming better understood as investigations focus on houses, ventilation, biosecurity practices, external operators, and compliance, among other factors. It is evident that piecemeal approaches are likely to fail. Complementary measures include feed and drinking water treatments applied in either preventive or suppressive modes using agents including organic acids and their derivatives, also litter treatments, probiotics, prebiotics, and alterations to diet. Some treatments aim to reduce the number of Campylobacter organisms entering abattoirs by suppressing intestinal colonization just before slaughter; these include acid water treatment or administration of bacteriophages or bacteriocins. Experimental vaccines historically have had little success, but some recent subunit vaccines show promise. Overall, there is wide variation in the control achieved, and consistency and harmonization of trials is needed to enable robust evaluation. There is also some potential to breed for resistance to Campylobacter. Good and consistent control of flock colonization by Campylobacter may require an as‐yet undetermined combination of excellent biosecurity plus complementary measures.