Ultrastructure of Leukocytes in Acutely Inflamed Dermis and Muscle of Channel Catfish at Different Temperatures

Abstract

Channel catfish Ictalurus punctatus were acclimated for 35 d at 21°C, 15°C, and 9°C. Fish were injected 3 mm beneath the skin surface with 15 μL of turpentine, and inflamed skin and muscle samples were excised after 48 and 72 h for ultrastructural examination. Neutrophils, lymphocytes, and macrophages were present in the inflamed tissues at all times and temperatures; eosinophils and basophils were not found. Neutrophils were identified by their oval-to-elongate granules with a striated or crystalline core, heavy deposits of glycogen, longitudinal cristae of the mitochondria, and eccentrically located nuclei. Macrophages were distinguished by their numerous pseudopodia, vacuoles, lysosomes, and rough endoplasmic reticulum. Lymphocytes were distinguished by their chromatin-dense nucleus, numerous free ribosomes, and small volume of cytoplasm. Neutrophils were the most common inflammatory cell present, and there were no apparent differences in relative abundance within the inflammatory foci of fish acclimated to the three temperatures. Compared with neutrophils in peripheral blood, neutrophils in inflamed tissues had comparatively rare, swollen mitochondria, and cytoplasmic tubules were not observed. A few neutrophils had vacuoles, phagosomes, or pseudopodia. Lymphocytes in inflamed foci did not contain a Golgi apparatus, granules, vacuoles, or vesicles and had less cytoplasm than did lymphocytes in peripheral blood. Macrophages were the rarest type of inflammatory cell within inflamed areas and differed from peripheral blood monocytes in that macrophages contained numerous lysosomes and vacuoles. No structural differences were associated with particular temperatures for any type of leukocyte.     

饲粮不同油脂来源对肉鸡脂类代谢及相关基因表达的影响

本试验旨在探讨饲粮不同油脂来源对肉鸡脂类代谢及相关基因表达的影响.选取160只平均体重为(46.00±0.26)g的1日龄爱拔益加(AA)肉仔鸡随机分成2组,每组10个重复,每个重复8只鸡,分别饲喂油脂为豆油和猪油的饲粮.试验期为21 d.结果表明:饲粮不同油脂来源对21日龄肉鸡血清甘油三酯(TG)、总胆固醇(TC)、...     

Effects of Dietary Zinc and Calcium on Select Immune Functions of Channel Catfish

Abstract

The effects of dietary zinc and calcium on immunocompetence of channel catfish Ictalurus punctatus (mean initial weight = 3.1 g/fish) were determined after a 10-week feeding trial. Fish were fed daily amounts equal to 3% of their body weight of one of six purified diets that were deficient in zinc (2 mg/kg of diet), calcium (0.02% of diet), or both; replete with zinc (20 mg/kg of diet) and calcium (0.5% of diet); or excessive in zinc (200 mg/kg of diet) or calcium (2.5% of diet). Immunocompetence of immunized and nonimmunized fish fed the various diets was assessed by measuring serum immunoglobulin M levels and mortality after an intraperitoneal injection of live Aeromonas hydrophila. Channel catfish fed diets deficient in zinc, calcium, or both had significantly (P ≤ 0.05) less weight gain and survival as compared with those fed diets replete with or excessive in zinc or calcium. Tissue mineral concentrations of fish indicated that various levels of zinc and calcium nutriture existed when immune functions were tested. Diet affected mortality of only nonimmunized fish in the bacterial-challenge test; zinc deficiency and calcium excess decreased mortality. Whereas growth and survival of fish were reduced by dietary zinc or calcium deficiency, the measured immunological characteristics were not equally impaired by these mineral deficiencies.     

不同脂肪来源对断奶仔猪生长性能和脂类代谢的影响

本试验旨在研究不同脂肪来源对断奶仔猪生长性能及脂类代谢的影响.试验采用单因子设计,选用48头(28±1)日龄杜洛克×长白×大白三元杂交断奶仔猪,随机分为3组,每组16个重复(公母各占1/2),每个重复1头猪.3组试验猪分别饲喂添加10％椰子油、10％鱼油和10％猪油的饲粮.试验分为2个阶段,共28 d.试验第21天所有...     

An Elevated Dietary Level of Ascorbic Acid Fails to Influence the Response of Anterior Kidney Neutrophils to Edwardsiella ictaluri in Channel Catfish

Abstract

Channel catfish Ictalurus punctatus (weight, 320–420 g) were fed diets with 100 or 1,000 mg ascorbic acid/kg of diet for 7 weeks in ponds. Anterior kidney neutrophil function was assessed by incubating the neutrophils with Edwardsiella ictaluri. Percent phagocytosis, phagocytic index (the mean number of bacteria phagocytized per cell by all neutrophils, including nonphagocytic ones), and bactericidal capabilities of the anterior kidney neutrophils were measured at 0, 90, 180, 270, and 360 min. Serum cortisol was also measured. No significant difference was observed between the two diets with respect to anterior kidney neutrophil function or serum cortisol levels. However, serum cortisol levels did affect mean phagocytic index of anterior kidney neutrophils. Catfish that had serum cortisol levels greater than 10 μg/dL displayed a significant decrease in the phagocytic index when compared with catfish that had cortisol levels less than 5 μg/dL.     

不同灌水量对紫花苜蓿产量的影响

甘肃省张掖市已被国家水利部列为节水型试点城市,黑河流域综合治理把退耕种草作为节水的一项重要措施。通过本试验,以摸清不同灌水量对紫花苜蓿产量的影响,为黑河流域综合治理退耕还草项目的实施提供科学依据,以促进草畜产业的发展。试验表明从节水和效益方面分析,种植紫花苜蓿以5250m3/hm2的灌水量较为有效。     

不同油脂对肉鸡生长性能、屠宰性能及肉品质的影响

本试验旨在研究不同油脂对肉鸡生长性能、屠宰性能及肉品质的影响。选取1日龄罗斯308肉鸡3 600只,随机分为4个处理,每个处理3个重复,每个重复300只,公、母各半。1～7 d,各处理组肉鸡饲喂相同日粮(豆油水平相同);7 d后日粮分别添加相同水平(中期3%和后期5%)的豆油、鸭油、棕榈油、米糠油。试验期37 d。结果表明:各处理组肉鸡各阶段及全期生长性能无显著差异(P>0.05);与豆油组相比,其他油脂有升高全期肉鸡耗料增重比和胸肌率的趋势(P<0.1);各处理组肉鸡胴体出成率无显著差异(P>0.05),但棕榈油组肉鸡胴体出成率最高,腹脂率最低;豆油组鸡胸肌离心损失最大,米糠油组胸肌滴水损失最大,肉品质较差;棕榈油组硫代巴比妥酸值和剪切力最小,且胸肌亮度和黄度较低,肉品质较好。综上所述,日粮中使用豆油有利于改善肉鸡生长性能,使用棕榈油能够提高胴体出成率和胸肌率,降低腹脂沉积,对肉品质有一定的改善作用。     

日粮钙源颗粒大小对不同年龄产蛋鸡生产性能和蛋壳质量的影响

在蛋鸡生产中,人们主要关注其产蛋后期的蛋壳质量比较差,易碎.影响蛋鸡产蛋后期蛋壳质量的主要因素是蛋鸡的年龄和日粮中的钙.NRC(1994)估测蛋鸡钙的营养需要为每天每100g摄入的日粮中含有32.5 g/kg.然而,许多专家通过试验证实,当66～78周龄蛋鸡日粮中钙的含量由24～25 g/kg提高到36～40 g/kg时可以将产蛋率从79%提高到86%,蛋壳重量可以由5.64 g提高到6.12g,壳重/壳表面积由712提高到77.4mg/cm2.日粮中钙的含量提高至48～50 g/kg并不能进一步提高产蛋率,但是可以改善蛋壳重量和蛋壳厚度.58～73周龄伊莎蛋鸡日粮中添加40 g/kg钙就可以保证其产蛋性能和蛋壳质量.     

不同磷源对育成母牛日粮磷表观消化率的影响

本文旨在采用消化试验研究育成母牛日粮中不同磷源(植物磷源或补充部分矿物磷源)对日粮总磷表观消化率的影响.试验选用体况良好、体重一致的15月龄荷斯坦育成母牛12头,随机分为3组,即试验1组、2组和3组,每组4头,分别定量(3.50kg/d)饲喂3种不同精料日粮,粗料(青贮)自由采食,以磷酸氢钙替代部分植物磷源,日粮总磷为0.57％～0.60％;试验期为30d,预试期20d后进入正试期,试验最后7d全收集粪样和尿样;结果表明不同磷源处理间日粮的总磷消化道表观消化量和表观消化率没有显著差异(P＞0.05),总磷的表观消化率为38.2％.     

不同脂肪源日粮对大鼠生长及餐后糖脂代谢的影响

通过饲喂不同脂肪源的等营养水平日粮,研究不同种类脂肪对生长期SD大鼠生长及餐后糖脂代谢的影响.试验采用单因子试验设计,将72只体重为60～90 g的SD大鼠随机分为6组,每组12个重复,每个重复1只大鼠.6组大鼠分别饲喂无脂纯合型日粮、普通型日粮和10%玉米油、牛脂、棕榈油及椰子油纯合型日粮.试验分为2个阶段,共28 d.每周称大鼠个体重,第15天及第29天,测糖脂代谢相关指标.结果表明,试验第8天,添加脂肪的纯合日粮组大鼠体重均高于无脂组,玉米油组大鼠体重显著高于牛脂组、棕榈油组及椰子油组(P<0.05);试验第8天、第15天、第22天和第29天,玉米油组的体重显著或极显著高于无脂组(P<0.05或P<0.01).试验第15天,添加脂肪的纯合日粮组大鼠餐后血脂水平均高于无脂组,且牛脂组及棕榈油组的甘油三酯、总胆固醇及游离脂肪酸均极显著高于无脂组(P<0.01).试验第15天和第29天,普通日粮及添加脂肪的纯合日粮组血糖水平均高于无脂组,但差异不显著(P>0.05);玉米油组和椰子油组胰岛素和胰高血糖素水平均显著极显著低于牛脂组及棕榈油组(P<0.05或P<0.01).结果显示,玉米油的促生长效果优于椰子油、牛脂及棕榈油,且玉米油和椰子油不会升高餐后血脂及血糖水平.     

不同脂肪源对鹅产肝性能和品质影响的研究

为研究不同脂肪源对鹅产肝性能和品质影响的研究,试验采用单因子设计将100只鹅分为4个组,在基础日粮中添加1％的鹅油、羊油、玉米油和豆油。结果表明：①鹅油、羊油和玉米油能够提高鹅肝重,豆油最差;②脂肪源对鹅肝和胸肌中不饱和脂肪酸总量影响较少,但能够明显改变脂肪酸成分的含量。     

Effect of Vitamin E on the Immune Response of Channel Catfish to Edwardsiella ictaluri

Abstract

Three-month-old fingerling channel catfish Ictalurus punctatus were fed purified diets supplemented with ∝-tocopherol acetate to provide 0, 60, and 2,500 mg vitamin E/kg for 180 d. A 30-s immersion bath and an oral booster were used to deliver a bacterin of formalin-killed Edwardsiella ictaluri to half of the fish from each dietary treatment. Resistance of red blood cells to peroxidation was used as an index of antioxidant status. The susceptibility of red blood cells to oxidative hemolysis decreased with increasing levels of dietary vitamin E. Vaccinated and nonvaccinated fish were evaluated for agglutinating antibody titers and macrophage activity. Humoral antibody titers in response to E. ictaluri were significantly (P ≤ 0.05) higher in vaccinated fish than in nonvaccinated fish; however, no such differences in agglutinating antibody titers were detected among any of the dietary treatment groups. Both vaccination and vitamin E significantly enhanced the ability of macrophages to phagocytize virulent E. ictaluri. Results of this study indicate that elevated levels of dietary vitamin E may affect the ability of channel catfish to respond immunologically to bacterial pathogens.     

不同锌源对肉用仔鸡的饲养效果

主要研究以不同锌源对内仔鸡的生产性能和血液锌、胰脏锌,胫骨锌含量的影响,以验证固相合成蛋氨酸锌对肉用仔鸡的饲养效果.结果表明:相对于无机的硫酸锌,日粮中添加蛋氨酸锌能有效提高肉鸡的生产性能,提高胫骨中的锌含量;同时也表明液相合成蛋氨酸锌与固相合成蛋氨酸锌饲养效果相当.     

日粮铜来源及水平对肉鸡肝损伤的影响

本研究旨在探讨日粮铜来源及水平对肉鸡肝铜沉积及其组织病理学变化的影响.288只1日龄肉鸡随机分为8组,每组6个重复,每个重复6只鸡.选用硫酸铜、蛋氨酸铜作为试验铜源,每种铜源均设4个水平,分为对照口粮(Cu 11 mg/kg)和高铜日粮(Cu 110 mg/kg;Cu 220 mg/kg;Cu 330 mg/kg).试验期60 d,并于12、36和60日龄采血,测定血清中丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST)的活性,60日龄取肝脏,测定肝铜沉积最并观察肝损伤情况.结果表明:2种来源口粮铜组随着铜水平的增加,肝铜沉积量存在普遍升高的趋势,当日粮铜水平达到330 mg/kg时,除12日龄蛋氨酸铜组外,其他各组肝铜沉积量均显著高于对照组(P<0.05),并具有时间依赖性;铜源之间比较,除11 mg/kg铜水平(对照组)外,在肉鸡36和60日龄时,硫酸铜各组肉鸡肝铜沉积量要低于相应的蛋氨酸铜组(P<0.05).随着日粮铜水平和日龄的增加,血清ALT和AST活性大部分呈现升高趋势,与对照组比较,220和330 mg/kg日粮铜均可显著提高肉鸡36和60日龄血清ALT、AST活性(P<0.05).铜源之间比较,在肉鸡36和60日龄时,330 mg/kg蛋氨酸铜组的肉鸡血清ALT和AST活性显著高于330 mg/kg硫酸铜组(P<0.05).60日龄时,高水平日粮铜可造成肝细胞肿胀、胞浆内颗粒变性、肝细胞索和肝窦结构模糊等组织病理变化,在电子显微镜下则可见到胞浆内吞饮空泡增多、线粒体膜模糊和形态不规则,胞浆和核内出现电子密度沉积体等病理学损伤.结果提示:高铜日粮可增加肉鸡肝铜沉积,肝功能受到抑制,并导致肝脏出现不同程度的病理学损伤,相同添加水平的蛋氨酸铜比硫酸铜可导致更多的肝铜沉积,也相应地出现肝功能下降及组织病理学损伤.     

饲粮不同能量来源对断奶仔猪肠道黏膜功能的影响

仔猪早期断奶常常导致仔猪能量摄入不足,使肠道黏膜细胞处于"饥饿状态",影响仔猪正常的肠道功能,从而加剧断奶应激,因此满足肠道黏膜细胞的能量供给至关重要。本文就谷氨酰胺(Gln)、葡萄糖(Glu)、脂肪这3种肠黏膜细胞主要的供能物质来分别论述它们对于断奶仔猪肠道黏膜功能的影响。     

钙源及水平对肉仔鸡体内电解质平衡及血脂水平的影响

本文旨在研究采用不同钙源及水平的日粮对肉仔鸡体内电解质平衡及血脂水平的影响.试验采用二因素有重复完全交叉区组设计,选用144只健康AA肉仔鸡,随机分成4处理,每个处理6个重复,每个重复6只.饲粮采用2种钙源(碳酸钙、氯化钙)、2个钙水平(0.90%、1.15%),试验期28 d.结果表明:①与碳酸钙相比,日粮中氯化钙可降低血清Na++K+-Cl-水平(P<0.05)、提高Cl-水平(P<0.05),降低腹脂率(P<0.05)和血脂水平.②高水平钙可提高血清Ca2+水平(P<0.05).降低腹脂率和血脂水平(P<0.05).③钙源和水平互作对各指标均无显著影响(P>0.05).总之,日粮选用1.15%氯化钙虽对电解质平衡产生了一些影响,但可以较好地降低腹脂率和血脂水平.     

不同精粗比日粮对安格斯杂交阉牛生产性能的影响

[目的]为了掌握不同日粮对安格斯杂交阉牛生产性能的影响.[方法]试验对采用不同精粗比的全混合日粮对舍饲条件下杂交阉牛的育肥效果和生产性能进行研究.[结果]表明:随着时间的增加,精粗比为67.1:32.9(粗蛋白12.86,消化能12.38MJ· kg-1)的全混合日粮对安格斯与秦川杂交阉牛的育肥效果优于精粗比为57.0:43.0(粗蛋白质11.92,消化能10.82 MJ·kg-1)和45.7:54.3(粗蛋白质11.29,消化能10.62MJ·kg-1).育肥杂交阉牛的增重得到显著提高,53 d育肥日增重1 019.47 g.[结论]说明在本试验条件下日粮的精粗比可有效提高安格斯牛与秦川牛杂交的育肥效果和生产性能.     

复合酸化剂抗蛋鸡热应激效果的研究

通过在日粮中添加复合酸化剂,研究其对蛋鸡生产性能和血液理化指标的影响,探讨复合酸对蛋鸡热应激的作用效果,并筛选出适宜的添加水平。结果表明:①复合酸A1、A2使产蛋率、蛋重和采食量分别提高0.82%￣8.25%、0.48%￣2.19%和0.92%￣3.66%,死淘率降低1.85%￣3.70%。②复合酸使蛋鸡血清ALP、GLU升高,LDH、BUN、UA及pH值降低,TP、ALB、GLOB变化呈降低趋势,A/G则相反;血清钙各组间差异不显著,血清磷则随着酸添加量的增加逐渐下降。③复合酸化剂能缓解夏季产蛋鸡的热应激,可以作为抗应激添加剂应用。A1、A2抗热应激的效果总体上优于乳酸宝,A2尤为明显。A1和A2的最适添加剂量分别为0.3%和0.2%。     

γ-氨基丁酸对蛋鸡生产性能的影响

γ-氨基丁酸(GABA)又名氨酪酸,是一种中枢神经镇静剂,研究结果表明,GABA具有镇静、抗惊厥、降血压、增进脑活力、营养神经细胞、促进生长激素分泌的作用[1].近年来,GABA在饲料工业中的应用也越来越受到人们的关注,已有文献报道GABA对禽类、猪具有促进摄食和生长等作用[2,3].……     

Effect of Temperature and Dissolved Oxygen Concentration on Edwardsiella ictaluri in Experimentally Infected Channel Catfish

Abstract

Channel catfish Ictalurus punctatus were experimentally infected with Edwardsiella ictaluri by immersion exposure. After clinical disease ran its course for 52 d, the surviving fish were exposed to one of the following environmental regimes in troughs: 25°C with aeration, 25°C with no aeration, or variable temperature (18–23°C) with no aeration. After 29 d of exposure to the environmental regimes, various organs and tissues of the fish were assayed to determine the effects of these conditions on E. ictaluri concentrations (colony-forming units/mL of tissue sample). The concentrations of this pathogen were significantly (P < 0.05) higher in all tissues (trunk kidney, liver, head kidney, blood, spleen, gallbladder, muscle, brain, and gonad) 52 d postinfection than 29 d after exposure to any of the environmental regimes (81 d postinfection). Fish exposed to a near-normal concentration of dissolved oxygen (6.4 mg/L) and a constant temperature of 25°C had E. ictaluri concentrations that were significantly (P < 0.01) lower than those offish exposed to a low oxygen concentration (2.6 or 1.8 mg/L) and either a constant or a variable temperature.