多不饱和脂肪酸代谢及其对炎症的调节

炎症是一种机体对感染或组织损伤的保护性反应。适度的或可控的炎症对于入侵病原微生物的清除以及受损组织的修复是必需的,然而过度的或不可控的炎症往往会导致病理性炎症反应发生,大大提高了各种感染性和代谢性疾病的发病风险。多不饱脂肪酸代谢生成的脂质调控介质对炎症的启动、发展以及消退均具有重要的调节作用,了解多不和脂肪酸的代谢及其代谢产物对炎症反应的调节机制,对于通过饲粮营养途径控制疾病发生以及改善人和动物健康具有重要的理论和现实意义。鉴此,本文综述了多不饱和脂肪酸的代谢途径,并就其代谢产物对炎症反应的调节进行了详细论述。     

玉米芯水解液生产酵母蛋白的研究

我国玉米产量非常大,副产物玉米芯中富含纤维素、半纤维素、木质素[1],其水解液中含大量戊糖(主要是木糖)和六碳糖。迄今大量玉米芯仍作为废弃物燃烧掉,不仅浪费了木质素资源,其烟尘还造成了二次污染[2]。利用玉米芯水解液生产酵母蛋白,既解决了环境问题,又能变废为宝,为木质素资源的利用开辟了新的途径。为此,本实验利用能同化木糖和六碳糖的酵母菌株Y-2.05对玉米芯水解液生产酵母进行工艺研究。1材料与方法1.1材料原料:玉米芯,市场采购;菌种:酵母Y-2.05,本实验室提供。1.2培养基斜面培养基:木糖20g/l、酵母膏10g/l、蛋白胨10g/l、pH值5.…     

37 ℃持续热应激肉鸡血气改变的动态分析

80只25日龄雄性AA肉鸡,随机分为对照组(21～24 ℃,相对湿度50%±5%)和试验组(37 ℃±0.5 ℃,相对湿度70%±5%),自由采食和饮水.在12 d的试验期间,动态检测血气指标、呼吸频率、直肠温度和生产性能的变化.结果显示热暴露初期呈现代偿性呼吸性碱中毒,其特点为动脉血二氧化碳分压(3.82±0.36)降低,pH(7.48±0.04)升高;中期呈现失代偿性代谢性酸中毒,其特点为血浆HCO-3浓度(19.00±2.55)降低,pH(7.37±0.06)显著下降(P＜0.05);后期酸碱平衡趋于正常.热应激后,肉鸡日增重和日采食量极显著下降(P＜0.01)、料肉比极显著升高(P＜0.01);呼吸频率极显著升高(P＜0.01);热暴露第1、5、7、9和12天体温极显著升高(P＜0.01).动脉血氧分压与呼吸频率呈极显著负相关(P＜0.01),与体温呈显著负相关(P＜0.05);血氧饱和度与体温极显著负相关(P＜0.01).表明37 ℃持续热应激的肉鸡呈现由代偿性呼吸性碱中毒转变为失代偿性代谢性酸中毒,最后趋于正常的动态变化过程.     

Effect of Supplementing Alfalfa Powder to Diet on Growth Performance and Meat Quality of Goose

The experiment was aimed to investigate the effects of dietary alfalfa powder on the growth performance,body size,slaughter performance,organ index and meat quality of Siji geese.A total of 256 15-day-old geese (half male and half female) with similar body weight were randomly divided into four groups with 4 replicates of 16 geese each.The geese in control group were fed with corn-soybean meal-based diet (control diet),and geese in the experimental groups were fed the basal diet replaced with 10%,20% and 30% alfalfa powder,respectively.The results showed that,compared with the control group,dietary alfalfa powder supplementation had no significant effect on the average daily intake,average daily gain,feed conversion ratio,body oblique length,keel length,shin circumference,semi diving length,chest width and shin length (P>0.05),and also had no effect on the carcass ratio,half-eviscerated carcass ratio and pectoral muscle ratio (P>0.05).However,dietary 20% and 30% alfalfa powder supplementation significantly increased the chest depth (P<0.05),dietary 30% alfalfa powder significantly decreased the full-eviscerated carcass ratio (P<0.05),and dietary 10% alfalfa powder significantly increased the leg muscle ratio (P<0.05) of geese.In addition,dietary alfalfa powder significantly decreased the abdominal fat ratio (P<0.05),raised the growth index of liver,jejunum,ileum,and cecum (P<0.05),and increased the water loss rate of pectoral muscle and leg muscle (P<0.05) compared with the control group.Dietary 10% and 30% alfalfa powder significantly increased duodenal growth index (P<0.05) of geese.In conclusion,dietary alfalfa powder supplementation might improve the slaughter performance (increase chest depth and leg muscle ratio,reduce abdominal fat rate) and organ growth index (increase the growth index of liver,duodenum,jejunum,ileum and cecum).However,dietary alfalfa powder increased water loss rates in pectoral muscle and leg muscle,and 30% alfalfa powder reduced the full-eviscerated carcass ratio of geese.The appropriate supplementation level of alfalfa powder was recommended at 10% in the present study.     

不同桑树品种在土壤水分胁迫下膜伤害和保护酶活性变化

以北方蚕区现行主要桑树品种选792、沙2、新一之舽、陕305、湖桑32号、农桑14号的1年生绿枝扦插苗为实验材料,研究了水分胁迫对不同桑树品种的膜伤害和保护酶活性的影响。在水分胁迫下,细胞膜受到伤害,细胞膜透性增加,电导率随之增强,作为膜脂过氧化产物的丙二醛(MDA)含量增加,各品种细胞膜受到的伤害度有差异。保护酶SOD、POD、CAT活性都表现出先升后降的变化趋势,但变化规律又有所不同。推测各品种抗旱性存在较大差异,6个供试桑品种抗旱能力从大到小依次为选792>陕305>农桑14号>湖桑32号>新一之舽>沙2。     

饲料行业的新形势与应对

10月17-18日,中国饲料工业协会第五届理事会第二次全会暨第四届大型企业联谊会在扬州召开。会议指出,十七大的胜利召开,为饲料企业发展带来新机遇,企业要以此为契机,以科学发展观为指导,以确保饲料产品质量安全为主线,争取加快发展,做强做大,为饲料工业发展做出更大贡献。会议期间,针对饲料行业的新形势与协会的工作、产业发展等业内普遍关注的问题,本刊记者采访了部分与会领导和知名企业家,对精彩观点节录成文,以飨读者。     

鸡实验性尿酸盐沉积症的肾脏病理学研究

将１２０只３５日龄迪卡商品代蛋用雏鸡随机分为高钙组、高蛋白组和对照组,分别饲喂高钙（含钙３．９％）、高蛋白（含粗蛋白４４．０％）和全价（含钙０．８％,粗蛋白１８．２％）饲料。试验第２５天,各组剖检５只鸡,作肾脏的光镜和电镜观察。结果表明,高钙、高蛋白饲料均能引发尿酸盐沉积。高钙组鸡肾脏肿大,表面及切面有大量尿酸盐结晶;输尿管扩张,管内充满白色尿酸盐沉积物。光镜观察,肾小球肿胀,近曲及远曲小管上皮细胞肿胀、变性。电镜观察,近曲小管上皮绒毛短缩、肿胀、断裂、脱落,线粒体肿胀、嵴断裂;远曲小管线粒体肿胀,呈现空泡,核呈锯齿型。高蛋白组眼观病变不明显,肾脏的光镜、电镜病变与高钙组相似,但损伤程度较轻。作者认为,高钙、高蛋白所致肾脏损害是鸡尿酸盐沉积症的重要原因。     

稻瘟病菌无毒基因研究进展

水稻与稻瘟菌间存在广泛而特异的相互作用,是研究寄主与病原物互作的重要模式系统。无毒基因是病原物遗传因子,能诱发寄主植物产生抗病性,是稻瘟菌与水稻互作最重要的激发子。为寻求稻瘟病防治的新策略,本研究概述了研究稻瘟病菌无毒基因的意义,归纳了抗性基因与无毒基因互作的3种模式,总结了国内外稻瘟病菌无毒基因的克隆及功能研究,探讨了无毒基因在生产上病害流行预测中的应用,指出利用抗性基因与无毒基因的关系对稻瘟菌分类将会更为科学和实用,应进一步加快稻瘟病菌无毒基因的克隆。     

柠条锦鸡儿营养成分动态变化及其在绵羊瘤胃内的降解

本试验旨在研究内蒙古呼和浩特地区不同生育期柠条锦鸡儿营养成分的动态变化及其在绵羊瘤胃内的降解特性。分别于孕蕾期、开花期和结实期采集当年生柠条锦鸡儿嫩枝条,测定初水分后在65℃烘箱中烘干,测定常规营养物质含量;选用安装有永久性瘤胃瘘管的内蒙古小尾寒羊3只,采用瘤胃尼龙袋法评定不同生育期柠条锦鸡儿营养成分的瘤胃降解特性。试验结果表明:1)开花期和结实期柠条锦鸡儿的干物质(DM)和粗蛋白质(CP)含量显著高于孕蕾期(P<0.05);不同生育期柠条锦鸡儿有机物(OM)、粗脂肪和无氮浸出物含量无显著差异(P>0.05);结实期粗灰分含量显著高于孕蕾期和开花期(P<0.05);孕蕾期和开花期柠条锦鸡儿中性洗涤纤维(NDF)含量显著高于结实期(P<0.05),而酸性洗涤纤维(ADF)含量显著低于结实期(P<0.05);随着生育期的延续,柠条锦鸡儿木质素含量逐渐升高,开花和结实期显著高于孕蕾期(P<0.05);随着生育期的延续,柠条锦鸡儿钙含量显著提高(P<0.05),磷含量显著降低(P<0.05)。2)随着生育期的延续,柠条锦鸡儿DM的72 h消失率和有效降解率逐渐降低,开花期和结实期DM的有效降解率无显著差异(P>0.05);不同生育期柠条锦鸡儿CP的72 h消失率无显著差异(P>0.05),但有效降解率孕蕾期显著高于开花期和结实期(P<0.05);随着生育期的延续,柠条锦鸡儿OM和NDF的72 h消失率和有效降解率均显著降低(P<0.05);开花期和结实期柠条锦鸡儿ADF的72 h消失率和有效降解率无显著差异(P>0.05),但显著低于孕蕾期(P<0.05)。试验结果提示,结合不同生育期柠条锦鸡儿营养物质含量、饲草DM产量以及营养物质的瘤胃降解特性,开花期柠条锦鸡儿营养物质的利用效率最高,为最佳刈割时期。     

Detection of antibodies and risk factors for infection with bovine respiratory syncytial virus and parainfluenza virus 3 in dual-purpose farms in Colima, Mexico

A cross-sectional study was carried out, from November 2007 to March 2008, to estimate the prevalence of and to determine risk factors associated with bovine syncytial respiratory virus (BRSV) and parainfluenza 3 virus (PIV3) in dual-purpose herds in Colima, México. One hundred and seventy-six sera from 33 herds for PIV3 and 232 sera from 44 herds for BRSV were used. Sera were analyzed by indirect ELISA for the detection of antibodies against BRSV and PIV3 in cattle herds to determine the seroprevalence of respiratory diseases. The apparent and true prevalences for PIV3 were 60.8% and 54.4% and for BRSV 52.2% and 50.8%, respectively. The percentage of herds showing at least one positive animal was 78.7% for PIV3, and 93.2% for BRSV. Age (≤12, 13-48, and >48?months old) and respiratory signs (no, yes) showed significant association (P?相似文献