奶牛泌乳早期日粮能量类型对机体能量分配和乳成分的影响

通过对能量负平衡与代谢失调之间的关系研究显示,日粮中生脂和生糖营养素的平衡在泌乳早期奶牛日粮中有着重要作用。为了证实生脂营养素和生糖营养素对机体能量分配和能量平衡及氮平衡的影响。16头泌乳奶牛,饲养于环控仓中,通过间接热量测定法确定其产后2周到产后9周机体的能量平衡和氮平衡。产前3周至产后9周分别饲喂高浓度生脂日粮和生糖日粮(两种日粮净能和小肠可消化蛋白均相等)。两种日粮对代谢能摄入和产热量没有影响。生脂日粮的奶牛比饲喂生糖日粮的奶牛能将更多的能量分配到泌乳中[1175±18 vs.1073±12kJ(kg0.75d)],同时其乳脂产量也高于生糖日粮处理组乳脂产量(1.89±0.02vs.1.67±0.03 kg/d),其原因在于乳脂中C16:0、C18:0和C18:1升高所致。另外,能量以体蛋白形式储存在两种日粮处理中没有差异;但饲喂高浓度生脂日粮的奶牛体脂动员高于生糖日粮奶牛[190±23 vs.113±26 kJ/(kg0.75d)]。总的结果表明,在产乳和体组织间的能量分配可通过饲喂相同能量不同能量形式来源的日粮进行调控。     

营养因素对禽病防治的影响

1饲料中脂肪水平对疾病预防的影响日粮所含脂肪酸作为一种营养素,是动物体内能量的重要来源,同时供给机体所需的必需脂肪酸,在机体代谢中发挥着重要的作用,它对动物机体免疫功能的影响也逐渐被人们所揭示。日粮中的脂肪酸通过改变细胞膜的结构或调节前列腺素的合成来影响家禽的     

日粮营养素对反刍动物免疫能力的影响

近年来，由于禁用或限用某些抗生素药物添加剂，人们的饲料安全意识提高，倍加关注动物营养与免疫关系的研究。 影响反刍动物免疫能力的营养素包括：蛋白质、能量、维生素和矿物质。每种营养素都可能影响特异免疫或非特异免疫。了解这些营养素间的互作很重要。任何一种营养素缺乏或过量都能影响其他营养素的作用。本文仅讨论日粮能量与蛋白质、维生素Ｅ与硒、锌、铜和铬对反刍动物免疫能力的影响。１特异免疫与非特异免疫 动物通过调节特异免疫和非特异免疫的反应强度来维持机体正常的防御机能。特异免疫主要有两种：１）体液免疫：血液循环…     

奶牛泌乳早期日粮能量类型对机体代谢物和代谢激素的影响

通过对泌乳早期能量负平衡与机体代谢失调的研究表明,有效生脂和生糖能量源之间的平衡在奶牛日粮中扮演着重要角色。所以本研究目的在于比较奶牛泌乳早期生糖和生脂日粮对肝脏甘油三酯、代谢物及其代谢激素的影响,并研究分析了代谢物浓度与能量蓄积之间的相关性。试验选用16头奶牛,从产前3周至产后9周分别饲喂生脂和生糖日粮(两种日粮净能相等),且产后第2周到第9周于环控仓中饲养。产后饲喂生脂日粮的奶牛NEFA浓度较高(0.46±0.04 vs 0.37±0.04mmol/L),而胰岛素较低(4.0±0.5 vs 5.5±0.6μIU/ml);血浆中葡萄糖、β-羟基丁酸、IGF-Ⅰ、甲状腺素在两种日粮中没有较为明显差异。两种日粮处理奶牛产前和产后2周肝脏甘油三酯浓度相一致;饲喂生糖日粮奶牛产后4周肝脏TAG含量较低,但无显著的日粮差异。本试验也发现能量蓄积和乳脂以及能量蓄积与NEFA呈负相关,而能量蓄积与胰岛素浓度呈正相关。总之,试验结果显示,胰岛素调控着奶牛泌乳早期产奶和机体组织之间的能量分配。与饲喂生脂日粮相比,泌乳奶牛早期饲喂生糖日粮能减低机体体脂动员;当饲喂生脂日粮时,可提高乳中的生脂营养素,降低血浆胰岛素和增加NEFA浓度。     

日粮添加复合植物营养素对小尾寒羊生长性能和血清指标的影响

试验旨在探究日粮中加入复合植物营养素对舍饲小尾寒羊生长性能和血清指标的影响.试验选取体重(24.18±0.31) kg、健康的4月龄小尾寒羊母羊16只,分为2组,每组8个重复.对照组小尾寒羊饲喂基础日粮,试验组小尾寒羊饲喂在基础日粮中添加3％‰复合植物营养素的试验日粮.试验期97 d,预试期7d,正式试验期90 d.结...     

饲料氮营养素水平对断奶仔猪回肠黏膜屏障的影响

为了检测日粮氮营养素水平对断奶仔猪肠道形态和黏膜免疫功能的影响选用健康杜×长×大三元杂交断奶25日龄仔猪12头,分别饲喂17.09%(低蛋白质组)和20.05%(NRC标准)的粗蛋白水平日粮,饲养至第25天采样。结果显示:低蛋白组和标准日粮组肠绒毛高度、隐窝深度、绒毛高度与隐窝深度比值,以及细胞连接蛋白(claudin-1和E-cadherin)的表达水平和绒毛中杯状细胞的数量差异均不显著(P0.05)。同时,低蛋白日粮组中回肠Ig A分泌细胞的面积和上皮内淋巴细胞(IELs)数量与高蛋白日粮组一致。结果表明:在NRC标准日粮基础上适当降低粗蛋白水平,不影响断奶仔猪的肠黏膜屏障功能和黏膜免疫水平。     

营养因素对禽病防治的影响

日粮所含脂肪酸作为一种营养素，是动物体内能量的重要来源，同时供给机体所需的必需脂肪酸，在机体代谢中发挥着重要的作用，它对动物机体免疫功能的影响也逐渐被人们所揭示。日粮中的脂肪酸通过改变细胞膜的结构或调节前列腺素的合成来影响家禽的免疫能力，前列腺素能降低抗体水平，对包括免疫反应的许多生理过程起着重要的调节控制     

刺五加多糖对肉鸡生长性能、免疫功能和抗氧化能力的影响

试验研究刺五加多糖(ASP)对肉鸡生长性能、免疫功能和抗氧化能力的影响.选取240只1日龄AA肉鸡,随机分为4组,每组6个重复,每个重复10只.对照组肉鸡饲喂基础日粮,ASP低量组肉鸡饲喂基础日粮+500 mg/kg ASP,ASP中量组肉鸡饲喂基础日粮+1000 mg/kg ASP,ASP高量组肉鸡饲喂基础日粮+20...     

择食饲喂对肉鸡生产性能和养分代谢的影响

试验研究择食饲喂对肉鸡生产性能、饲料养分利用率和肉鸡整体CP、能量转化率的影响。将144只22日龄艾维茵肉鸡随机分成3组,每组4个重复,每重复12只,分别饲喂粉碎玉米 浓缩料、豆粕 平衡料的试验日粮和基础全价对照日粮,每处理均设两个食槽。结果表明:(1)择食饲喂比饲喂全价混合日粮时生产性能略有下降;(2)择食饲喂对日粮干物质、粗蛋白和能量的表观代谢率无显著影响(P>0.05);(3)择食饲喂对肉鸡整体CP、能量沉积率无显著影响(P>0.05);(4)择食饲喂玉米组,日粮CP以及赖氨酸转化为体增重的效率显著高于另两组(P<0.05)。     

不同能量水平对围产期奶牛脂肪动员的影响

将围产期健康奶牛30头随机分为三组,分别于产前第28d开始饲喂标准日粮(能量摄入100%组)、标准日粮增加20%日粮(能量摄入120%组)和标准日粮减少20%日粮(能量摄入80%组),产后各组奶牛均饲喂标准泌乳日粮,至产后第56d结束,观察干奶期不同能量摄入水平对围产期健康奶牛血液甘油三酯、非酯化脂肪酸和总酮体浓度的影响。实验结果表明,产前低能饲喂可以降低产后奶牛血液甘油三酯、非酯化脂肪酸和总酮体浓度。提示干乳期能量摄入水平是影响和调节产后能量平衡状态的重要因素。     

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。     

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。     

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。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

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.     

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。