养肉牛增效益的几项措施

(一)选用良种或杂交牛养肉牛的目的是为了增产增效.而好的品种是增产增效的决定因素.推荐引进生产速度快、饲料报酬高、肉质好的国外优良品种.如皮埃蒙特牛、德国黄牛、利木赞牛、短角牛及夏洛莱牛,山区可引进安格斯牛.这些外来品种既可用来直接饲养,其公牛又可用于与本地母牛进行杂交改良,获取优良的杂交后代进行育肥,在短期内可生产大量优质肉牛.利用杂交后代育肥,既综合了父母代的优势,又适应当地气候环境.且温驯易于管理,生长速度、产肉量高出本地牛31%和42%以上.     

青海高原地区良种肉牛改良当地黄牛的效果

在青海高原环境下,用引进的良种肉牛蓝白花、利木赞、西门塔尔和皮尔蒙特改良当地黄牛。结果显示:四个杂交组合F1代不同年龄的生长速度和体尺指标均明显优于青海黄牛(P<0.01),说明用良种肉牛改良青海黄牛效果明显;在不同杂交后代的比较中,皮×黄F1代各年龄段体重均高于蓝×黄F1、利×黄F1和西×黄F1(P<0.01),皮×黄F1代还保留了青海黄牛抗逆性强,耐粗饲等优良特性,杂交组合较为理想;皮尔蒙特牛可作为当前高原环境下改良青海黄牛的理想父本品种使用。     

青海高原地区良种肉牛改良当地黄牛的效果

在青海高原环境下,用引进的良种肉牛蓝白花、利木赞、西门塔尔和皮尔蒙特改良当地黄牛.结果显示四个杂交组合F1代不同年龄的生长速度和体尺指标均明显优于青海黄牛(P＜0.01),说明用良种肉牛改良青海黄牛效果明显;在不同杂交后代的比较中,皮×黄F1代各年龄段体重均高于蓝×黄F1、利×黄F1和西×黄F1(P＜0.01),皮×黄F1代还保留了青海黄牛抗逆性强,耐粗饲等优良特性,杂交组合较为理想;皮尔蒙特牛可作为当前高原环境下改良青海黄牛的理想父本品种使用.     

肉牛增产技术措施

(一)选择良种育肥牛要选择改良的西门塔尔肉牛、夏洛莱肉牛、利木赞肉牛等,以及我国优秀地方品种如秦川牛、鲁西牛、南阳牛、晋南牛等品种牛为母本生产的杂交牛。杂交肉牛品种综合了不同品种的优良性状,具有明显的杂种优势,犊牛的初生重高,生长发育快,肉质好。(二)产犊与配种坚持自繁自养,可以减少购买牛犊的费用支出,保证品种质量,合理安排生产     

青海高原环境下良种肉牛的杂交利用

在青海高原环境下,用引进的良种肉牛西门塔尔、蓝白花、利木赞和皮尔蒙特改良当地黄牛.四个杂交组合F1不同年龄的生长速度和体尺指标均明显优于青海黄牛(P＜0.01),说明用良种肉牛改良青海黄牛效果明显;在不同杂交后代的比较中,皮×黄F1各年龄段体重均高于蓝×黄F1、利×黄F1和西×黄F1(P＜0.01),杂交组合最为理想.     

皮埃蒙特肉牛繁殖及犊牛饲养方法

1纯种与杂交繁殖皮埃蒙特肉牛的纯种繁育采用皮埃蒙特肉牛细管冻精与引进的皮埃蒙特肉牛母牛直接进行补纯种繁育,扩大母牛群。母牛留作自繁或想市场提供部分优质种母牛。公牛按常规方法快速育肥,向市场提供优质牛肉。皮埃蒙特肉牛与其他品种杂交繁育采用皮埃蒙特肉牛与改良黄牛西门塔尔、夏来、法国黄牛、利木赞进行三元杂交,所产生的后代全部作为商品牛,按     

皮埃蒙特牛杂交利用效果分析

互助县利用良种肉牛细管冻精与本地黄牛进行杂交改良,已取得了显著的经济效益,但是引进大型肉牛品种皮埃蒙特牛改良本地黄牛尚属首次,为了探讨皮埃蒙特牛与本地黄牛的杂交效果,互助县自2002年起引进该品种牛细管冻精,利用人工授精技术在互助县双树乡、威远镇、台子乡、五峰乡进     

鲁西黄牛的选育与杂交性能的调查研究

通过对黄河三角洲地区的保种基地、杂种肉牛基地以及肉牛加工企业实地考察,对以鲁西黄牛的肉用性能为主的选育与杂交改良效果等内容进行了调查研究.调查结果表明,鲁西黄牛在肉用性能上目前虽然还无法与利木赞、西门塔尔、夏洛莱等国际肉牛优良品种相比,但鲁西黄牛其独特的肉用品质和适应性,通过合理的利用和开发必将成为中国肉牛业的一个重要品种.     

优质肉牛生产--西杂牛

我国肉牛生产主要是通过引进优良肉用品种(西门塔尔牛、夏洛莱牛、利木赞牛等)来改良提高本地黄牛的肉用生产性能.肉牛杂交生产的主体是利用杂交公犊,在杂交利用上要求以杂交犊牛快速生长为主来选择父本,同时考虑能提高本地母牛的泌乳能力和带犊能力.因此在第一轮杂交中应尽可能用泌乳性能好的肉用品种作父本,在第二轮杂交中根据市场对牛肉胴体的需求再选择不同的肉牛品种作父本.     

利复和三元杂交犊牛生长发育观察初探

大连市的黄牛改良工作起源于20世纪70年代，主要采用利木赞、德国黄牛等国外肉牛及兼用品种对复州牛进行杂交改良，并取得显著成效。为了进一步提高改良效果，培育高档肉牛，我们从2002年开始，引进日本和牛，与利复一代母牛，开展三元杂交生产，取得了良好的效果，现将利复和三元杂交犊牛生长发育情况报告如下。     

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。     

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。     

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。     

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.