环境、营养与牦牛繁殖

牦牛是生活在青藏高原的特种家畜之一,在高寒环境下,环境因素对牦牛的生产、繁殖有着重大的影响。海拔、温度、光照等环境因素不但直接影响牦牛的繁殖,而且通过对天然草场牧草生长的影响,间接影响牦牛的生产、繁殖。笔者从母牦牛的发情机理,环境、营养对母牦牛发情、初情期和妊娠的影响,环境、营养对公牦牛性成熟、初配年龄、射精量和精液品质的影响等几方面阐述了环境、营养与牦牛繁殖之间的关系。     

环境因素对家畜繁殖的影响(综述)

家畜的生活环境受各种环境因素的影响,环境因素的变化会改变家畜与其环境之间的能量交换,从而影响家畜的行为、生长、繁殖和生产性能。本文以牛羊为例讨论环境因素对家畜繁殖的影响。     

牦牛繁殖调控技术研究进展

本文对牦牛的繁殖现状,影响牦牛繁殖性能的因素及牦牛繁殖调控技术的研究进展进行了综述,针对目前牦牛繁殖调控技术应用中存在的主要问题及影响牦牛繁殖力的相关因素,建议在牦牛繁殖调控技术推广中应采取全面、合理的综合繁殖调控技术.     

牦牛暖季补饲研究进展

作为青藏高原的特殊物种之一,牦牛以其抗寒、耐劳、耐粗饲的特性受到专家和学者们的广泛关注。文章从牦牛生长性能、屠宰性能、繁殖性能、泌乳性能等方面对近几年牦牛暖季补饲的研究进行综述。分析发现,暖季合理补饲能有效提高牦牛增重,改善肉质和繁育性能,缓解草畜矛盾,提高经济效益。     

提高天祝白牦牛繁殖力的措施

本文对影响天祝白牦牛繁殖力的遗传、环境、营养、管理等因素进行了分析,提出了加强草原生态建设;强化对繁殖牛群的饲养管理;适时断奶,挖掘母牦牛的繁殖潜力;使用生殖激素调控,促进母牦牛及早发情;开展遗传改良等提高天祝白牦牛繁殖力的措施,以期为提高白牦牛生产性能和养殖效益提供参考。     

环境因素对家畜繁殖的影响

家畜的生活环境受各种环境因素的影响,后者的变化会改变家畜与其环境之间的能量交换,从而影响家畜的行为、生长、繁殖和生产性能。本文以牛羊为例讨论环境因素对家畜繁殖的影响。一、温度环境公、母畜的繁殖过程对热负荷极为敏感,所受应激的程度取决于气温、湿度、风速、热辐射、畜体大小、毛被、风土驯化或适应的情况,以及影响产热或散热的其它因素。     

大通牦牛提纯复壮当地牦牛效果的研究

为改良青海当地地方牦牛的生产性能和品种退化,利用大通牦牛冻精与当地母牛进行二元杂交,进行提纯复壮当地牦牛。结果表明:改良F1代母牦牛的受胎率、产犊率、犊牛成活率、繁殖成活率依次分别为75.2%、95.1%、90.15%、46.5%(n=562),比当地牦牛的上述繁殖指标依次分别提高0.04%、0.06%、0.02%、0.086%。因此,引入大通牦牛改良当地牦牛,其繁殖性能略有提高,如果再加强牦牛饲养管理,改善饲养条件,可提高当地牦牛的繁殖性能。     

冷季补饲精料对牦牛繁殖性能和生长性能的影响

试验旨在探究冷季补饲精料对怀孕牦牛繁殖性能、生长期牦牛生长性能的影响。试验一选用6岁左右、健康无病的经产怀孕麦洼牦牛10头,随机分为2组(5头/组),即对照组(全放牧)和精料组(放牧+精料补饲料400g/d)。试验二选用2岁左右、健康无病的生长期麦洼牦牛21头,随机分为3组(7头/组),即对照组(全放牧)、玉米组(放牧+补饲玉米500 g/d)和玉米菜粕组(放牧+补饲玉米菜粕500 g/d,各50%)。结果表明:试验一,精料组犊牦牛初生重比对照组极显著提高47.48%(P<0.01);试验二,对照组生长牦牛体重下降9.25 kg,补饲玉米组和玉米菜粕组生长期牦牛分别增重12.38 kg和2.33 kg,均极显著高于对照组(P<0.01),而且玉米组生长牦牛增重极显著高于玉米菜粕组(P<0.01)。结果提示,冷季给予怀孕牦牛补饲精料可提高犊牦牛初生重;冷季生长牦牛补充精料有助于提高生长性能,同时补饲能量饲料(玉米)的效果高于蛋白饲料(菜粕)。     

亚丁牦牛繁殖性能调查

[目的]为了了解亚丁牦牛品种的繁殖性能,更加深入了解其资源特性,为后续制定选育标准和提高繁殖存活率提供理论依据。[方法]调查了亚丁牦牛主产区养殖亚丁牦牛的2016—2018年存栏情况,统计亚丁牦牛繁殖存活率。[结果]结果显示亚丁牦牛繁殖存活率达到61.78%,表明亚丁牦牛具有繁殖性能高的特点。     

甘南牦牛繁殖性能调查及提高繁殖性能的技术措施

本文调查了甘南牦牛的繁殖性能,调查发现甘南牦牛繁殖性能比上世纪八十年代降低,繁殖性能的高低与营养好坏和挤奶次数密切相关.通过控制载畜量,提高母牛的营养水平,犊牛定期断奶,可提高甘南牦牛的繁殖性能.     

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。     

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。     

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。     

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.     

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.     

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。 …