影响种蛋受精率的因素及对策

种蛋受精率的高低直接影响种鸡场的信誉和经济利益,而影响种蛋受精率的因素很多,笔者根据实践体会,现将影响种蛋受精率的因素及对策介绍如下,供参考. (一)种鸡方面的因素 1.遗传因素:不同品种类型的种鸡存在着一定的差异.某些品种鸡所产的蛋其壳质量较差,或蛋内异物率较高,其种蛋受精率较低.     

AA鸡种蛋孵化性能影响因素分析

选择从种鸡CD品系15批次19200枚种蛋,研究种蛋入孵时间、饲养方式、饲养管理对种蛋受精率和受精孵化率的影响.结果表明,种蛋受精率和受精孵化率受气候条件的影响,3、4月入孵的种蛋比5、6月入孵的种蛋各项指标都高;笼养种鸡的受精率远高于平养种鸡;不同孵化器对孵化效果有影响;不同饲养员因其负责程度不同,饲养效果也有差异.因此,根据种鸡场的实际生产情况,适当提高笼养种鸡的比例,制定合理的饲养员奖励机制,提高综合饲养管理水平,将有利于提高种鸡场的生产效益.     

提高笼养种鸡种蛋受精率的探讨

比较全面地分析了影响笼养种鸡种蛋受精率的因素，包括来自种公鸡与种母鸡的影响，人工受精操作技术，种蛋早期管理等，可以作为种鸡场制订提高种蛋受精率措施的参考。     

如何让笼养种鸡种蛋受精率保持在95%以上

现在种鸡生产大都采用笼养,种鸡由公母自交配改为人工授精,大大提高了种蛋的受精率。笔者在凤翔家禽公司从事种鸡生产管理工作多年,公司种鸡生产全部采用笼养人工授精操作,经过不断的人员培训和强化生产管理,每批种鸡整个生产过程种蛋受精率都保持在95%以上,现在把工作过程中的几点体会与同行交流。一、影响笼养种鸡种蛋受精率的因素1.人员的人工授精操作因素:采精手法、采精时间、每羽公鸡被采精次数、输精周期、输精时间、输精量、输精用具的消毒。2.影响种公鸡精液质量的因素:营养、疾病。3.疾病因素:种母鸡的疾病(生殖器炎症)、营养。二…     

种鸡周龄与三率的关系

在养鸡企业中,孵化工作的好坏对经济效益影响很大,孵化率和健雏率是衡量孵化工作优劣的重要指标.影响孵化率和健雏率的因素很多,如种鸡的营养水平、种蛋的受精率、种蛋的贮存条件、孵化场的卫生管理等等,在这些因素中,种蛋的受精率是决定条件,而受精率则受种鸡周龄的影响,弄清种鸡周龄与孵化率和健雏率的关系,对合理安排种鸡群,保证雏鸡的正常供应,具有重要意义。材料和方法某养鸡场饲养的星杂“288”父母代种鸡16000只,笼养、人工授精、雌雄比例为20:1。将25周龄至60周龄种鸡所产种蛋按入孵批次逐项记录种鸡周龄、入孵蛋数及三率并进行统计分析。     

提高鸡人工授精率的关键技术

随着家禽饲养业集约化和规模化程度的提高,种蛋受精率的高低将直接影响到养殖户的经济效益。影响种蛋授精率的因素有很多,主要包括种鸡遗传因素、饲养管理、营养水平、精液品质、配种时间和配种间隔等。     

影响笼养种鸡受精率的因素

正种蛋受精率作为衡量种鸡饲养管理质量的一个关键性指标,不仅反映出饲养管理水平的高低,同时在很大程度上影响到种鸡场的经济效益和可持续发展的后劲。要取得良好的种蛋受精率,作为种鸡生产管理者必须了解影响种蛋受精率的各种因素,以便于在实际工作中当种蛋受精率出现非正常下降时能针对性地采取措施加以解决。以下归纳了影响种蛋受精率的各种因素,以供参考:1精液品质精液质量可以从精子活力、密度(数量)等指标来衡量。它是影响种蛋受精率较为关键和常见     

种鸡日龄对种蛋孵化成绩的影响

种鸡日龄对种蛋孵化成绩的影响林均德林金（辽宁熊岳农业高等专科学校）由于种鸡的日龄不同，各器官系统生长发育和生理功能状态有所不同，对种蛋的受精率和出雏率等方面均有一定的影响，为了研究种鸡的不同日龄对所产种蛋的受精率和出雏率的影响，以提高种鸡种蛋的利用价...     

夏季鸡蛋受精率低的原因及对策

1 造成种蛋受精率低的原因 1.1 遗传因素 不同品种种鸡的耐热性及对热应激的反应和受精率的高低不尽相同.肉种鸡比蛋种鸡耐热性差,其受精率就低;同样是蛋鸡,褐壳蛋(或体重大)种鸡比白壳蛋(或体重小)种鸡耐热性差,其受精率下降的幅度就大;同品种鸡中,周龄大的鸡比周龄小的鸡种蛋受精率下降幅度大.     

种鸡周龄和受精率的关系

<正> 在一个综合养鸡企业中,孵化工作的好坏对经济效益至关重要。孵化率是衡量孵化工作优劣的主要指标之一。影响孵化率的因素很多,如种鸡的营养水平、种蛋的受精率、种蛋的贮存条件、孵化场的卫生管理等等。在影响孵化率的诸多因素中,种蛋的受精率是第一位的,而受精率则受种鸡饲养周龄的影响。弄清种鸡周龄对孵化率的影响,对合理的安排种鸡群,保证雏鸡的正常供应,具     

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。     

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。 …