蛋重、蛋形和蛋壳厚度对庄河大骨鸡孵化率的影响

为研究蛋重、蛋形指数、蛋壳厚度对庄河大骨鸡种蛋孵化率的影响,选取36周龄健康种鸡产种蛋1 257枚,按蛋重分为5组,相同条件孵化,分析蛋重、蛋形指数、蛋壳厚度对种蛋失重率、孵化率和初生重的影响.试验期28d.结果显示,36周庄河大骨鸡所产种蛋平均蛋重为64.13 g,各种蛋组间7、12、19胚龄蛋重均差异显著(P＜0....     

南丹瑶鸡产蛋期蛋品质变化分析

为探究广西地方鸡品种南丹瑶鸡的蛋品质变化规律,以南丹瑶鸡为试验材料,在饲养条件相同的情况下,对其整个产蛋期的蛋品质进行了研究。检验指标包括蛋重、蛋形指数、蛋壳厚度、蛋壳强度、哈氏单位、蛋黄颜色、蛋黄重等。结果显示:蛋重随着产蛋周龄的增加而增大,产蛋后期极显著高于产蛋前、中期(P0.01),蛋形指数和蛋黄比率随着产蛋周龄的增加呈上升趋势,蛋壳强度和蛋壳厚度在整个产蛋周期内无明显的变化规律,蛋壳比率随着产蛋周龄的增加呈下降趋势,哈氏单位在产蛋前期和产蛋中期无明显变化,在产蛋末期急剧下降,蛋黄颜色在产蛋初期颜色最深,随着产蛋周龄的增加呈下降趋势,在产蛋末期急剧下降。总体而言,南丹瑶鸡鸡蛋蛋重较小、蛋壳较薄、蛋形规则、蛋白浓稠、蛋黄比率高、蛋黄颜色较深。由此可见,南丹瑶鸡作为广西地方鸡品种具有较好的蛋品质,且在不同产蛋期的蛋品质具有一定的变化规律。     

不合格种蛋的孵化能力及其形成原因分析

种蛋的合格率是养鸡生产中的一个重要生产指标，它和鸡场、孵化场的经济效益都有密切的关系。种蛋不合格，将不同程度地影响孵化率及雏鸡品质。笔者在生产实践中，挑拣多类不合格种蛋进行多次孵化试验，总结出了这些蛋的孵化能力（见表１） 一、入孵前可观察到的不合格种蛋 １．畸形蛋 多见蛋形偏瘪或扁平，部分蛋壳侧面平滑细簿，四周有皱纹。照时可见部分蛋气室过小或倾斜错位。其形成可能是由母鸡产蛋期内受到惊吓，或者母鸡体过于肥大，造成产蛋节奏紊乱，有两个以上的蛋在子宫内相互挤压引起的，也可能是种鸡患有传染性支气管炎或鸡群…     

禽蛋质量对孵化率影响的研究进展

种蛋孵化率的高低，主要取决于它的质量、孵化条件及操作技术。种蛋质量的好坏直接影响孵化率和雏禽的品质，因而种蛋质量与养殖业的经济效益和发展密切相关。为此，人们对种蛋质量做了广泛研究。在种蛋内部质量相对稳定的情况下，蛋重、蛋型指数、蛋壳颜色、蛋比重、蛋壳厚度及蛋壳气孔数（通透性）对孵化率的影响尤为重要。本文将对相关的研究作简要综述，可望为选择优质种蛋并提高孵化率提供科学依据。１蛋重对孵化率的影响蛋重是评定家禽产蛋性能和所含营养物质多少的重要指标，种蛋的重量直接影响孵化率的高低及初生雏禽的体重。早在１…     

东兰乌鸡产蛋期蛋品质变化规律研究

为了研究广西地方鸡品种东兰乌鸡不同周龄蛋品质及其变化规律,试验在饲养条件相同的条件下,测定了东兰乌鸡不同周龄(28,32,36,40,44,48,52,56,60周龄)的蛋品质指标,检测指标包括蛋重、蛋形指数、蛋黄颜色、哈氏单位、蛋壳比率、蛋壳强度、蛋壳厚度、蛋黄比率。结果表明:蛋重随着产蛋周龄的增加而增大,产蛋后期显著高于产蛋前、中期(P0.05),蛋形指数和蛋黄比率随着产蛋周龄的增加呈上升趋势,蛋壳强度和蛋壳比率随着产蛋周龄的增加呈下降趋势,蛋壳厚度、哈氏单位和蛋黄颜色在整个产蛋周期内无明显的变化规律。总体而言,东兰乌鸡蛋蛋重较小、蛋壳较薄、蛋形规则、蛋白浓稠、蛋黄比率高、蛋黄颜色适中。说明东兰乌鸡作为广西地方鸡品种具有较好的蛋品质,且在不同产蛋期的蛋品质具有一定的变化规律。     

肉种鸭产蛋周龄与蛋重对种蛋孵化效果的影响

禽蛋孵化率的高低是由种禽年龄、种蛋品质和孵化条件等决定的[1,2]。本试验对肉种鸭在相同孵化条件下,就不同产蛋周龄和不同蛋重对孵化率和健雏率的影响进行了研究,旨在探讨产蛋周     

蛋用鸡种蛋蛋龄与孵化率的关系

过了产蛋高峰期,随着鸡日龄的增加,种蛋的受精率不变,平均受精率在94.4—95.4%之间。然而,蛋及蛋壳品质均有降低的趋势。经测定,尽管64周以后的蛋与38周、50周的蛋比重相同,但64周以后的种蛋在孵化时,早期胚胎死亡率较高,孵化率较低。随着鸡日龄增加,蛋重增大。42周一过,平均蛋重在58—60克,但这时的蛋对孵化率的影响没     

同一保种基地内地方鸡种蛋品质的比较与分析

为比较保种基地内各地方鸡种蛋品质的变化情况,在该基地按统一方式饲养的10个地方鸡群同日所产的鸡蛋中,各选择具备该鸡种特征的蛋30枚,进行蛋品质测定、主成分分析和各品种鸡蛋品质的同质性分析。结果表明:异地保种后各鸡种蛋的品质均有所下降,并趋于同质化;异地保种鸡的蛋重平均降幅达到了18.27%,且鸡种间蛋重的降幅差异明显(P<0.05);现有评价蛋品质的指标,其重要性从大到小依次为蛋壳厚度、蛋壳颜色、蛋重、蛋黄相对重、蛋形指数、蛋壳强度、蛋黄颜色和哈氏单位。     

在孵化过程中如何灵活调节湿度

种蛋的失重在一定程度上取决于孵化器中的相对湿度，它是空气间接交换的象征，被证实为控制胚胎发育的有效手段。但是不同周龄的种蛋在同一孵化湿度下，失重率是相差很大的。种鸡初产种蛋，蛋重。胶护膜均较厚，蛋白也较稠，随周龄增加，品质大幅度提高，直至42周龄左右，以后则蛋壳、胶护膜逐渐变商，蛋白变稀，55周龄后，蛋壳又开始变厚，置重急剧增加，但品质急剧下降。采用本公司种鸡一场30周龄960225批次AA鸡所产种蛋．和56周龄950817批次AA鸡所产种蛋，用福尔马林。高锰酸钾消毒30分钟，于20℃常温、相对湿度75％的蛋库内存放2天后…     

植酸酶对蛋种鸡生产性能的影响

本试验用１４０ｍｇ／ｋｇ植酸酶制剂替代对照组饲粮中骨粉的全部磷饲喂产蛋种鸡。结果表明,鸡的产蛋率、产蛋量、产蛋重、产蛋壳重、料蛋比、死亡数、蛋品质部分指标以及种蛋受精率均未受到不良影响,但种蛋蛋壳质量变差,孵化率降低。     

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.