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《中国畜牧杂志》2021,(7)
为探究乌蒙凤鸡产蛋规律,本实验以360只零世代乌蒙凤鸡为研究对象,统计28～40周龄产蛋率和累计产蛋数,采用伍德模型、分室模型和杨宁模型拟合产蛋率曲线,累计产蛋数采用Logistic、Gompertz和Von Bertalanffy 3种模型进行拟合,并对产蛋率及累计产蛋数的拟合值和实际观测值进行比较。结果表明:产蛋率曲线拟合度(R2)以杨宁模型最佳(R2=0.940),分室模型次之(R2=0.849),伍德模型最差(R2=0.589);Logistic、Gompertz和Von Bertalanffy模型对累计产蛋数的R2高于0.980,Von Bertalanffy模型拟合值与观测值更为接近,拐点产蛋周龄为33.950周,拐点产蛋数为20.253个,极限产蛋数为68.354个。因此,在实际生产中可运用杨宁模型和Von Bertalanffy模型对乌蒙凤鸡的产蛋规律进行预测和评估。 相似文献
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《中国家禽》2015,(18)
以"京海黄鸡1号"配套系父母代母鸡18~66周龄产蛋率和累计产蛋数变化规律为研究对象,探索其产蛋率与累计产蛋数拟合曲线。产蛋率采用伍德模型、分室模型与杨宁模型,累计产蛋数采用Logistic模型、Gompertz模型和Von Bertalanffy模型,对产蛋率及累计产蛋数(HH)的估计值与实际值进行比较。结果表明:伍德模型、分室模型与杨宁模型的产蛋率曲线拟合度分别为R2=0.649、R2=0.916、R2=0.955;Logistic模型、Gompertz模型和Von Bertalanffy模型的累计产蛋数曲线拟合度(R2)都在0.98以上。与实际生产数据比较发现,杨宁模型和Von Bertalanffy模型曲线拟合效果最佳。在实际生产中可以利用它们对该配套系产蛋率和累计产蛋数变化规律进行估计与预测,为该配套系育种以及管理提供参考。 相似文献
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《中国家禽》2016,(24)
以"三高青脚鸡3号"配套系父母代种鸡21~66周龄产蛋率和累计产蛋数变化规律为研究对象,探索其产蛋率和累计产蛋数拟合曲线。产蛋率采用伍德模型、分室模型及杨宁模型拟合,累计产蛋数采用Gompertz、Logistic以及Bertalanffy三种模型拟合,并对产蛋率及累计产蛋数的估计值和实际值进行比较。结果表明:杨宁模型拟合的产蛋率曲线效果最好,拟合度(R2)为0.991;Gompertz、Logistic以及Bertalanffy模型均能拟合累计产蛋数,且拟合度在0.996以上,与实际值相比较,Bertalanffy模型拟合累计产蛋数效果最佳,产蛋拐点周龄为开产后38.05周,拐点产蛋数为70.42个。因此,建议在实际生产中可通过杨宁模型与Bertalanffy模型对"三高青脚黄鸡3号"父母代种鸡产蛋率和累计产蛋数进行估计与预测。 相似文献
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研究旨在筛选出适合本交笼养种鸡产蛋率的产蛋曲线模型。采集20~58周龄海兰褐父母代鸡的产蛋记录,运用伍德模型、分室模型和杨宁模型拟合其产蛋率,并比较3种模型的拟合效果。结果显示:三种模型均可用于产蛋率拟合,杨宁模型、分室模型和伍德模型的R值分别为0.98530、0.98336和0.60158,说明杨宁模型的拟合效果最好,分室模型次之,伍德模型最差。模型比对结果进一步显示杨宁模型适合于原始数据程度约为分室模型11倍。产蛋曲线特征结果显示不同生产阶段产蛋率呈不同特征。结果表明,杨宁模型最适用于本交笼养种鸡的产蛋曲线模型。 相似文献
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苏禽黑羽青壳蛋鸡产蛋性能及蛋品质分析 总被引：1，自引：0，他引：1
本研究选取苏禽黑羽青壳蛋鸡母鸡250只,统计21～66周龄产蛋率,运用McMillan模型、杨宁模型、Wood模型拟合产蛋曲线;并在21、32、36、40、44、48、52、56、60及66周龄测定鸡蛋品质.结果表明,黑羽青壳蛋鸡21～66周龄平均产蛋率为54.6％,产蛋高峰接近80％;3种模型中杨宁模型对产蛋曲线拟合度最高(R2=0.916),较适合用于产蛋曲线拟合;鸡蛋品质达到A级水平;随着日龄增加,蛋重逐渐增大,而蛋白高度、蛋黄色泽、哈氏单位等指标也呈现一定的变化规律. 相似文献
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为了研究二郎山山地鸡的产蛋规律,试验以二郎山山地鸡SD02与SD03品系一世代300日龄产蛋量建立产蛋曲线,并采用伍德模型、分室模型与杨宁模型对两品系进行产蛋率曲线拟合,然后对实际产蛋率曲线进行分析。结果表明:品系SD03的产蛋性能优于SD02。经过拟合分析,SD02品系的伍德模型、分室模型、杨宁模型的拟合度(R2值)分别是0.811 7,0.906 2,0.967 7,SD03品系拟合度分别是0.796 9,0.910 2,0.954 8;杨宁模型拟合效果最佳。 相似文献
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《中国畜牧杂志》2021,(10)
为探究海兰W-80父母代种鸡在我国饲养环境下的产蛋规律,本实验分别测定了3个种鸡场各10827、10147、21204只海兰W-80父母代种鸡全期产蛋性能,分别采用伍德模型(Woodmodel)、分室模型(McMillan model)和杨宁模型拟合其产蛋率曲线,使用Gompertz、Logistic和Von Bertalanffy模型拟合其累计产蛋数曲线,根据R~2、赤池信息准则(AIC)和贝叶斯信息准则(BIC)选择最优模型,并与饲养标准进行产蛋性能比较。结果显示,曲线拟合模型F检验均差异显著,可用于海兰W-80父母代种鸡产蛋率和累计产蛋数拟合;产蛋率拟合杨宁模型R~2最高(R~2=0.987～0.994),分室模型次之(R~2=0.927～0.977),伍德模型拟合度最低(R~2=0.509～0.652),且AIC与BIC指数依次为杨宁模型分室模型伍德模型。Gompertz、Logistic、Von Bertalanffy模型拟合3个种鸡场累计产蛋数曲线R~2分别为0.996～0.997、0.989～0.990、0.998～0.999,且VonBertalanffy模型AIC与BIC指数最低。本实验中海兰W-80父母代种鸡开产较饲养标准早4～11 d,70周龄累计产蛋数高于标准上限5～12个,但92%产蛋率高峰持续时间较短。综上,杨宁模型和Von Bertalanffy模型分别适用于海兰W-80父母代种鸡产蛋率和累计产蛋数的拟合,可评估和预测其产蛋规律。此外,应避免种鸡开产过早,以防产蛋高峰持续时间缩短,影响全期产蛋性能。 相似文献
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为探究豁眼鹅在辽宁地区群体饲养环境下的产蛋规律,本试验测定了3 000只豁眼鹅种鹅全期产蛋性能,分别采用伍德模型（Wood model）、分室模型（McMillan model）和杨宁模型拟合其产蛋率曲线,根据R值和赤池信息准则（AIC）选择最优模型。结果显示,曲线拟合模型F检验均差异显著,可用于豁眼鹅种鹅产蛋率拟合;产蛋率拟合杨宁模型R最高（R =0.874）,分室模型次之（R =0.855）,伍德模型拟合度最低（R=0.424）,且 AIC指数依次为杨宁模型<分室模型<伍德模型。本试验中豁眼鹅群体开产较实际晚,40%以上产蛋率高峰持续时间较短。综上,杨宁模型适用于豁眼鹅种鹅产蛋率拟合,可评估和预测其产蛋规律,生产过程中要根据模型和产蛋曲线特征科学合理地进行饲养管理,以达到生产效益最优化。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
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。 相似文献
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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。 相似文献
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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。 相似文献
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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. 相似文献
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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. 相似文献