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微量元素对于动物具有重要的营养及生理作用。母猪微量元素的营养研究越来越受到重视。繁殖母猪由于其特殊的生理特点,需要充足的微量元素供应。高产母猪由于付出较重,微量元素若缺乏可能是导致其生产性能下降的一个重要原因。本文对各种微量元素对母猪繁殖的影响的一些研究做了综述。1生产母猪体内微量元素含量的变化对于生产母猪来讲,在生产年限内都要保持较高的生产水平,因此满足其各种营养素的需要至关重要。在母猪的生产周期的不同阶段,对于微量元素的需求变化很大。这些微量元素除了满足自身的组织生长和维持需要之外,还要满足… 相似文献
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母猪的繁殖性能是影响养猪业经济效益的重要因素。对于生产母猪而言,较高的生产水平是养殖户获利的保障,因此满足其各种营养素的需要至关重要。其中,饲料添加剂是配合饲料中的必需成分,是影响配合饲料质量与饲用效果的重要因素之一。有机微量元素、 相似文献
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微量元素对母猪繁殖性能具有重要的影响。微量元素除满足母猪自身组织生长和维持需要外,还要满足胚胎的生长发育和泌乳的需要,并通过调节内分泌和生理状况来影响母猪的生产性能。加之,养殖业的集约化程度越来越高,现代育种的出色成果也使畜禽的生长性能大幅提升,使母猪在泌乳期很难通过天然常规饲料来满足对必需元素的需求。在一般情况下,母猪日粮都添加无机状态的微量元素。许多研究显示,无机微量元素因其生物学效价 相似文献
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微量元素对母猪繁殖性能具有重要的影响,在一般情况下,母猪日粮都添加无机状态的微量元素,许多研究显示,无机微量元素因其生物学效价低,拮抗影响饲料中其他成分,在一定程度上无法满足母猪的需要,同时无机微量元素也易造成环境污染。而有机微量元素具有独特的理化性质和较高的生物学效价。为了比较有机微量元素和无机微量元素的差异,笔者选用螯型氨基酸微量元素作为有机微量元素进行以下试验。 相似文献
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高产母猪应加强微量元素的营养 总被引:1,自引:0,他引:1
要使母猪在生产年限内都保持较高的生产水平,满足其各种营养素的需要至关重要。在母猪生产周期的不同阶段,对于微量元素的需求变化很大,这些微量元素除了满足母猪自身组织生长和维持需要之外,还要满足胚胎的生长发育和泌乳的需要。在妊娠后期和泌乳期,母猪的负担加重,对各种微量元素的需求最大。若饲料中微量元素水平较低或者这些元素利用率低,母猪会动用自身组织中沉积的各元素来满足生产需求,容易使母猪的生产年限下降(Mahan,1990),同时也容易造成流产、死仔数增多等一系列的问题。Mahan和Newton(1995)比较了产仔3胎后平均断奶窝仔重大于60kg和小于55kg以及同龄未产母猪的体成分中各矿物元素的含量差异,发现未产母猪体内的大多数金属元素含量高于产仔母 相似文献
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高产母猪对矿物质的需要尚不是很明确.迄今为止的研究证实,随着胎次的增加,母猪体内的常量元素和微量元素储备逐渐减少,而且高繁殖力还加剧矿物质的丢失.母猪的繁殖周期中有些时期(通常是妊娠后期和哺乳阶段)对常量元素和微量元素的需要量很高,但这些元素在其它时期也同样非常重要.然而简单地增加母猪饲粮中的常量元素和微量元素的含量可能并不是理想的方法,因为这种方法可能降低母猪的繁殖性能.近期的研究表明,有机微量元素能提高母猪6胎以上的窝产仔数.已有研究表明,虽然有机硒具有提高母猪繁殖性能的功效,但其它微量元素可能也在提高母猪繁殖性能方面发挥了相应的作用. 相似文献
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在现代生产条件下,随着猪生产水平的不断提高,母猪对微量元素的需要量也不断增加。许多研究显示,无机微量元素的吸收和利用已无法满足高产母猪对微量元素的需求,而有机微量元素不仅具有较高的利用率,同时在代谢和生理方面还有更大的优势,可使母猪生产性能进一步发挥。 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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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
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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