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正1繁殖周期的选择一个繁殖周期是指从上胎产仔到下胎配种产仔的间隔时间。繁殖周期一般分为延期繁殖、半密集繁殖和密集繁殖。1. 1延期繁殖仔兔断奶后,才配种繁殖下一胎。1. 2密集繁殖母兔产仔后1～2 d(24～36 h较好)就把母兔送与公兔交配。一般又称"血配"。1. 3半密集繁殖在母兔产仔后8～16 d左右,对母兔进行配种繁殖。饲养獭兔的目的主要是为获取高质量的毛 相似文献
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1 獭兔生产的特点1 .1 繁殖力高 ,适于规模生产獭兔属于多胎高产动物 ,具有性成熟早、妊娠期短、胎产仔数多、哺乳期短 ,四季可繁殖等特点。在良好的饲养管理条件下 ,一般年产 5～ 6胎 (最多可达 1 0～ 1 1胎 ) ,每胎产仔 6～ 8只 (最多可达 1 4只 ) ,每只母兔年可提供断奶仔兔 40～ 5 0只。商品兔生长发育快 ,一般在 5月龄体重达 2 .5 kg左右即可宰杀剥皮 ,故生产周期较短。实践证明 ,獭兔既可小群饲养 ,也可进行规模饲养。从其繁殖力高和生产周期短的特点来看 ,獭兔是最适合发展规模养殖的畜种之一。1 .2 食草节粮 ,缓解人畜争粮獭兔是… 相似文献
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獭兔是皮用兔。繁殖力高,在良好的饲养管理条件下,一般年产5～6胎,每胎产仔6～8只,每只母兔可提供断奶仔兔40～50只。商品兔5月龄体重可达2.5kg左右可宰杀剥皮,所以生产周期短,见效快,但獭兔对疾病的抵抗能力较弱,所以养殖场必须采取综合性的防病措施,提高獭兔的成活率,减少损失,提高经济效益。1科学的饲养管理1.1定时分群饲养,掌握科学的饲养方法幼兔30～35日龄即可断乳分窝,分窝时根据体重大小、体质强弱等进行分群,以小群笼养为好,每笼饲养3～4只,若群养8～10只组成一个群,不可过多,因为兔的群居性较差。根据兔有昼伏夜出的生活习性,所以… 相似文献
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<正> 獭兔是一种多胎多产的小动物,怀孕期短,繁殖力高,可列为哺乳家畜之首。 (一)繁殖力强:獭兔具有很强的繁殖力,不仅表现在每窝产仔多,怀孕期短,而且还表现在一年多胎,母兔产后不久即可配种受孕等。据试验,在正常饲(?)管理和繁殖情况下,每只繁殖母兔可年产4～5窝,提供断奶仔兔25～30只。 相似文献
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正1合理利用繁殖年限一般种用獭兔的繁殖年限为3~4年。如果种兔体质好,生产性能优良,可适当延长使用年限,但不宜过长。一般种公兔以6~7年为限,母兔以4~5年为限。经后裔鉴定品质较差的种兔应及时淘汰。2制订繁殖计划獭兔的繁殖一定要有计划,以便集中配种,集中产仔,方便饲养管理,特别是规模较大的兔场,更需计划,不可盲目进行。在制定计划时要考虑市场需求、笼舍条件、饲料条件等来安排。皮用獭兔 相似文献
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獭兔的繁殖是饲养獭兔的一个重要环节 ,獭兔繁殖效率的高低直接关系到獭兔养殖场的经济效益。对于繁殖母兔来说 ,它的主要任务就是繁殖仔兔 ,如果不能优质高效地繁殖仔兔 ,它们就会成为纯消耗的动物 ,没有任何产出 ,也就不会有任何效益。因此 ,如何使繁殖母兔充分发挥其繁殖潜力 ,尽量在其繁殖利用年限内生产出更多的优良后代是獭兔繁殖管理的中心任务。对于繁殖母兔来说 ,一般以一年内每只繁殖母兔能够提供的达到出栏标准商品獭兔的数量作为衡量獭兔繁殖效率的指标 ,就我国现阶段来说 ,每只繁殖母兔在正常情况下应能提供 2 5 - 30只商品獭… 相似文献
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舟山市定海区某万只獭兔场,2003年11月1～15日共产仔兔90窝,计540只.其中11月6～8日所产15窝仔兔计90只,陆续在产后的第4～5天发生仔獭兔红爪病.经兽医及时诊治,多数仔兔得到康复,严重的4窝计24只仔兔死亡,死亡率为发病兔的26.67%.现将诊治情况报告如下: 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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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. 相似文献
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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献