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通过对504窝5828头杜长嘉商品猪的生产调查,发现群体中通常有全白色、棕红色、黑白花斑、棕白花斑、黑棕花斑和全黑色等6种毛色,且不同毛色长嘉母猪的后代毛色构成比例完全不同.①纯白长嘉母猪后代:全白色0.4486±0.1868、棕红色0.1842±0.1426、黑白花斑0.0708±0.1175、棕白花斑0.0264±0.0706、黑棕花斑0.0844±0.1203、全黑色0.1856±0.1240;②黑斑长嘉母猪后代:全白色0.3685±0.2191、棕红色0.0899±0.1069、黑白花斑0.1773±0.1482、棕白花斑0.0546±0.0874、黑棕花斑0.1045±0.1236、全黑色0.2052±0.1651.一般利用猪毛色遗传的最新研究进展,可解释杜长嘉商品猪的部分毛色遗传类型,但还不能完全解释其全部的毛色类型,且杜长嘉母猪杂种后代的毛色比例不符合已知基因座位基因型的遗传理论推测. 相似文献
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试验选用75头纯白长嘉母猪和13头白中带黑斑长嘉母猪与杜洛克公猪配种,根据猪的毛色遗传规律,研究杜长嘉杂种猪的毛色遗传类型.结果表明,表型为纯白的长嘉母猪比有黑斑的长嘉母猪后代全白猪比例高8.5%,棕红色猪比例高11.9%,全黑色猪比例低5.2%.对上述试验进行X2独立性检验,求得X2=39.41,当自由度df=5时,X20.05=11.07,说明长嘉母猪毛色对后代杜长嘉杂种猪毛色有一定影响(P＜0.05). 相似文献
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1 猪毛色遗传的生物学基础猪皮肤和毛的颜色是由黑色素引起的 ,黑色素是由酪氨酸氧化和聚合而产生的。黄色及红色的产生可能是因为黑色素形成过程的提前终止而引起的。另外色素颗粒的浓度和分布对皮肤和毛色的着色情况也起了很大的作用。黑色素有 2种类型 :(1)褐黑色素 ,为溶于碱的红色颗粒 ;(2 )真黑色素 ,为难溶于碱的黑色和褐色颗粒。2 杜长嘉商品猪毛色的基本类型杜长嘉商品猪 ,即用杜洛克公猪与长嘉母猪杂交所生的后代 ,这是江浙地区用于生产商品猪常用的三元杂交组合 ,其杂交后代毛色趋于混杂 ,类型多。作者近期对嘉兴地区 5 0 4窝 … 相似文献
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1毛色遗传猪的毛色主要有白色、黑色、棕红色、花斑四种，皮肤和毛的颜色是黑色素引起的，黑色素有两种类型：褐黑色素及真黑色素，黄色或红色是由于黑色素形成过程提前终止而引起。1．1控制毛色的基因位点A位点——控制真黑色素或褐黑色素在不同部位的分布。B位点——决定产生的色素是黑色还是褐色。C位点——控制色素合成的强度。D位点——控制色素表现的深浅程度，是一种修饰基因，又叫淡化基因。E位点——决定真黑色素对褐黑色素的扩展程度。S位点——决定色素沉着时，颜色是连续的还是花斑的。其中研究得比较清楚的有：显性白色基因… 相似文献
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[目的]家养水牛分沼泽型水牛和河流型水牛两大类型。沼泽型水牛是中国的主要牛种之一,其被毛主要为灰色和白色,而河流型水牛为黑色。本研究开展并统计了德宏水牛及其与河流型水牛杂交后代的被毛颜色以期探讨水牛的毛色遗传规律。[方法]统计了十几年来盈江县德宏水牛及其与河流型水牛(摩拉水牛和尼里—拉菲水牛)杂交后代的被毛颜色,经x2检验确定毛色的遗传规律。[结果]表明:沼泽型水牛白色与灰色交配的F1代全部为白色,F2代白色与灰色的比例为3∶1,白色对灰色完全显性;河流型水牛(黑色)与沼泽型纯合灰色交配,F1代全部为黑色,F2代黑色与灰色的比例为3∶1,黑色对灰色完全显性;河流型黑色与沼泽型白色交配,F1代表现型是两个亲本类型相对性状的综合,即棕褐色,F2代则出现了白色、棕褐色和黑色3种毛色,三者比例为1∶2∶1,白色对黑色为部分显性或不完全显性。[结论]因而推测沼泽型水牛白色与河流型黑色对灰色为完全显性,灰色为隐性纯合;沼泽型白色对河流型黑色为部分显性或不完全显性。 相似文献
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<正> 鸬鹚(Phalacrocorax Carbo Sinen-Sis)亦称“水老鸦”“鱼鹰”,在我们泰兴地区俗称“鸦子”。鸟纲,鸬鹚科。体羽主要为黑色而带有紫色金属光泽。生殖季节头、颈部生白丝状羽。(摘自《辞海》——生物分册)。 一、外部形态及生产性能: 一般只有二种毛色,纯白的较少,黑色和黑、白羽相间的灰黑色较多。幼雏期,肚底毛色呈白色,背上呈黑色,少数肚底呈黑白色,并随生长年会发生一定的变化。通常是,一年肚底白,二年肚底毛淡黑,三年全 相似文献
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鸬鹚亦称“水老鸦”、“鱼鹰”,在我们泰兴地区俗称“鸦子”。鸟纲,鸬鹚科。体羽主要为黑色而带有紫色金属光泽。繁殖季节,头、颈部生白丝状羽。一、外部形态及生产性能:鸬鹚一般只有二种毛色,纯白的较少,黑色和黑、白羽相间的灰黑色较多。幼雏期,肚底毛色呈白色,背上呈黑色,少数肚底呈黑白色,并随生长年龄发生一定变化。通常是,一年肚底白,二年肚底毛淡黑,三年全黑。眼睛和喙的颜色也是如此。一年内眼睛色素呈灰色,一年以后呈绿色;一年内的喙角为白色,一年以后变为黑色。如营养不好,喙角仍为白色。喙长并呈倒勾状。一般雄性喙长10—11公分。少数可能还要长一些,雌性喙长8—9公分。倒勾长约1.5公分。80—100日龄的体重雄性一般为2.5—3公斤,雌性一般为2 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