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影响母猪繁殖性状的主要因素 总被引：4，自引：0，他引：4
母猪繁殖指标具体包括:产仔数(总产仔、产活仔数)、初生头(窝)重、断奶(或60日龄)头(窝)重、仔猪育成率、断奶至发情间隔时间、配种受胎率等。 1 品种与生理 1.1 品种 品种影响繁殖力的实质是遗传因素,如太湖猪、金华两头乌猪等的繁殖性能极高,这是由遗传因素中的高产基因决定的。繁殖力属低遗传力性状,其杂种优势程度较高,但程度高 相似文献
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母猪一般排卵 2 0～ 2 5枚 /次 ,卵子受精率高达95%以上 ,但产仔数只有 1 1头左右 ,这说明 3 0 %～40 %的受精卵在胚胎期死亡。许多因素都能影响胚胎存活力 ,如遗传、营养、激素、子宫感染、热效应等。在生产实践中 ,为了提高养猪的经济效益 ,首先需要提高胚胎存活率和窝产仔数。选好种母猪 不同品种猪的胚胎存活率有一定的差异 ,可充分利用我国地方猪繁殖力高的特性和杂种优势 ,用地方优秀的母猪和外来公猪 (如大约克公猪 )杂交的后代作为母本。淘汰品种混杂 ,繁殖力低的劣质母猪。避免近亲繁殖 高度的近亲繁殖使母猪本身或胚胎生活力下… 相似文献
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测定杜长大三元杂交体系和斯格配套系各杂交组合的繁殖性能,计算出繁殖性状的杂种优势率;选用5个与繁殖性状紧密连锁的微卫星标记对测定个体进行基因型检测,利用混合效应线性模型计算出繁殖性状各位点的基因效应。结果表明:斯格祖代猪与父母代猪产仔数、产活仔数、断奶仔数、断奶窝重的差异均达到极显著水平(P<0.01),父母代猪与祖代猪的初生窝重差异显著(P<0.05),斯格父母代猪的产仔数、产活仔数、断奶仔数和断奶窝重与长大母猪的差异均达到极显著水平(P<0.01),斯格父母代猪与长大母猪的初生窝重差异显著(P<0.05),初生重、断奶重杂优率低,其余各性状的杂种优势率处于较高水平。显性效应在初生窝重、断奶窝重的杂种优势中起着很重要作用,加性效应是初生重和断奶重杂种优势的主要遗传学基础,产仔数、产活仔数、断奶仔数的杂种优势的产生存在上位效应。 相似文献
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按照常规抵御市场低迷的办法,要养好母猪抓繁殖,要在提高母猪繁殖力上下工夫,等待市场转机。1从遗传因素上加强选育品种对于繁殖力有很大影响,不同品种间种猪的繁殖力有很大差异,同品种、不同个体间也有一定差异,因而可利用杂交优势。以二元母猪为母本生产商品仔猪,再用纯种公猪或二元杂交公猪与之交配,这样终端产品能更好的利用个体杂种优势和遗传互补性。 相似文献
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对13/17易位杂合子猪与同场同期同品种非易位猪的繁殖力、生长发育进行了统计分析.13/17易位杂合子公猪的窝产仔数、初生窝重、20日龄窝重、断奶窝重、窝断奶头数,无论纯繁还是杂交,与非易位猪均无显著性差异(P>0.05).13/17易位杂合子母猪作为杂交母本,其繁殖力与同场同期同品种非易位母猪无显著性差异(P>0.05).在13/17易位杂合子公猪的后裔中,13/17易位杂合子猪的20日龄重、断奶重都与非易位猪差异不显著(P>0.05).13/17易位杂合子公猪6月龄的体高显著高于非易位公猪的体高(P<0.05),但体重、体长和胸围均无显著性差异(P>0.05).13/17易位公猪的女儿与非易位公猪的女儿6月龄的体重与体尺也无显著性差异.本文还提出了对家畜染色体易位的育种措施. 相似文献
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梅山猪以高繁殖性能得到国内外育种专家的重视。沙县畔溪种猪场１９９０～１９９７年间,用７个外来良种公猪与梅山猪杂交生产二元、三元杂交猪,就产仔数、断奶窝重及其相关性状进行分析研究,筛选出较佳的４个杂交组合。１ 材料与方法１１ 种猪 良种公猪４６头,品种有梅山、大约克、长白和杜洛克等。梅山母猪从原产地（上海、太仓）引进５０余头。１２ 选育方案１２１ 选育目标 母本以产仔数和初生窝重为选育性状,要求梅山猪第３胎后两性状分别为１４５头与１０５ｋｇ以上,梅山杂交猪为１３５头和１２０ｋｇ以上… 相似文献
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经过多次杂交筛选 ,在淮南猪中引入一定比例的杜洛克猪外血组建基础群 ,开展群体继代选育工作。对五个世代母猪繁殖性能的分析表明 ,培育的新品系基本保持了淮南猪繁殖力高的特性 ,母猪初生窝重增大 ,仔猪哺乳期生长速度加快 ,主选性状进展显著。与零世代相比 ,五世代总产仔数增加 2 .92头 (P <0 .0 1) ,产活仔数增加 2 .83头 (P <0 .0 1) ,初生窝重增加 5 .72kg(P <0 .0 1) ,2 0日龄头数增加 2 .31头 (P <0 .0 5 ) ,2 0日龄窝重增加 19.73kg(P <0 .0 1) ,断奶头数增加 1.2 6头 (P >0 .0 5 ) ,断奶窝重增加 18.2 7kg(P <0 .0 5 ) 相似文献
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观察了长·大杂种母猪及其亲本(父本长白、母本大约克)和杂种母猪的与配公猪本洛克猪近两年初产和第二胎268窝的繁殖成绩:1.初产:总产仔数分别为10.2头,9.29头、9.46头和9.20头;产活仔数分别为10.05头、8.88头、8.98头和9.07头;35日龄断奶45日龄窝重分别为138.37千克、113.86千克、115.23千克和117.52千克。2.经产:总产仔数分别为11.81头、10.2头、11.61头和9.92头;产活仔数分别为11.56头、9.70头、11.39头和9.67头;35日龄断奶45日龄窝重分别为149.30千克、113.1千克、128.47千克和121.35千克。长·大杂种母猪的繁殖性能显著优于双亲及其与配公猪品种,表现出显著的杂种优势。 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