猪氟烷基因的检测及其对生长与肉质的影响

对中国瘦肉猪新品系ＤＩ和ＳＪ系３０１头仔猪进行氟烷测验,阳性率为１．３３％。随机抽取氟烷阴性猪３４头进行基因型检测,有６头为杂合子,由此推知ＮＮ、Ｎｎ和ｎｎ的频率分别为８１．２６％１７．４１％和１．３３％,Ｎ和ｎ的频率分别为８９．９７和１０．０３％。对三种基因型的肉质进行评定结果显示,４头氟烷阳性猪（ｎｎ）肉质最差,出现３头严重ＰＳＥ肉和一头轻度ＰＳＥ肉,而氟烷阴性猪未发生ＰＳＥ肉。２８头ＳＪ系氟烷阴性猪用阳性公猪测交,对产出的２０窝２０８头后代进行氟烷测定,共检出４窝中的２１头阳性猪,对测交后代进行肥育性能和肉质测定,结果阳性猪的日增重和饲料转化率等较低,屠宰率、眼肌面积和瘦肉率等较高,肉质较差。     

撒坝猪及其配套系氟烷基因检测与遗传效应分析

利用PCR -RFLP技术对云南省楚雄州种猪场 1 0 4头种猪 (包括撒坝纯种 71头 ,加系大约克 1 0头 ,丹系长白 8头 ,美系杜洛克 9头及三元杂大长撒 6头 )进行了氟烷基因检测。发现杂合子猪(Nn) 4头 ,包括 2头大约克 ,2头大长撒 ,未发现阳性猪 (nn) ,其余皆为阴性 (NN)。对大长撒氟烷基因杂合子与同群阴性猪作生长和肉质性状比较 ,显示其杂合子在瘦肉率、日增重和料重比等有优势 ,而肉质性状无明显差异。本文还就氟烷基因对地方母系及其配套系建设的影响作了初步分析     

上海白猪(上系)氟烷基因位点多态性分析

采用PCR-RFLP技术,对41头上海白猪(上系)氟烷基因进行基因型检测。结果表明:上海白猪(上系)未检测到多态性,优势基因型均为NN,未出现Nn和nn型基因。实验结果为上海白猪(上系)品种资源的保护以及合理开发利用提供了有效的理论依据。     

猪氟烷基因的RFLP技术检测及其对繁殖性能的影响

试验通过PCR-RFLP技术,利用HhaI内切酶检测261头大白猪、265头长白猪、140头杜洛克猪和40头福建槐猪氟烷隐性等位基因(Haln)的携带情况.结果被检测所有猪的基因型均为NN,未出现Nn和nn基因型,表明外来品种猪群中已很少存在携带隐性等位基因的个体.这为种畜的选择提供了信息,并为槐猪品种资源保护及合理开发利用提供理论依据.     

军牧1号白猪、杜洛克猪和藏猪的氟烷基因和酸肉基因多态性分布

为了研究军牧1号白猪、杜洛克猪和藏猪氟烷基因和酸肉基因的多态性分布情况,试验采用PCR-RFLP方法对61头军牧1号白猪、51头杜洛克猪和51头藏猪的氟烷基因和酸肉基因多态性进行了检测。结果表明:军牧1号白猪的氟烷基因表现为单一的NN型;杜洛克猪的氟烷基因表现为多态性,等位基因N的频率为0.196 1,基因型分布符合哈代-温伯格平衡(χ2=3.033 9,P=0.081 5);藏猪的氟烷基因表现为单一的nn型。3个猪种的酸肉基因均表现为单一的rn/rn型。     

氟烷基因的效应同猪的体重有关

设在拉康比的加拿大农业部研究站,通过试验得出了有关氟烷基因对未来经济影响的重要结论。根据这项研究,氟烷基因的效应随携带该基因的猪的上市体重不同而不同。拉康比的研究者们用三种类型的猪进行了研究:氟烷敏感猪(nn基因型)、抗氟烷猪(NN基因型)以及两者的杂交一代猪(Nn基因型)。他们对这些猪在不     

RYRl基因对母猪繁殖性能的影响

用 PCR- RFL P法检测 2 2 5头大约克母猪的 RYR1(ryanodine receptor,RYR1)基因 ,它具有 NN、Nn和 nn3种基因型 ,其频率分别为 0 .76、0 .14和 0 .10 ;等位基因 N和 n的基因频率分别为 0 .83和 0 .17。该基因处于遗传不平衡状态 (P<0 .0 1)。具有 NN、Nn和 nn基因型母猪第 1胎产仔数分别为 10 .2 1、9.6 2和 8.2 2头 ;断奶仔猪数分别为9.2 1、8.13和 7.11头。等位基因 n使仔猪断奶应激效应具上升趋势 ,对增重有不利影响 ;降低母猪的产仔数和仔猪成活率 ,对繁殖性能有不良的遗传效应 ,有必要从母猪群中清除该等位基因。     

新疆某规模化猪场氟烷基因的检测

为了提高新疆本地区猪肉品质,生产出令消费者满意的猪肉产品,迫切需要在各猪场猪群特别是种猪群全面进行氟烷基因检测并淘汰氟烷阳性基因携带者,从遗传上控制PSE肉的产生.采用PCR-RFLP法鉴别猪是否含有氟烷敏感基因具有简便易行、重复性好的优点,仅需要采集血液、组织或毛发等样品,即可区分正常猪(NN)、应激敏感猪(nn)和...     

抗病育种技术在引进美国SPF种猪后代选育中应用探究

为探索利用现代分子育种技术培育抗病新品系种猪,本试验对引进美国的44头杜洛克、138头大约克、28头长白纯种猪进行耳组织采样,采用基因检测技术分别进行氟烷基因（抗应激基因）、抗腹泻基因及KPL2基因（精子短尾基因）检测。结果表明,1）氟烷基因检测：杜洛克种猪检测出氟烷基因型Nn个体（应激易感基因个体）1头,占2.33%（1/44）;大约克种猪检测出氟烷基因型Nn个体2头,占1.45%（2/138）;长白种猪未检测到氟烷基因型Nn个体（0/28）,所检测的28头猪全部为氟烷基因型NN个体（抗应激基因个体）。2）抗腹泻基因检测：杜洛克种猪群中含有抗腹泻GG基因型个体37头,占杜洛克猪检测总数的86.05%（37/43）;长白种猪群中腹泻抗性有利GG基因型个体有11头,占40.74%（11/27）;大约克种猪腹泻抗性有利基因个体有23头,占16.79%（23/137）,3个品种中杜洛克种猪群占有腹泻抗性个体最多,其次是长白种猪,大约克种猪最少。3）KPL2基因检测：所检测的138头大约克种猪,没有检出携带精子短尾遗传疾患的个体。在种猪繁育中,只要加大世代有利纯合抗性个体的选留比例,最终可以建立纯系杜洛克、大约克、长白种猪等抗应激、抗腹泻、无精子短尾症等专门化新品系。     

CPA对已知MH基因型猪PSE肉产生的影响

恶性发热(MH)和环匹阿尼酸(CPA)都与骨胳肌的异常钙离子平衡有关,异常钙离子平衡是PSE肉产生的关键性潜在因素。为确定家畜饲料成分中自然存在的CPA是否与肉品工业PSE肉不同发生率有关,在已知MH基因型(NN=正常,Nn=MH携带者,nn=MH阳性)达出栏重的阉公猪(52头,以下简称试猪)日粮中添加不同水平的CPA(0.1～50mg/kg饲粮)。nn型猪同NN和Nn型猪相比,提高了动物生产性能(采食量、日增重和饲料效率),但却降低了腰肌品质(45分钟pH值,简称 pH45减小)(P<0.01),超过了CIEL~*比色值(P<0.05),并增大了失水率(P<0.01)。CPA的影响不尽相同,在试验1中,CPA在正常室外温度(2℃)下对动物的生产性能和肉质均无影响影响PSE肉的产生(Pommier和Houde,1993),诸如应激、温度和饲料被菌毒素污染等环境因素。 CPA是从大量的谷实类植物中分离出的某种曲霉菌和青霉菌种(Hermansen等,1984)代谢产生的有毒副产物(Holzapfel,1968)。CPA的毒性在某种程度上归因于对骨胳肌Ca~(2 )-ATP酶的特异性抑制(Feidter等,1989 Voss,1990),而此酶能在兴奋-收缩耦联过程中使增高了的肌浆 Ca~2 浓度恢复至静息的水平。随着Ca~(2 )通道的MH突变,CPA就可能提高肌浆Ca~(2 )浓度,且MH基因型和饲料中CPA间的互作可增强PSE肉的产生,这种互作也可因CPA影响骨胳肌     

Halothane gene and swine performance.

One hundred thirty-one pigs representing seven different breed groups (Minnesota No. 1 [M], Pietrain [P], Yorkshire [Y], and crosses PY, P[PY], P[NP], and P[YP]P) and three halothane gene genotypes (NN, Nn, and nn) were tested for breed, sex, and halothane gene (HAL) effects on growth and carcass performance. Breed effects were significant for all traits measured. Sex effect was significant for most traits except for meat scores. The HAL-locus linkage group explained 20 to 30% of the total variation for meat quality scores and 1 to 10% for meat quantity and growth traits. Pietrain x Yorkshire was the fastest growing breed group and had relatively good carcass quality. Pietrain and its related crosses had the most lean muscle but the lowest meat quality. The HN (HAL negative, genotype Nn) individuals within the PPY and PNP groups grew more quickly and had higher meat quality scores and less muscling than HP (HAL positive, genotype nn) individuals. A second experiment with 40 pigs showed significant differences in fat concentration in the loin muscle between breeds (M, Y, and P) and between genotypes within the NP population (NP[HP] and NP[HN]). The phenotypic correlation between fat percentage and marbling was .59 (P less than .01). The NP(HP) had higher water percentage in lean than the NP(HN). The water percentage was negatively correlated with meat quality scores of color, firmness, and marbling with phenotypic correlations of -.10, -.23, and -.57 (P less than .01), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of the halothane genotype and slaughter weight on texture of pork

The objective of this study was to investigate the effects of the halothane (HAL) genotype, slaughter weight (SW), and the HAL x SW interaction on compositional and textural traits of raw and cooked pork. Pigs were bred to exhibit one of the three HAL genotypes (NN, Nn, and nn) with otherwise equivalent genomes. The nn halothane reactors are known to typically produce PSE pork, whereas NN pigs do not typically produce PSE pork. Pietrain x Large White gilts and boars, all with verified Nn genotype (by DNA test), were mated to obtain F2 littermates of the three HAL genotypes. These pigs were slaughtered at either 101 +/- 3 ("light") or 127 +/- 3 ("heavy") kg BW and were evaluated for longissimus muscle traits. The pH at .5 h after death (pH1) was 6.35, 6.13, and 5.68 in NN, Nn, and nn pigs, respectively. Sarcomere length was greater in nn than in NN and Nn pigs (1.94 vs 1.83 and 1.85 microm, respectively). Mechanical resistance was higher in nn than in NN pigs for both raw and cooked meat. Meat from nn pigs was judged by a trained panel to be less rough, more cohesive, harder, more fibrous, less granular, more elastic, and less easy to swallow than meat from NN pigs. For most traits under study, the heterozygotes were intermediate between the homozygotes but closer to NN than to nn pigs. Muscle from heavy pigs had longer sarcomeres and less moisture than muscle from light pigs. The n allele of the HAL gene unfavorably affects pork texture, and this effect is maintained throughout the range of 101 to 127 kg BW.     

Influence of halothane genotype and body-weight on myosin heavy chain composition in pig muscle as related to meat quality

In an effort to understand the relationship between muscle fiber type, live weight, genotype, and PSE development, enzyme-linked immunosorbent analyses were used to evaluate myosin heavy chain (MyHC) isoform content in the longissimus muscle of pigs differing in halothane gene status (nn, homozygous mutant; Nn, heterozygous; NN, homozygous normal) that were slaughtered at three different weights (100, 120 and 140 kg). Pigs carrying the n gene (Nn and nn) exhibited more IIB MyHC and less slow type I MyHC than those pigs free of the n gene, while NN pigs had greater amounts of IIAX MyHC. The relative abundance of IIB and IIAX MyHC in muscle of all pigs studied was strongly negatively correlated (r=−0.834). Heavier pigs (140 kg) had the greatest amounts of slow and IIA MyHC. Across all genotypes, the relative abundance of IIB MyHC and muscle pH at 45 min postexsanguination (pH45) was negatively correlated (r=−0.418). In addition, the relative amount of slow was positively correlated with pH45 (r=0.386). Because muscle of homozygous nn positive pigs exhibited similar IIB/slow MyHC ratios to that of heterozygous Nn pigs, yet less desirable pH45 values and ultimate meat quality scores argues against a role of MyHC content per se in contributing to PSE development. However, these data do not preclude that those pigs with greater amounts of IIB MyHC are more ‘susceptible’ to adverse pork quality development than those pigs with less IIB MyHC.     

通过猪毛检测丹麦长白猪氟烷基因的变异

采集５６头丹麦长白猪（其中１头为１周龄的仔猪，２６头种公猪，２９头种母猪）猪毛样品，粗提ＤＮＡ，进行ＰＣＲ扩增，得到６５９ｈｐ在氟烷基因中（即兰尼定受体基因）中第１８４３个碱基的异片段，经过ＨｈａＩ酶切和电泳来检测氟烷基的变异，即其基因型，结果表明，（１）５６头长白猪中，阳性猪（ｎ／ｎ）１头占１．７９％，杂合子猪（Ｎ／ｎ）为１８头，占３２．１４％，阴性猪（Ｎ／Ｎ）为３７头，占６６．０７％杂合子数实     

Impact of RYR1 genotype of Piétrain boars on litter traits of Czech Large White × Czech Landrace crossbred sows

Summary Piétrain boars of different ryanodine receptor (RYR1) genotypes (NN, Nn and nn, three boars each) were mated with approximately 10 Czech Large White × Czech Landrace sows (genotype NN) each to produce one litter per sow. The progeny of nn boars had a significantly higher individual weaning weight (7.31 kg versus 6.86 kg) and average daily gain from birth to weaning (252 g/day versus 240 g/day) than the progeny of NN boars. Furthermore, piglets from nn boars differed statistically significant also from piglets of boars with the Nn genotype for these two traits. The litters of the NN boars were greater by 0.5 piglets than the litters of the nn boars for the total number of piglets born, piglets born alive and piglets weaned, but the differences were not significant. The Nn genotype showed for all litter size traits and the number of stillborn piglets the best values. The difference between the genotypes Nn and nn was statistically significant at the 0.05 level for the number of piglets born alive and the number of piglets weaned.     

猪氟烷基因型的PCR检测及杂合子氟烷阳性猪的发现

对１４７头猪进行了氟烷测验,测得氟烷阳性猪３头,阳性率为２．０４％。运用ＰＣＲ－ＲＦＬＰ分析法对氟烷阳性猪及其同胞进行了基因型检测,结果４头被测猪中有２头为隐性纯合子,２头为杂合子。结合氟烷测验结果,２头隐性纯合子表现为氟烷阳性,符合一般规律;而２头杂合子中发现１头为氟烷阳性,此前尚未见报道,这一结果证明了氟烷表现与基因型并非完全对应     

PCR-RFLP技术检测新嘉兴黑猪氟烷基因

本试验随机抽取嘉兴地区部分猪场新嘉兴黑猪血样,通过PCR-RFLP技术进行氟烷基因检测,结果表明,37头新嘉兴黑猪基因型均为NN,未出现Nn和nn基因型。检测结果为新嘉兴黑猪品种资源保护及合理开发利用提供理论依据。     

Effects of transport stress on concentrations of cortisol, corticosteroid-binding globulin and glucocorticoid receptors in pigs with different halothane genotypes

Effects of stress on concentrations of cortisol and corticosteroid-binding globulin (CBG) in blood plasma and on glucocorticoid receptor concentrations in muscle cytosol were studied in pigs representing three Halothane (Hal) genotypes (NN, Nn, nn). At 12 wk of age, animals were divided into four groups: pigs subjected to transport (5 h in a truck), pigs treated with amperozide prior to transport, pigs not transported but treated with amperozide and pigs neither transported nor given amperozide. Animals were slaughtered the week they reached 100 kg live weight (3 mo later). The Hal gene showed no major influence on the variables studied except for cortisol concentrations (P = .06) measured directly after transport at 12 wk of age (NN = 66.8 nM, Nn = 61.4 nM, nn = 69.4 nM). However, the response in each Hal genotype differed, depending on whether or not the pigs had been exposed to transport. Two weeks after transport, NN pigs developed higher cortisol concentrations than untransported animals, whereas the response was reversed in nn animals; Nn pigs showed no difference in this regard. At slaughter, the effect of transport (12 wk of age) on cortisol and CBG was still apparent. In NN pigs cortisol and CBG concentrations were elevated (P less than or equal to .05, P = .08, respectively), whereas concentrations tended to be lower in nn pigs (P = .17, P = .07, respectively) when compared with untransported pigs. Transported pigs had lower receptor concentrations at slaughter (P less than or equal to .01) than untransported pigs. However, pigs given amperozide in connection with transport had a receptor concentration comparable to that in untransported pigs. Our study shows conclusively that transport stress had long-term effects on cortisol, CBG and glucocorticoid receptor concentrations. In addition, amperozide had long-term effects on cortisol and receptor concentrations.     

The effect of cyclopiazonic acid on the development of pale, soft, and exudative pork from pigs of defined malignant hyperthermia genotype

Malignant hyperthermia (MH) and the mycotoxin cyclopiazonic acid (CPA) are each associated with abnormal calcium homeostasis in skeletal muscle, a key underlying factor in the development of pale, soft, and exudative (PSE) pork. To determine whether the natural presence of CPA in livestock feed ingredients contributes to the varying incidence of PSE in the pork industry, various levels of CPA (.1 to 50 mg/kg of diet) were included in the diets of market weight hogs (n = 52) of defined malignant hyperthermia genotype (NN = normal, Nn = a MH carrier, and nn = MH-positive). Animals with two copies of the MH mutation (nn) displayed improved live animal performance compared with NN and Nn animals (increased feed intake, average daily gain, and feed efficiency) but yielded lower quality loin chops as indicated by lower 45-min pH (P<.01), higher Commission Internationale de l'Eclairage (CIE) L* color coordinate values (P<.05), and higher drip losses (P<.01). The effects of CPA varied. In the first feeding trial, conducted under normal outside temperatures (2 degrees C), CPA had no effect (P> .2) on either live animal performance or meat quality. During the second trial, conducted under extreme outside temperatures (-18 degrees C), CPA-dependent reductions (P<.05) in feed intake, average daily gain, and 45-min pH in nn hogs support the possibility of interactions between malignant hyperthermia and dietary CPA on skeletal muscle calcium homeostasis and the development of PSE pork. These results suggest that this interaction may require stressful environmental conditions or the ingestion of CPA doses much higher than occur under natural conditions.