苏钟Ⅰ系和Ⅱ系猪的氟烷基因及其对产肉性能的影响

:对 3 0 1头瘦肉型新品系苏钟 系和 系仔猪进行氟烷测验 ,阳性率为 1 .3 3 %。随机抽取氟烷阴性猪 3 4头进行基因型检测 ,有 6头为杂合子 ,由此得知 NN、Nn和 nn3种基因型的频率分别为 81 .2 6%、1 7.4 1 %和 1 .3 3 %,N和 n2种基因的频率分别为 89.97%和 1 0 .0 3 %。对 3种基因型猪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 1头轻度 PSE肉 ,而氟烷阴性猪 ( NN或 Nn)未发生 PSE肉。2 0头苏钟 系氟烷阴性猪用阳性公猪测交 ,对产出的 2 0 8头后代进行氟烷测验 ,共检出 4窝中的 2 1头阳性猪。对测交后代进行肥育性能和肉质测定 ,发现阳性猪的日增重和饲料报酬等较低 ,屠宰率、眼肌面积和瘦肉率较高 ,肉质较差     

猪的氟烷基因和连锁标记基因单倍型推断

实验猪群由从ＥＳ特殊实验群和湖北白猪Ⅳ系选出的７头公猪、１４头母猪及其生产的１９窝１３６头仔猪组成。利用子代的氟烷测验结果和连锁标记位点的表型（ＰＨＩ、ＰＯ２、ＰＧＤ）推断了５头公猪、１０头母猪及其１５窝１０９头仔猪的氟烷和连锁标记基因的单倍型（Ｈａｌ－ｍａｒｋｅｒｈａｐｌｏｔｙｐｅ），并推断了其余４窝３７头仔猪亲代和子代的标记基因单倍型（ｍａｒｋｅｒｈａｐｌｏｔｙｐｅ）。结果发现，只有以家系为单位，在已知亲本一方为ＨＡＬ＋个体或是Ｈａｌｎ携带者，或者子代中有ＨＡＬ＋阳性个体的条件下，才能进行ＨＭ单倍型推断。本试验测得Ｈａｌｎｎ基因型的外显率为９１．８９％。     

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     

猪的氟烷基因和连锁标记基因蝉倍型推断

实验猪群由从ＥＳ特殊实验群和湖北白猪Ⅳ系选出的７头公猪、１４头母猪及其生产的１９窝１３６头仔猪组成。利用子代的氟烷测验结果和连锁标记位点的表型（ＰＨＩ、ＰＯ２、ＰＧＤ）推断了５头公猪、１０头母猪及其１５窝１０９头仔猪的氟烷和连锁标记基因的单倍型，并推断了其余４窝３７头仔猪亲代和子代的标记基因单倍型。结果发现，只有以家系为单位，在顺亲本一方为ＨＡＬ个体或是Ｈａｌ携带者，或者子代中有ＨＡＬ阳性个体条件     

中国瘦肉猪新品系DⅣ系氟烷敏感性检测

采用英国产Ｆｌｕｏｔｅｃ型半封闭式氟烷麻醉仪，对中国瘦肉新品系ＤⅣ系１９６头猪进行氟烷测验（其中公４５，母１５１），结果２头呈阳性反应，阳性率为１．０３％。公母猪间对氟烷的耐受性差异不显著（Ｐ＞０．０５）。个体间氟烷耐受性的差异颇大。选择３６头氟烷阳性猪进行肥育测定至９０ｋｇ屠宰和肉质评定，各肉质指标均在正常范围内。     

撒坝猪及其配套系氟烷基园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１０４头种猪包括撒坝纯种７１头,加系大约克１０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     

猪应激敏感性生化遗传标记的研究

８３头猪用于ＰＨＩ，ＰＧＤ，ＰＯ２生化多态性分析，结果显示，在３种表型分布内，氟烷阳性猪发生率，背最长肌ｐＨ值，系水力等肉质性状差异极显著（Ｐ〈０．０１），同一个优良基因数目与氟烷敏感性，肉质指标呈现线性关系，对四种亲本交配组合共计１９窝１３２头猪的亲子代进行了ＨＭ单倍型推断的遗传分析，结果表明，前三种交配组合可以根据亲子代的ＰＨＩ，ＰＯ２，ＰＧＤ表型及子代的氟烷测验结果对ＨＭ单倍型进行推断，Ｈａ     

瘦肉型猪母本品系选育

本研究用长白猪与枫泾猪杂交,产生长×（长×枫）杂交猪,组建品系选育基础群。横交固定,形成育种核心群。经过４个世代的选育,品系主要性能指标：产仔数１３．７１头,产活仔数１２．８７头,平均日增重６１５克,料重比３．１８,体重达９０千克日龄１７８．９天,背膘厚１７．０９毫米,胴体瘦肉率５９．６５％,肉质优良,无ＰＳＥ和ＤＦＤ肉。经配合力测定,筛选出大×中组合,窝产瘦肉量４７６千克。研究结果表明,选育中的母系具有产仔多、生长快、瘦肉率高、肉质好等优良特性     

引进种猪氟烷敏感基因检测结果报告

猪氟烷敏感基因 (ＨａｌｏｔｈａｎｅｇｅｎｅＨａｌ)的隐性纯合子 (Ｈａｌｎｎ)是猪产生应激综合症 (ＰＳＳ)和ＰＳＥ肉的主基因。现代分子生物学研究的进展 ,采用ＰＣＲ技术 ,已能快速、准确地鉴别猪的氟烷基因型。该技术在猪的育种上的应用正在广泛展开 ,近期已有不少报告。     

杜洛克猪产肉与肉质性能评定

利用屠宰测定，肉质分析，氟烷测定的方法，对杜洛克猪的产肉性能，肉质特性和氟烷敏感性进行了评定，其结果是：屠宰率７３．３５％－７３．９６％，腿胴比３２．３２％－３２．５６％，胴体瘦肉率６２．５３％－６３．０６％；肉质正常，无劣质肉出现；氟烷反应阴性。     

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.     

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.     

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.     

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。     

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.     

皮特兰猪的氟烷基因检测与分子选育

以PCR-RFLPs法为检测方法,针对氟烷基因开展无应激皮特兰猪的分子选育,共检测从2003-2007年若干世代共28批次皮特兰猪。结果显示,在所检测的共994头样本中,具NN基因型的为361头,具Nn基因型的为374头,具nn基因型的为259头。试验结果表明,随着世代选育的进展,群体中N基因和NN基因型的频率逐渐升高,至第17批次时均达100%,后均维持在较高水平,Hard-Weinberg平衡亦呈现平衡-不平衡-平衡的现象,直至此基因最终在群体中失去平衡。试验结果还表明,利用基因技术对家畜进行分子育种是可行的。     

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