运输应激对2种Hal基因型猪肌纤维特性的影响

以二花脸与皮特兰杂交F2代猪为研究对象,应用组织学、组织化学方法与电镜技术研究运输应激对2种猪背最长肌琥珀酸脱氢酶(SDH)、乳酸脱氢酶(LDH)、糖原以及肌纤维超微结构的影响,并分析比较了2种氟烷基因(HalNN,Halnn)猪背最长肌各肌纤维类型。研究发现:(1)HalNN猪背最长肌SDH活性比Halnn猪的极显著高(P<0.01);(2)背最长肌LDH活性Halnn猪比HalNN猪的极显著高(P<0.01);(3)Halnn猪糖原含量比HalNN猪的显著高(P<0.05);(4)透射电镜显示HalNN猪背最长肌肌纤维超微结构形态较清晰完整,而Halnn猪肌纤维收缩剧烈,肌节混乱,明带暗带区分不明显,有的肌节甚至降解,线粒体不同程度肿胀和裂解,肌浆网不明显等。结果表明:氟烷基因野生型HalNN猪对运输应激相对不敏感;而阴性纯合子Halnn猪则对应激很敏感,其肌纤维损伤较大。     

藏香杂野猪与杜长大三元猪肉质特性比较

为解析藏香杂野猪肉质鲜美的风味基础,分别对藏香杂野猪与杜长大(杜洛克×长白×大白)三元猪的背最长肌进行肉质性状和氨基酸含量分析测定。测定结果显示：藏香杂野猪背最长肌的滴水损失和剪切力显著低于杜长大三元猪(P<0.05),亮度L^*值极显著低于杜长大三元猪(P<0.01),肌内脂肪含量显著高于杜长大三元猪(P<0.05);在检测出的16种氨基酸中,藏香杂野猪背最长肌中14种氨基酸的含量极显著高于杜长大三元猪(P<0.01),其余2种氨基酸含量显著高于杜长大三元猪(P<0.05)。结果表明：藏香杂野猪猪肉营养丰富、肉质鲜美,与杜长大三元猪相比具有明显优势。     

野家杂交猪与东北民猪肌肉组织学特性的比较研究

为探讨东北民猪和野家杂交猪的肉质特点与差异,以东北民猪和野家杂交猪的背最长肌和股二头肌为试验材料,采用常规组织学技术和免疫组织化学技术,对东北民猪和野家杂交猪的肌纤维组织学特性进行比较研究。结果显示,野家杂交猪背最长肌的肌纤维直径显著大于东北民猪背最长肌的肌纤维直径(0.01P0.05),野家杂交猪股二头肌的肌纤维直径比东北民猪股二头肌的肌纤维直径大(P0.05),同品种不同部位的肌纤维直径差异不显著(P0.05),野家杂交猪的肌纤维密度比东北民猪的肌纤维密度大(P0.05),野家杂交猪背最长肌的肌纤维面积比东北民猪背最长肌的肌纤维面积大(P0.05),野家杂交猪股二头肌的肌纤维面积比东北民猪股二头肌的肌纤维面积小(P0.05)。野家杂交猪的快肌比东北民猪的多(P0.01),野家杂交猪的快肌所占比例比东北民猪的高。结果表明,东北民猪的猪肉品质比野家杂交猪的肉品质好。     

品种、体重和营养对猪背最长肌肌纤维组织学特性的影响

选用荣昌(RC)猪和杜×长×大(DLY)杂交猪为试验对象,研究猪背最长肌肌纤维直径和密度的发育性变化及品种与营养影响特点。结果表明:2个品种猪的背最长肌肌纤维直径和密度的发育规律较为类似,肌纤维直径随体重增加呈线性增长,而肌纤维密度则随体重增加呈乘幂方程式降低。相关分析表明,肌纤维密度与直径均存在极显著负相关(P≤0.003)。背最长肌肌纤维直径和密度在20～50kg阶段品种间差异不显著(P≥0.099),但在80kg,RC猪的肌纤维直径显著低于DLY猪(P=0.0043),而RC猪的肌纤维密度则显著高于DLY猪(P=0.0049)。饲粮营养水平对2个品种猪背最长肌的肌纤维直径和密度均无显著影响。以上结果提示,2个品种猪的背最长肌肌纤维的生长规律较为类似,但不同品种的肌纤维直径存在差异,主要表现在80kg,RC猪显著低于DLY猪,可能与其优良肉质有关。     

杂交对小梅山猪肉品质的影响

小梅山猪杂交后,除背最长肌嫩度改善外,其它肉品质指标都有不同程度下降,除背最长肌肉色外,全部肉品质指标均为小梅山猪大于约小梅猪,约小梅猪大于长约小梅猪.一些肉质性状间相关显著.背最长肌和半腱肌肌纤维直径均为长约小梅猪显著大于小梅山猪和约小梅猪,小梅山猪和约小梅猪差异不显著,全群猪肌纤维直径除与熟肉率呈正相关外,与其它肉质指标都呈负相关.     

杂交对小梅山猪肉品质的影响

小梅山猪杂交后，除背最长肌嫩度改善外，其它肉品质指标都有不同程度下降，除背最长肌肉色外，全部肉品质指标均为小梅山猪大于约小梅猪，约小梅猪大于长约小梅猪。一些肉质性状间相关显著，背最长肌和半肌肌纤维直径约为长约小梅猪显著大于小梅山猪和约小梅猪，小梅山猪和约小梅猪差异不显著，全群猪肌纤维直径除与熟肉率呈正相关外，与其它肉质指标都呈负相关。     

莱芜猪肌肉肌纤维类型的组成与肉质关系的研究

采用2因子多水平有重复试验的方法,对14头纯种育肥莱芜猪不同屠宰体重(A因子)及不同解剖部位(B因子)的新鲜肌肉直接冰冻切片,并进行琥珀酸脱氢酶(SDH)的组织化学处理,结果表明:莱芜猪肌肉的结构单位肌纤维是异质的,即肌纤维类型有3种,红肌纤维(RF)、白肌纤维(WF)和中间型肌纤维(IF)。随屠宰体重的提高,肌肉中RF含量显著增大(P相似文献   

纯种与杂种猪肌肉生长相关分子表达的差异分析

本研究旨在了解纯种与杂种猪肌肉生长发育过程中存在的分子调控差异,并分析其对猪胴体和肉质的影响。选用体重50kg左右的纯种杜洛克猪、长白猪和大白猪以及杜长大三元杂交猪为研究对象,每个重复6头猪,从表型和分子水平上对其背最长肌进行分析。结果表明,与纯种猪相比较,杂种猪背最长肌的肌纤维面积、白肌纤维比率、乳酸脱氢酶A基因表达量和线粒体DNA拷贝数显著提高(P0.01);虽然与纯种猪相比较,有些基因的表达量在杂种猪背最长肌中的提高或降低不显著(P0.05),但总体上来说,促进肌纤维生长发育的相关基因IGF1、PDK1和GLUT4的表达量显著提高(P0.05),抑制肌纤维生长发育的相关基因MSTN和FOXO1的表达量显著降低(P0.05);促进白肌纤维转化的相关基因PGC1A的表达量显著提高(P0.05),抑制白肌纤维转化的相关基因MEF2A、MYOZ1、MRF4和NFATC1的表达量显著降低(P0.05);促进肌纤维增殖的miR-1和miR-133表达量显著提高了(P0.01),抑制白肌纤维生长的miR-499表达量显著降低(P0.01)。结果提示,杂交改善猪的胴体性状是通过改变其分子调控水平来实现的,但对肉品质有不利影响。     

饲粮能氨水平对不同品种猪肉质性状及相关基因表达的影响

本试验旨在研究饲粮能氮水平对不同品种猪肉质性状以及肌纤维类型和细胞因子相关基因表达的影响.选取巴马香猪和长白猪共96头(48头/品种),随机分为4组(每组24头猪),分别为长白猪饲喂NRC饲粮组、长白猪饲喂我国地方猪标准(GB)饲粮组、巴马香猪饲喂NRC饲粮组、巴马香猪饲喂GB饲粮组.试验从5周龄开始,至出栏时结束.分别于保育期、生长期和肥育期末,每组选择8头体况相近猪只屠宰,采集肌肉样品分析.结果表明:生长阶段显著影响了试验猪背最长肌熟肉率和肌球蛋白重链(MyHC)Ⅱx、MyHCⅡ易及白细胞介素-15(IL-15)mRNA表达水平(P<0.05),且随生长阶段呈增加趋势;与长白猪相比,巴马香猪的背最长肌熟肉率、MyHC Ⅰ mRNA表达水平显著升高(P<0.05),而滴水损失显著降低(P<0.05);与NRC饲粮相比,GB饲粮显著提高了生长期长白猪和巴马香猪的pH45 min(P<0.05),显著上调了保育期和肥育期猪背最长肌MyHC Ⅰ mRNA表达水平(P<0.05);与GB饲粮相比,NRC饲粮显著上调了生长期猪背最长肌MyHC Ⅰ mRNA表达水平(P<0.05).由此可见,品种和生长阶段均可显著影响肉质性状及相关基因的表达,饲粮能氮水平则主要通过与生长阶段产生互作效应影响肉质性状及肌纤维类型相关基因的表达.     

长白山野杂猪和商品猪骨骼肌组织学特性的比较研究

为了探讨长白山野杂猪和商品猪肉质特点及差异,以长白山野杂猪和商品猪半腱肌、背最长肌、股二头肌和腰大肌为试验材料,采用常规组织化学染色方法,对长白山野杂猪和商品猪骨骼肌组织学特性进行比较研究。结果显示,长白山野杂猪的股二头肌与腰大肌肌纤维的直径和面积均低于商品猪,而肌纤维密度显著高于商品猪,但是长白山野杂猪的半腱肌和背最长肌的肌纤维直径、面积及密度同商品猪相比均没有显著差异。结果表明,长白山野杂猪的猪肉品质优于商品猪的猪肉品质。     

瘦肉型和脂肪型肥育猪胴体性状和肉质的比较研究

选用体重为50 kg左右的宁乡猪和三元杂交猪各4头,屠宰后对其胴体性状、肉质及肌肉氨基酸与脂肪酸组成和含量进行比较。结果表明,宁乡猪的胴体重、皮重、脂肪重、脂肪率和均膘厚均显著高于三元杂交猪,肌肉重、瘦肉率和眼肌面积显著低于三元杂交猪（P<0.05）;宁乡猪的肉色显著优于三元杂交猪（P<0.05）;贮存损失显著低于三元杂交猪（P<0.05）;三元杂交猪肌肉各氨基酸含量均高于宁乡猪（P>0.05）;宁乡猪背最长肌和半腱肌的油酸含量显著高于三元杂交猪（P<0.05）,而背最长肌硬脂酸和亚油酸含量及半腱肌亚油酸含量均显著低于三元杂交猪（P<0.05）。     

Carcass, muscle and meat characteristics of lean and obese pigs

Six pigs obtained from a lean selected strain and six pigs obtained from an obese selected strain were slaughtered at about 110 kg live-animal weight. Carcasses were evaluated; hams were dissected into bone, skin, fat and lean, and loin samples were obtained for fiber type characteristics, percentage of fat and moisture, collagen analysis, sensory characteristics, textural properties and objective color analysis. Carcasses from lean pigs were longer, had less backfat and larger longissimus muscle cross-sectional areas than carcasses obtained from obese pigs. Hams from lean pigs had less fat, more bone and more lean than hams from carcasses of obese pigs. The percentages and cross-sectional areas of red and white muscle fibers of the longissimus muscle from lean and obese pigs were not different. However, lean pigs had intermediate fibers that were only 79% as large (P less than .10) as intermediate muscle fibers from obese pigs. Intermediate fibers represented only 7 and 10% of total fiber area, whereas white fibers represented 84 and 79% of total fiber area in longissimus muscle of lean and obese pigs, respectively. Overall, lean pigs tended to possess fewer fibers (-16%) per unit of area than obese pigs, indicating that total muscle fiber hypertrophy was partially responsible for the increased longissimus muscle area of the lean strain. Sensory properties of longissimus meat samples from lean and obese strains were not different. However, the shear force requirement of the longissimus samples from the lean strain were slightly, but significantly (P less than .10), higher than those from the obese strain. No differences were observed in meat color.     

深县猪肉质及营养价值分析

本研究选择国外猪种杜洛克和中国地方猪深县猪体重 95 kg 的阉割公猪各 5 头,比较 2 个猪品种背最长肌之间肉质、氨基酸、脂肪酸和微量元素的差异。结果表明:杜洛克猪的肌内水分、肉色、大理石纹、滴水损失、粗蛋白质和脂肪含量低于深县猪(P<0.01);杜洛克猪背最长肌中谷氨酸、天冬氨酸、精氨酸、组氨酸、丝氨酸、脯氨酸、甘氨酸、苏氨酸、半光氨酸、丙氨酸、缬氨酸、苯丙氨酸、异亮氨酸、酪氨酸、亮氨酸、呈味氨基酸总量、必需氨基酸和总氨基酸含量低于深县猪(P<0.01);杜洛克猪背最长肌的饱和脂肪酸含量棕榈酸、豆蔻酸、硬脂酸和花生四烯酸多不饱和脂肪酸亚油酸和亚麻酸低于深县猪(P<0.01);单不饱和脂肪酸棕榈油酸含量低于深县猪(P<0.01),而油酸没有显著性差异;杜洛克猪背最长肌中微量元素钾、锶、铜、锌、硅和铬含量均低于深县猪(P<0.01),镍差异显著(P<0.05)。结果显示,中国地方猪深县猪在肉质及营养价值方面优于瘦肉型的杜洛克猪,为深县猪的品种资源保护和肉产品的开发利用提供依据。     

Study on Muscle Fiber Types and Meat Quality Traits of Chinese Simmental Cattle

The aim of this test was to study muscle fiber characteristics and meat quality traits of Chinese Simmental cattle.Ten Chinese Simmental bulls were selected and longissimus dorsi,psoas major and semitendinosus were collected.Histological characteristics,pH,water holding capacity,shear force and texture profile analysis (TPA) were measured.The results showed that the diameter of these muscle fibers increased in the rank order type Ⅰ < ⅡA < ⅡB.The number and area percentage of type Ⅰ muscle fiber were highest in longissimus dorsi and that of ⅡB muscle fiber was highest in psoas major and semitendinosus.Longissimus dorsi and semitendinosus had lower pH,springiness,pressing lossing rate and higher shear force,hardness and resilience comparing with psoas major.In conclusion,muscle fiber characteristics could affect meat quality,especially textural properties of Chinese Simmental bulls.Increasing the percentage of type Ⅰ muscle fiber and decreasing ⅡB type could improve beef tenderness.     

中国西门塔尔牛肌肉肌纤维类型和肉品质特性研究

为研究中国西门塔尔牛的肌纤维和肉品质特性,本试验以10头中国西门塔尔公牛为研究对象,测定了背最长肌、腰大肌和半腱肌的组织学特性、pH、系水力、剪切力和质构剖面分析。结果显示,肌纤维直径Ⅰ型 < ⅡA型 < ⅡB型,腰大肌中Ⅰ型具有最高的肌纤维数比例和肌纤维面积比,背最长肌和半腱肌中ⅡB型具有最高的肌纤维比例和肌纤维面积比。与腰大肌相比,背最长肌和半腱肌具有较低pH、弹性和压力失水率,较高的剪切力、硬度和回复性。综上所述,肌纤维特性影响牛肉品质,特别是牛肉的质构特性,提高Ⅰ型纤维比例和降低ⅡB型纤维比例能够改善牛肉嫩度。     

不同体重阶段川藏黑猪和杜长大猪肌肉中氨基酸含量研究

为了研究不同猪种背最长肌中氨基酸沉积规律,试验采用高效液相色谱检测了不同体重梯度（90、110和130 kg）的川藏黑猪和杜长大（DLY）猪背最长肌中氨基酸含量。结果表明,谷氨酸在两猪种肌肉中含量最高,含硫氨基酸总量在90和130 kg体重梯度时表现为川藏黑猪显著高于DLY猪（P〈0.05）,110 kg体重梯度时极显著高于DLY猪（P〈0.01）,而同一猪种不同体重梯度间各种氨基酸组成差异均不显著（P〉0.05）,鲜味氨基酸占总氨基酸比例（FAA/TAA）在90 kg体重梯度表现为川藏黑猪极显著高于DLY猪（P〈0.01）,130 kg体重梯度时显著高于DLY猪（P〈0.05）。本研究说明川藏黑猪肌肉中与风味相关的氨基酸含量高于DLY猪,我们认为这也是川藏黑猪的肌肉风味比DLY猪更浓郁的重要原因之一。我们的研究初步揭示了不同猪种背最长肌中氨基酸的沉积规律及构成差异,为进一步研究猪肉风味形成机理提供数据。     

猪肌肉糖原磷酸化酶基因的多态性及其与胴体和肉质性状的相关分析

试验旨在寻找不同品种猪的差异表达基因,并对其遗传效应进行初步分析。应用抑制消减杂交技术获得了在梅山猪、长白猪和大白猪中差异表达的肌肉糖原磷酸化酶(glycogen phosphorylase,muscle form,PYGM)基因及其全长cDNA序列,序列分析结果表明,猪PYGM基因编码842个氨基酸,与人、牛、狗、小鼠、大鼠和羊的氨基酸序列具有96%、97%、96%、96%、96%和97%的相似性,而且该基因在各组织中表达量均很高。通过序列比对发现,在3′非翻译区(3′UTR)125 bp处存在1个突变。利用PCR-RFLP方法,在大白猪、梅山猪、长白纯种猪和170头大白×梅山F2代资源家系中检测了该突变位点的多态性并进行性状关联分析,结果表明,该位点的多态性与瘦肉率、骨率、肥肉率、平均背膘厚、眼肌面积、胴体长显著相关,尤其是活体瘦肉率AA基因型(大白猪、长白猪优势基因)比BB基因型(梅山猪优势基因)高3%,肥肉率低5%,与外来猪种瘦肉率显著高于本地猪的性状表现是一致的。因此,猪PYGM基因125 bp位点可能是一个潜在的分子标记辅助常规育种位点。     

Production,performance, slaughter characteristics,and meat quality of Ziwuling wild crossbred pigs

Wild boars, because of their large size and ability to survive adverse conditions, are usually used to cross with domestic breeds to improve the quality of domesticated pigs. This study aimed to investigate the growth performance, slaughter performance, and meat quality of Ziwuling crossbred pigs. Crossbred pigs in four groups (n = 8 per group, 4 boars and 4 sows, all aged 100 days), F₁ [wild × B (Bamei)], F₁ × B, F₁ × Y (Yorkshire), and F₁ × F₁, were selected at a commercial pig farm. Growth performance, slaughter performance, and meat quality of these crossbred pigs were determined. Characteristics of fatty acids, amino acids, and longissimus muscle fiber in relation to growth, carcass, and meat quality traits were also investigated. Pigs in F₁ and F₁ × F₁ groups had lower average daily weight gain, water and storage loss rates, larger meat color score, higher muscle amino acid levels, larger muscle fiber diameter, and higher ratio of flavor amino acids to unsaturated fatty acids compared to other groups. Crossbred pigs with higher rate of wild boar’s consanguinity could improve production performance, slaughter performance, and meat quality. Thus, crossbreeding wild pig with domestic breeds might be an effective method to improve meat quality and flavor.