Characterization of biological types of cattle (Cycle V): carcass traits and longissimus palatability     

Wheeler TL  Cundiff LV  Shackelford SD  Koohmaraie M 《Journal of animal science》2001,79(5):1209-1222

Carcass (n = 854) and longissimus thoracis palatability (n = 802) traits from F1 steers obtained from mating Hereford, Angus, and MARC III cows to Hereford or Angus (HA), Tuli (Tu), Boran (Bo), Brahman (Br), Piedmontese (Pm), or Belgian Blue (BB) sires were compared. Data were adjusted to constant age (444 d), carcass weight (333 kg), fat thickness (1.0 cm), fat trim percentage (21%), and marbling (Small00) end points. Results presented in this abstract are for age-constant data. Carcasses from BB- and HA-sired steers were heaviest (P < 0.05) and carcasses from Bo- and Tu-sired steers were lightest (P < 0.05). Adjusted fat thickness was greatest (P < 0.05) on carcasses from HA-sired steers and least (P < 0.05) on carcasses from BB- and Pm-sired steers. Numerical USDA yield grades were lowest (P < 0.05) for carcasses from Pm- and BB-sired steers and highest (P < 0.05) for carcasses from HA- and Br-sired steers. Marbling scores were highest (P < 0.05) for carcasses from HA- and Tu-sired steers and lowest (P < 0.05) for carcasses from Br-, BB-, and Pm-sired steers. Longissimus thoracis from carcasses of HA-, Pm-, and Tu-sired steers had the lowest (P < 0.05) 14-d postmortem Warner-Bratzler shear force values. Carcasses from HA-sired steers had longissimus thoracis with the highest (P < 0.05) tenderness ratings at 7 d postmortem. Longissimus thoracis from carcasses of Br- and Bo-sired steers had the highest (P < 0.05) Warner-Bratzler shear forces and the lowest (P < 0.05) tenderness ratings at 7 d postmortem. Adjustment of traits to various slaughter end points resulted in some changes in sire breed differences for carcass traits but had little effect on palatability traits. Carcasses from BB- and Pm-sired steers provided the most desirable combination of yield grade and longissimus palatability, but carcasses from HA-cross steers provided the most desirable combination of quality grade and longissimus palatability. Tuli, a breed shown to be heat-tolerant, had longissimus tenderness similar to that of the non-heat-tolerant breeds and more tender longissimus than the heat-tolerant breeds in this study.  相似文献   

猪肌生成抑制素在COS-7细胞中的表达及检测   总被引：1，自引：0，他引：1  

吕文发  逢大欣  欧阳红生 《中国畜牧杂志》2005,41(10):33-34

本研究室构建的猪肌生成抑制素(MSTN)成熟蛋白编码序列的真核表达质粒pef-dhfr1a-MSTN,转染到COS-7细胞中,使猪MSTN成熟蛋白编码序列全长358个氨基酸在COS-7细胞中进行表达,利用Trizol试剂提取转染细胞的总RNA,借助RT-PCR和SDS-PAGE电泳方法,分别从mRNA水平和蛋白质水平上检测到了猪MSTN在COS-7细胞中的表达,并应用Western-blotting方法证实了猪MSTN表达的特异性。  相似文献   

猪群HEV血清抗体调查及一株新的猪HEV ORF2部分基因序列分析   总被引：5，自引：2，他引：5  

伏丽萍  王晓钧  魏丽丽  赵宇军  于敏  赵立平  吕晓玲  沈荣显  赵宏坤  相文华 《中国预防兽医学报》2005,27(2):119-123

戊型肝炎病毒(Hepatitis E virus,HEV)主要引起人的戊型肝炎,新近研究发现猪在病毒传播中可能发挥重要作用.本研究对我国部分省区HEV感染血清学调查,在被检的1 138份血清中,有666份(57.5%)为HEV抗体阳性,猪群抗体阳性率随着月龄增长而升高.通过RT-PCR方法从一份猪粪中扩增并克隆了HEVORF2 N端主要抗原决定区339bp基因片段,序列分析显示,该段基因与我国人群HEV基因4型毒株核苷酸序列同源性为85.9%,但氨基酸序列完全一致.这一结果提示我国猪群存在广泛的HEV感染,并在一定程度上与人群HEV毒株密切相关.  相似文献   

F18ac菌毛A亚单位基因的克隆与序列分析     

成大荣  徐建生  吕玲  曹军  唐波  孙怀昌 《中国预防兽医学报》2005,27(2):144-147

根据已经发表的F18ab菌毛A亚单位(FedA/ab)的基因(fedA/ab)[1],设计一对引物,利用PCR技术从表达F18ac菌毛的大肠杆菌2134P株[2]、8199株[3]、8813株[3]中分别扩增到一段序列,并克隆至pGEM-T载体,获得重组质粒T2134PA、T8199A、T8813A.琼脂糖凝胶电泳、序列测定及分析表明,该3个序列大小均为516bp,与fedA/ab(513bp)具有较高的同源性,分别为96.3%、96.5%、95.9%,推导的Fed/ac氨基酸序列与FedA/ab同源性分别为93.0%、93.6%、92.4%.数据表明该实验所克隆的序列均为F18ac菌毛A亚单位(FedA/ac)的基因(fedA/ac).  相似文献   

Effects of heterosis on maternal performance and milk production in Hereford, Angus and Shorthorn cattle     

L V Cundiff  K E Gregory  F J Schwulst  R M Koch 《Journal of animal science》1974,38(4):728-745

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The relationship between ultrasound measurements and carcass fat thickness and longissimus muscle area in beef cattle     

Greiner SP  Rouse GH  Wilson DE  Cundiff LV  Wheeler TL 《Journal of animal science》2003,81(3):676-682

Five hundred thirty-four steers were evaluated over a 2-yr period to determine the accuracy of ultrasonic estimates of carcass 12th-rib fat thickness (CFAT) and longissimus muscle area (CLMA). Within 5 d before slaughter, steers were ultrasonically measured for 12th-rib fat thickness (UFAT) and longissimus muscle area (ULMA) using an Aloka 500V real-time ultrasound machine equipped with a 17.2-cm, 3.5-MHz linear transducer. Overall, correlation coefficients between ultrasound and carcass fat and longissimus muscle area were 0.89 and 0.86, respectively. Correlations for UFAT with CFAT were similar between years (0.86 and 0.90), whereas the relationship between ULMA and CLMA was stronger in yr 1 (r = 0.91; n = 282) than in yr 2 (r = 0.79; n = 252). Differences between ultrasonic and carcass measurements were expressed on both an actual (FDIFF and RDIFF) and absolute (FDEV and RDEV) basis. Mean FDIFF and RDIFF indicated that ultrasound underestimated CFAT by 0.06 cm and overestimated CLMA by 0.71 cm2 across both years. Overall mean FDEV and RDEV, which are indications of the average error rate, were 0.16 cm and 3.39 cm2, respectively. Analysis of year effects revealed that FDIFF, FDEV, and RDEV were greater (P < 0.01) in magnitude in yr 1. Further analysis of FDEV indicated that leaner (CFAT < 0.51 cm) cattle were overestimated and that fatter (CFAT > 1.02 cm) cattle were underestimated with ultrasound. Similarly, steers with small CLMA (< 71.0 cm2) were overestimated, and steers with large CLMA (> 90.3 cm2) were underestimated. The thickness of CFAT had an effect (P < 0.05) on the error of UFAT and ULMA measurements, with leaner animals being more accurately evaluated for both traits. Standard errors of prediction (SEP) adjusted for bias of ultrasound measurements were 0.20 cm and 4.49 cm2 for UFAT and ULMA, respectively. Differences in SEP were observed for ULMA, but not UFAT, by year. These results indicate that ultrasound can be an accurate estimator of carcass traits in live cattle when measurements are taken by an experienced, well-trained technician, with only small differences in accuracy between years.  相似文献   

Comparison of models for estimation of genetic parameters for mature weight of Hereford cattle     

Rumph JM  Koch RM  Gregory KE  Cundiff LV  Van Vleck LD 《Journal of animal science》2002,80(3):583-590

Genetic parameters of mature weight are needed for effective selection and genetic evaluation. Data for estimating these parameters were collected from 1963 to 1985 and consisted of 32,018 mature weight records of 4,175 Hereford cows that were in one control and three selection lines that had been selected for weaning weight, for yearling weight, or for an index combining yearling weight and muscle score for 22 yr. Several models and subsets of the data were considered. The mature weight records consisted of a maximum of three seasonal weights taken each year, at brand clipping (February and March), before breeding (May and June), and at palpation (August and September). Heritability estimates were high (0.49 to 0.86) for all models considered, which suggests that selection to change mature weight could be effective. The model that best fit the data included maternal genetic and maternal permanent environmental effects in addition to direct genetic and direct permanent environmental effects. Estimates of direct heritability with this model ranged from 0.53 to 0.79, estimates of maternal heritability ranged from 0.09 to 0.21, and estimates of the genetic correlation between direct and maternal effects ranged from -0.16 to -0.67 for subsets of the data based on time of year that mature weight was measured. For the same subsets, estimates of the proportions of variance due to direct permanent environment and maternal permanent environment ranged from 0.00 to 0.09 and 0.00 to 0.06, respectively. Using a similar model that combined all records and included an added fixed effect of season of measurement of mature weight, direct heritability, maternal heritability, genetic correlation between direct and maternal effects, proportion of variance due to direct permanent environmental effects, and proportion of variance due to maternal permanent environmental effects were estimated to be 0.69, 0.13, -0.65, 0.00, and 0.04, respectively. Mature weight is a highly heritable trait that could be included in selection programs and maternal effects should not be ignored when analyzing mature weight data.  相似文献   

硒对硒蛋白-谷胱甘肽过氧化物酶基因表达及其酶活性的调节     

于昱  吕林  张亿一  罗绪刚 《动物营养学报》2007,19(Z1)

本文根据国内外研究现状详细综述了硒调节细胞型谷胱甘肽过氧化物酶(GPX1)mRNA水平、蛋白水平及酶活3个水平的可能分子机理,初步概述硒对其余GPX基因表达的影响及其作用机制,为深入研究硒调节GPX基因表达的作用机制提供参考。  相似文献   

内蒙古旅游业发展的实践分析及总体评价   总被引：4，自引：7，他引：4  

刘丽梅  吕君 《干旱区资源与环境》2006,20(1):62-67

内蒙古自治区的旅游业经过多年的培育发展取得初步成绩,按照旅游地生命周期理论其发展实践历程基本经历了探索阶段、初步增长阶段,刚刚步入发展阶段,开始了规模扩张。在这个阶段,内蒙古旅游业的发展还存在提高对国民经济的贡献度、深度开发旅游资源、完善产业链条、优化行业结构、提升旅游企业竞争能力等诸多问题。需要优化旅游空间与布局;聚集具有创新能力的企业群体和企业家群体;深入旅游发展研究,重视科研队伍培养;进行营销策划,树立良好形象;加强生态保护与建设。  相似文献   

内蒙古入境旅游市场结构研究   总被引：4，自引：4，他引：4  

刘丽梅  吕君 《干旱区资源与环境》2006,20(5):128-132

旅游业的发展离不开客源市场。通过对内蒙古入境旅游市场的年际变化、地域构成、境内分布情况和消费构成的分析,阐明了内蒙古入境旅游市场的基本特点。提出了确定市场重点,定位客源结构;合理进行空间布局,扩大入境游客在自治区境内的流向;深度开发旅游资源,打造名牌产品;优化旅游消费结构等进一步开拓入境旅游市场的建议。  相似文献