牛TG基因启动子区遗传变异与肉质和胴体性状的相关性研究

以8个肉牛品种为试验材料,扩增TG基因启动子区,测序后发现G82A和C422T 2个突变位点。利用SAS软件采用最小二乘法拟合线性模型将2个位点的不同基因型与牛胴体组成和肉质性状进行关联分析。结果发现,C422T位点与先前报道的大理石花纹等级无相关性,与其它胴体组成和肉质性状也未发现相关性。位于C422T位点上游的G82A位点与宰前活体质量和眼肌面积显著相关（P〈0.05）,GG为有利基因型,G等位基因为有利等位基因。因此,G82A可能是影响牛胴体性状的分子标记。     

莱芜猪及其杂种猪血液指标与胴体品质性状关系的研究

本试验分析测定了３６头莱芜猪及其杂种猪的血液指标。分析结果表明,血液指标与胴体品质性状存在着一定的相关,且宰前血液指标的测定可用为预测宰后的胴体品质。     

科技

肉牛胴体性状的遗传机制被揭示近日,牛遗传育种创新团队基于全基因组重测序数据,整合选择信号、单性状关联分析以及多性状关联分析,发现了与胴体性状相关的选择信号及候选基因,揭示了肉牛胴体性状的遗传机制,为肉牛胴体性状的选育奠定了理论基础。相关成果发表在《Genomics(基因组学)》。胴体性状作为肉牛重要经济性状之一,直接决定了牛肉的产量和质量,是肉牛育种中的关键目标。解析肉牛胴体性状的遗传机制与机理并挖掘相关的候选标记与基因,不仅可以为肉牛胴体性状的选育提供相关理论基础,还可以推动肉牛育种进展,切实地提高我国牛肉产量。目前,国内外已大量开展了对肉牛胴体性状遗传基础解析工作,捕获到NCAPG、LCORL等重要候选基因,但利用全基因组重测序数据对胴体性状遗传机制解析的分析方法仍需创新。     

不同杂交牛胴体组成差异及其与血浆激素水平相关性研究

实验旨在研究利杂、西杂、夏杂3种杂交牛在胴体组成和血浆激素水平的差异,并探索Leptin、GH、IGF-I对胴体肌肉和脂肪分配的影响。用79头体重平均为249.67 kg的利杂、西杂、夏杂3个杂交品种牛进行饲养试验,选择宰前活重在550 kg左右43头牛作为1个屠宰组进行屠宰试验。结果表明:利杂的脂肪沉积能力显著高于夏杂,而夏杂的胴体骨率显著高于利杂(P<0.05);利杂血浆Leptin浓度显著高于西杂(P<0.05);血浆Leptin与胴体脂肪重和胴体脂肪率呈显著正相关(P<0.01);血浆GH与胴体重和肌肉重呈显著正相关(P<0.01);血浆IGF-I与肌肉重存在正相关(P<0.05)。可见,利杂、西杂、夏杂在胴体组成上存在明显差异;血浆Leptin、IGF-I、GH水平是反映胴体组成的重要指标,可作为判定肉牛胴体组成和胴体质量等级的宰前预测因子。     

大巴沙猪胴体性状和肉质性状研究及相关性分析

试验旨在对大约克×(巴克夏×沙子岭)(简称大巴沙)猪的胴体性状和肉质性状进行评估。选取99头大巴沙猪进行屠宰测定,主要测定屠宰率、胴体长、背膘厚、眼肌面积和瘦肉率等胴体性状及pH、肉色、大理石纹和肌内脂肪等肉质性状。结果表明,大巴沙猪的屠宰率和瘦肉率分别为72.24%和59.22%,系水力损失和肌内脂肪含量分别为93.16%和2.90%。性状间相关性分析表明,大巴沙猪宰前活重与胴体重、胴体长、眼肌面积呈极显著正相关(P<0.01),与屠宰率、pH1、肌苷酸含量呈显著正相关(P<0.05),与嫩度呈极显著负相关(P<0.05),并构建了宰前活重与相关指标的回归方程。研究结果表明,大巴沙猪胴体性状优良、肌肉保水力强、肉质鲜美,可通过宰前活重快速估测屠宰率、胴体长、眼肌面积、肌内脂肪含量,大大节省屠宰测定成本。     

肉牛PRKAG3基因多态性及其与胴体和肉质性状的关联分析

本研究以晋南牛、鲁西牛、西门塔尔、安格斯、海福特、利木赞和夏洛莱7个品种共267头肉牛为试验材料,采用PCR-RFLP技术检测PRKAG3基因多态性,找到了PRKAG3基因DNA序列中的2个突变位点T2643C和T2885C(DQ082736),同属第4内含子.2个基因多态性位点与肉牛胴体和肉质共9个性状的关联分析表明:PRKAG3基因T2885C变异位点的3个基因型间嫩度性状差异显著(P<0.05),CC基因型最dx-乘均值显著低于CD和DD基因型最dx-乘均值.本研究结果可为肉牛肉质性状标记辅助选择提供依据.     

草原红牛胰岛素样生长因子结合蛋白6基因外显子2的遗传多态性及遗传效应分析

本试验旨在研究草原红牛不同基因型与屠宰肉用性状的关联性。选用草原红牛作为试验群体,采用PCR-SSCP方法检测胰岛素样生长因子结合蛋白6(insulin-like growth factors binding proteins 6,IGFBP6)基因外显子2的多态性,采用最小二乘法拟合线性模型将突变位点的不同基因型与牛屠宰肉用性状进行关联分析。结果表明,在IGFBP6基因外显子2上发现1个多态性位点A180G,具有3种基因型:AA、AB和BB。SPSS 13.0统计分析结果表明,IGFBP6基因外显子2 AB和BB基因型净肉重极显著高于AA基因型(P<0.01);眼肌面积和骨重显著高于AA基因型(P<0.05),而在宰前活重、胴体重、肾脂重和肋脂重方面3种基因型个体之间差异不显著(P>0.05)。结果显示,IGFBP6基因的多态性与屠宰肉用性状具有一定的关联性,可为今后草原红牛的育种保种工作提供理论依据,并对草原红牛肉用性状的改善提供参考。     

啤酒的酒精含量测定的研究进展

对啤酒的酒精含量检测技术的应用研究进展作一综述。内容包括非蒸馏法、基于BP神经网络、偏最小二乘法、气相色谱法及正交信号校正(OSC)在啤酒酒精度近红外光谱分析中的应用,对各种方法的实验结果做了分析,对进一步研究啤酒酒精度测定方法的发展有很大的参考价值。     

宰前运输对肥育猪胴体、内脏及肉质的影响

本试验对10头宰前运输应激的大长淮(大白×长白×淮猪)肥育猪(试验组)和5头宰前无应激的大长淮肥育猪(对照组)作了胴体、内脏及肉质测定.试验组与对照组在胴体性状和内脏重量(心脏除外)方面无显著差异.应激组和对照组的肌肉pHu和肉色评分分别为5.50,2.25和5.88,3.00,差异显著(P<0.01).试验组肉质有下降趋势.     

啤酒的酒精含量测定的研究进展

对啤酒的酒精含量检测技术的应用研究进展作一综述。内容包括非蒸馏法、基于BP神经网络、偏最小二乘法、气相色谱法及正交信号校正(OSC)在啤酒酒精度近红外光谱分析中的应用,对各种方法的实验结果做了分析,对进一步研究啤酒酒精度测定方法的发展有很大的参考价值。     

中国荷斯坦牛早期生长曲线拟合研究

对947头0～24月龄中国荷斯坦牛体高、胸围、体斜长进行测定,用线性回归、二次回归和三次回归方程进行拟合。结果表明:中国荷斯坦牛体高、胸围、体斜长的生长曲线呈抛物线型,三次回归方程拟合结果与实测值吻合度最高。除体高离回归平方和高于二次回归方程外,胸围和体斜长的离回归平方和都明显低于用线性回归和二次回归方程计算的结果,表明三次回归方程曲线拟合效果最好,线性回归方程曲线拟合效果最不理想。体高的拐点月龄为16.5,胸围和体斜长的拐点月龄均为18。     

The effect of life history events on carcass merit and price of cull dairy cows

Cull dairy cows contribute almost 10% of national beef production in the United States. However, different factors throughout the life of dairy cows affect their weight and overall body condition as well as carcass traits, and consequently affect their market price. Therefore, the objectives of this study were: (1) to assess relationships between price ratio and carcass merit of cull dairy cows sold through several sites of an auction market and (2) to investigate the effect of animal life history events and live weight on sale barn price (BP) and price ratio (as a measure of relative price), as an indicator of carcass merit. Data from 4 dairy operations included 3,602 cull dairy cow records during the period of 2015 to 2019. Life history events data were collected from each dairy operation through Dairy Comp software; live weight and price were obtained periodically from the auction market, and the carcass data were provided by a local packing plant. Cow price in dollars per unit of live weight ($/cwt) and price ratio were the 2 outcome variables used in the analyses. Price ratio was created aiming to remove seasonality effects from BP (BP divided by the national average price for its respective month and year of sale). The association between price ratio and carcass merit traits was investigated using canonical correlation analysis, and the effect of life history events on both BP and price ratio was inferred using a multiple linear regression technique. More than 70% of the cows were culled in the first 3 lactations, with an average live weight of 701.5 kg, carcass weight of 325 kg, and dressing percentage of 46.3%. On average, cull cows were sold at $57.0/cwt during the period considered. The canonical correlation between price ratio and carcass merit traits was 0.76, indicating that price ratio reflected carcass merit of cull cows. Later lactations led to lower BP compared with cows culled during the first 2 lactations. Injury, and leg and feet problems negatively affected BP. Productive variables demonstrated that the greater milk production might lead to lower cow prices. A large variation between farms was also noted. In conclusion, price ratio was a good indicator of carcass merit of cull cows, and life history events significantly affected sale BP and carcass merit of cull cows sold through auction markets.     

撒坝猪部分生长发育性状的典型相关分析

采用SAS统计分析系统对577头撒坝猪的3个体重性状和5个体尺性状进行了典型相关分析。结果表明,体重与体尺性状的第一、第二典型相关系数达到了显著水平(P<0.01),分别为0.9532和0.3044,占总相关的99.97%。体重性状与体尺性状间的相关主要是由于4月龄体重、6月龄体重与6月龄胸围、6月龄腿围的相关引起的。在达到显著水平的两对典型变量中,体重性状的两个典型变量对6月龄体长、胸围和腿围的预测能力较强,体尺性状的两个典型变量对4月龄体重和6月龄体重的预测能力较强,在实际育种中,选择体尺性状可同时达到提高体重性状之目的。     

多元回归方程估测北京鸭屠体性状的研究

试验测定了202只6周龄北京鸭公鸭的体重X1、体尺性状(体斜长X2、龙骨长X3、胸宽X4)和屠体性状(胸肉重Y1、腿肉重Y2、皮脂重Y3、腹脂重Y4、瘦肉重Y5和脂肪重Y6)共10项指标,在分析体重、体尺性状与屠体性状的相关关系的基础上,以体重、体尺性状为自变量,屠体性状为依变量,构建了估测北京鸭活体屠体性状的回归方程。结果表明:6周龄北京鸭胸肉重、腿肉重、皮脂重、瘦肉重、脂肪重分别与体重、体尺性状呈极显著正相关(P<0.01),腹脂重与体重呈极显著正相关(P<0.01),与体尺性状呈显著正相关(P<0.05);建立的6个最优多元回归方程,经F检验回归关系均达极显著水平(P<0.01),各回归系数也均达到极显著水平(P<0.01),表明各方程的自变量与依变量之间真实存在着多元回归关系,可为估测北京鸭活体胸肉重、腿肉重、皮脂重、腹脂重、瘦肉重和脂肪重提供理论依据,具有一定的参考使用价值。     

飞鸭体尺与屠宰性能测定及其相关性分析

试验测定了8周龄天农飞鸭的体尺与屠宰性能,分析了各指标间的相关性。结果表明,半潜水长、胫长和宰前体重在公母鸭之间存在极显著差异(P＜0.01),体斜长、龙骨长和胫围在公母鸭之间存在显著差异(P＜0.05);屠体重、半净膛重、全净膛重、腿肌重在公母鸭之间存在极显著差异(P＜0.01),瘦肉重在公母鸭之间存在显著差异(P＜0.05)。宰前体重与体尺各指标（胸宽除外）间存在着极显著相关(P＜0.01);试验所测的9个体尺指标均与宰前体重、屠体重、半净膛重、全净膛重之间存在显著(P＜0.05)或极显著(P＜0.01)正相关;宰前体重、屠体重、半净膛重、全净膛重、胸肌重、腿肌重和瘦肉重相互之间呈强相关(P＜0.01),但体重和屠体重却与以上其它重量性状的百分率指标间无明显相关(P＞0.05)。     

新疆褐牛主要屠宰性状与体尺的相关性分析

[目的]为了进一步了解新疆褐牛的生产性能,找到合理的新疆褐牛经济价值的估算方法.[方法]我们在塔城和昭苏选择了102头在放牧状态下饲养的新疆褐牛进行屠宰测定,对反映产肉性能的主要性状进行了统计分析,[结果]表明:体高、体长、胸围、管围与屠宰重、胴体重的相关极显著(P<0.01),并根据统计结果建立了体尺与胴体重的回归方...     

Application of ultrasound for feeding and finishing animals: a review.

The ability to evaluate carcass traits in live animals is of value to research, educational, and industry personnel. Ultrasonic technology has been tested since the early 1950s and continues to be under investigation as a means of accomplishing this task. The accuracy of ultrasound in predicting carcass traits is variable and is dependent on species, ultrasonic instrumentation, and(or) the skill of the technician. Based on this review, the ranges of correlation coefficients (r) for carcass traits as predicted by ultrasound to the respective carcass measurement are as follows: swine (fat .20 to .94; longissimus muscle .27 to .93), sheep (fat .42 to .95; longissimus muscle .36 to .79) and beef (fat .45 to .96; longissimus muscle .20 to .94; marbling .20 to .91). Although these correlation coefficients give an indication of the accuracy of ultrasound, it should be noted that these statistics do not reflect population variation or bias. Applications of ultrasound in swine finishing programs include the successful prediction of market weight carcass characteristics and the prediction of percentage of lean cuts before slaughter. In contrast, the application of ultrasound in lamb finishing programs has met with limited success. Most data indicate that weight and(or) visual estimations of fat are at least as accurate as ultrasound predictions of carcass composition. In beef finishing programs, ultrasound has, at times, been used successfully to predict fat and muscle traits before slaughter and beef carcass chemical composition. The ability to predict marbling, however, remains unclear and requires further investigation. Ultrasound has also been used in beef finishing programs to predict days on feed to a constant body compositional end point. When summarized, these data indicate that a single ultrasonic measurement of fat can be helpful in predicting days on feed in yearling cattle. When used alone, however, a single backfat measurement does not provide adequate accuracy. Therefore, factors such as age, sex, breed type, weight, and hip height are needed to help predict days on feed more accurately.     

鲁西黄牛GH基因3′末端序列多态性及其与生产性状的关联分析

本研究检测了鲁西黄牛GH基因3′末端序列的多态性,并分析了其与生产性状的相关性。结果发现,由于2639 bp处碱基C→G的突变造成HaeⅢ内切酶增加了一个酶切位点,该位点检测到AA、AB、BB 3种基因型。利用最小二乘拟合线性模型对GH基因多态位点不同基因型与生产性状指标进行显著性检验,结果发现,GH位点上AB基因型的体重、体高、体斜长、胸围和肉用指数显著高于AA、BB基因型(P0.05);BB基因型的个体体重、体高、体斜长、胸围和肉用指数略高于AA基因型,但差异不显著(P0.05)。因此,等位基因B可初步确定为影响牛体重、体高、体斜长、胸围和肉用指数的优势基因。     

Genome wide association study on beef production traits in Marchigiana cattle breed

A genomewide association study was carried out on a sample of Marchigiana breed cattle to detect markers significantly associated with carcass and meat traits. Four hundred and nine young bulls from 117 commercial herds were genotyped by Illumina 50K BeadChip assay. Eight growth and carcass traits (average daily gain, carcass weight, dressing percentage, body weight, skin weight, shank circumference, head weight and carcass conformation) and two meat quality traits (pH at slaughter and pH 24 h after slaughter) were measured. Data were analysed with a linear mixed model that included fixed effects of herd, slaughter date, fixed covariables of age at slaughter and SNP genotype, and random effects of herd and animal. A permutation test was performed to correct SNP genotype significance level for multiple testing. A total of 96 SNPs were significantly associated at genomewide level with one or more of the considered traits. Gene search was performed on genomic regions identified on the basis of significant SNP position and level of linkage disequilibrium. Interesting loci affecting lipid metabolism (SOAT1), bone (BMP4) and muscle (MYOF) biology were highlighted. These results may be useful to better understand the genetic architecture of growth and body composition in cattle.     

广义回归神经网络在凉山半细毛羊成年性状早期预测中的应用研究

通过凉山半细毛羊初生到断奶的5个生产性状:羔羊初生重、羔羊断奶重、初生至断奶日增重、断奶毛长度、断奶毛细度,预测成年(2.5年)的2个生产性状:成年体重、成年剪毛量。用Matlab7.1软件建立广义回归神经网络,并通过预测结果和实测结果的统计分析验证了所构建的广义回归神经网络的有效性。结果显示,该预测模型具有较高的准确性,可以快速高效地预测羔羊成年后的体重和剪毛量,为羔羊的选育和养殖场经济的预算提供依据。