肉用绵羊繁殖性能及杂交组合研究

为筛选适宜当地规模化生产的肉羊品种及杂交组合,选用健康小尾寒羊繁殖母羊50只(分成2组,每组25只)、无角陶赛特羊×小尾寒羊F1繁殖母羊25只,分别与小尾寒羊、无角陶赛特羊、特克塞尔羊成年种公羊自然交配,测定母羊繁殖性能及羔羊生长性能。结果表明:无角陶赛特羊×小尾寒羊F1母羊的产羔率比小尾寒羊低,但羔羊成活率高于小尾寒羊;在同等饲养管理条件下,无角陶赛特羊×小尾寒羊F1羔羊的生产性能显著高于纯繁小尾寒羊(P0.05),特×陶×寒杂交组合羔羊的生长性能极显著高于小尾寒羊(P0.01),陶×寒组合F1也有良好的杂交效果,但其羔羊的生长性能均低于特×陶×寒组合。     

无角陶赛特改良蒙古羊的效果分析

采用随机抽样的方法,对甘肃省永昌县引进的肉羊品种无角陶赛特杂交改良蒙古羊的杂种F1 (DMF1)、F2(DMF2)和F3(DMF3)在不同年龄阶段通过测定体重体尺指标,以当地蒙古羊(M)为对照进杂交效果的分析.结果表明杂种后代的主要生产性能均优于蒙古羊,无角陶赛特杂交改良蒙古羊杂交效果显著,在条件允许的情况下可以对当地蒙古羊进行大规模杂交,尤其是高代杂交经济效应更为显著.     

无角陶赛特改良蒙古羊的效果分析

采用随机抽样的方法,对甘肃省永昌县引进的肉羊品种无角陶赛特杂交改良蒙古羊的杂种F1（DMF1）、F2（DMF2）F3（DMF3）在不同年龄阶段通过测定体重体尺指标,以当地蒙古羊（M）为对照进杂交效果的分析。结果表明杂种后代的主要生产性能均优于蒙古羊,无角陶赛特杂交改良蒙古羊杂交效果显著,在条件允许的情况下可以对当地蒙古羊进行大规模杂交,尤其是高代杂交经济效应更为显著。     

无角陶赛特和波德代改良蒙古羊生长发育性状效果分析

为了对引进的肉羊品种无角陶赛特羊及波德代羊与蒙古羊杂种F1、F2、F3在不同月龄进行体重体尺指标的测定,以综合评价引进的肉羊品种无角陶赛特羊和波德代羊对当地蒙古羊的杂交改良效果,试验以引进的无角陶赛特羊及波德代羊与蒙古羊不同杂交组合的后代(F1、F2及F3)为研究对象,采用随机抽样的方法对已培育出的西北肉用绵羊新品种群部分杂交组合生长发育性状在不同月龄通过测定体重、体尺指标进行研究,探讨最佳杂交组合模式.结果表明:杂种F3生长发育速度快于对应杂种F2,杂种F2生长发育速度优于对应杂种F1;陶波蒙杂交组合改良蒙古羊效果较好于陶蒙杂交组合,尤其是高代或三元杂交经济效果更为显著.     

旱农寿阳类型区引进肉羊品种开展杂交的示范

引入夏洛莱、无角陶赛特和边区莱斯特三个肉羊品种与当地细毛杂种羊开展杂交示范。结果表明 :杂交一代 4月龄断奶羔羊平均活重分别达到 2 2 11、2 2 2 0和 2 1 77kg ,差异不显著 (P >0 0 5 )。受胎母羊断奶羔羊重依次为 18 17、2 0 79和2 0 5 1kg ,前者较后者分别降低 14 3 %和 12 6%     

萨福克羊、陶赛特羊和特克塞尔羊在山西晋中地区的生长发育测定分析

1 材料与方法 1.1 试验目的 在山西省畜牧所种羊场选择成年母羊萨福克羊、无角陶赛特羊、特克塞尔羊共146只,通过对母羊的妊娠率、产羔率、羔羊成活率以及羔羊1～4月龄生长发育数据的分析,来比较3个品种优种羊的生产性能,从而提高优种羊在肉羊生产中的利用率.     

羔羊先天性锁肛和直肠闭锁的手术疗法

2006年大通县畜牧兽医站在良种肉羊繁育推广项目中,引进无角陶赛特等优良肉羊品种,与当地土种藏系母羊杂交.2007年2月,当地产羔高峰期,笔者遇到一例先天性锁肛和直肠锁闭无角陶赛特与藏系羊杂交的F1代羔羊,经手术治疗后痊愈.现将病例介绍如下:     

不同良种肉羊与小尾寒羊杂交效果对比试验

将100只健康无病的成年小尾寒羊繁殖母羊分成4组,每组25只,分别与无角陶赛特羊、萨门羊、波德代羊和小尾寒羊成年种公羊杂交,测定母羊繁殖性能、杂交一代羔羊的生长性能和屠宰性能,以期筛选出适宜当地肉羊规模化生产的肉羊品种及杂交组合。结果表明：萨×寒、陶×寒、波×寒杂交组合母羊的产羔率虽比小尾寒羊纯繁母羊低,但杂交组合的羔羊成活率均高于小尾寒羊;在同等饲养管理条件下,陶×寒F1、萨×寒F1和波×寒F1羔羊的生产性能、屠宰性能均显著高于纯繁小尾寒羊（P〈0.05）,其中陶×寒F1、萨×寒F1杂交效果差异极显著（P〈0.01）,波×寒F1也有良好的杂交效果,但其生长性能和屠宰性能均低于陶×寒F1、萨×寒F1。     

无角陶赛特羊与湖羊杂交效果的研究

本试验研究了无角陶赛特肉羊与湖羊的杂交效果。陶湖F1代羔羊初生体重高于湖羔羊,差异极显著(P<0.01),6月龄陶湖F1代平均体高于湖羔羊,差异极显著(P<0.02)。陶湖F1代体长、身高分别比同龄湖羔羊高3.4%、1.2%,差异显著(P<0.04),胸围提高16.4%,差异极显著(P<0.01),其外观更趋向于父本,表现为生长发育快、体大、胸阔、背圆的肉用羊特征。陶湖F1代屠宰率、净肉率比湖羊高21.27%、14.51%,差异显著(P<0.01)。无角陶赛特羊与湖羊杂交优势明显。     

不同肉羊品种与小尾寒羊杂交一、二代羊毛品质分析

试验通过对纯种无角陶赛特羊与萨福克羊及其杂交一、二代进行羊毛细度、长度和净毛率的测定。结果表明:无角陶赛特羊、陶寒一代、陶寒二代羊的羊毛平均细度分别为26·25、21·82、23·17μm,平均伸直长度分别为13·30、11·89、12·13cm,净毛率分别为73·98%、81·96%、83·56%;萨福克羊、萨寒一代、萨寒二代羊羊毛平均细度分别为27·60、23·30、23·72μm,平均伸直长度分别为11·50、10·15、10·86cm,净毛率分别为69·73%、84·68%、87·98%。纯种无角陶赛特羊的羊毛品质优于萨福克羊,杂种二代羊的羊毛品质更接近纯种羊的羊毛品质,同时也得出陶寒杂种后代的羊毛细度、长度优于萨寒杂种后代,而净毛率萨寒杂种后代高于陶寒杂种后代。     

肃南牦牛屠宰性能和肉品质研究

为研究肃南牦牛的屠宰性能及肉品质,揭示其遗传特性,选取12头(公母各半)4岁放牧肃南牦牛进行屠宰试验和肉品质分析,并与文献中已报道的甘南牦牛、天祝白牦牛、雪多牦牛、环湖牦牛等进行了对比分析.结果显示,肃南牦牛的活重和胴体重均高于环湖牦牛和天祝白牦牛,屠宰率高于查乌拉牦牛和环湖牦牛,净肉率高于甘南牦牛和环湖牦牛,熟肉率高...     

影响猪肉质性状遗传因素的研究进展

非遗传因素和遗传因素对猪肉质性状均有影响。前者包括饲养条件、转运、屠宰等众多因素。后者即遗传因素是影响猪肉品质的一个重要因素,主要包括控制肌内脂肪(intramuscular fat,IMF)沉积的主效基因MI基因,候选基因心脏脂肪酸结合蛋白(heart fatty acid binding protein,H FABP)基因和脂肪细胞型脂肪酸结合蛋白(A FABP)基因;MyoD基因家族是影响猪肉质性状的又一个遗传因素;此外还有氟烷基因、RN基因(rendement napole,RN)等。作者就影响猪肉品质的遗传因素作一综述。     

Genetic parameters for carcass and meat quality traits and their relationships to liveweight and wool production in hogget Merino rams.

Genetic parameters for carcass and meat quality traits of about 18-month-old Merino rams (n = 5870), the progeny of 543 sires from three research resource flocks, were estimated. The estimates of heritability for hot carcass weight (HCW) and the various fat and muscle dimension measurements were moderate and ranged from 0.20 to 0.37. The brightness of meat (colour L*, 0.18 +/- 0.03 standard error) and meat pH (0.22 +/- 0.03) also had moderate estimates of heritability, although meat relative redness (colour a*, 0.10 +/- 0.03) and relative yellowness (colour b*, 0.10 +/- 0.03) were lower. Heritability estimates for live weights were moderate and ranged from 0.29 to 0.41 with significant permanent maternal environmental effects (0.13 to 0.10). The heritability estimates for the hogget wool traits were moderate to high and ranged from 0.27 to 0.60. The ultrasound measurements of fat depth (FATUS) and eye muscle depth (EMDUS) on live animals were highly genetically correlated with the corresponding carcass measurements (0.69 +/- 0.09 FATC and 0.77 +/- 0.07 EMD). Carcass tissue depth (FATGR) had moderate to low genetic correlations with carcass muscle measurements [0.18 +/- 0.10 EMD and 0.05 +/- 0.10 eye muscle area (EMA)], while those with FATC were negative. The genetic correlation between EMD and eye muscle width (EMW) was 0.41 +/- 0.08, while EMA was highly correlated with EMD (0.89 +/- 0.0) and EMW (0.78 +/- 0.04). The genetic correlations for muscle colour with muscle measurements were moderately negative, while those with fat measurements were close to zero. Meat pH was positively correlated with muscle measurements (0.14 to 0.17) and negatively correlated with fat measurements (-0.06 to -0.18). EMDUS also showed a similar pattern of correlations to EMD with meat quality indicator traits, although FATUS had positive correlations with these traits which were generally smaller than their standard error. The genetic correlations among the meat colour traits were high and positive while those with meat pH were high and negative, which were all in the favourable direction. Generally, phenotypic correlations were similar or slightly lower than the corresponding genetic correlations. There were generally small to moderate negative genetic correlations between clean fleece weight (CFW) and carcass fat traits while those with muscle traits were close to zero. As the Merino is already a relatively lean breed, this implies that particular attention should be given to this relationship in Merino breeding programmes to prevent the reduction of fat reserves as a correlated response to selection for increased fleece weight. The ultrasound scan traits generally showed a similar pattern to the corresponding carcass fat and muscle traits. There was a small unfavourable genetic correlation between CFW and meat pH (0.19 +/- 0.07).     

4个肉用绵羊品种微卫星标记的多态性与系统发育分析

利用10个微卫星座位对4个肉用绵羊品种进行遗传检测,计算出了各品种的平均杂合度、平均多态信息含量及品种间的遗传距离,并进行了系统发育分析。结果表明:10个微卫星座位上共检测到了107个等位基因,等位基因数在5~13个之间。各基因座位多态信息含量为0.498 5~0.890 4,均表现出了高度多态性。各基因座位杂合度较高,为0.563 0~0.899 5,说明肉用绵羊品种有着较丰富的遗传多样性。4个肉用绵羊品种间的遗传距离相对较远,萨福克羊和陶赛特羊先聚在一起,他们之间的遗传距离最近,为0.345 25,然后与夏洛来羊聚在一起,最后与中国美利奴羊聚在一起,中国美利奴羊与夏洛来羊之间的遗传距离最远,为0.516 39。研究结果对我国肉用绵羊资源的评估、保存和预测杂种优势具有一定的指导意义。     

云南肉山羊黑色品系内不同家系遗传多样性分析

应用QIAxcel全自动遗传分析仪进行毛细管电泳,对云南肉山羊黑色品系5只公羊134只后代的基因组DNA进行了11个微卫星位点多态性分析,以期为这一品系的选育提高和合理选配提供科学依据。结果表明,在11个微卫星位点共检测到101个等位基因,片段大小在115～249 bp之间,全群平均期望杂合度和平均多态信息含量均在0.5以上,表明云南肉山羊黑色品系遗传多样性丰富。对5只公羊UPGMA聚类分析表明:5只公羊间遗传一致度较高,说明云南肉山羊黑色品系具备了相对统一的遗传基础;系统聚类图直观地显示出公羊N7379和N7373存在较近的亲缘关系,被聚为一支,而公羊N5043、N7303、N5049间也存在较近的亲缘关系,被聚为另一支,分属于不同分支的公羊间亲缘关系相对较远。     

Genetic correlations between ewe reproduction and carcass and meat quality traits in Merino sheep

Genetic correlations between reproduction traits in ewes and carcass and meat quality traits in Merino rams were obtained using restricted maximum likelihood procedures. The carcass data were from 5870 Merino rams slaughtered at approximately 18 months of age that were the progeny of 543 sires from three research resource flocks over 7 years. The carcass traits included ultrasound scan fat and eye muscle depth (EMDUS) measured on live animals, dressing percentage and carcass tissue depth (at the GR site FATGR and C site FATC), eye muscle depth, width and area and the meat quality indicator traits of muscle final pH and colour (L*, a*, b*). The reproduction data consisted of 13 464 ewe joining records for number of lambs born and weaned and 9015 records for LS. The genetic correlations between reproduction and fat measurements were negative (range ?0.06 ± 0.12 to ?0.37 ± 0.12), with smaller correlations for live measurement than carcass traits. There were small favourable genetic correlations between reproduction traits and muscle depth in live rams (EMDUS, 0.10 ± 0.12 to 0.20 ± 0.12), although those with carcass muscle traits were close to zero. The reproduction traits were independent of meat colour L* (relative brightness), but tended to be favourably correlated with meat colour a* (relative redness, 0.12 ± 0.17 to 0.19 ± 0.16). There was a tendency for meat final pH to have small negative favourable genetic correlations with reproduction traits (0.05 ± 0.11 to ?0.17 ± 0.12). This study indicates that there is no antagonism between reproduction traits and carcass and meat quality indicator traits, with scope for joint improvement of reproduction, carcass and meat quality traits in Merino sheep.     

An evaluation of four candidate genes for use in selection programmes aimed at increased intramuscular fat in Duroc swine

Summary A sufficient level of intramuscular fat (IMF) is needed to enhance consumer acceptance of pork products, and is currently receiving greater attention within swine genetic improvement programmes. An examination of previously described and novel genetic variants within candidate genes for IMF deposition was performed to evaluate potential use of genetic markers in marker-assisted selection (MAS). Biological candidate genes implicated to play a role in adipogenesis were investigated within two different lines of purebred Duroc pigs. These included MC4R , FABP3 , DLK1 , and TCF7L2 . Significant variation in IMF within the control line was described by the MC4R genotype and a novel Bsr fI single nucleotide polymorphism within the FABP3 gene. Genetic markers for DLK1 and TCF7L2 evaluated in this population are not currently recommended for selection in Duroc swine. Existence of MC4R and FABP3 mutations may be useful markers in MAS aimed at IMF improvement, provided that gene effects are segregating and the presence of an association is detected within the population. However, additional work to confirm the use of the investigated genetic markers in selection programmes is needed.     

Comparison between haplotype-based and individual snp-based genomic predictions for beef fatty acid profile in Nelore cattle

The aim of this study was to evaluate the genomic predictions using the single-step genomic best linear unbiased predictor (ssGBLUP) method based on SNPs and haplotype markers associated with beef fatty acids (FAs) profile in Nelore cattle. The data set contained records from 963 Nelore bulls finished in feedlot (±90 days) and slaughtered with approximately 24 months of age. Meat samples from the Longissimus dorsi muscle were taken for FAs profile measurement. FAs were quantified by gas chromatography using a SP-2560 capillary column. Animals were genotyped with the high-density SNP panel (BovineHD BeadChip assay) containing 777,962 markers. SNPs with a minor allele frequency and a call rate lower than 0.05 and 0.90, respectively, monomorphic, located on sex chromosomes, and with unknown position were removed from the data set. After genomic quality control, a total of 469,981 SNPs and 892 samples were available for subsequent analyses. Missing genotypes were imputed and phased using the FImpute software. Haplotype blocks were defined based on linkage disequilibrium using the Haploview software. The model to estimate variance components and genetic parameters and to predict the genomic values included the random genetic additive effects, fixed effects of the contemporary group and the age at slaughter as a linear covariate. Accuracies using the haplotype-based approach ranged from 0.07 to 0.31, and those SNP-based ranged from 0.06 to 0.33. Regression coefficients ranged from 0.07 to 0.74 and from 0.08 to 1.45 using the haplotype- and SNP-based approaches, respectively. Despite the low to moderate accuracies for the genomic values, it is possible to obtain genetic progress trough selection using genomic information based either on SNPs or haplotype markers. The SNP-based approach allows less biased genomic evaluations, and it is more feasible when taking into account the computational and operational cost underlying the haplotypes inference.     

畜禽肉中代谢物质对肉品质的影响及相关基因研究进展

肉质风味是味觉和嗅觉感知的感官印象,其根本是由肉中的代谢物质的含量及复杂的化学过程所决定。随着代谢物质测定技术的不断进步,肉中代谢物质的含量对肉品质的影响也越来越受到关注,肉中代谢物质含量也逐渐成为研究及育种工作的热点,进而挖掘出了很多调控代谢物质的候选基因。本文综述了畜禽肉中代谢物质的种类、形成风味的代谢物质化学反应、代谢物质对肉品质的影响以及代谢物质遗传调控。旨在阐明肉中代谢物质对肉质风味形成的调控机制,为畜禽肉质风味的改良提供理论基础和研究思路。