PCR Amplification and Bioinformatics Analysis of IL-7 Gene in Tibetan Sheep

In order to get the interleukin-7 (IL-7) gene sequence of Tibetan sheep, and research the characteristics of this sequence and structure and function of encoding protein, IL-7 gene was amplified from Tibetan sheep by RT-PCR. The nucleotide sequence,amino acid sequence, homology and phylogenetic tree were analyzed by the DNAStar software. The secondary and tertiary structures, hydrophilicity, signal peptide and post-translational modification site of the encoding protein were predicted by DNAStar software and online servers. The results showed that the length of IL-7 gene was 531 bp (contained termination codon), and encoded 176 amino acids. Compared with IL-7 gene of Ovis aries, Capra hircus, Pantholops hodgsonii, Bubalus bubalis, Bos indicus, Bison bison bison, Bos taurus and Bos mutus, IL-7 gene of Tibetan sheep showed a great similarity from 97.2% to 99.8%, the amino acid sequence homology varied from 94.9% to 99.4%, and the relationship was the closest between Tibetan sheep and Ovis aries. Result from protein structure prediction indicated that the IL-7 protein was mainly composed of α-helix, it was a hydrophilic and secretory protein. Furthermore, it had six kinds of post translational modification sites, including one N-myristoylation site, one amidation site, one cAMP-and cGMP-dependent protein kinase phosphorylation site, three N-glycosylation sites, four protein kinase C phosphorylation sites and six casein kinase Ⅱ phosphorylation sites. These results might provide references for further study and clinical application of IL-7 gene in Tibetan sheep.     

绵羊Hoxc8与d11基因甲基化的量子力学特征与功能

文章研究了蒙古羊和德国美利奴肉羊、陶赛特肉羊、澳洲美利奴细毛羊的Hoxc8和Hoxd11基因及其第1位外显子的甲基化位置、数量、稳定程度,以及甲基化的量子力学性质。与蒙古羊相比,内含子序列有数个碱基的差异,外显子一致。外显子序列的甲基化在转录和翻译过程中的功能,与甲基化导致的分子轨道和量子力学变化有关。甲基化胞嘧啶在密码与反密码中的第2位,决定甲基化是否对转录和翻译产生效应。蒙古羊14枚胸椎个体的父本Hoxc8 exon-1和Hoxd11 exon-1序列甲基化程度高,母本的甲基化程度低;13枚胸椎个体的父本和母本相应序列的甲基化程度都低。     

品系育种中细毛(半细毛)羊选择指数的研制和应用探讨

品系育种是迄今畜禽纯种选育与杂交利用系统中最为安全高效的途径,综合选择指数则是多性状选择改良的理想方法。该研究试将综合选择指数与绵羊品系育种相结合,提供了一种制作绵羊品系选择指数的方法示例,以便高效可控并有预见性地推进绵羊品系育种进程。     

利用微卫星标记对六个羊群体性的研究

采用中心产区典型群随机抽样方法采集了67只洼地绵羊样品,并用PCR-PAGE电泳技术检测了其7个微卫星位点(oarFCB11,oarFCB128,oarFCB48,oarFCB304,MAF33,MAF70和oarAE101)的遗传多态性,同时引用了小尾寒羊、滩羊、湖羊、同羊及长江三角洲白山羊(参照群体)相同资料进行群体遗传关系分析。研究结果表明:7个微卫星标记在洼地绵羊、小尾寒羊、滩羊、湖羊、同羊及长江三角洲白山羊6个品种中均存在多态性,可以用于绵羊群体遗传多样性的评估;7个微卫星标记在6个群体中的多态信息含量、平均有效等位基因数和平均杂合度分别为0.9182、13.9839、0.9511、0.9250、14.5013、0.9579、0.9157、12.9416、0.9446、0.9249、15.1723、0.9639、0.8835、10.0377、0.9333、0.8880、12.5156、0.9550、0.9078、12.1543、0.9389,其中oarFCB304遗传变异最大,oarAE101最小;6个绵(山)羊群体中小尾寒羊和洼地羊的遗传变异较大,对照群体(山羊)最小。通过计算DA距离和DS标准遗传距离,采用非加权配对算术平均法(UPGMA)绘制聚类图,得出洼地羊先和小尾寒羊聚为一类,然后和滩羊合并为一类;同时湖羊和同羊聚为一类;绵羊五个品种为一类后与山羊合并为一类。     

Evaluation of tall fescue (Festuca arundinacea) as a forage for sheep in the temperate high‐rainfall zone of south‐eastern Australia

Tall fescue (Festuca arundinacea Schreb.) is currently seldom used in the high‐rainfall (>600 mm) zone of south‐eastern Australia. To determine its potential to improve forage availability during the summer‐autumn feed‐deficit period, a field plot‐scale experiment with sheep evaluated a Continental cultivar of tall fescue (cv. Quantum) at Hamilton, Victoria, between September 2006 and January 2009. Four grazing treatments represented set stocking or rotational grazing at the two‐, three‐ or four‐leaf stage, in a completely randomized design with three replications. Grazing treatment effects on tall fescue tiller population dynamics, forage accumulation rates and consumption, sward nutritive value and botanical composition were measured. Results showed tall fescue can persist and support year‐round grazing by sheep, subject to water availability for summer growth from summer rain or on moisture retentive heavy soils. During the summer‐autumn (December–April) vegetative phase, grazing at the three‐leaf stage optimized forage consumption, with no difference in feed value or botanical composition between the grazing treatments during these months. During the reproductive phase (September–November), feed value was highest under set stocking and declined with the production of each successive leaf. Grazing at the three‐ or four‐leaf stage prevented winter weed invasion, but winter forage consumption was low in these treatments. Set stocking or grazing at the two‐leaf stage improved winter forage consumption rates, but these swards were invaded by winter growing weeds.     

日粮中不同水平棉秆对育肥期绵羊瘤胃发酵参数和屠宰性能的影响

【目的】研究不同棉秆水平的日粮对育肥期绵羊瘤胃发酵参数和屠宰性能的影响。【方法】选取60只6月龄、体重为(43.08±5.93) kg的小尾寒羊,驱虫后依据体重进行单因素完全随机试验设计,随机分为6组,每组10只。以等能等氮原则配制试验日粮,其中CK1组不添加棉秆和棉籽粕,CK2组添加棉籽粕,20％组、30％组、40％组和50％组分别添加20%~50%的棉秆,试验期70 d。【结果】(1)瘤胃pH值CK1组比CK2组高6.25%,差异极显著(P<0.01);30%组和40%棉秆添加组分别比CK2组高5.48%和4.85%,差异显著(P<0.05)。(2)瘤胃NH₃-N浓度40%棉秆添加组分别比CK1组和CK2组低40.44%(P<0.01)和39.40%(P<0.05);30%组比CK1组低26.89%,差异显著(P<0.05)。(3)瘤胃乙酸、丙酸、丁酸和总挥发性脂肪酸的浓度各处理组间差异均不显著(P>0.05);乙酸/丙酸比例CK2组分别比20%组、30%组和40%棉秆添加组低34.58%、31.69%和35.69%,差异均极显著(P<0.01);异丁酸浓度CK1组分别比20%组、40%组和50%棉秆添加组高195.31%、243.64%和220.34%,差异均极显著(P<0.01),CK1组分别比CK2组和30%组高166.19%和182.09%,差异显著(P<0.05);异戊酸浓度CK1组分别比CK2组、20%组、40%组和50%棉秆添加组高116.45%、101.18%、151.47%和119.23%,差异均极显著(P<0.01),CK1组比30%组高71.00%,差异显著(P<0.05);戊酸浓度CK1组比40%棉秆添加组高178.05%,差异显著(P<0.05)。(4)日粮添加不同棉秆水平对绵羊活体重、胴体重、屠宰率、心脏和睾丸重均无显著影响(P>0.05);肝脏重20%组比40%棉秆添加组高28.37%,差异显著(P<0.05);脾脏重20%组均比CK2组、30%组、40%组和50%棉秆添加组高50.00%,差异显著(P<0.05);肺重40%棉秆添加组显著低于其它处理组(P<0.05);肾脏重CK2组比20%棉秆添加组低42.85%,差异极显著(P<0.01),CK2组分别比40%和50%棉秆添加组低22.22%和25.00%,差异均显著(P<0.05)。【结论】在育肥期绵羊日粮中添加棉花秸秆,以20%的添加量为宜。     

Direct and maternal (co)variance components and heritability estimates for body weights in Chokla sheep

Estimates of (co)variance components were obtained for weights at birth, weaning and 6, 9 and 12 months of age in Chokla sheep maintained at the Central Sheep and Wool Research Institute, Avikanagar, Rajasthan, India, over a period of 21 years (1980–2000). Records of 2030 lambs descended from 150 rams and 616 ewes were used in the study. Analyses were carried out by restricted maximum likelihood (REML) fitting an animal model and ignoring or including maternal genetic or permanent environmental effects. Six different animal models were fitted for all traits. The best model was chosen after testing the improvement of the log-likelihood values. Direct heritability estimates were inflated substantially for all traits when maternal effects were ignored. Heritability estimates for weight at birth, weaning and 6, 9 and 12 months of age were 0.20, 0.18, 0.16, 0.22 and 0.23, respectively in the best models. Additive maternal and maternal permanent environmental effects were both significant at birth, accounting for 9% and 12% of phenotypic variance, respectively, but the source of maternal effects (additive versus permanent environmental) at later ages could not be clearly identified. The estimated repeatabilities across years of ewe effects on lamb body weights were 0.26, 0.14, 0.12, 0.13, and 0.15 at birth, weaning, 6, 9 and 12 months of age, respectively. These results indicate that modest rates of genetic progress are possible for all weights.     

中国农牧户绒毛用羊养殖效益及其影响因素实证研究

根据内蒙古、新疆、吉林、辽宁、山西和云南等6个绒毛用羊主产省（自治区）12个县（旗）绒毛用羊养殖户调研数据对中国绒毛用羊养殖效益及其影响因素进行研究,结果表明,2012年绒毛用羊养殖户每只细毛羊、半细毛羊和绒山羊平均养殖纯收益分别为192．95元、333．33元和222．17元;绒毛产量和产品畜产出水平对绒毛用羊养殖效益有显著的正向影响,饲草料成本和疾病灾情损失对绒毛用羊养殖效益有显著的负向影响,细毛羊养殖户单纯扩大养殖规模不利于养殖效益的提高,而半细毛羊和绒山羊养殖户扩大养殖规模能够提高养殖效益,绒毛价格、养殖户文化程度、政策支持以及接受技术培训情况对绒毛用羊养殖效益的影响皆不显著。最后,从提高产出水平、降低养殖成本、加强疾病灾情防御、加强科技和政策扶持力度等方面提出提升中国绒毛用羊养殖效益的对策建议。     

肃南牧区细毛羊四季营养调控试验

针对肃南牧区绵羊冬春季节因营养匮乏导致大量死亡的实际,试图结合当地四季牧场牧草供应状况和气候特点以及细毛羊生产发育规律,科学应用四季放牧调控技术和营养调控手段来改善羊只生长水平,彻底摆脱冬乏、春死的恶性循环,并具有高产、优质的生产性能,为同类地区细毛羊产业可持续发展积累成功经验。