中国美利奴与青海半细毛羊杂交F1代生产性能研究

在高寒牧区天然草地放牧条件下,测定中国美利奴与青海半细毛羊杂交一代羊从出生、4月龄和12月龄的生长发育指标。结果表明:在青海高原严酷的生态环境条件下,杂交一代羔羊生长发育快于青海半细毛羊,4月龄活重为28.84 kg,12月龄活重为35.07 kg,分别比青海半细毛羔羊提高5.19 kg和5.77 kg(P<0.01);体长、体高、胸围、胸深均极显著高于青海半细毛羔羊(P<0.01);杂种羊羊毛长度比半细毛高1.93cm,细度提高1.3支纺,剪毛量提高1.07 kg,羊毛品质得到大的改善。     

新疆细毛羊与澳州美利奴杂交的杂交优势

利用19只公羊和5群母羊来测定初生、断奶和周岁时的杂交优势水平。公羊的基因型包括:纯种新疆细毛羊(XX)、纯种澳州美利奴(AA)和它们的一代杂种(F_1):母羊的基因型只有两个,即(XX)和(F_1)。试验于1987—1989年在新疆维吾尔自治区南山种羊场进行,试验设计了一个不同基因型之间的随机交配,以便估计性状的遗传参数和杂交优势水平。 用计算机分析了552个后代的记录。初生重、断奶重、周岁体重、断奶毛长、周岁毛长和周岁剪毛量的杂交优势分别是4.0％、2％、11.55％、0.4％、6.05％和3.49％。生长发育性状的杂交优势水平明显地高于羊毛生长性状的杂交优势水平。     

萨福克羊与青海半细毛羊杂交试验

萨福克羊与青海半细毛羊杂交试验张廷华，雅文海，雷良煜（青海省畜牧兽医科学院西宁８１０００３）前言萨福克羊具有早熟、体大、肌肉发育良好的特点。本试验旨在利用这些特点，通过与青海半细毛母羊杂交，提高后代羔羊生长发育速度和产肉力。试验地区的自然概况青海省海...     

无角美利奴细毛羊选育研究

自1996年以来，以强毛型澳洲美利奴无角系公羊为父本，康拜克、邦德等品种母羊为母本进行杂交育种，培育无角美利奴细毛羊。几年来共培育出无角美利奴细毛羊16987只，存栏5250只，核心群羊达3250只，其中特一级羊占83．18％；成年公、母羊剪毛后体重分别为107.9kg和57.48kg，毛长分别为12.35cm和11．02cm，净毛量分别为10.91kg和5.2kg。选育的无角美利奴细毛羊具有体格大、毛长、产毛量高、产肉多、净化率高和羊毛品质好等特点，各项生产性能和体型外貌接近澳洲美利奴羊水平。应用无角美利奴细毛羊改良低产细毛羊，取得了明显效果。     

中国美利奴多胎细毛羊及杂交后代多胎性状基因型分析

首次在国内采用了多胎性状基因型诊断法对多胎性状进行选择。试验采集中国美利奴多胎细毛羊及其与Romilly·Hills杂交后代、横交一代样品数分别为 47份、3 8份、2 6份 ,提取DNA确定多胎主效基因FecB 位点 ,酶切检测纯合基因BB、杂合基因B 和非多胎基因 。通过检测 ,三种基因型占样品数百分比分别为 :多胎细毛羊为 2 5 5 3 %、48 94%、2 5 5 3 % ,基因型与产羔符合率为 85 3 7% ;杂交一代为 0、76 3 2 %、2 3 68% ,基因型与产羔符合率为 76 19% ;横交一代为3 0 77%、5 7 69%、11 5 4%。在多胎性状的选择中 ,要坚决剔除非多胎基因个体 ,以缩短选育时间。     

陶赛特羊与青海半细毛羊杂交试验

试验在高寒牧区天然草地放牧条件下 ,测定陶×半细杂交一代羊出生到 4月龄和 6月龄的生长发育指标 ,结果表明 :在青海高原严酷的生态环境条件下 ,杂交一代羔羊生长发育快于青海半细毛羊 ,4月龄活重为 2 2 .73kg ,6月龄活重为 2 7.96kg ,分别比青海半细毛羔羊提高 3 .0 2kg、3 .64kg(P <0 .0 1)。体长、体高、胸围、胸宽、管围和尻宽显著高于青海半细毛羔羊 (P <0 .0 1)     

南非肉用美利奴羊与甘肃高山细毛羊杂交效果分析

为研究南非肉用美利奴羊杂交改良甘肃高山细毛羊的效果,试验选用南非肉用美利奴种公羊与甘肃高山细毛羊母羊杂交F1代羔羊20只(南甘杂交试验组)与20只甘肃高山细毛羊(纯繁对照组),在相同舍饲条件下,测定分析两组F1代生长发育、屠宰指标及产毛性能。结果表明:南甘F1代羔羊初生重、2月龄体重、6月龄体重均显著高于甘肃高山细毛羊(P0.05);南甘F1代羔羊宰前活重、胴体重、屠宰率均显著高于甘肃高山细毛羊(P0.05),且杂交一代公羔最高;南甘F1公羔胴体脂肪含量(GR)值为1.53 cm,眼肌面积达11.95 cm2。研究表明,南非肉用美利奴羊杂交改良甘肃高山细毛羊效果较佳,具有良好的推广应用价值。     

南非肉用美利奴羊与东北细毛羊杂交效果分析

东北细毛羊是上个世纪60年代培育的毛肉兼用型细毛羊品种,是东北农牧交错地区饲养的主要绵羊品种,但存在着肉用性能不突出等缺陷。因此,利用南非肉用美利奴羊作为父本品种与其进行二元杂交,将其F1代(SN)与同龄纯种东北细毛羊进行了生长发育及产毛性能的比较,目的在于探索利用南非肉用美利奴羊与其杂交的可行性。结果表明,南东F1代羊的3月龄重、6月龄重和周岁体重、哺乳期日增重均极显著高于同龄的东北细毛羊(P0.01);南东F1代羊的被毛仍为同质细毛,虽然羊毛长度和产毛量低于东北细毛羊,羊毛纤维直径有所增加,但剪毛后体重显著高于东北细毛羊。南非肉用美利奴羊与东北细毛羊的杂交组合可以作为较佳的杂交组合在东北农牧交错区推广应用。     

中国美利奴多胎肉用细毛羊羊毛品质分析

对正在培育的中国美利奴多胎肉用细毛羊的羊毛品质做了综合分析.在毛丛自然长度方面，断奶公羔为4.37cm，母羔为4.43cm，周岁公羊为12.60cm，周岁母羊为11.47cm；羊毛的伸直长度周岁公羊为15.01cm.周岁母羊为14.86cm；羊毛纤维直径周岁公羊为21.67μm.周岁母羊为20.36μm；羊毛密度周岁公羊为5212根/cm^2.周岁母羊为5430根/cm^2.比2002年中国美利奴羊周岁羊相比还有较大差距；羊毛净毛率周岁公羊为64.60％.周岁母羊为65.64％。由上可知.除羊毛密度外.中国美利奴多胎肉用细毛羊总体上符合品种培育的要求.在今后的选育中要注意羊毛密度的提高。     

日粮钙水平对空怀云南半细毛羊能量代谢的影响

本文旨在通过饲养试验和消化代谢试验,以研究日粮钙水平与空怀云南半细毛羊能量代谢间可能存在的互作。试验选取50只日龄、体重和体况相近,经产两胎空怀期云南半细毛羊,随机分为5组,每组10只,分别饲喂5个钙含量分别为0.40%、0.44%、0.53%、0.65%和0.84%的日粮。进行44d饲养试验,包括14d预饲期和30d正式试验。饲养试验开始和结束各称一次体重,消化代谢试验进行5d,每天全收粪尿。结果表明:(1)0.84%Ca组、0.65%Ca组的粪能较0.44%Ca组降低18.90%、17.17%(P<0.05);代谢损失能都降低15.66%(P<0.05)。(2)0.40%Ca组、0.53%Ca组、0.84%Ca组的摄入总能较0.44%Ca组低5.11%、3.35%、4.66%(P<0.01),较0.65%Ca组高3.58%、5.50%、4.07%(P<0.01),0.44%Ca组较0.65%Ca组高9.16%(P<0.01)。(3)尿能、甲烷能、尿能占总能的比例、甲烷能占总能的比例、尿能占消化能的比例、总能消化率和总能代谢率各组间差异不显著(P>0.05)。由此可见,日粮钙水平越高,粪能和代谢损失越低,而日粮钙水平对空怀云南半细毛羊的能量代谢没有显著性影响(P>0.05)。     

凉山半细毛羊3号染色体遗传连锁框架图的构建

研究基于四川凉山半细毛羊资源参考家系,选取位于绵羊3号染色体的9个多态微卫星位点,共275个个体,构建了凉山半细毛羊3号染色体的遗传连锁框架图。结果表明:9个位点等位基因数目为3~9个,杂合度为0.404~0.766,多态信息含量为0.378~0.738。构建的3号两性平均遗传连锁框架图的总长为339.7cm,与USDA图谱位点顺序一致,图谱总长较USDA长。可在此基础上增加标记和群体样本数构建更精细的遗传连锁图,并对具有重要经济性状的基因座进行精细定位。     

Retardation of wool growth in Merino sheep caused by bacteria

A condition evidenced by retarded growth of wool with alteration of the yolk into a yellow, sticky, wax-like substance was investigated. The condition was associated with hyperaemia and cellular infiltration into the dermis in the affected areas. Three bacterial species, viz. Enterobacter aerogenes, E. agglomerans and Hafnia alvei, which could grow on the water-extractable component of wool-yolk, were incriminated as the cause of the condition.     

不同钙水平饲粮对云南半细毛羊妊娠期能量代谢的影响

试验旨在研究不同钙水平饲粮对云南半细毛羊妊娠期能量代谢的影响,为综合考虑云南半细毛羊妊娠期钙营养和能量需要提供理论依据。选取50只经产妊娠期云南半细毛羊按饲粮不同钙水平随机分为5组,每组10个重复,即妊娠前期(妊娠61～90 d)和中期(妊娠91～120 d)分为0.42%、0.45%、0.56%、0.65%和0.82%钙水平组,妊娠后期(妊娠121～150 d)分为0.40%、0.50%、0.60%、0.69%和0.87%钙水平组,日粮其它营养成分保持一致,进行104 d饲养试验。分别在妊娠71、101 d和131 d时从各组中随机挑选5只羊进行消化代谢试验。结果表明:①在妊娠前期,除0.42%钙水平组消化能代谢率极显著高于0.56%钙水平组外(P0.01),总能消化率、总能代谢率和消化能代谢率在不同钙水平饲粮下差异均不显著(P0.05)。②在妊娠中期,与0.45%和0.56%钙水平组相比,0.82%钙水平组总能消化率、总能代谢率和消化能代谢率显著增加(P0.05),但0.42%、0.65%和0.82%钙水平组间差异不显著(P0.05)。③在妊娠后期,0.40%钙水平组总能消化率和总能代谢率显著高于0.50%和0.87%钙水平组(P0.05),但0.40%、0.60%和0.69%钙水平组间差异不显著(P0.05)。④随着妊娠天数的增加,母羊DE、ME、总能消化率、总能代谢率及消化能代谢率呈不断上升的趋势。综上所述,饲粮钙水平显著影响云南半细毛羊妊娠期能量的消化代谢,当妊娠前期、中期、后期饲粮分别含0.42%、0.82%、0.40%钙水平时母羊能量利用率最佳。     

Genetic correlations among and between wool, growth and reproduction traits in Merino sheep

Summary Data from seven research resource flocks across Australia were combined to provide accurate estimates of genetic correlations among production traits in Merino sheep. The flocks represented contemporary Australian Merino fine, medium and broad wool strains over the past 30 years. Over 110 000 records were available for analysis for each of the major wool traits, and 50 000 records for reproduction and growth traits with over 2700 sires and 25 000 dams. Individual models developed from the single trait analyses were extended to the various combinations of two-trait models to obtain genetic correlations among six wool traits [clean fleece weight (CFW), greasy fleece weight, fibre diameter (FD), yield, coefficient of variation of fibre diameter and standard deviation of fibre diameter], four growth traits [birth weight, weaning weight, yearling weight (YWT), and hogget weight] and four reproduction traits [fertility, litter size, lambs born per ewe joined, lambs weaned per ewe joined (LW/EJ)]. This study has provided for the first time a comprehensive matrix of genetic correlations among these 14 wool, growth and reproduction traits. The large size of the data set has also provided estimates with very low standard errors. A moderate positive genetic correlation was observed between CFW and FD (0.29 ± 0.02). YWT was positively correlated with CFW (0.23 ± 0.04), FD (0.17 ± 0.04) and LWEJ (0.58 ± 0.06), while LW/EJ was negatively correlated with CFW (−0.26 ± 0.05) and positively correlated with FD (0.06 ± 0.04) and LS (0.68 ± 0.04). These genetic correlations, together with the estimates of heritability and other parameters provide the basis for more accurate prediction of outcomes in complex sheep-breeding programmes designed to improve several traits.     

青海高原毛肉兼用半细毛羊现状及发展

青海半细毛羊自育成以来，由于经营体制的转变、市场上肉毛比价不合理、农牧民群众文化素质和科技意识低、饲养管理粗放，加之社会服务网络不健全，造成青海半细毛羊数量大幅度减少，质量下降。随着青海半细毛羊巩固提高项目的实施，半细毛羊整体水平有所提高，为进一步提高质量，增加数量，进行探讨。     

Some physiological responses associated with reduced wool growth during blowfly strike in Merino sheep

OBJECTIVE: To examine the effect on wool growth of physiological changes associated with experimental flystrike in superfine Merino wethers. DESIGN: An animal house study comparing experimentally fly struck sheep with non-infected control groups that were pair fed or fed ad libitum. PROCEDURE: Sheep in the blow fly larval challenge group were each artificially infected with 500 first instar larvae per day for 8 days. Infections were terminated with insecticide on day 10. For all sheep, live weight change, feed intake and body temperature were monitored and blood collected for analysis of haematology, cortisol, serum haptoglobin, serum amyloid A and the pro-inflammatory cytokines, TNFa, IL-1 b, IL-6 and IL-8. Wool growth and staple strength were examined 4 months after infection. RESULTS: Experimental fly strike included moderate fever, depressed feed intake, and elevated cortisol, IL-6, serum amyloid A and haptoglobin. Staple strength was significantly decreased in struck sheep and did not differ between wool from sites adjacent to and remote from strike lesions. CONCLUSIONS: The results suggest that depression in feed intake alone is not sufficient to account for the decline in staple strength seen during fly strike. Cortisol, IL-6 and metabolic consequences of the acute phase response are likely to be major contributors to the systemic effects of blowfly strike on wool.