B超活体测定对种猪瘦肉性状的遗传改良

猪背膘厚和眼肌面积与其瘦肉率直接相关,是种猪遗传育种和性能测定中的两项重要指标,也是全国种猪遗传评估规定的两个重要测定性状。要获得某些性状较高的遗传进展因素,就要对这些性状进行准确度量。传统测定方法是以屠宰测定同胞或后裔来估测种猪,屠宰损失大,测定耗时,存在误差。随着超声波技术的发展,猪背膘厚和眼肌面积的活体测定成为可能,许多国家都开始将超声波的活体测量结果作为判断依据,运用于猪胴体性状和某些肉质性状的遗传改良。     

沙乌头猪二元杂种猪活体背膘厚与眼肌面积的研究

为比较沙乌头猪二元杂种猪不同体重阶段背膘厚和眼肌面积,试验通过B超测定两种二元猪80~100 kg活体背膘厚和眼肌面积。结果表明,沙乌头猪二元杂种猪背膘厚和眼肌面积随体重增加而增加。鲁莱黑猪×沙乌头猪(LS)组背膘厚在80~90 kg极显著增加(P<0.01),眼肌面积在80~90 kg缓慢增加(P>0.05)。杜洛克猪×沙乌头猪(DS)组背膘厚在80~100 kg显著增加(P<0.05),眼肌面积在80~90 kg缓慢增加(P>0.05),90 kg后显著增加(P<0.05)。沙乌头猪二元杂种猪背膘厚和眼肌面积因杂交组合方式(地方猪血统比例)不同而异。DS组80~90 kg背膘厚均极显著低于LS组(P<0.01),而其80~90 kg眼肌面积均极显著高于LS组(P<0.01)。相关性分析结果显示,沙乌头猪二元杂种猪活体背膘厚、眼肌面积与体重均呈正相关。综上,在考虑活体背膘厚和眼肌面积方面,DS组优于LS组。研究为沙乌头猪的开发利用提供相关理论及数据支持。     

利用超声波图像活体预测北京黑猪肌内脂肪含量

本研究旨在利用超声波图像来活体预测北京黑猪背最长肌肌内脂肪含量。试验选用382头北京黑猪开展活体测定,性状包括体质量、10～11肋间眼肌面积、背膘厚和眼肌深度,并且采集猪左侧9～13肋之间距离背中线5cm处纵向超声波图像2张,在每张图像10～11肋间选定1个大小为80×80像素的区域作为研究对象,利用图像分析软件(matlab)分别获取了灰度梯度、灰度共生矩阵、小波变换3类图像参数。屠宰后立刻取胴体左侧10～11肋间背最长肌肉样,利用石油醚抽提法测定肌内脂肪含量(IMF)。以实际测定肌内脂肪含量(IMF)为因变量,体质量、背膘厚、眼肌面积、眼肌深度和图像参数为自变量,通过逐步回归分析法建立预测肌内脂肪含量(PIMF)的模型。重新选择112头北京黑猪利用实测肌内脂肪含量与预测肌内脂肪含量的相关分析进行模型验证。回归分析结果表明,有9个自变量达到显著水平(P<0.05),包括背膘厚、眼肌面积和7个图像参数。预测模型的决定次数(R-Square)和均方误差根(Root MSE)分别为0.305 8和0.006 5。相关性分析结果得到皮尔逊积矩相关系数(Pearson Correlation Coefficients)和斯皮尔曼相关系数(Spearman Correlation Coefficients)分别为0.553 4和0.627 2(P<0.000 1)。结果表明,利用超声波图像活体预测猪肌内脂肪含量是一种可行的方法,可为北京黑猪的育种工作提供一个技术基础。     

种公牛超声波活体测定分析与研究

对河南省鼎元种牛育种有限公司的西门塔尔、夏洛来、利木赞和安格斯4个品种不同年龄阶段种公牛超声波活体测定的背膘厚和眼肌面积进行方差分析和相关性检测。结果表明:(1)4个品种随着年龄的增加背膘厚和眼肌面积均值均呈现递增趋势。品种间除安格斯牛和西门塔尔牛24月龄背膘厚、夏洛来牛和利木赞牛18月龄及24月龄眼肌面积三组数据差异显著外(P0.05),品种间不同年龄种公牛背膘厚和眼肌面积差异均不显著(P0.05)。(2)年龄对各品种种公牛背膘厚和眼肌面积的影响差异各异。西门塔尔牛和夏洛来牛品种内各年龄阶段间背膘厚均差异不显著(P0.05)。利木赞牛和安格斯牛品种内除12月龄与18月龄背膘厚均差异不显著(P0.05)外,品种内其它年龄阶段组合均达到极显著(P0.01)或者显著(P0.05)水平。利木赞牛和安格斯牛品种内各年龄阶段间眼肌面积均差异不显著(P0.05)。西门塔尔牛和夏洛来牛眼肌面积除夏洛来牛的眼肌面积在18月龄和24月龄间差异不显著(P0.05)外,品种内其它各年龄阶段间眼肌面积差异均达到显著(P0.05)或者极显著(P0.01)水平。(3)年龄与种公牛背膘厚和眼肌面积极显著相关(P0.01),背膘厚与眼肌面积不显著相关(P0.05)。     

B超活体检测技术的应用初探

眼肌面积和背膘厚度是种羊在选种、选育中的重要指标,也是判定肉品质的重要参数。使用B超仪对我国优良地方品种——哈萨克羊进行眼肌面积和背膘的活体测定,并与屠宰后测定数据进行对比分析。     

猪眼肌面积和背膘厚的B超测定技术

猪眼肌面积和背膘厚度与瘦肉率直接相关。在猪的遗传育种和性能鉴定上作为两项重要的指标参数深受重视 ,其精确测定有重要的意义。测定活体的背膘厚度在实施超声技术中已广泛应用 ,而眼肌面积的测定则往往依赖于屠宰试验 ,其活体测定技术国内尚未完全成熟。本人采用加拿大 AMI- 90 0兽用B超仪 ,利用其直观的 B超影像对猪的眼肌面积和背膘厚度同时活体测定时进行了较详细的探讨 ,摸索出一套趋于成熟的测定技术。1　测定仪器1.1　 B型超声波扫描仪 ( B超 )　湖南国际企业合作公司从加拿大阿米公司引进 AMI-90 0型兽用 B超仪 (重量轻。机…     

舍饲型合作猪胴体品质性状相关性分析

选择4个屠宰体重区间对舍饲型合作猪胴体品质进行了研究。结果表明:25~30 kg屠宰,后腿丰满度理想,产肉性能高,瘦肉率59.62%,屠宰率66.315%,具有皮薄(0.5 cm)、背膘薄(0.797 cm)、眼肌面积大(16.15 cm2)的特点,属于优良的瘦肉型小型猪。宰前活重与胴体重、眼肌面积,胴体重与屠宰率、眼肌面积呈极显著正相关(P0.01);宰前活重与屠宰率、背膘厚、骨率,胴体重与背膘厚、骨率,屠宰率与眼肌面积,背膘厚与眼肌面积,皮厚与后腿比例,眼肌面积与瘦肉率、骨率,瘦肉率与皮率呈显著正相关(P0.05);背膘厚与瘦肉率,后腿比例与脂率,瘦肉率与骨率存在显著负相关(P0.05)。     

山西白猪的微卫星标记与其体重、体尺性状的关联分析

 采用单变量动物模型分析了21个微卫星标记对山西白猪初生重、断奶重、6月龄体重、体长、体高、胸围和活体背膘厚等7个性状的影响。结果表明，S0227和S0218标记对6月龄活体背膘厚有显著影响（P<0.05）。在S0227座位上，杂合子AB型个体的6月龄背膘厚最薄；在S0218座位上，BB和CC型个体的背膘最薄。S0101标记对6月龄体高有显著影响（P<0.05），对6月龄体重的影响也接近显著水平（P=0.0854）。在S0101座位上， CC型个体的6月龄体重最大，显著高于AB型个体，而与其他类型差异不显著；BC型个体的体高最高，显著高于AB型，而与其他类型差异不显著。     

B超活体测定牦牛眼肌面积和背膘厚的研究

为了提高牦牛肉用性能选育效率,试验采用B超测定技术活体测定牦牛背膘厚与眼肌面积。结果表明:成年牦牛(4岁以上)背膘厚为(4.87±1.09)mm、眼肌面积为(25.58±1.75)cm2,青年(1岁)牦牛背膘厚为(1.93±0.28)mm、眼肌面积为(12.93±2.78)cm2。说明牦牛脂肪沉积晚,这可能与牦牛在高寒牧区生长发育慢、体成熟迟有关。     

舍饲型合作猪胴体性状相关性分析

选择四个屠宰体重区间对舍饲型合作猪12个胴体性状相关性进行了研究.结果表明:25～30 kg(即6月龄)屠宰,瘦肉率59.62 % ,屠宰率66.32%,具有皮薄(0.5 cm)、背膘薄(0.797 cm)、眼肌面积大(16.15 cm2)的特点,表明合作猪属于优良的瘦肉型小型猪.经分析可知,宰前活重与胴体重、眼肌面积,胴体重与屠宰率、眼肌面积呈极显著正相关(P＜0.01);宰前活重与屠宰率、背膘厚、骨率,胴体重与背膘厚、骨率,屠宰率与眼肌面积,背膘厚与眼肌面积,皮厚与后腿比例,眼肌面积与骨率,瘦肉率与皮率呈显著正相关(P＜0.05);背膘厚与瘦肉率,后腿比例与含脂率,瘦肉率与骨率存在显著负相关(P＜0.05).12个胴体性状指标经主成分分析可获得5个主成分因子,可代表胴体性状总变异量的87.025%.     

杜蒙羊肉用性能活体检测及屠宰性能对比分析

[目的] 评价杜蒙羊的肉用性能、屠宰性能及肉品质。[方法] 选取60只杜蒙羊,公母各半,于5月龄时利用超声波背膘检测仪对羊只进行活体肉用性能检测,于6月龄时对羊只进行屠宰,测定主要屠宰性能指标以及肉品质和安全性评价指标;对杜蒙羊公羊和母羊的活体肉用性能指标、主要屠宰性能指标、肉品质和安全性评价指标进行统计学分析和比较。[结果] 杜蒙羊活体肉用性能指标检测结果表明,公羊的腰肌厚度和眼肌面积显著（P<0.05）大于母羊,背膘厚度与母羊差异不显著（P>0.05）;屠宰后肉用性能指标测定结果表明,公羊的背脂厚和眼肌面积显著（P<0.05）大于母羊。屠宰性能指标测定结果表明,杜蒙羊公羊的胴体重、净肉重、宰前活重均显著（P<0.05）高于母羊,公羊的屠宰率、胴体净肉率高于母羊,但无显著（P>0.05）差异;母羊的大腿骨重、小腿骨重、大腿骨长、小腿骨长均显著（P<0.05）低于公羊,公羊和母羊的4个骨指标两两之间呈正相关,大腿骨重和小腿骨重更接近线性相关。肉品质和安全性评价指标测定结果表明,杜蒙羊公羊的肌内脂肪含量显著（P<0.05）低于母羊;公羊的胴体肌肉水分含量与母羊差异不显著（P>0.05）;公羊和母羊肌肉中的铅、铬、汞、砷元素含量均符合《农产品安全质量 无公害畜禽肉安全要求》（GB 18406.3—2001）,母羊肌肉中的铬含量和汞含量显著（P<0.05）低于公羊。[结论] 杜蒙羊公羊的活体肉用性能和屠宰性能优于母羊,母羊的肉品质优于公羊。     

强冷应激对阿勒泰及杂交种羔羊脂质代谢相关基因mRNA表达量及脂肪沉积的影响

为探讨强冷应激对阿勒泰羊、阿勒泰和萨福克杂交羊、阿勒泰断尾羊脂肪酸合成酶(Fatty acid synthase,FAS)和脂蛋白脂酶(Lipoprotein lipase,LPL)基因mRNA表达量、屠宰性能及血脂指标的影响,本实验设置常温组(15~20℃)与冷应激组(-25^-30℃),每组每个品种3只,选择体况相近、体重(34±4)kg的6月龄羔羊,12 d后采取血液及不同部位脂肪组织。使用荧光定量PCR技术检测FAS和LPL基因mRNA含量变化,通过酶联免疫吸附试验(ELISA)检查羔羊血脂指标,同时测定其屠宰性能。结果表明:相较于常温组,冷应激后LPL mRNA在阿勒泰羔羊与杂交种羔羊胸部脂肪中的表达量均增高,而在断尾羊中呈下降趋势;肩胛间脂肪和腹股沟脂肪中3种羔羊的LPL mRNA的表达量都呈升高趋势。冷应激后阿勒泰羊与杂交羊胸部脂肪FAS含量升高,而断尾羊的表达下降;3种羊冷应激后肩胛间脂肪和腹股沟脂肪中FAS mRNA的表达都呈升高趋势。冷应激前后肩胛间脂肪和腹股沟脂肪中LPL表达量高于FAS。冷应激后阿勒泰羊与杂交羊总胆固醇含量显著增高,断尾羊则显著降低,冷应激后阿勒泰羊与断尾羊甘油三酯含量升高,杂交羊降低,3种羊高密度脂蛋白和低密度脂蛋白含量均升高。3种羊冷应激后宰前活重、胴体重、脂肪重、肌肉重、骨重、肉骨比、屠宰率、净肉率、背膘厚、GR值、眼肌面积均有所下降,皮重增高,脏器变化不明显。此结果表明寒冷环境下,机体为了抵御寒冷,需要动员更多的脂肪组织来维持机体的正常生理功能,冷应激对3种绵羊不同部位脂肪沉积与代谢有一定影响,且不同品系之间具有一定差异性。     

Muscle metabolism and real-time ultrasound measurement of muscle and subcutaneous adipose tissue growth in lambs fed diets containing a beta-agonist

Rambouillet X Finn crossbred wether lambs were evaluated for differences in longissimus muscle cross-sectional area and overlaying subcutaneous adipose tissue thickness resulting from the use of the beta-agonist clenbuterol. Treatment groups received 0 and 2 ppm clenbuterol in the diet for approximately 40 d prior to slaughter. Longissimus muscle cross-sectional area and fat depth over the 12th-13th rib juncture were measured by real-time ultrasound before and during administration of the compound. At slaughter, muscle metabolism in vitro and carcass characteristics were measured. Based on comparisons with an initial-kill group of sheep, longissimus muscle cross-sectional area increased in control sheep by 12% (P greater than .05) over the 40-d experimental period, and increased in clenbuterol-fed sheep by 48% (P less than .05). Conversely, subcutaneous fat thickness increased significantly in the control sheep (88%) during this period, but was unchanged in the clenbuterol-fed animals. Warner-Bratzler shear force values of cooked longissimus samples from clenbuterol-fed sheep were significantly greater than shear force values in cooked samples from control lambs; this was not correlated with the extractable neutral lipid content of the muscle. Simple linear regression between ultrasound and carcass measurements of longissimus muscle cross-sectional area and subcutaneous fat thickness yielded correlation coefficients of .80 and .64, respectively. A significantly greater amount of net glycogen synthesis from [U-14C]glucose was observed in longissimus muscle strips from clenbuterol-fed animals than in muscle strips from control sheep.(ABSTRACT TRUNCATED AT 250 WORDS)     

Using ultrasound technology to predict pork carcass composition

Twenty market hogs were evaluated with real-time ultrasound both before and after slaughter. Fat measures (n = 9) were taken at various body locations along with the longissimus muscle area measurement at the 10th rib. After live ultrasound, the hogs were slaughtered and the unsplit carcasses were measured with ultrasound at the same live ultrasound locations. After chilling, carcass measures were taken at the same locations using a backfat probe for fat measures and a loin eye dot grid for measuring the longissimus muscle area. One side of each carcass was fabricated into the four lean cuts, which then were expressed as a percentage of the side weight. The most appropriate prediction equation found was a two-variable equation (fat thickness at the anterior tip of gluteus medius and longissimus muscle area) with a R2 of .83 and a RSD value of 1.67. This prediction equation was verified on a different sample of 20 market hogs; actual vs predicted four lean cuts revealed that the prediction equation had a R2 of .63 and a RSD value of 2.04. Although some accuracy and precision was lost when this live animal prediction equation was incorporated in market hog evaluation, this equation offers producers an objective mechanism for identifying carcass merit in live hogs.     

西北寒旱地区舍饲湖羊生长发育特征研究

湖羊是世界上稀有的绵羊地方品种,以多胎、早熟、早期生长发育快、宜舍饲等优良性能而著名。为系统了解湖羊生长发育的基本规律,更好地开发利用湖羊这一优良地方品种资源,本研究以3,6,12和24月龄湖羊公羊为对象,每个时间点随机选择6只,共24只,测定其体重、组织器官及消化道各个部分重量、肠道长度及肉品质相关参数。结果表明,3~6月龄湖羊生长速率最快,6月龄之后逐渐降低;3~6月龄之间心、肝、脾、肺、肾、头蹄和皮的增长强度随着日龄的增大而增长,除头、蹄、皮外,其他内脏器官的生长强度逐渐降低,12月龄之后趋于稳定;头、蹄、皮的生长在6月龄之后趋于稳定,仍然保持较高的生长强度;瘤胃的生长强度始终大于体重生长强度,小肠的生长始终小于体重,而除直肠外,大肠的生长强度与体重相近。6月龄湖羊公羔与12月龄相比屠宰率、眼肌面积无显著差异,而6月龄湖羊公羔背膘厚极显著增高,随着年龄的增长肉色逐渐变暗。综合以上各项指标认为,本试验条件下,6月龄为肥羔生产最佳屠宰日龄。     

引入肉羊品种与湖羊杂交的屠宰性能、肉品质及血液生化指标比较研究

旨在研究引入外来品种与湖羊杂交后对湖羊屠宰性能、肉品质及血液生化指标的影响。试验采用单因子试验设计,分为AH组(澳湖杂交F1代)、DH组(杜湖杂交F1代)和H组(纯繁湖羊对照组)3组,每组分别选取4月龄体重相近、体况良好的公羊3只、母羊2只。结果表明,在屠宰性能上,AH组和DH组的内脏脂肪占胴体重百分比、眼肌面积均显著高于H组(P<0.05),H组比高于AH组与DH组骨肉显著低于H组(P<0.05),DH组胴体脂肪含量值显著高于H组(P<0.05)。在肉品质上,肌肉剪切力DH组与AH组显著低于H组(P<0.05),AH组与DH组肌肉水分含量显著高于H组(P<0.05),DH组肌肉脂肪含量显著高于H组(P<0.05)。血液生化指标显示,AH组和DH组的球蛋白、谷草转氨酶及乳酸脱氢酶含量均显著高于H组(P<0.05)。综上,引入的2个绵羊品种与湖羊杂交,不仅可以提高湖羊屠宰性能及肉用品质,还可以有效地改善湖羊血液生化指标。     

不同屠宰活重豫西黑猪的营养成分及肉质特性分析

【目的】探讨豫西黑猪营养成分及肉质性状在不同体重阶段的发育性变化规律。【方法】选取平均体重约为60、75、90、105、120 kg 5个体重阶段的豫西黑猪,每组5头,共25头,每组随机选取3头进行屠宰,公母随机。屠宰后取背最长肌测定眼肌面积、背膘厚、脂肪率、失水率、脂肪酸、氨基酸和胆固醇等指标,测定肌内脂肪含量、脂滴直径和脂滴数目,采集100 g腰大肌测定熟肉率。【结果】豫西黑猪在体重达到120 kg之前,随着屠宰活重的增加,眼肌面积、背膘厚、脂肪率、熟肉率、肌内脂肪含量、肉色、剪切力、脂滴数目和脂滴直径均随之增加。眼肌面积在105、120 kg时均极显著高于60、75 kg(P＜0.01),显著高于90 kg(P＜0.05);背膘厚在90、105、120 kg时均极显著高于60 kg(P＜0.01);肌内脂肪含量在90、105、120 kg时均显著高于60、75 kg(P＜0.05);脂滴直径和脂滴数目在75、90、105、120 kg时均显著高于60 kg(P＜0.05);脂肪酸中饱和脂肪酸以肉豆蔻酸、棕榈酸、硬脂酸等为主,不饱和脂肪酸以棕榈油酸、油酸、亚油酸等为主,氨基酸种类丰富,组氨酸、酪氨酸、缬氨酸和异亮氨酸含量在120 kg时均显著高于105 kg(P＜0.05)。体重与熟肉率、粗蛋白质、肉色、粗脂肪呈极显著或显著正相关(P＜0.01;P＜0.05);肌内脂肪含量与大理石花纹、粗脂肪、肉色、脂滴直径呈极显著或显著正相关(P＜0.01;P＜0.05)。【结论】屠宰活重在120 kg时,豫西黑猪肌内脂肪含量适中,大理石花纹丰富,不饱和脂肪酸与饱和脂肪酸比例适宜,鲜味氨基酸含量增加,胆固醇含量较低,肉色鲜嫩,胴体品质和肉品质最佳。     

Predicting carcass composition of beef cattle using ultrasound technology.

We evaluated 20 slaughtered cattle with ultrasound before hide removal to predict fat thickness and ribeye area at the 12th rib for possible use in carcass composition prediction. Carcasses were fabricated into boneless subprimals that were trimmed progressively from 2.54 to 1.27 to .64 cm maximum fat trim levels. Stepwise regression was used to indicate the relative importance of variables in a model designed to estimate the percentage of boneless subprimals from the carcass at different external fat trim levels. Variables included those obtained on the slaughter floor (ultrasound fat thickness and ribeye area; estimated percentage of kidney, pelvic, and heart [KPH] fat; and warm carcass weight) and those obtained from carcasses following 24 h in the chill cooler (actual fat thickness, actual ribeye area, estimated percentage of KPH fat, warm carcass weight, and marbling score). At all different subprimal trim levels, percentage KPH was the first variable to enter the model. In the models using measures taken on the slaughter floor, ultrasound fat thickness was the only other variable to enter the model. Ultrasound fat thickness increased R2 and decreased residual standard deviation (RSD) in models predicting subprimals at 2.54-cm maximum fat trim; however, at 1.27- and .64-cm trim levels, R2 and RSD increased. Models using the same two variables (except actual fat instead of ultrasound) in the cooler were similar to those using data from the slaughter floor. However, as more cooler measurement variables entered the models, R2 increased and RSD decreased, explaining a greater amount of the variation in the equation. Ultrasonic evaluation on the slaughter floor may be of limited application compared with the greater accuracy found in chilled carcass assessment.     

Prediction of carcass characteristics by real-time ultrasound in barrows and gilts slaughtered at three weights.

The carcass characteristics of 27 market barrows and 27 market gilts were evaluated at various times (n = 8) with real-time ultrasound (Aloka 210 DX) from approximately 20 kg until slaughter at three end points. The pigs were randomly assigned to slaughter weight groups of 91, 104.5, and 118 kg at weaning time. Correlations were determined over slaughter weight group and sex, and the accuracies of ultrasound measurements were also evaluated. The regressions of ultrasound 10th-rib fat and ultrasound longissimus muscle area on live weight were also developed. Correlations between actual and ultrasound-measured last-rib fat, 10th-rib fat, and longissimus muscle area were high (r = .91, .63, and .53, respectively; P less than .01). The accuracy of ultrasound longissimus muscle area prediction was lower for 118-kg pigs than for the two lighter groups, whereas the accuracy for prediction of last-rib fat was lower for 91-kg pigs than for the two heavier groups, as indicated by higher absolute differences (P less than .05). Last-rib fat and longissimus muscle area tended to be overestimated and 10th-rib fat tended to be underestimated by real-time ultrasound. Prediction of last-rib fat by ultrasound was more accurate for gilts than for barrows, as indicated by a lower absolute difference (P less than .05).     

鲁西黄牛背截面指标为参数的胴体产肉率回归分析

７头商品鲁西牛胴体第１１肋后缘截面的客观测量值及相应的其它屠宰数据应用ＳＡＳ软件对胴体产肉率进行了回归分析,结果表明半胴体重、皮下脂肪厚、背眼肌面积、腔脂％组建的四元方程对后腿分割肉产率的预测力最大,其次是后躯分割肉产率、全部可食肉产率、主要分割肉产率对全部分割肉产率的预测力最小。眼肌面积是主要分割肉产率最重要的独立预测指标;腔脂％对全部分割肉产率、全部可食肉产率、后躯分割肉产率单独的预测作用最大