商品肉猪胴体性状的测定及其相关性分析

引进丹麦先进仪器FAT—O—MEAT’ER(肉脂仪)对中国鲁梅克斯食品总公司名山县屠宰场中5821头猪进行了现场测定，测量性状为最后一根肋骨处离背中线4～5cm处的膘厚(P2)和倒数第三、四根肋骨之间，离背中线4—5cm处的膘厚(RF)以及眼肌厚度(RM)，并估测出瘦肉率。对所测胴体各性状的均数和相关性分析，表明本地商品肉猪胴体质量低于国外水平。     

二元与三元杂交猪胴体性状的比较研究

选择江苏龙山亲和农牧有限公司4头长约二元杂交猪和6头杜长约三元杂交猪进行屠宰比较试验。结果表明,三元杂交猪平均膘厚比二元杂交猪显著减少,差异显著(P<0.05),后腿比例和板油比例差异极显著(P<0.01),屠宰率、眼肌面积、脂肪比例、胴体长和瘦肉率差异不显著(P>0.05)。对杜长约三元杂交猪进行瘦肉率与各胴体性状的相关性分析后发现,瘦肉率与眼肌面积、胴体重、屠宰率呈强正相关,而与脂肪比例呈强负相关。利用眼肌面积、平均膘厚、屠宰率分别建立了对胴体瘦肉率的回归方程,其中眼肌面积、平均膘厚对瘦肉率回归方程R=0.9417;平均膘厚、屠宰率对瘦肉率回归方程R=0.8540。     

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%.     

F2代海南特种野猪生长发育和胴体品质研究

为了研究海南特种野猪的生长发育规律和胴体品质,试验通过对F2代海南特种野猪的生长发育性状和胴体品质各项指标进行测定。结果表明:F2代海南特种野猪体型较小,初生重和断奶重较低,生长速度较缓慢;F2代海南特种野猪胴体重为25.19 kg,屠宰率为73.56%,背膘厚为2.46 mm,眼肌面积为37.47 cm2,后腿比例为14.93%,瘦肉率为52.38%,骨率为28.66%;屠宰率与宰前活重、眼肌面积、瘦肉率、后腿比例呈极显著正相关(P0.01),而与胴体重、皮脂率、背膘厚、板油比例、骨率呈极显著负相关(P0.01);瘦肉率与皮脂率、骨率、胴体重、背膘厚、板油比例呈极显著负相关(P0.01),与眼肌面积、后腿比例、屠宰率、宰前活重呈极显著正相关(P0.01)。海南特种野猪体型小,生长缓慢,但屠宰率和瘦肉率均较高,胴体品质呈现中国优质猪的特点。     

二元杂交商品猪胴体性状的相关及通径分析

以100头二杂商品肉猪为研究对象,利用相关分析和通径分析确定了影响二杂商品肉猪瘦肉率的主要胴体性状是眼肌面积、胴体长和平均背膘厚。3个性状对瘦肉率单独作用的决定系数分别为0.509 1、0.057 1和0.055 0。此外,眼肌面积和平均背膘厚间的互作效应对瘦肉率产生的共同决定系数为0.201 5。利用多元逐步回归分析的方法获得了估测二杂商品肉猪胴体瘦肉率的最优回归方程。     

广益黑猪胴体和肉质性状研究及相关性分析

试验旨在对广益黑猪的胴体性状和肉质性状进行评估。选取105 kg左右的健康广益黑猪30头,进行屠宰测定,主要测定屠宰率、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,广益黑猪的屠宰率和瘦肉率分别为72.02%和57.41%,滴水损失和肌内脂肪分别为1.75%和3.09%。性状间相关性分析表明,广益黑猪的胴体瘦肉率与宰前活重、胴体重、平均背膘厚呈显著负相关(P0.05);肌内脂肪与大理石纹呈极显著正相关(r=0.956,P0.01),二个指标间线性模型Y=0.037+0.98X,决定系数R~2为0.9141,模型准确度较高。研究结果表明,广益黑猪具有良好的胴体性状和肌肉品质,性状间也存在一定的相关性,为今后的进一步选育提供了参考。     

猪HK2基因第17外显子多态与胴体和肉质性状的相关性研究

采用PCR—RFLP技术,分析了HK2基因第17外显子中MspI的酶切突变多态位点（A171G）在6个群体186头猪中的多态性分布及其与胴体性状和肉质性状间的相关性。研究结果表明：3个纯种猪群和3个杂交猪群中A和B等位基因频率分布情况较一致,均为B等位基因占绝对优势;在6个群体中,没有发现AA基因型个体,AB与BB基因型效应与胴体长、肋骨数和眼肌面积的相关性极显著（P〈0．01）,与肩部背膘厚、胸腰椎间背膘厚、三点平均背膘厚、眼肌高度、眼肌宽度、肥肉率、瘦肉率和肌内脂肪等性状的相关显著（P〈0．05）。该位点是否可用作改良猪胴体、肉质性状的标记位点并在标记辅助选择中加以应用还有待进一步的研究。     

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)。     

不同屠宰体重日照大白猪胴体肉质性状及其相关关系研究

研究测定了83~106 kg体重阶段34头日照大白猪的胴体性能,以分析日照大白猪胴体性状随屠宰体重的变化规律及其相关程度,为确定适宜上市屠宰体重提供参考。结果表明,83~106 kg体重阶段,随体重增大,胴体重极显著升高,胴体直长和大理石纹在100.5~106 kg体重阶段分别极显著、显著高于83.5~89 kg体重阶段,其它指标变化不显著。胴体性状间相关程度有强有弱,相关系数有正有负。相同性状间有较强的正相关,相反性状间有较强的负相关。屠前体重与胴体重、胴体直长都极显著正相关;胴体重与屠宰率、胴体直长极显著正相关,与眼肌面积显著正相关;屠宰率与眼肌面积显著正相关;平均背膘厚与皮脂率、肉色极显著正相关,与瘦肉率极显著负相关;瘦肉率与皮脂率呈极显著负相关;皮脂率与肉色显著正相关。在83~106 kg阶段,胴体重和胴体直长分别与体重之间呈极显著的回归关系,大理石纹与体重之间呈显著的回归关系,其它指标与体重间的线性相关不显著。     

杜洛克猪新品系生长和胴体性状遗传参数的初步估测

应用多性状动物模型DFREML方法估计了杜洛克猪新品系生长和胴体性状的遗传参数。生长性状平均日增重(ADG)、100Kg体重日龄(AGE)、达100Kg体重背膘厚(BF)和料重比(FCR)的遗传力估计值分别为0.48、0.30、0.21、0.57。各性状均存在明显的窝效应,变化范围为0.05-0.51。胴体性状宰前活重、胴体重、胴体长、肋皮厚、肋膘厚、眼肌面积、腿臀比、屠宰率和瘦肉率的遗传力估计值分别为0.17、0.49、0.58、0.19、0.76、0.50、0.48、0.55和0.37。生长性状ADG/AGE、ADG/BF、ADG/FCR、AGE/BF、AGE/FCR、BF/FCR的遗传相关分别为-0.35、0.33、-0.70、-0.38、0.25和-0.12。胴体性状屠宰率和瘦肉率与胴体重呈较强的正相关,分别为0.575和0.498;肋膘厚与宰前活重、胴体重、胴体直长呈正相关,与肋皮厚、眼肌面积、腿臀比、屠宰率和瘦肉率呈负相关,但相关程度不高。屠宰率和腿臀比与瘦肉率的遗传相关分别为0.687和0.558。     

辽育白牛胴体产肉量预测模型研究

为了快速且准确的预测辽育白牛胴体产肉量,进而建立完善的胴体分级体系,本试验对60头辽育白牛进行屠宰胴体分割试验,分别测量了胴体重(X₁),第5肋侧厚度(X₂),第5~6肋眼肌宽高乘积(X₃),第5~6肋眼肌面积(X₄),第12肋侧厚度(X₅),第12~13肋眼肌宽高乘积(X₆),第12~13肋眼肌面积(X₇),肾脏油、心脏油和膈肌油之和(X₈),后腿围(X₉)和大腿肌肉厚(X₁₀)等与产肉量、产肉率相关的10项指标,利用SPSS 19.0软件对数据进行相关分析和线性回归分析。结果显示,X₁、X₈与产肉量和产肉率相关性最强,依此推导出2个可信度高、实践中方便应用的产肉量预测方程:①产肉量(眼肌宽高乘积)=0.809X₁+0.158X₆+0.857X₈-13.967 (R²=0.986);②产肉量(眼肌面积)=0.779X₁+0.318X₇+0.933X₈-17.779 (R²=0.990)。     

Predicted Regression Model for Beef Carcass Yield of Liaoyu White Cattle

To investigate the predicted regression model for beef carcass yield and percentage of Liaoyu White cattle,60 cattles were slaughtered and determined 10 indicators about beef carcass yield and percentage,including carcass weight (X₁),the 5th rib thickness (X₂),product of 5th to 6th rib eye width and height (X₃),5th to 6th rib eye area (X₄),the 12th rib thickness (X₅),product of 12th to 13th rib eye width and height (X₆),12th to 13th rib eye area (X₇),the weight of kidney,heart and diaphragm fat (X₈),hind leg circumference (X₉) and thigh muscle depth (X₁₀).Then correlation and regression analysis between 10 indicators and beef carcass yield and percentage were taken using SPSS 19.0.The results showed that the correlation were the highest between X₁ and beef carcass yield,X₈ and beef carcass yield percentage.Besides,there were two credible regression model for beef carcass yield of Liaoyu White cattle:① Beef carcass yield (product of 12th rib eye width and height)=0.809X₁+0.158X₆+0.857X₈-13.967 (R²=0.986);② Beef carcass yield (12th rib eye area)=0.779X₁+0.318X₇+0.933X₈-17.779 (R²=0.990).     

牛胴体部位肉营养成分和理化指标差异性分析

试验选取10头24月龄的科尔沁公牛,对其肩肉、辣椒肉、板腱、脖肉、上脑、眼肉、外脊、里脊等部位肉进行营养成分、理化指标测定,并对数据进行统计分析。结果表明,粗蛋白质、粗脂肪、水分、嫩度、pH、a*值在不同部位间差异显著（P<0.05）;反映肉色的L*值和b*值在不同部位间差异不显著（P>0.05）;牛前部肉中肩肉和板腱的蛋白质、脂肪、水分和嫩度、肉色与中部高档部位肉很相近,无显著性差异（P>0.05）,这些部位肉的价值有待进一步挖掘。     

Beef production from cull dairy cows: a review from culling to consumption

Although more than 3 million head of dairy cows enter the food supply chain in the U.S. every year, research on this topic remains limited and scarce. Meat production from dairy cows is a significant component of beef production, accounting for almost 10% of U.S. commercial beef production. Thus, the purpose of this review is to demonstrate the importance of dairy cows as a beef source, and to provide an overview on topics from farm to meat product—culling, marketing, transportation, welfare, body composition and its relationship with lactation particularities, carcass characteristics, meat quality, and traceability. Current scientific evidence has shown that culling a dairy cow at an appropriate time has beneficial effects on cow welfare and, consequently, cow value. During marketing the dairy cow is visually evaluated for health and factors associated with its expected carcass value; thus, marketing a well-conditioned cow will ensure that the animal is fit for transportation and provides high carcass yield. However, limitations such as low body condition score, lameness or mobility problems, and visual defects remain persistent. Even though beef harvest plants accommodate cows in all body composition states, the current carcass grade system does not reflect the mature cow industry needs. Therefore, improvement of the grading system could maximize carcass utilization and increase cow carcass value by recognizing subprimal cuts that could be merchandised as whole muscle cuts. Lastly, implementation of a traceability system would unify information from the farm to harvest assisting the industry in making further advancements.     

不同屠宰体重美系杜洛克母猪胴体肉质性能初报

于2001年从美国引进杜洛克原种第二代种猪群中随机抽取28日龄48头杜洛克母猪,并保育至70日龄,体重达33kg,在生长到肥育阶段饲喂含DE 13.39 MJ/kg,CP 18%～16%的饲粮.分别在100kg、120 kg、150 kg体重级别从48头母猪中随机选择12头(4×3,每个体重级别4头)进行屠宰,检测体重和日龄对胴体和肉质的影响.结果表明,当体重从100kg增至150 kg时,瘦肉率从66.8%显著降至62.4%,即使在150kg体重,瘦肉率也完全符合市场需求.然而,板油和花油的增加值得注意.此外,肌内脂肪,体重120kg、150kg(3.32%、3.69%)高于100 kg(2.86%).这个结果提示,随着体重增大肌内脂肪提高而改善肉质,但嫩度降低.     

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.     

动物胴体组成图像分析系统的研制

本文介绍动物胴体组成图像计算机分析系统的设计思想。动物胴体组成图像分析系统实现了对胴体组成图像的自动识别和计算。计算的参数包括面积、面积比、长度、角度等。对眼肌、背膘的识别和计算在遗传育种工作中是很重要的，该系统为提高处理的效率，加强了眼肌、背膘识别分析过程自动化，这对胴体组成性状的选择比较有用。     

The value of incorporating carcass trait phenotypes in terminal sire selection indexes to improve carcass weight and quality of heavy lambs

Genetic selection for carcass traits is paramount to maximize the profitability and long‐term sustainability of any meat‐producing livestock species. The main objectives of this research were to evaluate the efficiency of indicator traits for the genetic improvement of lamb carcass traits and to determine the value of including carcass traits into terminal sire selection indexes for the Canadian sheep industry. The carcass traits included hot carcass weight (HCW), fat depth at the GR site (FATGR) and average carcass conformation score (AVGCONF), and were measured on heavy lambs (slaughter age less than 365 days and HCW greater than 16.3 kg) in commercial abattoirs. Growth traits were found to be moderately efficient indicator traits for the genetic improvement of HCW but selection on ultrasound traits was necessary to substantially improve the carcass quality traits (FATGR and AVGCONF). Economic selection indexes were designed by adding various combinations of carcass traits into the Canadian Sheep Genetic Evaluation System terminal indexes. Records measured on individuals and progeny were assumed to be the sources of information for live animal and carcass traits, respectively. The changes in index accuracy, efficiency and expected correlated response were used to assess the value of their inclusion. HCW was found to have a large economic value, and its inclusion into terminal selection indexes was expected to substantially increase their accuracy (0.08–0.12 points) and efficiency (20%–30%). However, further including FATGR (measured 110 mm from the carcass midline over the 12th rib) and AVGCONF had little impact on the accuracy (≤0.03) and efficiency (1%–7%) of the proposed indexes. Thus, the inclusion of carcass traits into the existing terminal selection indexes could be beneficial for the genetic improvement of HCW, but further research is needed to determine optimal methods of increasing carcass fatness and muscularity.     

Evaluating hydrolyzed yeast in the diet of broiler breeder hens

One of the greatest challenges for nutritionists is ensuring that breeder hens consume the quantity of nutrients necessary to ensure proper development while also ensuring the production of good quality chicks. However, new studies must investigate how nutrition can positively affect the performance of these poultry. The present study aimed to evaluate hydrolyzed yeast supplementation in the diet of Cobb 500 broiler breeder hens, starting from 25 wk of age, and to evaluate the performance of the hens and their progeny. Broiler breeder hens fed hydrolyzed yeast supplement exhibited better performance compared with the control group. The results of the progeny demonstrated improved performance in chicks from the breeder hens fed the hydrolyzed yeast supplement. However, no improvement was observed in breast or leg yields; only carcass yield improved in these broilers. The results demonstrate that supplementation with hydrolyzed yeast in the diet of broiler breeder hens improves the performance of hens and their progeny.