不同月龄新疆褐牛阉牛胴体性状及肉品质比较研究

选择相同营养模式下低月龄组(28~30月龄)12头、高月龄组(32~34月龄)8头新疆褐牛阉牛进行屠宰,分别对胴体性状、营养成分、部分食用品质指标进行测定和比较分析,旨在探索新疆褐牛阉牛生产高档牛肉的适宜月龄。结果表明,高月龄组大理石花纹、胴体等级、脂肪、肉色均优于低月龄组,低月龄组脂肪色泽、水分、蛋白质、蒸煮损失、剪切力值优于高月龄组,且脂肪、肉色L^*值差异显著(P<0.05),其余组间差异均不显著(P>0.05);上脑、里脊、外脊作为高档牛肉,除肉色、pH外,脂肪、蛋白质、水分、蒸煮损失、剪切力值指标均优于其他部位,表现出了极好的营养价值和食用品质。28~34月龄阶段的新疆褐牛阉牛可以生产高档牛肉,其肉品都可作为牛排和涮牛肉的原材料。     

育成荷斯坦奶公牛与其他3个品种牛的肉品质比较研究

通过对育成荷斯坦奶公牛与西门塔尔牛、新疆褐牛及新疆土种牛肉品质部分指标的比较分析研究,旨在探讨荷斯坦奶公牛的肉品质。选择在相同营养模式下18月龄左右4个品种牛各3头进行屠宰,取右半边胴体的背最长肌作为肉品质试验样品,分别对牛肉的肉品质、常规营养成分及氨基酸含量进行测定和分析。结果表明,荷斯坦奶公牛肉色、失水率、系水力、熟肉率、大理石花纹等指标均优于新疆褐牛、新疆土种牛,次于西门塔尔牛;荷斯坦奶公牛嫩度优于新疆土种牛;粗蛋白质、粗灰分含量分别为20.14%、1.11%,且各品种间差异均不显著(P>0.05),干物质含量为26.30%,显著高于新疆褐牛和新疆土种牛(P<0.05),低于西门塔尔牛(P>0.05),粗脂肪含量为10.04%,显著高于其他品种牛(P<0.05);荷斯坦奶公牛含有人体需要的各种氨基酸,其中蛋氨酸、谷氨酸、甘氨酸、组氨酸、牛磺酸等含量丰富,氨基酸组成比例良好。     

Comparison of carcass and meat characteristics of Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis)

This study was conducted to determine and compare the live traits, carcass yield and the physical, chemical, processing and sensory properties of meat from 20 Brahman grade cattle (crossbred cattle) and crossbred water buffalo (Philippine carabao × Murrah, Bulgarian or Indian) with an average age and weight of 29 months and 434 kg, respectively. The animals were fed a similar diet for 180 days before slaughter. A survey was performed to establish consumer meat preference between the two species. Live weights before slaughter of the two species were found to be different (P < 0.05) with the crossbred water buffalo showing higher bodyweight. However, the crossbred water buffalo had a lower (P < 0.05) dressing yield based on hot carcass weight and chilled carcass weight. The lower dressing yield of crossbred water buffalo can be attributed to its higher (P < 0.05) weights of edible and non‐edible slaughter by‐products. The chilled carcass yield of the forequarters and hindquarters from crossbred cattle and crossbred water buffalo were comparable when expressed as percent of live weight and chilled carcass weight. The estimated lean yield was higher in crossbred cattle than crossbred water buffalo. Crude protein, ash, fat, cholesterol, myofibrillar, sarcoplasmic and insoluble protein contents of the beef and carabao meat were all similar. Water holding capacity, pH, muscle fiber diameter, tenderness, firmness and marbling score in carabeef were all comparable to the beef. Redness was found to be higher (P < 0.05) in carabeef than the beef as measured with a color meter. The consumer meat preference survey showed that 55.9% selected the beef while 44.1% preferred carabeef. The color and amount of fat on the outside of the beef sample were primary in buyer selection.     

新疆褐牛产肉性能分析

试验选择新疆褐牛30头,育肥4个月后进行屠宰,分析新疆褐牛综合生产性能,为新疆褐牛生产相关标准的制定提供依据.结果表明,短期育肥后的新疆褐牛具有较高的产肉性能,屠宰率55.42％,肉骨比4.47∶1,高档肉占净肉重的17.24％,优质肉占净肉重的27.76％,并对胴体产肉性状指标进行了相关性研究,建立了以体尺测定指标、屠宰测定指标预测新疆褐牛生产性能相关指标线的性回归方程.发现眼肌面积与高档肉产量、高档肉比例具有相关性,可作为新疆褐牛胴体产肉量评定的参考指标,但仅适合在比较重量不同的胴体间使用,对相同重量的胴体,眼肌面积不能作为胴体产肉量评定参考指标.     

肉用西门塔尔牛与和牛杂交群体的肉品质分析

本研究旨在对肉用西门塔尔牛与杂交和牛两试验群体进行肉质性状比较,以期为肉品质性状遗传机制剖析及优质肉牛培育提供理论指导。收集肉用西门塔尔牛与杂交和牛两试验群体肉质性状表型数据,包括眼肌面积、剪切力、系水力、pH、肉色、脂肪颜色和大理石花纹等指标,进行相关性及差异性分析,从而综合评价两群体的肉品质。结果显示,两群体的脂肪颜色、系水力及剪切力呈现两两正相关;肉色与脂肪颜色、pH呈正相关,且肉色与pH呈显著相关（P < 0.05）,而系水力与pH、肉色和大理石花纹呈负相关。在两试验群体间,和牛杂交群体的大理石花纹、眼肌面积、pH性状表现为极显著优于肉用西门塔尔牛（P < 0.01）。从性别比较来看,肉用西门塔尔牛母牛在大理石花纹、pH、剪切力等性状上极显著或显著优于公牛（P < 0.01;P < 0.05）;而和牛杂交群体母牛的肉色和剪切力性状表现为显著或极显著高于公牛（P < 0.05;P < 0.01）。总体而言,和牛杂交群体的肉质性能优于肉用西门塔尔牛;群体内比较表明,肉用西门塔尔牛群体母牛肉质性能优于公牛,而和牛杂交群体母牛肉质性能低于公牛。     

阉割处理对12月龄早胜黄牛公牛肉品质的影响

[目的]为了研究阉割对早胜黄牛公牛肉质的影响,[方法]试验选择健康无病、发育正常、养殖环境一致的12月龄早胜黄牛公牛和阉牛（6月龄早期阉割处理）各3头,短期育肥3个月,屠宰后取背最长肌,对蒸煮损失、滴水损失、剪切力、pH值、肉色（L^*、a^*和b^*）、系水力、粗蛋白、粗脂肪、水分、粗灰分及氨基酸组成和含量进行了研究。[结果]试验结果表明：阉割公牛背最长肌的pH、红度（a^*）、黄度（b^*）、系水力、粗脂肪、Glu、Leu含量显著高于公牛（P<0.05）;而背最长肌蒸煮损失、滴水损失、剪切力、亮度（L^*）、粗蛋白、水分显著低于公牛（P<0.05）,在公牛和阉牛的氨基酸组成及含量中,多数氨基酸含量不存在显著差异,但阉牛氨基酸含量略高于公牛氨基酸含量。[结论]阉割处理可以显著提高12月龄早胜黄牛的嫩度和系水力,改善牛肉的色泽,增加牛肉干物质和氨基酸含量,说明阉割有助于提高早胜黄牛育肥公牛的肉品质。     

Study on Genetic Polymorphism and Ultrasound Measurements for Major Meat Quality Traits in Beef Cattle

In this study,we used PCR-SCCP connect with ultrasonic vivo assay techniques, analysis of correlation between Leptin gene exon Ⅱ E2JW polymorphism and part meat quality traits of backfat thickness, eye muscle area, fat content, plot eye height in Xinjiang Brown cattle at ante-mortem, post-mortem. The results showed that Leptin gene exon Ⅱ E2JW site PIC was moderate polymorphisms (0.25 < PIC < 0.5), there were three genotypes of AA, AB and BB, AB genotype were the predominant genotype, B was the predominant allele. In addition, the forecast value of AB and AA gennotypes individual muscle fat content were inconsistent with actual value.Leptin gene exon Ⅱ E2JW was identified the theroy of a candidate gene loci of beef quality traits in Xinjiang Brown cattle.Genetic polymorphism and ultrasound measurements could not only fastly and accurately measure portion meat traits, but also as a means of marker-assisted selection.     

基因多态性与超声波活体测定相结合对肉牛主要肉质性状的研究

本试验采用PCR-SSCP与超声波活体测定相结合的方法,对Leptin基因外显子Ⅱ E2JW的SNP位点与宰前/宰后新疆褐牛背膘厚度、眼肌面积、脂肪含量、眼肌高度的部分肉质性状进行关联性分析。结果表明,外显子Ⅱ E2JW位点的PIC处于中度多态（0.25 < PIC < 0.5）,E2JW多态位点存在3个基因型：AA、AB和BB,其中AB为优势基因型,B为优势等位基因。相关性结果表明,除预测值中AB、AA基因型个体的肌肉脂肪含量与实测值的分析结果不一致外,其他均表现出新疆褐牛Leptin基因外显子Ⅱ E2JW多态性与预测肉质性状和实测肉质性状关系的一致性。因此,Leptin基因外显子Ⅱ E2JW是影响新疆褐牛肉质性状的候选基因位点,基因多态性结合超声波活体测定技术不仅可以快速、准确地测量部分肉质性状,而且可作为分子标记辅助选择的一种手段。     

Genetic parameters for carcass traits of field progeny and their relationships with feed efficiency traits of their sire population for Japanese Black cattle

Genetic parameters for carcass traits of 1774 field progeny (1281 steers and 493 heifers), and their genetic relationships with feed efficiency traits of their sire population (740 bulls) were estimated with REML. Feed efficiency traits included feed conversion ratio (FCR) and residual feed intake (RFI). RFI was calculated by the residual of phenotypic (RFI_phe) and genetic (RFI_gen) regression from the multivariate analysis of feed intake on metabolic weight and daily gain. Progeny traits were carcass weight (CWT), rib eye area (REA), rib thickness (RBT), subcutaneous fat, yield estimate (YEM), marbling score (MSR), meat quality grade, meat color, fat color, meat firmness and meat texture. The estimated heritability for CWT (0.70) was high and heritabilities for all the other traits were moderate (ranged from 0.32 to 0.47), except for meat and fat color and meat texture which were low (ranged from 0.02 to 0.25). The high genetic correlation (0.62) between YEM and MSR suggests that simultaneous improvement of high carcass yield and beef marbling is possible. Estimated genetic correlations of RFI (RFI_phe and RFI_gen) of sires with CWT (− 0.60 and − 0.53) and MSR (− 0.62 and − 0.50) of their progeny were favorably negative indicating that the selection against RFI of sires may have contributed to produce heavier carcass and increase in beef marbling. The correlated responses in CWT, REA and RBT of progeny were higher to selection against RFI than those to selection against FCR of sires. This study provides evidence that selection against RFI is preferred over selection against FCR in sire population for getting better correlated responses in carcass traits of their progeny.     

饲粮蛋白质水平和棉籽粕取代豆粕对肉牛育肥的影响

本试验在满足肉牛营养需要的基础上,采用棉籽粕替代饲粮中的豆粕,形成不同蛋白质水平和成本的饲粮,旨在探讨饲粮蛋白质水平和棉籽粕替代豆粕对肉牛育肥的影响,同时为降低肉牛育肥成本和提高育肥效果提供依据.试验选用年龄(平均年龄为28月龄)、体重[初始均重为(678±122)kg]相近的健康杂交一代阉牛(日本和牛♂×鲁西黄牛♀)40头,随机分成4个试验组,每组10头牛.预试期为15 d,正试期240 d.结果表明:蛋白质水平为14.8％的饲粮组试验牛的日增重比蛋白质水平为12.8％的饲粮组提高18.57％(P ＞0.05).与饲喂蛋白质水平为12.8％的饲粮相比,饲喂蛋白质水平为14.8％的饲粮可以显著或极显著提高肉牛的屠宰率、净肉率、肋部脂肪厚、背膘厚(P＜0.05或P＜0.01),而对肉牛的胴体产肉率、眼肌面积、高档肉块占活重比例、肉骨比影响不显著(P＞0.05).同等蛋白质水平下,用棉籽粕全部或部分替代豆粕对肉牛日增重及各项屠宰性能指标的影响均不显著(P＞0.05),但棉籽粕组饲粮单价、肉牛每千克增重成本都低于豆粕组.由此得出,在肉牛育肥后期可以用棉籽粕替代豆粕,以降低成本.目前我国《肉牛饲养标准》(2004)推荐的肉牛育肥所需的蛋白质水平低于本试验用杂交一代阉牛(日本和牛♂×鲁西黄牛♀)的需要.     

秦川肉牛新品系公牛肉用性能研究

 选取发育正常、健康无病、经标准化育肥、年龄为24月龄的秦川肉牛新品系公牛5头进行屠宰及胴体分割,测定屠宰率、净肉率、胴体产肉率、肉骨比等产肉性能指标,并对里脊、西冷、眼肉、上脑、臀肉、胸肉、黄瓜条、牛腩、肋条肉、牛前10个部位取样进行水分、粗灰分、粗蛋白、粗脂肪、剪切力、失水率、系水力和熟肉率8项指标的测定。结果表明,秦川肉牛新品系公牛日增重、屠宰率、产肉率、胴体产肉率、肉骨比等生产性能较传统秦川牛均有较大幅度提高,经过标准化育肥,24月龄时已具备良好的肉用生产性能,达到国际优质肉牛品种标准;秦川肉牛新品系公牛胴体不同部位间肉品质差别较大,通过对其10个部位牛肉品质评定,西冷、上脑、里脊、眼肉为高档肉,肋条肉、臀肉、黄瓜条为中档肉,牛腩、胸肉、牛前为低档肉。     

Effects of vitamin A on growth performance and carcass quality in steers

Vitamin A plays a critical role in many essential life processes. In herbivores, it is either derived from plant β-carotene or directly as a dietary supplement. In cattle, vitamin A has the potential to influence various carcass traits that are sought by specific beef markets. A group of 20 Angus steers was removed from pasture and fed a low β-carotene and vitamin A cereal-based ration on a feedlot for 308 days. Ten of the steers were supplemented with vitamin A (retinyl palmitate, 60 IU of vitamin A/100 kg body weight/day) and the other ten received no supplement. The results demonstrated that restriction of vitamin A intake changed intramuscular fat deposition without changing subcutaneous fat depots. Angus steers that had been depleted of vitamin A showed increased intramuscular fat in the longissimus thoracis et lumborum (LTL) by 35% (P < 0.026) and seam fat area at the quartering site by 33% (P < 0.0273), when compared with cattle supplemented with vitamin A. There were no changes in intramuscular fat in the semitendinosus. Visually assessed marbling scores were also higher (19%; P < 0.094) in the non-supplemented, depleted group. There was no effect of vitamin A depletion on cattle growth and other meat traits (eye muscle area, meat colour, pH, meat cut weight), meat eating attributes (tenderness, cooking loss) or muscle fibre diameter. The only difference (P < 0.0177) among the meat traits was fat colour where depleted animals had whiter fat than the controls. Moreover, the fat from the vitamin A depleted group was softer with a lower melting point. We conclude that the reduced vitamin A consumption, leading to vitamin A depletion, increases intramuscular fat. On the other hand, the vitamin A depletion did not increase subcutaneous fat depth or change other meat quality traits, suggesting that marbling and these other traits are not invariably related.     

张掖肉牛屠宰性能和肉质评定报告

[目的]通过屠宰分析和测定评价,明确张掖肉牛的屠宰性能和肉质风味,作为依据制定下一阶段的选育目标和选配方案。[方法]选择核心育种场育肥牛,检疫后定点集中屠宰测定分析;分割排酸取样,真空包装不同部位肉样带北京试验室根据相应的测定标准进行肉质评定。[结果]张掖肉牛公牛育肥至22.4月龄屠宰,活重、胴体重分别达635.4 kg,371.4 kg,产净肉303.66 kg;屠宰率、净肉率和胴体产肉率分别达58.48%,47.8%和81.76%;胴体脂肪覆盖度良好,肉色和脂肪颜色达到日本胴体分级标准中较高级别。牛肉肉质细嫩,高蛋白,低脂肪,但大理石花纹欠缺。熟肉制品风味独特,多汁性良好,与北京市场销售西门塔牛肉相比,具有较高的适口性和营养价值。[结论]张掖肉牛品种改良、培育成效显著,生产水平达到肉用牛标准,肉质风味能够满足目前的市场需求;若开拓高端牛肉市场,需着力大理石花纹的培育。     

新疆褐牛主要屠宰性状与体尺的相关性分析

[目的]为了进一步了解新疆褐牛的生产性能,找到合理的新疆褐牛经济价值的估算方法.[方法]我们在塔城和昭苏选择了102头在放牧状态下饲养的新疆褐牛进行屠宰测定,对反映产肉性能的主要性状进行了统计分析,[结果]表明:体高、体长、胸围、管围与屠宰重、胴体重的相关极显著(P<0.01),并根据统计结果建立了体尺与胴体重的回归方...     

Analysis of Meat Quality and Mineral Content in Muscle of Mongolia Beef in Kubuqi Desert

The assay was aimed to explore the beef quality and characteristics of Mongolia beef by comparative on beef quality and mineral elements of Mongolia beef and Simmental cattle.6 Mongolia beef and 6 Simmental cattle were chosen to collect the longissimus for analysis.The results showed that the color of Mongolia beef was wine-colored.The a^* value, b^* value, water holding ratio, cooked meat rate and shear force of Mongolia beef were significantly higher than Simmental cattle (P<0.05), and the drip loss rate and pH were significantly lower than Simmental cattle (P<0.05).The amount of Cr, Cu, Fe, Mn, Se and Zn were significantly higher in longissimus in Mongolia beef comparing to Simmental cattle (P<0.05), while the amount of P and I were significantly lower (P<0.05), and other elements contents were no significant difference (P>0.05).It suggested that the taste, juiciness and chromaticity of Kubuqi Mongolia beef were better and it had richer particle minerals than Simmental cattle, indicating that Mongolia beef had higher meat quality.     

库布齐沙漠蒙古牛肉品质及肌肉矿物质元素含量分析

试验通过对库布齐蒙古牛与西门塔尔牛肉品质部分指标及肌肉矿物质含量进行分析测定,研究库布齐蒙古牛的肉品质特性。选择库布齐蒙古牛与西门塔尔牛各6头,采集背最长肌进行样品分析。结果表明:蒙古牛肉色泽深红,红度a^*、黄度b^*、系水率、熟肉率、剪切力均高于西门塔尔牛,且均呈显著性差异(P<0.05),而失水率及pH显著低于西门塔尔牛(P<0.05);蒙古牛肌肉微量元素Cr、Cu、Fe、Mn、Se、Zn含量均显著高于西门塔尔牛(P<0.05),肌肉中P和I含量均显著低于西门塔尔牛(P<0.05),其他元素含量差异不显著(P>0.05)。说明库布齐蒙古牛肉口感、多汁性及色度方面较优,肌肉中大部分矿物质元素含量高于西门塔尔牛,肉品质较高。     

德宏高峰牛肉品质分析

［目的］研究性别、部位对肉质的影响,了解德宏高峰牛肉质特性。［方法］选择放牧饲养的德宏高峰牛为试验动物,屠宰分割后取肉样,进行失水率、剪切力、蒸煮损失、肉色、水分、粗蛋白、粗脂肪、灰分测定。［结果］阉割公牛枕头肉的L*值显著(P<0.05)高于公牛和母牛,并且母牛L*值显著(P<0.05)高于公牛。阉割公牛辣椒肉L*值显著(P<0.05)高于公牛。母牛辣椒肉失水率显著(P<0.05)低于阉割公牛,阉割公牛眼肉的水分显著(P<0.05)高于公牛和母牛。辣椒肉剪切力极限著(P<0.01)低于眼肉和枕头肉,显著(P<0.05)低于霖肉。枕头肉L*值极限著(P<0.01)高于霖肉,显著(P<0.05)高于眼肉和辣椒肉,b值显著(P<0.05)高于霖肉。眼肉水分极限著(P<0.01)低于枕头肉、霖肉和辣椒肉。眼肉粗蛋白极限著(P<0.01)高于霖肉。［结论］性别对肉色有显著影响,对失水率和水分含量有影响。部位对肉质有显著影响。市售德宏高峰牛牛肉品质有待进一步提高。     

波杂肉羊屠宰性能及肉品质研究

选取同等饲养条件下的6月龄、周岁及成年波杂肉羊各8只(公母各半),对其屠宰性能及肉品质进行系统的研究。结果表明:年龄和性别对波杂肉羊的宰前活重、胴体重、净肉重和眼肌面积均有显著或极显著的影响;周岁羊和成年羊胴体产肉率、肉骨比相当,显著高于6月龄羊(P<0.05),屠宰率在3个年龄组间差异不显著(P>0.05);性别对屠宰率、胴体产肉率和肉骨比均无明显影响(P>0.05)。肉质方面,成年羊的肉色、嫩度极显著高于6月龄羔羊(P<0.01),但周岁内无显著性变化(P>0.05);失水率在周岁内变化很大,随年龄的增加显著减少,但周岁羊与成年羊间无显著性差异(P>0.05);粗脂肪含量随年龄的增长,呈明显的增加趋势(P<0.01);其它理化指标在3个年龄组中差异均不显著(P>0.05);除母羊肌肉脂肪含量显著高于公羊、周岁内公羊熟肉率显著高于母羊外,其它指标在性别间均无显著差异(P>0.05)。     

新疆褐牛不同生长阶段体尺体重的遗传参数估计

试验旨在构建新疆褐牛不同生长阶段体尺体重性状的遗传参数估计模型,估计新疆褐牛生长发育性状的遗传参数,为新疆褐牛育种目标性状的确定和综合选择指数的制定提供理论依据。以1983－2017年收集的4个新疆褐牛核心育种场81头公牛后代的2 504条新疆褐牛体尺体重数据为研究材料,以初生及6、12和18月龄阶段的体重、体高、体斜长和胸围性状为研究对象,通过DMU软件构建多性状动物模型,以场、出生年份、出生季节和性别为固定效应,以加性效应和母体效应为随机效应,估计各性状的遗传力和遗传相关。结果显示,新疆褐牛初生至18月龄阶段体重遗传力估计值为0.22~0.61,体高遗传力估计值为0.43~0.46,体斜长遗传力估计值为0.29~0.52,胸围遗传力估计值为0.35~0.61。相同和不同生长阶段新疆褐牛各体尺体重性状间均呈现正的遗传相关和表型相关,其中相同生长阶段各体尺体重性状间的遗传相关系数为0.11~0.92,表型相关系数为0.05~0.92;不同生长阶段各体尺体重性状间的遗传相关系数为0.08~0.92,表型相关系数为0.01~0.72。18月龄与其他各生长阶段间体尺体重性状的遗传相关系数较高,且均属于中高遗传力性状。因此,在制定新疆褐牛综合选择指数时,应重点考虑18月龄阶段的体尺体重性状,从而进一步提升新疆褐牛生长发育性状的遗传进展。     

香蕉茎叶育肥云南小黄牛屠宰试验及肉品质研究

[目的]为了掌握了解香蕉茎叶育肥云南小黄牛的效果。[方法]通过对香蕉茎叶为粗饲料育肥的云南小黄牛进行屠宰分割试验,并对肉品质各项理化指标进行检测,来验证香蕉茎叶作为饲料对牛肉品质的影响。测定平均宰前活重289.33kg,净肉重118.83kg,高档肉块(牛柳、上脑、眼肉、西冷)重22.46kg,屠宰率63.49%,经专家评定肌内脂肪沉积分布细密、气味纯正,鲜嫩多汁,整体食用品味高档,胴体等级A(2±1),达到了优质牛肉的标准。并对13个主要部位采样分析。结果表明各部位肉样切块平均脂肪含量8.62%,蛋白含量21.76%,水分70.56%,剪切力值3.91kg,其中以上脑肉最优,平均剪切力2.40kg,且保水性好,平均失水率26.70%、蒸煮损失19.92%,各项指标同一部位之间差异不显著(P0.05)。[结论]云南小黄牛经香蕉茎叶肥育后肉品质较好,香蕉茎叶育肥生产优质牛肉是基本可行的。