不同品种肉牛产肉性能、牛肉营养品质及风味物质的比较

本文旨在比较不同品种肉牛的产肉性能、牛肉营养品质及风味物质的差异。试验选取6月龄健康西杂牛、犏牛和宣汉黄牛去势公牛各6头,平均体重分别为(616.67±9.50)kg、(457.01±15.73)kg、(462.67±12.57)kg。所有试验牛均在相同饲养条件下人工育肥至30月龄。结果表明:1)西杂牛的胴体长、胴体深、胴体胸深、后腿长、后退宽和后腿围均显著高于犏牛和宣汉黄牛(P<0.05),西杂牛的腰部肉厚、肋部肉厚和大腿肉厚显著高于犏牛(P<0.05)。2)西杂牛的金钱展、前腱子、上脑、外脊、里脊、大黄瓜条、小黄瓜条、霖肉和臀肉的产量都显著高于犏牛和宣汉黄牛(P<0.05)。犏牛的辣椒条和眼肉产量占胴体重比显著高于西杂牛(P<0.05),宣汉黄牛的上脑、眼肉和外脊产量占胴体重比显著高于西杂牛(P<0.05)。3)西杂牛背最长肌中钙、磷、钠、钾和镁含量均显著高于犏牛和宣汉黄牛(P<0.05)。4)犏牛背最长肌中的总氨基酸、必需氨基酸含量以及必需氨基酸/总氨基酸、必需氨基酸/非必需氨基酸均显著高于西杂牛和宣汉黄牛(P<0.05),犏牛背最长肌中的鲜味氨基酸和甜味氨基酸含量显著高于西杂牛(P<0.05),犏牛的背最长肌氨基酸评分也要优于西杂牛和宣汉黄牛。5)犏牛背最长肌中的谷氨酸钠含量显著高于西杂牛(P<0.05),犏牛背最长肌中硫胺素和肌苷含量均显著高于宣汉黄牛和西杂牛(P<0.05)。综上所述,西杂牛的产肉性能和肉中矿物质含量要高于犏牛和宣汉黄牛,犏牛肉的氨基酸组成和评分以及风物物质含量要优于西杂牛和宣汉黄牛。     

南德温杂交三代牛的育肥效果分析

为了测定南德温杂交三代牛(F3)的生长性能、育肥效果,特在蚌埠近郊及三县进行了南杂F3牛饲养情况调查与6、12和18月龄生长性能指标测定,并进行了南杂F3牛与本地黄杂牛育肥对比试验。结果表明:南杂F3牛适应性强,在农家饲养条件下,6月龄的体斜长较当地黄杂牛提高13.06%(P<0.05);12月龄体斜长和后管围分别提高15.52%(P<0.05)和11.39%(P<0.05);6～12月龄和12～18月龄平均日增重比当地黄杂牛分别提高9.30%(P<0.05)和8.48%(P<0.05);6、12和18月龄体重分别提高30.77%(P<0.01)、21.59%(P<0.01)和18.60%(P<0.01)。在相同强度育肥条件下,南杂F3牛日均耗精料2.61 kg,采食粗饲料17.72 kg,平均日增重达1 329.50 g,较当地牛提高17.43%(P<0.01),宰前活重、胴体重、屠宰率、净肉率及高档肉块比均高于本地牛,但差异均不显著(P>0.05);经济效益较饲养本地牛提高70.46%(P<0.01),育肥效果明显。     

安西杂交一代牛肉脂肪酸组成及含量研究

旨在研究西门塔尔杂种牛(西杂牛)肉用性能的利用。选用黑安格斯牛杂交西杂牛,随机选取同期出生断奶的杂交一代安西杂牛(黑安格斯♂×西杂牛♀)和西杂牛,在同一饲养管理条件下持续育肥至20月龄,屠宰安西杂牛和西杂牛公牛各9头,取其背最长肌,利用气相色谱法测定安西杂牛和西杂牛肌内脂肪酸组成及含量。结果表明,安西杂牛和西杂牛背最长肌中饱和脂肪酸(SFA)均达到52%以上,以长链棕榈酸和硬脂酸为主,安西杂牛中SFA显著低于西杂牛(P0.05);不饱和脂肪酸(UFA)占测定脂肪酸总量46%以上,安西杂牛中UFA极显著高于西杂牛(P0.01);单不饱和脂肪酸(MUFA)和多不饱和脂肪酸(PUFA)在安西杂牛和西杂牛中差异不显著(P0.05),油酸的含量在安西杂牛中显著高于西杂牛(P0.05),γ-亚麻酸、顺-11,14,17-二十碳三烯酸、顺-8,11,14-二十碳三烯酸、花生四烯酸和EPA等功能性脂肪酸在安西杂牛中显著高于西杂牛(P0.05)。综上表明,与西杂牛相比,安西杂牛牛肉中脂肪酸的营养价值明显改善和提高。     

兼用型短角牛改良湘西黄牛的效果

为了了解兼用型短角牛改良湘西黄牛的效果,本试验随机选择湘西黄牛和短本F1、F2、F3代各30头,研究其生长发育、生产性能、外貌特征和适应性。结果表明,短本杂牛体重随代次的增加而有不同程度的提高,F1与湘西黄牛相比差异极显著(P<0.01),F2与F1相比差异显著(P<0.05),F3与F2相比差异不显著(P>0.05);短本杂F1的育肥日增重、屠宰率、净肉率分别比湘西黄牛提高69.23%、21.67%和8.41%,骨肉比下降9.82%,差异极显著(P<0.01);短本杂母牛10日龄、30日龄、60日龄和120日龄的泌乳量分别比湘西黄牛提高150.70%、106.10%、162.12%和209.94%,差异极显著(P<0.01);短本杂牛随改良代次的增加,体型外貌逐渐趋于短角牛;短本杂牛表现出良好的适应性。     

不同硒源对胎衣滞留母牛血清P_4和E_2水平的影响

选用90头2～4胎次,体况良好的西门塔尔经产母牛,采用完全随机区组设计,研究亚硒酸钠、赛乐硒、蛋氨酸硒和包被硒(0.6mg/kg)对分娩前后胎衣滞留母牛外周血P4、E2水平及P4/E2比例的影响。结果表明,产前第2天和产犊时各加硒组和胎衣滞留对照组血清P4含量显著高于正常牛(P<0.05);E2水平显著低于正常牛(P<0.05),但亚硒酸钠组、赛乐硒组、蛋氨酸硒组和包被硒组显著高于胎衣滞留对照组(P<0.05);加硒组和正常牛组血清P4/E2比例显著低于胎衣滞留对照组。产后加硒组和胎衣滞留对照组血清P4含量显著高于正常牛(P<0.05);胎衣滞留对照组血清E2含量与正常牛无显著差异,但亚硒酸钠组、赛乐硒组、蛋氨酸硒组、包被硒组血清E2含量显著提高,各硒源间无显著差异;胎衣滞留对照组血清P4/E2显著高于正常牛组(P<0.05),各硒源组显著低于胎衣滞留对照组(P<0.05),赛乐硒组、蛋氨酸硒组和包被硒组显著低于亚硒酸钠组(P<0.05),但与正常牛组无显著差异(P>0.05),亚硒酸钠组显著高于正常牛组(P<0.05)。上述结果表明,产前第10天到第6天P4/E2比例升高可以作为牛胎衣滞留的指征,添加硒可以减缓这些指征,有机硒和包被硒优于无机硒。     

荷斯坦牛及其杂种公牛养分表观消化率、小肠组织形态及消化酶活性差异研究

本试验旨在探索荷斯坦牛及其杂种公牛小肠养分消化吸收能力差异。选择7月龄、体重230～240 kg的健康荷斯坦牛、夏杂牛(夏洛来牛♂×荷斯坦牛♀)及阿杂牛(金色阿奎丹牛♂×荷斯坦牛♀)公牛各6头,分阶段育肥273 d后屠宰,测定各阶段养分表观消化率,以及育肥结束时各组肉牛小肠酶活性和肠道组织形态。结果表明：1)荷斯坦牛各育肥阶段饲粮干物质、有机物、粗蛋白质和中性洗涤纤维表观消化率均显著或极显著高于夏杂牛和阿杂牛(P<0.01或P<0.05),荷斯坦牛育肥各阶段酸性洗涤纤维表观消化率高于夏杂牛和阿杂牛,但无显著差异(P>0.05)。2)荷斯坦牛空肠胰蛋白酶活性,以及十二指肠、空肠脂肪酶活性极显著或显著高于夏杂牛和阿杂牛(P<0.01或P<0.05)。3)荷斯坦牛十二指肠、空肠黏膜绒毛长度极显著高于夏杂牛和阿杂牛(P<0.01),隐窝深度显著高于阿杂牛(P<0.05);十二指肠、空肠、回肠肌层厚度极显著高于夏杂牛和阿杂牛(P<0.01)。综上所述,荷斯坦牛养分表观消化率、小肠消化酶活性以及小肠各部位黏膜绒毛长度、隐窝深度和肌层厚度均较高,表明其...     

河西肉牛最优杂交组合筛选试验

为了确定河西肉牛最优杂交组合,试验采用单因素方差分析,将河西肉牛5个杂交组合的F1代公牛架子牛分为5个试验组(夏♂×西杂♀组、西♂×西杂♀组、皮♂×西杂♀组、安♂×西杂♀组、德♂×西杂♀组),用自行设计的配方日粮进行育肥及屠宰试验。结果表明:5个杂交组合F1代育肥牛的始重、末重(屠宰前活重)、胴体重及屠宰率差异均不显著(P>0.05);安♂×西杂♀F1代肉牛日增重最高[(2.18±0.06)kg],且与其他4个组合相比差异显著(P<0.05),说明安♂×西杂♀为最优杂交组合。     

德系西门塔尔牛对本地西门塔尔杂交牛的改良效果

为研究德系西门塔尔牛在中原农区改良本地西门塔尔杂交牛的杂交效果,为养牛业生产提供科学理论依据。本研究选择500头商丘本地西杂牛为母本,以德系西门塔尔牛(Fleckvieh)为父本,采用人工授精的方法进行杂交改良。测定杂交一代(F1)和二代(F2)各阶段的生长性能、屠宰性能、产奶性能、乳成分等各项指标。结果表明,杂交后代初生时的各项生长性能指标与西杂牛无明显差异,随着年龄的增长,杂交后代的体尺、体重在一定程度上超过西杂牛;F1和F2代公牛的胴体重、屠宰率、净肉率均不同程度高于LSC牛,牛肉的品级提高;产奶量显著增加(P<0.05),乳品质较高。说明以德系西门塔尔牛为父本改良本地西杂牛不仅可以提高杂交后代的生长性能、屠宰性能,还可以显著改善其泌乳性能,使杂交后代由单一的肉用型转变为乳肉兼用型,提高肉牛养殖的经济效益。     

蹄病奶牛血液中6种微量元素和自由基代谢的变化

本研究选取广州各大型奶牛场蹄病牛和不同生理阶段的正常奶牛作为试验样本,通过研究其血液中微量元素含量的变化和血清中抗氧化指标超氧化物歧化酶(SOD)、丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)含量的变化,阐明蹄病与微量元素之间的相关性以及微量元素代谢紊乱下的自由基代谢规律。结果表明:蹄病牛组与青年牛组、高产牛组、低产牛组以及干奶牛组相比较,全血中铜(Cu)、锰(Mn)、锌(Zn)含量降低(P<0.05);铁(Fe)升高(P<0.05);镁(Mg)变化不明显(P>0.05);蹄病牛组硒(Se)含量较高产牛组、低产牛组、干奶牛组降低(P<0.05),较青年牛组升高但是差异不显著(P>0.05);蹄病牛组血清中SOD、GSH-Px显著降低(P<0.05),MDA显著升高(P<0.05)。     

西杂牛产奶性能试验研究

用西门塔尔级进杂交改良本地黄牛,产生西杂一代、二代、三代牛。分别对其1、2、3胎产奶量进行测定,结果表明：各代胎次之间奶量差异不显著（P〉0.05）,但从1胎到3胎上升势头明显,3胎最高;各代305 d平均产奶量差异极显著（P〈0.01）,西杂一代最低、三代最高,产奶天数随着杂交代次提高而逐渐增加;西杂牛产奶收益显著。开展西杂牛挤奶是增加奶源、提高养殖效益的重要举措。     

影响肉牛大理石花纹形成的主要因素

决定大理石花纹水平的肌内脂肪(IMF)含量是影响牛肉感官质量(包括嫩度、多汁性、风味和颜色)的重要因素之一。肉牛体内IMF的形成始于受孕后6个月左右,并在动物的一生中持续增长。大理石花纹的沉积受到品种、遗传、营养和管理(包括去势、断奶年龄)等多方面因素的影响。本文综述了肉牛大理石花纹沉积的主要影响因素,为品种选择以及在肉牛生长发育过程中有效调整饲料、优化营养、因地制宜改善管理提高牛肉品质提供有效依据。     

康乐县肉牛产地检疫存在的问题及应对措施

随着康乐县肉牛产业的发展壮大,动物疾病防控工作显得尤为重要,如何搞好肉牛出栏产地检疫,保证上市交易肉牛健康,是摆在我们面前的首要问题,但由于我县肉牛养殖场、散养户多,宣传不到位,养殖者意识不强,交易市场开办方主体责任不明等原因导致肉牛产地检疫工作严重滞后。     

贵州地方黄牛不同组织中PPARγ基因表达水平研究

试验旨在研究威宁牛、思南牛、关岭牛和黎平牛不同组织中过氧化物酶体增殖物激活受体γ（peroxisome proliferators-activated receptors γ,PPARγ）基因mRNA的表达差异。以这4个贵州地方品种黄牛为试验动物,提取心脏、肝脏、脾脏、肺脏、肾脏、脂肪和背最长肌组织的总RNA,设计PPARγ基因的实时荧光定量引物,以牛GAPDH基因为内参,应用实时荧光定量PCR技术检测PPARγ基因在4个品种不同组织中mRNA的相对表达量。结果显示,PPARγ基因在4个品种黄牛的心脏、肝脏、脾脏、肺脏、肾脏、脂肪和背最长肌组织中均有表达,但在脂肪组织中的表达量高于其他组织,且差异极显著（P<0.01）,在脾脏和肺脏中也有较高表达,而在肾脏、肝脏、心脏和背最长肌中表达量较低;不同品种PPARγ基因的表达在部分组织中存在差异。研究表明,PPARγ基因在不同组织中的表达量存在差异,可能与其在不同组织中的功能有关,而品种对于PPARγ基因的表达影响不大。     

A study of outbreaks of Aujeszky's disease in cattle. I. Virological and epidemiological findings.

Twenty-nine outbreaks of Aujeszky’s disease in cattle, involving 54 animals, were studied virologically and epidemiologically. The outbreaks could be divided into two distinct groups, viz., such with pruritus on the anterior (Group I) and such with pruritus on the posterior part of the body (Group II). Though low, the average number of affected animals per outbreak was twice as high in Group I as in Group II. Besides in the tissue of the central nervous system, virus was demonstrated in the oral, pharyngeal, and nasal mucous membranes of eight out of 12 animals from Group I outbreaks, which was thought to be indicative of respiratory infection, and in the vagina of the three animals with perineal pruritus from which such material was examined. It is concluded that the site of pruritus need not be identical with the site of virus entry. The probable routes of infection in the outbreaks examined will be discussed in detail in a subsequent paper.     

Demographics of cattle positive for Mycobacterium avium subspecies paratuberculosis by faecal culture,from submissions to the Cork Regional Veterinary Laboratory

The demography of bovine infections caused by Mycobacterium avium subspecies paratuberculosis (MAP) in Ireland is poorly defined. The objective of this study was to describe the demographics of cattle positive to MAP on faecal culture, based on submissions to the Cork Regional Veterinary Laboratory (Cork RVL) from 1994 to 2006. The study focused on all available faecal samples from adult cattle with non-responsive chronic diarrhoea that were submitted by private veterinary practitioners to Cork RVL for MAP culture. For each MAP-positive by faecal culture animal, data were collated from Cork RVL and Cattle Movement Monitoring Scheme (CMMS) records. Johne's disease (JD) was confirmed in 110 animals from 86 herds by the Cork RVL between 1994 and 2006, with a rate of positive cases between 15% and 18% over last four years of the study. Two breeds (Holstein/Friesian or Limousin) made up 78% of submissions. Movements were assessed for the 57 study animals with available movement information, 90% died within one year of the test and 26% tested positive in the herd they were born into. The study provides preliminary information about movement trends and demographics of animals with MAP positive submissions. Although the study area is restricted, it includes the most intensive (and economically-important) dairy region in Ireland. The demographics of JD infection from the study area are in agreement with international reports. Further work is required to determine demographic trends, incidence and prevalence of JD throughout Ireland. It is hoped this work may contribute to the development of a surveillance strategy for MAP by regional veterinary laboratories.     

皮埃蒙特牛胚胎移植种公牛培育生产技术

引进皮埃蒙特牛胚胎,利用南阳牛作受体进行胚胎移植。不仅所生胚胎牛更适应当地环境条件,而且还节约外汇,减少疾病传播,充分发挥种公牛的遗传潜力。南阳牛作受体母牛体重在430～450kg,很少发生难产。皮埃蒙特牛种公牛年均采精次数72.1次,每次平均射精量5.11mL,一年四季均衡生产。同时,皮埃蒙特牛冻精的推广应用为皮南牛新品种培育提供优异的遗传材料。     

Haemolytic anaemia in cattle in NSW associated with Theileria infections

Several outbreaks of anaemia, jaundice, abortion and mortality in cattle in New South Wales were attributed to the intracellular parasite, Theileria buffeli . Disease occurred predominantly in periparturient animals that had been moved from inland to coastal areas. Diagnosis was made via exclusion of other causes of haemolytic anaemia and observation of the parasite in blood smears. Treatments included both registered and non-registered products. There is a possibility of a new strain of Theileria sp. in Australia and the possible vectors encountered in NSW are discussed.     

Novel Propionibacterium infection in cattle

OBJECTIVE: To describe four cases of infection in cattle, from geographically different places, with a presumptive new species of Propionibacterium, which causes granulomatous lesions in the head, thorax, abdomen, pelvic area and skin. PROCEDURE: Gross lesions, ranging from 0.5 to 15 cm and detected during routine carcase inspection at the abattoir, were submitted to the laboratory for routine testing in the National Granuloma Submission Program. The bacterium isolated was identified using morphological characteristics, biochemical reactions, cell wall components, products of fermentation and 16S rRNA gene sequencing. RESULTS: Gross lesions submitted for examination consisted of a fibrous outer capsule enclosing thick yellow pus-like material. A Gram-Glynn stain of the histological sections revealed colonies of Gram-positive, filamentous, branching bacteria. Bacteriological culture, cell wall analysis, biochemical reactions and 16S rRNA sequencing identified the organism as a Propionibacterium sp closely related to P cyclohexanicum and the P freudenreichii cluster. CONCLUSION: This is the first report of a Propionibacterium sp closely related to P cyclohexanicum and the P freudenreichii cluster associated with extensive granulomatous lesions in cattle in Queensland. Sequencing data are suggestive of a previously undescribed species of the Propionibacterium genus.     

不同β-受体激动剂添加模式对肉牛血液生化指标和激素水平的影响

试验旨在研究不同β-受体激动剂添加模式对肉牛血液生化指标和激素水平的影响。选取15头体况良好、体重相近（257.9 kg±33.3 kg）的西门塔尔肉牛,随机分为3组,每组5头。对照组饲喂基础日粮;试验Ⅰ组添加莱克多巴胺,添加剂量为670.0 μg/kg体重;试验Ⅱ组添加莱克多巴胺、沙丁胺醇和克伦特罗的混合物,添加剂量分别为223.3、50.0、5.3 μg/kg体重。给药期28 d,停药期28 d。结果表明,与对照组相比,在给药第28天时,试验Ⅰ组肉牛血浆中游离脂肪酸（FFA）浓度显著降低（P<0.05）,试验Ⅱ组肉牛血浆中葡萄糖（GLU）和游离脂肪酸浓度均显著降低（P<0.05）;整个试验过程中,除停药第28天时试验Ⅰ组肉牛血浆中胰岛素（INS）水平显著高于对照组外（P<0.05）,β-受体激动剂对各试验组血浆中激素水平均无显著影响（P>0.05）。综合上述试验结果,肉牛血浆中的FFA可作为β-受体激动剂潜在的生物标志物,可通过对其的监测来监管β-受体激动剂在肉牛生产环节中的非法使用。     

A study of outbreaks of Aujeszky's disease in cattle. II. Further investigations on the routes of infection.

The probable routes of infection in 29 outbreaks of Aujeszky’s disease in cattle are discussed in the light of virological and epidemiological data, given in a preceding paper, and of histories of the individual outbreaks given in the present paper. The view was substantiated that anterior pruritus is mostly associated with infection by the respiratory route. In outbreaks with posterior pruritus the route of infection appeared to be a question of a more complex nature. With reference to cases examined later, it is concluded that perineal pruritus is often associated with vaginal infection. In a few cases there was evidence of virus transmission by man. Three cases with pruritus on a hind leg were suggestive of an alimentary infection. In many outbreaks with posterior pruritus, the route of infection remained obscure.