年龄对蓝白花种公牛冻精质量的影响

以16头蓝白花种公牛为对象,对其采精适宜年龄及不同年龄对冻精质量的影响进行了研究。结果表明,蓝白花种公牛最初采精以20月龄为宜,3-6岁精液质量最好,7岁后精液质量呈下降趋势。     

Abnormal clonalities of B-lymphocytes in bovine leukemia virus-infected cattle with persistent lymphocytosis

Peripheral B-lymphocyte clonality of 274 bovine leukemia virus-infected cattle with lymphocytosis was analyzed using clonality PCR based on sequences of the variable region of the bovine immunoglobulin H chain. None of the cattle showed monoclonal proliferation, while 10, 31, and 233 showed minor-clonal, oligoclonal, and polyclonal proliferation, respectively. A total of 163 cattle were analyzable the following year, and lymphocytosis was maintained in 157, indicating persistent lymphocytosis (PL). B-lymphocyte clonality of the 157 PL cattle was minor-clonal in 6 (3.8%), oligoclonal in 8 (5.1%), and polyclonal in 143 (91.1%). A higher rate of enzootic bovine leukosis (EBL) onset within a year was observed in PL cattle with minor-clonal (50.0% (3/6)) and oligoclonal (25.0% (2/8)) proliferation compared to those with polyclonal (5.6% (8/143)) proliferation. Minor-clonal and oligoclonal proliferation in PL cattle may be a prognosis factor for developing EBL.     

BPI指数在西杂牛经济类型划分上的应用研究

[目的]进一步提高我区西杂牛的选育水平,为培育河西肉牛新类群提供理论依据。[方法]通过采用BPI指数法,对172头西杂牛的测定分析。[结果]一岁公牛BPI指数平均为6.81±1.24、二岁公牛为7.14±1.38、三岁公牛为5.58±1.47,均达到或超过5.9的肉用型指标;一岁母牛BPI指数平均为4.45±1.07、...     

初情期启动过程中小尾寒羊下丘脑GnRH基因甲基化状态及表达量关系研究

初情期启动的早晚关系到雌性动物的繁殖性能,GnRH是动物初情期启动过程中的关键基因,其启动子区甲基化状态与GnRH mRNA表达量之间的关系尚不清楚。本研究选择初情期前、临近初情期和初情期雌性小尾寒羊的下丘脑作为样本,利用亚硫酸氢盐测序(BSP)技术和实时荧光定量PCR(qRT-PCR)技术检测了初情期不同阶段小尾寒羊GnRH启动子区的甲基化状态和GnRH mRNA的表达量,并分析二者之间的关系。结果表明:小尾寒羊到达初情期时,GnRH基因启动子区甲基化水平显著降低(P0.05),尤其是在启动子区-570位点降低最明显,而随着初情期的启动GnRH mRNA表达量呈上升趋势。结果提示,初情期启动过程中,GnRH mRNA表达量升高可能与下丘脑GnRH基因启动子区特定位点甲基化水平降低存在一定的关系。     

Eradication of enzootic bovine leukosis from Finland

Enzootic bovine leukosis (EBL) was recognized among Finnish cattle in 1966. Administrative decisions specifying and refining official control measures were given in 1966, 1976, 1980, and 1993. The measures' key principle always has been 'test and slaughter'. The EBL/bovine leukosis virus (BLV) infection situation was monitored at meat inspection, and hematologically between 1970 and 1977 and serologically between 1978 and 1989. Annual surveys including all dairy herds and samples from beef animals were conducted in 1990-2001. Bulk-tank milk samples represented the dairy herds in the surveys; the beef animals were sampled individually at slaughter. The maximum positive herd-level percentage in the surveys was 0.03%. EBL/BLV infection was evenly dispersed in the southern part of the country and nonexistent in the northern part. We conclude that herd-level prevalence of EBL/BLV infection never exceeded 5%. It nevertheless took 30 years to eradicate the disease and the infection. EBL was eradicated from mainland Finland in 1996 and from the island district of Ahvenanmaa in 1999. Annual monitoring of the EBL situation continues.     

ASCL2基因在体细胞克隆牛和自然繁殖牛肺脏中的甲基化分析

为探讨ASCL2基因在体细胞克隆牛中的重编程状态,本研究通过亚硫酸氢盐测序法（BSP）对体细胞克隆牛和自然繁殖牛肺脏中ASCL2基因启动子区CpG岛上的CpG位点进行了甲基化状态分析。结果显示,体细胞克隆牛的甲基化水平（28.41%）显著高于正常对照组（7.62%）（P＜0.05）。推测ASCL2基因的异常甲基化可能是造成体细胞克隆牛新生死亡及肺脏发育异常的原因之一。     

泾源县肉牛养殖业现状问题及对策

草畜产业是宁夏农业优势特色产业之一,自治区提出建设以泾源县为核心区的"环六盘山清真肉牛产业带",先后实施了"两轮"肉牛产业项目,极大的助推了泾源肉牛养殖业快速发展。经过6年连续发展,肉牛养殖业已成为全县农民增收,带动地方经济可持续发展的主导产业。同时,泾源县肉牛产业发展成功经验,被自治区农牧厅总结形成了"泾源肉牛发展模式",在全区进行推广。     

Seroprevalence of enzootic bovine leukosis in Trakya district (Marmara region) in Turkey

In this study, 481 cattle belonging to 77 farms from nine localities in Trakya district in the Marmara region of Turkey were blood sampled and serologically tested for enzootic bovine leukosis (EBL). Antibodies to bovine leukosis virus (BLV) were detected in 51 cattle sera (11%) belonging to nine farms in five localities. Cattle tested were mostly female Holstein or Brown Swiss of ages ranging between 18 months and 10 years. Analysis of the relationships between age, breed or sex and seropositivity to EBL in seropositive herds indicated no significant associations (p>0.05). The relationship between seropositivity and haematological changes was also studied, and seropositive cattle had higher lymphocyte percentage and lower neutrophil percentage than seronegative cattle (p<0.001).     

Experiences in the control of brucellosis in cattle herds in the government district of Hannover

Caused by imported beef cattle new outbreaks of Brucellosis (subtype III) were observed in the government district of Hannover, which was "Brucellosis free" over a long period. With the aim to interrupt the series of infections from herd to herd it seemed to be necessary to introduce a herd screening system including frequent tests. It was not possible to screen the herds by the usual way of blood serum testing because of reasons of practicability and economy. A practicable alternative was the ELISA supported tank investigation. Four of the last six outbreaks were detected by this milk sampling. The other two infected herds were detected by only clinical symptoms because the lactating cows were not infected and had no contacts to the infected separately held heifers. The required test frequency in the dairy cattle herds could only be realized applying an ELISA supported highly sensitive tank milk test method. This method offered the chance of discovering infected herds as soon as possible and prevented greater economical losses and animal health risks. The tank milk screening of the dairy cattle herds to detect antibodies against Brucellosis (and additional EBL and IBR) has now become a standard method to continue the official status "free from..." This is a safer and a more economic alternative to the previous blood sampling of cattle older than two years with a three years interval because this method guarantees a safe information about the serological status of each cow which is now tested at least once a year, depending on the time of dry standing status.(ABSTRACT TRUNCATED AT 250 WORDS)     

固原市四县一区肉牛产业养殖现状分析与对策建议

固原市丰富自然资源为肉牛养殖提供了极好的条件。肉牛产业作为固原市畜牧业经济的重要支柱,其发展水平直接关系到当地市县经济的稳定增长和农民增收。笔者通过对固原市下辖四县一区的肉牛产业发展现状进行深入调研,充分了解了所面临的挑战,并提出了一些可行的对策建议,旨在促进该地区肉牛产业的高质量发展。     

Treatment of slipped capital femoral epiphysis in cattle: 11 cases (1974-1988)

A mixed population of 11 cattle (7 dairy, 4 beef; 9 male, 2 female) were examined because of acute onset of non-weightbearing hind limb lameness. Radiography revealed slipped capital femoral epiphyseal fracture in all cattle, with the exception of one large bull. Ten of the 11 cattle were treated with open reduction and internal fixation, using intramedullary pins. Cattle affected with slipped capital femoral epiphyseal fracture in previous reports typically have been calves that required forced extraction during dystocia. Cattle in this report were in the following 2 age groups in which trauma was the likely cause: 3 to 5 months and 1.5 to 2.3 years. Follow-up information was provided for 7 of the 10 cattle. Four of the 7 were functional and had no clinical signs of arthritis, abnormal gait, atrophy, scarring, contralateral compensation, breakdown, or other difficulty 6 months after surgical correction. If early diagnosis is achieved, it appears that reduction with intramedullary pinning can provide a good long-term prognosis in cattle when function as breeding animals is important to their future value.     

Association of a single nucleotide polymorphism in ribosomal protein L27a gene with marbling in Japanese Black beef cattle

Marbling, defined by the amount and distribution of intramuscular fat, is an economically important trait of beef cattle in Japan. The c2‐11#2 expressed sequence tag (EST) has been previously shown to possess expression difference in musculus longissimus muscle between low‐marbled and high‐marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus, the ribosomal protein L27a (RPL27A) gene containing the c2‐11#2 EST sequence was considered as a positional candidate for the gene responsible for marbling. In the present study, a single nucleotide polymorphism (SNP) in the promoter region of the RPL27A, referred to as g.3109537C>T, was detected between the 2 steer groups. The SNP was associated with the predicted breeding value for beef marbling standard number by the analyses using Japanese Black beef cattle population. The effect of genotypes of the SNP on the predicted breeding value for subcutaneous fat thickness was not statistically significant. These findings suggest that the RPL27A SNP may be useful for effective marker‐assisted selection to increase the levels of marbling in Japanese Black beef cattle.     

The recent prevalence of bovine leukemia virus (BLV) infection among Japanese cattle

A seroepidemiological survey of bovine leukemia virus (BLV) infection was conducted in Japan in 2007 using an enzyme-linked immunosorbent assay (ELISA) and an agar gel immunodiffusion (AGID) test. A total of 5420 cattle (dairy, 3966; breeding beef, 797; fattening beef, 657) from 209 farms in seven prefectures in Japan were tested. The overall prevalence of BLV infection was 28.6%. The prevalence of BLV infection in dairy cattle (34.7%) was higher than for both fattening beef cattle (7.9%) and breeding beef cattle (16.3%). Age-specific prevalence showed that BLV prevalence increased with age in all types of cattle and was notably different between dairy and beef cattle under 1 year of age. Among 207 farms, 141 herds (68.1%) had one or more positive animals. The proportion of these positive farms was significantly higher among dairy farms (79.1%) than among beef breeding farms (39.5%) and beef fattening farms (51.9%) (P < 0.001). Dairy farms (40.5%) also showed a significantly higher within-herd prevalence than beef breeding (27.4%) and fattening (14.9%) farms (P = 0.001). This study indicated that BLV is more widely spread in dairy cattle than in beef breeding cattle in Japan. Given the prevalence of BLV infection in dairy and beef cattle was 8- and 1.7-fold higher, respectively, than rates previously found in 1980–1982, BLV appears to be spreading particularly among the dairy cattle population during the last two decades. Further investigation is required to determine the risk factors necessary to control BLV infection that take into account the different farming practices that exist between dairy and beef sectors.     

内蒙古肉牛运输的动物福利问题及对策分析

随着近年来规模化肉牛养殖的兴起,内蒙古作为我国和世界重要的高品质牛肉输出基地,其肉牛产量持续增加,但由于运输环节福利理念的欠缺以及操作不规范,肉牛在运输后出现了瘀伤、血斑、DFD肉、胴体重量减轻、运输应激等问题,导致部分牛肉色泽不佳、风味劣化、肉品等级降低,严重影响着牛肉的营养和安全性、肉牛产业以及农牧民的经济效益。因此,肉牛运输过程中的动物福利日益成为生产者和消费者关注的热点。综述了内蒙古肉牛运输中的动物福利问题及国内外研究现状,并提出了改善肉牛运输中动物福利的措施,以期为改善肉牛运输福利提高牛肉品质提供借鉴。     

Prevalence and distribution of bovine coccidia in Japan

A field survey was carried out on prevalence of bovine coccidia in 9 prefectures of Japan in the autumn of 1985. A total of 1,015 fecal samples was obtained from dairy and beef cattle more than 2 weeks old. Coccidial oocysts were found in 59.0% of all the samples examined. There were no significant differences in the prevalence between dairy and beef cattle of the same age group. The prevalence was the highest in the animals between 6 and 11 months old and decreased to 25% in those more than 24 months old. In the majority of the samples positive for oocysts, OPG (the number of oocysts per gram of feces) was less than 200. No clinical coccidiosis was found except in a few cases. Eleven Eimeria and one Isospora species were identified. Of these species, E. bovis and E. ellipsoidalis were the most prevalent, followed by E. aubrunensis, E. brasiliensis, and E. cylindrica in all the prefectures. The other species identified were E. canadensis, E. alabamensis, E. zuernii, E. wyomingensis, E. bukidnonesis, E. subspherica, and Isospora sp. in the order of frequency. Isospora sp. will be a pseudoparasite caused by the contamination with feces of passerine birds.     

Serum bile acid concentrations in clinically normal cattle: comparison by type, age, and stage of lactation.

Serum total bile acid concentrations were determined for various types and ages of cattle. There was extreme variability among all the cattle, but the variance was twice as large (0.50 vs 0.22 in logarithmic scale) for beef cattle than for dairy cattle. There was no significant difference in serum total bile acid concentrations between beef cattle and dairy cattle in midlactation. Values for calves < 6 weeks old and for 6-month-old heifers were significantly (P = < 0.05) lower than values for lactating dairy cows. The 5th to 95th percentile range of values (mumol/L) for beef cattle was 9 to 126; for lactating dairy cattle, 15 to 88; and for 6-month-old dairy heifers, 11 to 64.     

重庆市肉牛产业发展现状分析与对策建议

以目前重庆市肉牛产业发展现状为背景,分析了近年来重庆市肉牛产业发展现状、生产水平、产业化水平以及肉牛业发展急需解决的关键技术问题,对今后重庆市肉牛产业发展提出了对策和建议,为推动新形势下重庆市肉牛产业可持续发展提供参考。     

品种、年龄及活重对牛产肉性能的影响

为了确定在优质牛肉生产中所需解决的宰前关键问题,本文在相同饲养条件下品种、年龄及体重等因素对牛产肉性能的影响做了研究。结果表明,品种对牛肉的品质和产量都有显著或较显著的影响,其中晋南牛牛肉品质最佳;活重对牛肉产量有较大影响;年龄主要对肉质影响显著,其中年龄在2-2.5岁间的牛肉嫩度最好,因此,要提高牛肉的生产水平应以产肉性能优良的品种作牛源,同时选择年龄小、体重大的个体。     

Alternative BSE risk assessment methodology for beef and beef offal imported into Japan

The Food Safety Commission (FSC) of Japan, established in July 2003, has its own initiative to conduct risk assessments on food stuffs known as "self-tasking assessment". Within this framework, the FSC decided to conduct a risk assessment of beef and beef offal imported into Japan from countries with no previous BSE reports; thus, a methodology was formed to suit to this purpose. This methodology was partly based on the previous assessments of Japanese domestic beef and beef imported from U.S.A./Canada, but some modifications were made. Other organizations' assessment methods, such as those used for BSE status assessment in live cattle by the OIE and EFSA's GBR, were also consulted. In this review, the authors introduce this alternative methodology, which reflects (1) the risk of live cattle in the assessed country including temporal risks of BSE invasion and domestic propagation, with the assessment results verified by surveillance data, and (2) the risk of beef and beef offal consisting of cumulative BSE risk by types of slaughtering and meat production processes implemented and the status of mechanically recovered meat production. Other possible influencing factors such as atypical BSE cases were also reviewed. The key characteristic of the current assessment is a combination of the time-sequential risk level of live cattle and qualitative risk level of meat production at present in an assessed country.