Genetic diversity and historic introgression in German Angler and Red Dual Purpose cattle and possibilities to reverse introgression

Recovering native uniqueness has major importance for breeds with historic introgression. The aim of the study was to estimate population genetic parameters for two local red cattle breeds from Northern Germany and to study possibilities to reverse introgression. Genealogical information consisted of 90,783 individuals for German Angler and 187,255 individuals for Red Dual-Purpose cattle breed, with additional information on sex, born, breed, status, and conventional breeding values. It is concluded that the native genetic contribution could be included as an additional trait in the total merit index in order to recover a part of the native genetic background. Native contributions should be estimated in the long term from marker data in order to account for Mendelian sampling. The maintenance of a sufficient genetic diversity of native alleles can be achieved by an advanced OCS with appropriate constraints.     

8味中药对奶牛乳房炎病原菌的体外抑菌试验

选用金银花、连翘、蒲公英等8味中药分别采用乙醇回流法进行提取,用试管二倍稀释法测定来自奶牛乳房炎的3种主要致病菌(金黄色葡萄球菌、无乳链球菌、停乳链球菌)的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。结果显示,以金银花和连翘对金黄色葡萄球菌抑菌效果最强,MIC值均为15.63mg/mL,其MBC值为31.25mg/mL和62.5mg/mL;芙蓉花对大肠杆菌和无乳链球菌的效果最强,MIC值为31.25mg/mL和15.63mg/mL,MBC值为62.5mg/mL。本试验结果,对临床用药选取合适的中药有直接的指导意义,同时为体内用药的浓度提供参考依据。     

大通养牛业发展现状及思路

近年来,大通县按照县委、县政府制定的实施意见、发展思路和规划,把畜牧业作为"牧业增效、农民增收"为奋斗目标。调整畜牧业内部结构,优化区域布局,逐步建立和发展奶牛、肉牛养殖生产基地。进行专业化生产,规模化经营,科学化饲养,转变传统养殖观念,逐步树立现代科学养殖观念,大力发展奶牛、肉牛等一批优势主导产业,逐步建立奶牛、肉牛养殖生产基地,推动全县畜牧业的快速发展。本文对大通县养牛业发展现状进行了详细分析,并对今后的发展思路进行了探讨。     

安徽部分地区奶牛乳房炎病原菌的分离鉴定和药敏试验

为了调查安徽地区奶牛乳房炎流行情况和筛选病原菌敏感药物.采集了安徽省奶牛主要养殖区的隐性乳房炎奶样,分离、鉴定了主要病原菌,并筛选了敏感药物.结果表明,乳房炎主要病原菌为金黄色葡萄球菌、大肠埃希菌和无乳链球菌,且2种或2种以上病原菌混合感染占大部分,这些主要病原菌对环丙沙星、恩诺沙星、头孢曲松钠和卡那霉素等抗菌药物高度敏感,为奶牛乳房炎的治疗药物的选择提供了直接依据.     

基于DiMP的类特定养殖奶山羊跟踪方法

为准确实时跟踪羊只目标,进行疾病异常预警,实现奶山羊精细化养殖,本文基于DiMP跟踪模型,利用奶山羊跟踪对象单一且图像样本丰富的特点,结合迁移学习和类特定融合方法,设计了一种类特定的奶山羊目标跟踪模型,能够有效克服DiMP算法在跟踪类特定目标时定位精度不足的缺点。利用构建的奶山羊视频跟踪数据训练集对跟踪算法进行迁移训练,加快模型收敛速度,使评估网络预测出的边界框更贴合奶山羊真实框的位置和尺寸。在线跟踪阶段,针对目标模板仅采用第1帧特征制作整个序列的调制向量,导致该调制向量相对整个跟踪阶段特征不具代表性,与后续帧差异大的缺点,使用训练集制作包含奶山羊各种姿态的类调制向量,以指数消融方式更新奶山羊类调制向量与第1帧调制向量间的比重,增强边界框回归任务中的奶山羊特征与背景的判别性。提出的算法在测试集上的AUC(Area under curve)和精准度(Precision)分别为76.20%和60.19%,比DiMP方法分别提升6.17、14.18个百分点,跟踪速度为30 f/s,满足实时跟踪的要求。实验结果表明,提出的类特定奶山羊目标跟踪方法可用于监测复杂场景下奶山羊的运动,为奶山羊精细化...     

湖南省牛无浆体虫株分子生物学鉴定

用原虫16 S rRNA基因序列通用引物对湖南5个地区牛无浆体感染的阳性血液样品进行PCR扩增,经测序和序列拼接,获得5个无浆体样品16 S rRNA基因的部分序列,应用分子生物学软件进行分析,并根据所获得序列的保守区间设计特异性引物,进行PCR诊断方法的探讨性研究.结果表明,在通用引物下,5个地区无浆体感染的阳性血液样品均获得1 425 bp大小的虫体16 S rRNA基因条带;测序后5个无浆体16 S rRNA序列同源性均在97%～98%.证明5个分离虫株初步鉴定为牛边缘无浆体.     

肉牛经济性状关联的微卫星标记研究进展

微卫星序列是以1～6个短核苷酸为基本重复单位的重复序列,呈共显性、重复性好、多态性丰富和操作简单,在基因定位与QTL分析、亲权分析、分子标记辅助选择等方面应用广泛.本文综述了与肉牛部分经济性状(生长发育性状、胴体性状、肉质性状、多胎性状和出生重)相关的微卫星标记研究进展.     

The potential of replacing conventional dairy supplements with forage legume-based diets in Zimbabwe’s smallholder dairy sector

The effect of replacing commercial supplements with isoenergetic and isonitrogenous velvet bean-, cowpeaand lablab-based supplements on milk yield, milk quality and economic returns in smallholder crossbred dairy cows was investigated in the 2013 and 2014 dry seasons. Using 3 × 3 Latin square designs, nine multiparous Red Dane, Guernsey and Holstein-Friesian crosses in mid-lactation (130 ± 19 d) were offered forage legume-based supplements for 63 d at 0.5 kg per litre of milk produced. Milk quantity and quality were significantly (P < 0.05) different among supplements in both seasons. Cows fed commercial supplements had higher milk yield than cows fed forage legume supplements. Milk fat content was significantly (p < 0.05) higher in cows fed lablab-based supplements than cows fed other supplements. Milk protein, total solids and lactose content of cows fed commercial supplements was significantly (p < 0.05) higher than those fed forage legume-based supplements, although protein content was similar to cows fed lablab-based supplements. Dietary gross margins were higher for cows fed velvet beanand lablab-based supplements by 17% and 16.5%, respectively. Based on supplement, production costs per litre of milk was higher by 28% and 23% using commercial supplements compared to velvet bean and lablab supplements, respectively.     

Comparison Study of Growth Performance,Nutrient Digestion,Rumen Fermentation and Blood Physiological Indexes between Yaks (Bos grunniens) and Cattle (Bos taurus) under Low-Concentrate Barn Fattening北大核心CSCD

This study was aimed to compare the growth performance, nutrient digestion, rumen fermentation and blood physiological indexes between yaks (Bos grunniens) and cattle (Bos taurus) under low-concentrate barn fattening, which provide data reference and technical support for breed and feeding technology selection of fattening beef cattle in the Qinghai-Tibetan Plateau. In this experiment, six healthy yaks [(211 ±6) kg] and six healthy Qaidam cattle [(210±7) kg], all castrated and 4 years of age, were selected and raised in individual metabolic cages. The experimental diets consisted of concentrate (2.0 kg / d per head) and forage (ad libitum) . The pre-experiment lasted for 10 days, and the trial lasted for 95 days. The results showed as follows: 1) total dry matter intake were significantly lower in yaks than cattle (P<0.05), whereas average daily gain was not different between yaks and cattle (P>0.05), therefore, feed / gain was significantly lower in yaks than cattle (P<0.05) . 2) There was no difference between yaks and cattle in apparent digestibilities of nutrients (P>0.05) . 3) Ruminal pH tended to be higher (P = 0.083), and the concentrations of iso-volatile fatty acids (VFAs) were significantly greater in yaks than cattle (P<0.05), whereas the concentrations of total volatile fatty acids (TVFA), acetate, propionate and butyrate were not significantly different between yaks and cattle (P>0.05) . 4) Concentrations of ammonia nitrogen, free amino acid nitrogen and soluble protein nitrogen in rumen were significantly greater in yaks than cattle (P<0.05) . 5) The red blood cells (RBC) amount, hemoglobin (HGB) content, hematocrit (HCT) and red blood cell volume distribution width (RDW-CV) were significantly lower (P < 0. 05), whereas mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) content and platelets (PLT) amount were significantly higher in yaks than cattle (P<0.05) . In conclusion, yaks have lower feed intake, but have a greater feed conversion efficiency than cattle, therefore, yaks can produce a greater economic benefits than cattle under low-concentrate barn fattening system. © 2023 Authors. All rights reserved.     

Prevalence and Aetiology of Mastitis in Cows from Two Major Ethiopian Dairies

The study was undertaken to determine the aetiology and prevalence of mastitis in hand-milked cows (n = 186) in two major Ethiopian dairies. The California Mastitis Test and culturing for bacteria revealed that 21.5% of the cows were clinically infected and 38.2% had subclinical mastitis. Most mastitis pathogens isolated from milk samples testing positive by the California Mastitis Test were Gram-positive cocci. Staphylococci constituted 57% of the isolates, of which the predominant cause of bovine mastitis was Staphylococcus aureus (40.5%). Other mastitis pathogens isolated include streptococci (16.5%), coliforms (9%) and corynebacteria (5%). Retrospective analysis of farm records indicated that mastitis was the second most important cause of culling and accounted for 27% of the cows removed from these two dairies.