Temperament assessments of lactating cows in three contexts and their applicability as management traits

The applicability of three behavioral assessments of lactating cows as management traits was verified. Flight responses to an approaching human (flight starting and walking distances, and flight walking speed) at pasture, entrance order into the milking parlour and step‐kick behavior to cup attachment were observed for 713 subject cows in six Australasian dairy farms. On all farms, cows were kept at pasture without any barn housing. Flight responses were measured once, and other assessments were recorded repeatedly for each subject cow. A principal component analysis was performed to verify whether these assessments appear to measure the same trait. A two‐way anova and correlation analyses were then used to test whether obtained principal components were affected by farm, age and milking stage of cows. Australian and some Japanese herd management systems were compared for flight distance using a one‐way anova and a multiple comparison test. Three behavioral assessments clustered in different principal components, indicating that these assessments did not appear to measure the same trait. Factor scores of four principal components were affected by farm (all, P < 0.01), and the scores of principal component 1, interpreted as fear of humans (r = ?0.16, P < 0.01), and component 2, interpreted as aversion to cup attachment (r = ?0.28, P < 0.01), were moderately correlated with age. These results emphasize the necessity of data standardization to reduce the non‐genetic variation resulting from these two affectors. The flight distance at pasture of herds in Australia (6.06 ± 2.85 m) was significantly (P < 0.05) different from the flight distances measured in paddocks (1.50 ± 0.82 m) and free‐stall barns (1.22 ± 1.09 m) in Japan. However, mean distances were not different between the Australian herds at pasture and the Japanese herds at pasture in tie‐stall barns (3.96 ± 2.16 m) or in a free‐stall barn (4.03 ± 1.79 m). This difference could be a result of the fact that only a single measurement was made, so that repeated measurement might improve the usefulness of flight distance as a management trait. In conclusion, it was verified that step‐kick behavior to cup attachment and flight responses to human approach were, although they have some affectors, applicable as objective management traits in lactating cows.     

中国奶牛周期的初步探索

本文对改革开放后我国生鲜乳价格、奶牛扩群和生鲜乳产量增速变化特点进行分析,提出奶牛养殖业存在类似典型畜牧业周期的“中国奶牛周期”,跨度长达8～9年,每个周期可分为“景气”+“调整”两阶段。牛奶消费增速不均衡、从业者非理性和奶牛繁殖长周期共同导致的生鲜乳供需错配,可能是中国奶牛周期产生的深层原因。通过4轮周期更替,当前我国奶牛养殖业在产业素质、一体化程度和产业成熟度方面均呈现积极变化。中国奶牛周期的探索对奶牛养殖业经营管理有积极参考意义。     

不同乳牛舍环境空气中细菌含量的比较研究

采用自然沉降法对南京3个规模化奶牛场和3个奶牛小区泌乳奶牛舍内细菌含量进行监测和比较。结果显示,牛舍环境空气中的细菌菌落总数,不同的牛舍不同采样点、不同的培养基其结果均不相同。运动场细菌菌落总数少于牛舍内。NA培养基菌落数最高达33.81×103 CFU/m3,MAC和S.S培养基在多个分布点无细菌生长。6个牧场空气中的细菌菌落总数为F场＞E场＞B场＞C场＞A场＞D场。牛舍的空气细菌总数与牛舍规模化程度无关,而与各牧场牛舍卫生管理有很大的相关性。从270个样本中共分离到338株细菌,A、B牧场主要是葡萄球菌,分别占分离菌的75.34%（55/73）和60.61%（40/66）;C、E、F牧场主要是肠杆菌,分别占分离菌的51.22%（42/82）、62.16%（23/37）、61.11%（33/54）;D牧场葡萄球菌占分离菌的46.15%（12/26）,肠杆菌和链球菌分别占26.92%（7/26）。结果表明,规模化奶牛场和奶牛小区空气细菌总数无明显差异。     

Locomotion Score and Its Impacts on Production Performance and Blood Routine Indexes in Chinese Holstein

To investigate the influencing factors of locomotion score (LS) and its impacts on production performance and blood routine index in Holstein,body condition score (BCS),LS and DHI (dairy herd improvement) of 1 486 lactating cows from two dairy farms,and the blood routine indexes of 101 lactating cows from one farm in Beijing were measured.The fixed model was used to analyze the impacts of herd,parity and lactation stage on LS,and the impacts of LS and BCS on daily milk yield,somatic cell score,milk composition and blood routine indexes in dairy cows.The results showed that both parity and lactation stage had significant impacts on LS.The LS increased with the increase of parit,the LS increased by 0.71 from first lactation to fifth and above lactation.The LS of cow in lactation stage Ⅲ(100-199 d) and Ⅵ (after 350 d) were significantly higher than cow in stage Ⅱ (45-99 d)(P<0.05),and both were higher than 2.The LS had no significant impacts on daily milk yield,milk composition and somatic cell score (P>0.05).However,the milk yield of the cow with LS≥4 was the lowest,and a decrease of 2.29 kg was found compared with the cow with LS=1.Among the various blood routine indexes,LS had significant impacts on red blood cell count,hemoglobin content,mean corpuscular hemoglobin concentration and lymphocyte count (P<0.05),and had no significant impacts on white blood cell count (P>0.05).With the increase of LS,the red blood cell count,hemoglobin content,mean corpuscular hemoglobin concentration and lymphocyte count of cows decreased with different extents.There were some problems on the body immunity and hematopoiesis of cows with poor LS.In dairy farm,regular evaluation of LS could be used to find the management problems of feet and legs,which had a great significance to reduce the loss of production performance and early culling caused by hoof disease.     

中国荷斯坦牛步态评分及其对生产性能和血常规指标的影响

为探究荷斯坦牛步态评分（locomotion score,LS）影响因素及其对生产性能和血常规指标的影响,本研究收集测定了北京地区2个规模化牧场1 486头泌乳牛的体况评分（body condition score,BCS）、LS和DHI（dairy herd improvement）数据,并测定了101头泌乳牛的血常规指标。采用固定模型分析了牧场、胎次和泌乳阶段对LS的影响,以及LS和BCS等因素对日产奶量、体细胞评分、乳成分和血常规指标的影响。结果表明,试验牛的胎次和泌乳阶段均对LS有极显著影响,LS随胎次的升高而增加,从1胎至5胎及以上,LS升高了0.71分;泌乳阶段Ⅲ（100~199 d）、Ⅵ（350 d以后）的LS均显著高于阶段Ⅱ（45~99 d）（P<0.05）,且均高于2分。LS对日产奶量、乳成分和体细胞评分均无显著影响（P>0.05）,但LS≥4分的奶牛日产奶量最低,较LS=1分的奶牛日产奶量降低了2.29 kg。各项血常规指标中,LS对奶牛红细胞数、血红蛋白含量、红细胞平均血红蛋白浓度、淋巴细胞数均有显著影响（P<0.05）,而对白细胞数无显著影响（P>0.05）。随LS升高,奶牛红细胞数、淋巴细胞数、血红蛋白含量和红细胞平均血红蛋白浓度均表现出不同程度的降低。LS较差的奶牛,其机体的免疫力和造血功能会受到不同程度的影响。在规模化牧场中,定期评估牛群的LS能及时发现牛群肢蹄管理的问题,对减少因肢蹄问题引起的生产性能损失和过早淘汰等具有重要意义。     

环境因素对散养奶牛的繁殖行为和繁殖性能的影响

1991～1994年在洛阳市奶牛场连续观察散养与栓系饲养体制下奶牛的发情表现、发情地点及每日的发情时间分布，统计每月的受胎率和奶牛的产后首次配种时间。结果表明，在散放饲养条件下，奶牛发情明显，发情行为期长；夏、冬季的受胎率低于春、秋季，明显地受温度的影响和五项气象因素的综合作用；五项气象因素对产后首次配种时间的综合影响显著。     

北流市(县)奶牛结核病流行病学调查研究

为预防、控制和净化北流市奶牛结核病,采用提纯牛型结核菌素(PPD)皮内变态反应诊断,开展奶牛结核病流行学调查。结果表明,厩棚阴暗潮湿、通风不良,无露天运动场,长期圈养,久而容易引起机体抵抗力降低,诱发奶牛结核病,11个奶牛养殖户中,有6户因如此环境饲养被检测有结核阳性牛共14头;4个奶水牛养殖户共奶水牛360头无一感染结核病,表明奶水牛更能适应北流市自然环境和对结核病不易感。     

海北州黑白花奶牛和黄牛唾液钠、钾含量的测定

对青海省海北州西海镇的30头黑白花奶牛和20头黄牛的唾液钠、钾含量进行了测定。结果表明：（1）黑白花奶牛唾钠为98．63mmol/L，唾液钾为16．87mmol／L, 钠／钾之比为6．68／1；（2）黄牛唾液钠为121．6mmol/L，唾液钾为16．41mmol/L，黄／钾之比为10．97／1；（3）黑白花奶牛和黄牛的唾液钠含量之间有显著性差异（P＜0．05）。     

奶牛酮病的防治

随着生活水平的提高,人民对牛奶的需求量也大幅增加,但频发的各类疾病却成为制约奶牛产业发展的重要因素。奶牛酮病是高产奶牛较常发生的营养代谢性疾病,可导致产乳量及受胎率明显降低,主要对该病的发病原因、发病规律及临床症状进行了介绍,并提出了具体的防治措施,以期为广大养殖户提供参考。     

温湿度指数与奶牛生产性能的关系

本研究用温湿度指数(THI)为指标,探讨了奶牛生产性能随THI变化的全年动态关系。奶牛的直肠温度、呼吸频率和乳中体细胞数在THI小于68时保持相对平稳,超过68时开始大幅度上升,而采食量、产奶量、乳脂率、乳蛋白率在THI小于70时保持相对平稳,超过70时开始大幅度下降。结果表明,只有当THI大于70时才会导致奶牛生产性能下降,THI每升高1个单位,产奶量下降0.4 kg。当THI从68上升到79时,THI每升高1个单位,乳脂率下降0.02%,乳蛋白率下降0.01%,体细胞数则上升2.77×104个/mL。奶牛生产性能指标、乳成分指标及乳中体细胞数与THI间均呈良好的三次曲线关系。因此,THI是用于评估温热环境对奶牛生产性能影响的一个有效且方便的指标。     

基于机器学习算法的奶牛疾病预测模型的研究

【目的】评估建立奶牛疾病预测模型的6种机器学习（machine learning,ML）算法的性能及预测变量的重要性。【方法】选取2020年12月至2021年11月,共计944头泌乳牛的生产信息、行为信息作为预测因子,疾病信息作为输出变量,训练并验证模型。将日产奶量、反刍量、活动量、胎次和泌乳天数作为输入变量,利用ML算法建立奶牛疾病的预测模型,评估决策树（Decision Tree,DT） C5.0、CHAID算法、人工神经网络（Artificial Neural Network,ANN）、随机森林（Random Forests,RF）、贝叶斯网络（Bayesian Networks,BN）和逻辑回归（Logistic Regression,LR）6种ML算法的性能,评估预测变量的重要性,以及将胎次和泌乳天数纳入预测变量后模型性能的改善情况。采用敏感性和特异性评估模型性能,按照权重排序评估输入变量对模型预测的重要性。【结果】DT C5.0算法敏感性>85%,特异性>90%,为性能最佳的模型;RF总敏感性为56.8%,对各类牛预测的性能较稳定;ANN、BN、DT CHAID则对样本量较多的疾病预测性能较好,可达74.4%;LR对病牛正确识别率不足40.0%,大多识别为健康牛。产奶量为RF、ANN、LR最重要的预测变量,泌乳天数为DT C5.0、CHAID和BN最重要的预测变量;纳入胎次和泌乳天数后,模型预测的敏感性平均提高9.8%。【结论】ML算法在对奶牛疾病的预测方面表现出很大潜力,其中,DT C5.0更适合用于预测奶牛疾病。产奶量和泌乳天数为疾病预测模型中相对重要的变量,此外,将胎次和泌乳天数纳入预测变量,可提高模型的预测精度。     

长三角地区冬季发酵床饲养与栓系式饲养奶牛泌乳性能和舒适度研究

本试验旨在比较长三角地区冬季发酵床与栓系式饲养奶牛泌乳、健康性能和舒适度等差异。于2018年1月21—27日在长三角地区某规模化奶牛场选择发酵床牛舍与栓系式牛舍的健康的4岁、2胎次、泌乳天数150 d左右荷斯坦奶牛各10头,检测泌乳性能、血液生化指标、舒适度。结果表明:发酵床与栓系式饲养奶牛的产奶量、乳品质、血常规指标无显著差异;在血液生化指标上,发酵床饲养奶牛胆碱酯酶和总胆固醇含量极显著低于栓系饲养奶牛;在舒适度指标上,发酵床饲养奶牛卧床躺卧率(75.05%)显著高于栓系式饲养奶牛(64.74%),其牛舍相对湿度(70.63%)也显著高于栓系式牛舍(61.58%),但卧床站立率(7.89%)极显著低于栓系式饲养奶牛(35.26%)。综上,长三角地区冬季发酵床饲养奶牛能在保持泌乳性能的基础上,在一定程度上提高奶牛的躺卧舒适度。     

Kisspeptin in the early post–partum of the dairy cow

Recently, a new molecule, kisspeptin (Kp), and in particular Kisspeptin 10 (Kp10), was implicated in stimulating the hypothalamic–pituitary–gonadal axis. The aim of this study was to evaluate circulating Kp10 levels in the early post–partum period of the dairy cow. Blood samples were collected from 40 dairy cows, at 10 (T10), 12 (T12), 14 (T14) and 16 (T16) days after calving. Progesterone (P4) levels were evaluated using ELISA, and levels of oestrogens (E2) and Kp were evaluated using a radio‐immunologic method. After an initial plateau, Kp10 significantly increased at T14 and decreased at T16. The P4 and E2 mean serum values remained in the physiological range. It is likely that Kp10 enhanced hypothalamic GnRH release as well as pituitary gonadotropin secretion, thus promoting follicular growth and the increase in E2 levels, which might have further enhanced Kp10 release through a positive feedback loop. To our best knowledge, this is the first report on the range of Kp10 blood concentration during the early post–partum period in the dairy cow. The results of our study will increase our current understanding of the complex neuro‐endocrine crosstalk underlying the resumption of ovarian cyclicity in the dairy cow.     

中草药对隐性乳房炎奶牛细胞免疫力的影响

选用当归、川芎、芍药、黄芪、蒲公英、丹参、益母草等中草药 ,配制成饲料添加剂 ,研究了其对奶牛淋巴细胞刺激指数 (SI)和中性粒细胞吞噬力的影响 ,并用北京隐性乳房炎检验液 (BMT)对供试牛进行疗效跟踪检验。结果表明 ,该中草药添加剂可显著提高SI(P<0 .0 5 )和中性粒细胞吞噬力 (P<0 .0 5 ) ,并能明显提高隐性乳房炎的转阴率。     

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.     

发酵床技术在奶牛养殖中的应用研究进展

随着奶牛集约化养殖规模的不断扩大,对周边环境造成的污染严重。发酵床养牛技术是一种新型环保养牛模式,核心技术是利用微生物的发酵处理达到粪尿免清理,有效解决了规模养殖带来的环境污染问题。综述了发酵床技术原理、发酵床中微生物、发酵床管理、发酵床的应用效果、奶牛粪污处理及资源化利用过程中存在的问题及策略,以期为集约化奶牛养殖和健康养殖提供参考。     

环形泰勒焦虫对奶牛免疫水平的影响

本试验选择5头感染环形泰勒焦虫的奶牛和5头健康奶牛,在第0天、第5天、第10天、第15天、第20天分别进行红细胞C3b受体花环率试验、红细胞免疫复合物花环试验、T淋巴细胞EA花环率试验和淋巴细胞转化率的测定。结果表明,感染环形泰勒焦虫的奶牛其红细胞免疫复合物花环、红细胞C3b受体花环率和淋巴细胞转化率明显低于健康奶牛,差异极显著。这说明环形泰勒焦虫对奶牛的免疫水平有明显的抑制作用。且随着检测时间的变化,免疫水平逐渐降低。     

日粮阳阴离子负平衡对预防奶牛围产期产褥热的影响(英文)

奶牛在围产期需经历内分泌、营养、代谢及生理状态上的一系列变化以适应分娩及泌乳的起动.如果营养管理不能较好的满足这些变化,那么奶牛则面临着发生各种围产期疾病的威胁.产褥热是一种常见的营养代谢病,多发于高龄及高产奶牛.奶牛分娩和泌乳的起动造成低血钙症,而当从肠道吸收的和从骨骼中动用的钙不能完全补充从血液中动用的血钙量时,产褥热就会发生.而有效的预防措施是减少产褥热带来经济损失的最佳途径.其中最常用的有效预防方法之一是饲喂阴离子日粮,即使得日粮阳阴离子负平衡(DCAD).这主要是由于日粮负离子平衡引起奶牛轻微的代谢酸中毒,并激发对骨钙的动员和吸收.然而,饲喂阴离子日粮亦存在一些问题:主要是其适口性较差,故可能降低干物质采食量.因此对于阴离子日粮饲喂管理的监控则十分重要,而尿液pH提供了一种有效且相对准确的用来判定添加是否适当的标准.此外,还对近年来此领域相关的研究结果进行了论述和探讨,以便读者了解利用日粮负离子平衡预防围产期奶牛产褥热发生的相关知识.     

Distribution of bacteria and seasonal and regional effects in a new database for mastitis pathogens in Finland

Abstract

A database containing pathogen-specific information on mastitis has been established in Finland. The data consist of the results from routine milk samples collected from clinical and subclinical mastitis and submitted to laboratories all over the country. In the database, bacteriological information has been recorded on an individual cow basis. A total of 77,051 pathogen records submitted to the database from 1 January 2004 to 1 January 2006 were retrieved for this preliminary report of pathogen distribution. Staphylococcus aureus (18.26% and 17.73%) and coagulase negative staphylococci (CNS) (17.57% and 23.51%) were the most frequently isolated pathogens from the milk samples. Seasonal and regional differences in pathogen distribution were also found. The pathogen information is primarily used for targeting the antimicrobial treatment of the cow, but also for designing specific mastitis control strategies for the herds. Pathogen data can also be useful for national mastitis control programmes and breeding programmes of dairy cattle for the selection of more resistant animals.     

脂肪对奶牛采食量及瘤胃消化的影响

随着人们对脂肪营养和生理功能认识的深入,多种脂肪产品用于高产奶牛生产中,大量试验结果证明,日粮中添加脂肪对奶牛采食量和瘤胃消化具有影响,作者综述了日粮脂肪在瘤胃内的代谢、日粮中添加脂肪对脂肪酸、干物质、碳水化合物、粗纤维和粗蛋白质采食量和瘤胃消化影响的研究进展。