Contagious impetigo in a dairy cattle herd

Abstract Impetigo and fürunculosis appeared in a dairy cattle herd in association with intensive showering of the lactating cows during the summer months. Heifers and dry cows in the same herd, as well as those in a neighbouring herd in the same village, which was not showered and served as a comparison herd, remained unaffected. Skin lésions declined with the termination of showering. Only six animals [three cows (7.3%) and three first-calving cows (20%)] had to be treated parenterally with antibiotics. Resumen En un rebafio de vacas de leche aparecieron cuadros de impetigo y fürunculosis asociados a las duchas frecuentes aplicadas durante los meses de verano a las vacas lactantes. Las novillas y vacas secas en el mismo rebaño, asi como las de un rebaño vecino de la misma localidad y que no recibian duchas fueron usadas como rebaño de comparación, no se vieron afectadas. Las lesiones cutáneas remitieron al dejar de aplicar las duchas. Tan solo en seis animales [tres vacas (7, 3%) y tres vacas en primer parto (20%)] fue necesario aplicar una terapia parenteral con antibióticos. [Yeruham, I., Elad, D., Perl, S., Nyska, A., Vishinsky, Y. Contagious impetigo in a dairy cattle herd (Impetigo contagioso en un rebaño de vacas de leche). Veterinary Dermatology 1996; 7 : 239–242.] Résumé Impétigo et füronculose se sont manifestés dans un troupeau laitier, en relation avec un douchage intensif des vaches allaitantes pendant les mois d'été. Les jeunes et les vaches taries du même troupeau, ainsi que celles d'un troupeau voisin du même village, non douchées et servant d'élément de comparaison, restèrent inaffectés. Les lésions cutanées ont régressé dês la cessation des douchages. Seuls six animaux (trois vaches-7, 3%-et trois vaches primipares-20%-) durent etre traités par antibiothérapie parentérale. [Yeruham, I., Elad, D., Perl, S., Nyska, A., Vishinsky, Y. Contagious impetigo in a dairy cattle herd (Impétigo contagieux dans un troupeau de vaches laitières). Veterinary Dermatology 1996; 7 : 239–242.] Zusammenfassung Eine Impetigo und Furunkulose trat bei einer Milchviehherde in Verbindung mit intensivem Abduschen bei den laktierenden Kühen während der Sommermonate auf. Färsen und trockenstehende Kühe in der selben Herde sowie die einer Nachbarherde im selben Ort, die nicht abgeduscht wurden und als Vergleichsgruppe dienten, blieben unverändert. Die Hautveränderungen reduzierten sich mit Beendigung des Abduschens. Nur sechs Tiere (drei Kühe (7, 3%) und drei Kalbinnen (20%)) mußten parenteral mit Antibiotika behandelt werden. [Yeruham, I., Elad, D., Perl, S., Nyska, A., Vishinsky, Y. Contagious impetigo in a dairy cattle herd (Ansteckende Impetigo bei einer Milchviehherde). Veterinary Dermatology 1996; 7 : 239–242.]     

Pregnancy loss in dairy cattle in the Waikato region of New Zealand

AIM: To define the incidence rate of pregnancy loss and risk factors for those losses in pasture-fed dairy cattle in the Waikato region of New Zealand.

METHODS: Cows (n=2,004) from 10 pasture-fed, spring-calving dairy herds in the Waikato were enrolled following confirmation of pregnancy 29–45 days after insemination, for inseminations that occurred within the first 16 days of the seasonal breeding period. Transrectal ultrasonographic examinations for pregnancy were conducted at approximately 6, 8, 10, 14 and 22 weeks gestation, and subsequent calving data were recovered. Pregnancy loss was defined as having occurred when a confirmed pregnancy was not rediagnosed, when gross abortion was detected, or when a cow calved <265 days after the confirmed conception date. Data were analysed using reverse stepwise logistic regression and Cox's proportional hazards analysis.

RESULTS: A total of 128 (6.4%) pregnancy losses were detected. The incidence rate was higher in early compared to late gestation (10.9 vs 2.8 losses/10,000 cow-days between Weeks 6–10 vs Weeks 10–14, respectively; p<0.001). Higher rates of loss were associated with the occurrence of clinical mastitis (Hazards ratio (HR)=1.57; p=0.071), being treated for anoestrus (HR=1.69; p=0.007), and in cows that had calving-to-conception intervals ≤63 days compared with those that had calving-to-conception intervals >92 days (HR=2.49; p=0.06). In addition, the rate of pregnancy loss differed between herds (p=0.05).

CONCLUSIONS: The highest rate of pregnancy loss occurred in early gestation. Clinical mastitis, anoestrus and calving late in the calving season were risk factors for pregnancy loss.

CLINICAL RELEVANCE: Pregnancy diagnosis using ultrasonography can be undertaken from 28 days post-insemination. However, due to the high rate of pregnancy loss at this stage of gestation, herdowners need to be warned of possible losses, and cows should be re-examined to confirm pregnancy before certification of pregnancy status is given.     

Genetic correlations between body condition scores and fertility in dairy cattle using bivariate random regression models

Genetic correlations between body condition score (BCS) and fertility traits in dairy cattle were estimated using bivariate random regression models. BCS was recorded by the Swiss Holstein Association on 22,075 lactating heifers (primiparous cows) from 856 sires. Fertility data during first lactation were extracted for 40,736 cows. The fertility traits were days to first service (DFS), days between first and last insemination (DFLI), calving interval (CI), number of services per conception (NSPC) and conception rate to first insemination (CRFI). A bivariate model was used to estimate genetic correlations between BCS as a longitudinal trait by random regression components, and daughter's fertility at the sire level as a single lactation measurement. Heritability of BCS was 0.17, and heritabilities for fertility traits were low (0.01-0.08). Genetic correlations between BCS and fertility over the lactation varied from: -0.45 to -0.14 for DFS; -0.75 to 0.03 for DFLI; from -0.59 to -0.02 for CI; from -0.47 to 0.33 for NSPC and from 0.08 to 0.82 for CRFI. These results show (genetic) interactions between fat reserves and reproduction along the lactation trajectory of modern dairy cows, which can be useful in genetic selection as well as in management. Maximum genetic gain in fertility from indirect selection on BCS should be based on measurements taken in mid lactation when the genetic variance for BCS is largest, and the genetic correlations between BCS and fertility is strongest.     

An overview of dropped hock syndrome cases in New Zealand cattle

ABSTRACT

Case history: Data were collected from 47 outbreaks of dropped hock syndrome (DHS) that were reported by veterinarians in New Zealand to the Ministry for Primary Industries between October 2012 and August 2017. There were 181 affected dairy cows from 44 farms. Of those with records, all 86 were aged between 2–3 years-old, and 4/94 (4%) were Friesian, 56/94 (60%) were Jersey and 33/94 (35%) were Jersey/Friesian cross. Of the 47 outbreaks, 45 (96%) occurred during winter and 37 (79%) in the South Island.

Clinical findings: Of 151 cases with records, hindlimb weakness (117 cows), shortened gait (112 cows) and dropped hocks (106 cows) were most commonly reported, with 110 cases being bilaterally affected. The level of diagnostic work-up and the data recorded by veterinarians for each outbreak were highly variable. Creatine kinase and aspartate aminotransferase activities were reported for 22 cases and were within normal ranges for cows with mild disease but increased in cows with severe disease. Concentrations of Cu in serum and liver were below normal for 13/22 and 9/10 cows, respectively, from six outbreaks. Of 41 cows with records for clinical outcomes, 12 had complete resolution, 18 had partial resolution, and 11 had no resolution.

Pathological findings: Post-mortem data were available from 26 cases. Muscle necrosis and haemorrhage of the origin of the gastrocnemius muscle were the key gross findings. In 14 cows with records for muscle histopathology, myodegeneration and recent haemorrhage were observed, and connective tissue pathology was reported to predate muscular pathology in seven cases.

Diagnosis: DHS appeared to be a degenerative rather than inflammatory condition primarily affecting the connective tissue of the hind limb, especially at the dense collagen interfaces of the gastrocnemius. Although no evidence of neuropathy was found, this cannot definitively be ruled out as a potential cause.

Clinical relevance: A more standardised and systematic approach to investigating cases and recording case data is required to make robust inferences about the aetiology, risk factors, and treatment interventions for DHS.     

A herd level analysis of a Corynebacterium pseudotuberculosis outbreak in a dairy cattle herd

Corynebacterium pseudotuberculosis infection in an Israeli dairy cattle herd is described. The disease was characterized by ulcerative granulomatous lesions, which occurred in an epidemic form. Thirty-two cows and two heifers were affected, the ratio of the number affected to number at risk being 17.5 : 1 and 9.5 : 1, respectively. The culling rate was 50% of the affected animals. Most of the affected animals were cows (91.2%), with one first-calving cow (2.9%) and two heifers (5.9%) also affected. The infection occurred during the summer to autumn months (August-December), and lasted 118 days. The incubation period is about 2 months. The disease appeared in two clinical forms - cutaneous and mastitic - or as a mixed form. C. pseudotuberculosis organisms that were isolated from the ulcerative granulomatous lesions and from milk samples failed to reduce nitrate. A decrease in milk production (4%) and an increase in the bulk-milk somatic cell count from a herd mean of 240 x 10(3) mL(-1) to 460 x 10(3) mL(-1) were noted during the morbidity period. The organism was isolated from milk samples of eight animals (25%). Clinical, epizootiological and microbiological aspects of the infection are described.     

不同牧草在奶牛瘤胃内的降解规律

试验用尼龙袋法研究了不同种类牧草(黑麦草Lolium multiflorum、羊草Leymus chinese、返青期和盛花期紫花苜蓿Medicago sativa)的干物质(DM)、粗蛋白(CP)和粗纤维(CF)的在奶牛瘤胃内动态降解率变化规律.结果表明:在相同培养时间段内,返青期的紫花苜蓿DM的降解率显著高于黑麦草、羊草和盛花期的紫花苜蓿;不同生长期的紫花苜蓿其DM、CP的降解率差异显著(P<0.05),且返青期高于盛花期;各种牧草在48 h 的 CP 降解率都趋于平稳;经相关分析,各种牧草的DM、CP表现为强正相关关系.     

Risk factors for and reproductive outcomes of phantom cows on New Zealand dairy farms

AIMS: To determine some of the risk factors for cows not observed in oestrus within 35–42 days of an unsuccessful artificial insemination (AI; phantom cows), and the reproductive outcomes and effect of treatment of phantom cows.

MATERIALS AND METHODS: Over 2 years, in dairy herds from the Waikato (n=10) and Canterbury (n=4) regions of New Zealand, pregnancy diagnosis was carried out 35–42 days after AI on cows that had been inseminated in the first 3 weeks after the start of mating (PSM) but had not been seen returning to oestrus. Risk factors for phantom cows were analysed using a generalised linear mixed effect model.

In Year 1, all phantom cows were left untreated. In Year 2, phantom cows were categorised as having a corpus luteum (CL) (CL+ n=120), or having ovarian follicles ≥10 (n=101) or <10 (n=40)?mm in diameter. Cows with a CL were treated with cloprostenol or untreated and placed with bulls. Cows with no CL received intravaginal progesterone (P4) for 7 days, with injection of gonadotrophin-releasing hormone (GnRH) on Days 0 and 9, and cloprostenol on Day 7 followed by AI. Pregnancy diagnosis of all cows took place 100–120 days after PSM and interval to conception and final pregnancy rate determined.

RESULTS: Overall, of cows inseminated in the first 3 weeks after PSM that did not return to oestrus, 610/6,734 (9.1%) were phantom cows. From the final multivariable analysis, treatment for anoestrus, BCS ≤4.0 at mating, being 2 or >6 years of age, and pure-bred, and decreasing interval between calving and mating, until 98 days post calving, were associated with increased odds of being a phantom cow. Compared to all other groups of cows, phantom cows had a longer interval to conception (p<0.001) and a lower final pregnancy rate (p<0.001).

Treatment of CL+ cows or cows with follicles ≥10?mm did not affect reproductive outcomes (p>0.3). For cows with follicles <10?mm treatment decreased the final percentage not pregnant (3/27; 11%; p=0.01) and interval to conception (21 days; p=0.02) compared with controls (7/13; 54% and 37 days, respectively).

CONCLUSIONS AND CLINICAL RELEVANCE: Risk factors for phantom cows were identified that could be manipulated to reduce the number of phantom cows in a herd, in particular increasing BCS. Treatment of the majority of phantom cows did not improve reproductive performance.     

单菌株与多菌株微生态制剂在提高奶牛产奶性能上的应用

文章综述了单菌株和多菌株微生态制剂在提高奶牛产奶性能上的应用,分析探讨了两种微生态制剂应用中存在的问题,并提出一些解决措施,为其进一步研究提供参考.     

黑龙江省主要栽培的禾本科牧草对奶牛的营养价值评价

通过对常见的13种栽培禾本科牧草的常规营养成分测定及用尼龙袋法测定的干物质在瘤胃72 h降解率(RDMD)的测定,结果表明:l)用营养成分和RDMD等指标进行评定,2个冰草Agropyron cristatum品种营养价值最高,猫尾草Phleum pratense次之,3个披碱草Puccinellia tenuiflora品种居中,羊草Leymuschinensis和墨西哥玉米Zea mays较差,谷莠子Setaria anceps和稗草Echinochloa crusgalli最差。2)禾本科牧草RDMD与ADF、ADL含量呈极显著负相关(P<0.05)。利用回归方程可以用ADF、ADL含量来预测禾本科牧草的RDMD。3)应用干物质采食量(DMI)、产奶净能(NEL)估测模型计算了各种禾本科牧草的分级指数(GI)值,并参照豆科和禾本科牧草质量分级标准对研究测定的禾本科牧草等级进行划分,其结果是:符合优质牧草等级的有高冰草、中间冰草,符合中等牧草等级标准的有无芒雀麦Bromus inermis、垂穗披碱草、东北羊草、吉生羊草、百特猫尾草、猎犬披碱草、润宝高丹草Sorghum×Sudan。属于劣质牧草的有粗穗披碱草Elymus dahuricus、墨西哥玉米、稗草、谷莠子。4)用单一的营养指标如化学成分、干物质降解率不能准确地评价牧草的营养价值。只有综合考虑DMI、养分含量、消化率和有效能才能对牧草的营养价值做出正确的评价。使用GI值能明显区分养分含量差异很小的不同种类牧草,这说明分级指数是评价牧草营养价值的最权威指标。     

铜缺乏对奶牛肝脏金属硫蛋白代谢的影响

为阐明金属硫蛋白在铜缺乏奶牛肝脏中的代谢特征 ,选择铜缺乏区有明显临床症状的奶牛 6头 ,采集肝脏样品后用差速离心法分离肝脏金属硫蛋白 ,以Sephadex G75进行层析纯化 ,测定各部分洗脱液中金属元素铜、锌、铁、镁的含量。将 6头健康奶牛的肝脏样品作为对照。试验结果表明 ,发病奶牛肝细胞浆Sephadex G75柱层析洗脱液中铜、铁含量峰值显著高于健康奶牛 ,且在后面部分层析液中出现小峰 ;发病奶牛肝细胞浆金属硫蛋白 (MT)层析液锌、镁含量曲线峰值宽阔且高于对照组 ,第 2峰形宽大且有前移现象。结论 :铜缺乏能够改变奶牛肝脏中金属硫蛋白的代谢     

不同粗饲料对奶牛乳产量和乳成分的影响

选择18头荷斯坦奶牛,设置3个处理,每个处理6个重复,每个重复1头奶牛,研究不同粗饲料对奶牛泌乳性能和乳成分的影响,3个处理的粗饲料分别为玉米秸(Ⅰ组)、玉米秸+青贮玉米秸(Ⅱ组)、羊草(Ⅲ组)。试验结果表明:①试验Ⅱ组与试验Ⅲ组平均产奶量差异不显著(P>0.05),试验全期分别比Ⅰ组提高了8.82%(P<0.05)和9.57%(P<0.05);②不同处理间的乳糖、乳脂含量差异不显著(P>0.05);对于乳蛋白,在试验40d时3个试验组差异不显著(P>0.05),在第15d时Ⅱ组、Ⅲ组分别比Ⅰ组降低了7.43%(P<0.05)和8.57%(P<0.05)。对于乳干物质,Ⅱ组与Ⅲ组差异不显著(P>0.05)。根据上述生产性能指标综合评定,玉米秸+青贮玉米秸可有效替代羊草饲喂奶牛,而不降低泌乳性能。     

Association between age and time from calving and reported lameness in a dairy herd in the Waikato region of New Zealand

Abstract

CASE HISTORY: During the 2014/2015 season 823 predominantly Holstein-Friesian cows calved on a pasture-based farm in the Waikato region of New Zealand. A high prevalence and recurrence rate of lameness had been noted for several years but cows feet were not routinely picked up and therapeutically trimmed.

CLINICAL FINDINGS: At a farm visit in December 2015, 23 cows feet were examined and 18/23 (78%) cows had white line disease and 17/23 (74%) sole haemorrhages, as well as severely overgrown and misshapen hooves.

EPIDEMIOLOGICAL INVESTIGATION: Lameness, culling and reproductive data were collected for the farm for the period from 01 July 2014 to 30 November 2015. In the 2014/2015 season, 207/823 (25.2%) cows were recorded lame, and in the first half of the 2015/16 season 120/850 (14%) cows were recorded lame. Of the cows recorded lame, 52/207 (25.1%) in the 2014/15 season had >1 case of lameness, and 39/120 (32.5%) cows recorded lame in the 2015/2016 season had been lame in the previous season. There was an apparent increase in prevalence between 29–37 weeks post-calving. Cows >7-years-old had seven times the odds of being recorded as lame compared to 2–3-year-old cows (p<0.001). Lameness was not associated with culling, empty rate or days to conception (p>0.3).

DIAGNOSIS: No direct cause for the lameness could be determined.

CONCLUSIONS AND CLINICAL RELEVANCE: It was hypothesised that, along with the degenerative changes in the pedal bone as dairy cows increased in age, suboptimal treatment and overgrowth of hooves resulted in permanent changes in the cows feet, resulting in a high prevalence of lameness in older cattle and a high recurrence rate of lameness within and between seasons. This case highlights the importance of prompt identification and treatment of lame cattle.     

乳牛衣原体病灭活疫苗的研制

将免疫原性稳定的鹦鹉热衣原体SX5菌株灭活，加入油佐剂制备乳牛衣原体病灭活疫苗，并对疫苗的安全性进行了检测。用该疫苗对成年牛和犊牛进行了最小免疫量试验、效力试验和免疫持续期试验；结果表明，最小免疫量分别为3mL和5mL，平均免疫保护率达94．4％。免疫持续期达10个月。疫苗保存期试验表明，在4℃条件下可保存12个月。本动物安全试验和田间小试免疫证明，该疫苗安全性好，乳牛注射疫苗后饮食、产乳量及注苗部位没有明显的异常变化。     

氧化应激对奶牛的危害及其防治

氧化应激是当机体遭受到体内外各种有害刺激时,氧化系统和抗氧化系统失衡,自由基的产生量超过机体的清除能力,抗氧化系统不能及时清除过多的自由基而造成的。氧化应激与多种疾病的发生相关。奶牛的代谢水平高,更易发生氧化应激。本文就奶牛氧化应激的产生、氧化应激对奶牛的影响以及如何抑制奶牛氧化应激做一综述。     

Quantification of pericaudal adipocyte diameter in dairy cattle during peripartum: a complementary method to study energetic status using conventional histology

The energetic status of high‐yielding Holstein‐Friesian dairy cattle was studied during peripartum under field conditions using body condition score (BCS), glycemia, seric ß–hydroxybutyrate and adipose tissue cellularity. This last method was tested as a complementary tool for energetic status assessment. Biopsies of pericaudal subcutaneous adipose tissue were obtained from 25 multiparous animals at 28 days before and 21 days after parturition. Samples were routinely processed for histological examination and stained with haematoxylin and eosin (H&E). The mean diameter of adipocytes (MDA) was measured with the aid of a digital image processor. During the same period, blood samples were collected weekly for metabolite determinations. The MDA at 28 days pre‐partum and 21 days post‐partum were 72.1 vs. 66.2 μm respectively (p = 0.055), and the corresponding BCS at these moments was 3.32 vs. 3.19 (p = 0.068). At ?28 days pre‐partum, the BCS was positively correlated with MDA (Pearson’s r = 0.521, p = 0.016) and with glycemia (Pearson’s r = 0.404, p = 0.056). Correlations between BCS and MDA, and between BCS and glycemia, with ß–hydroxybutyrate although not significant, suggest that routine histological preparations of biopsies from subcutaneous adipose tissue could be included as an easy and valuable tool for research purposes to evaluate metabolic adaptation of dairy cows to peripartum, as well as the incidence of metabolic disorders and productive performance.     

浅谈热应激对奶牛的影响及调控措施

在炎热的夏季,热应激会导致奶牛生理机能发生紊乱,采食量下降,生产性能降低,甚至导致奶牛发病,严重者造成死亡。预防夏季奶牛热应激的发生,为奶牛创造适宜的、良好的饲养环境,可使奶牛安全、顺利地度过炎热的夏季,防止热应激造成不必要的损失。笔者等从奶牛热应激发生的原因与生理机制入手,综合论述热应激对奶牛的危害和预防热应激的调控措施。     

全混合日粮对奶牛产乳性能的影响

试验选用了12头奶牛,根据产奶量、泌乳天数和胎次相近的原则分为试验组和对照组,研究全混合日粮对奶牛产乳性能的影响。试验结果表明,试验组4％标准乳产量比对照组提高1 24kg,差异显著(P<0．05),乳脂率及乳脂、乳糖和乳固形物含量也分别比对照组显著提高11．60％、17．50％、13．21％和9．86％(P<0.05)。     

肉牛和奶牛家庭牧场发展现状与对策

为保证我国肉牛养殖业和奶牛养殖业的高速发展,经过多种养殖模式的对比,发现以家庭为主体集约化生产、商品化经营的家庭牧场更加适合未来畜牧业的发展趋势,我们认为肉牛和奶牛的家庭牧场式养殖已经成为我国畜牧业未来的发展方向之一。本文对我国肉牛和奶业发达国家的奶牛的家庭牧场发展现状进行了分析,并与畜牧业发达国家的家庭牧场进行对比,总结了我国家庭牧场在发展中存在的问题,并针对这些问题提出了未来我国家庭牧场的发展对策,以期促进我国肉牛和奶牛的家庭牧场持续健康发展。     

直接饲喂微生物对奶牛瘤胃发酵和肠道的影响

直接饲喂微生物(DFM)能够提高奶牛的日增重和饲料效率,增加奶牛的产奶量,改善犊牛的健康状况。然而其作用模式不是很明确。本文对目前应用在奶牛养殖方面直接饲喂微生物的种类及其与瘤胃和肠道的关系及作用模式进行综述。     

Use of thermal imaging for identification of foot lesions in dairy cattle

The objective of this study was to investigate the use of infrared thermography (IRT) for detection of foot lesions in dairy cattle. Thermal images of the rear feet of 139 lactating dairy cows were taken with a thermal camera and evaluated using imaging software. Foot lesions identified in the study included white line disease (WLD), sole ulcer (SU) and digital dermatitis (DD). Temperatures at the coronary band (CBT) and the skin (ST) were recorded. Cows were scored for locomotion on a scale of 1–5 (1?=?normal and 5?=?severely lame). CBT was higher for all types of foot lesion (34.1?±?2.3, 33.8?±?1.6 and 33.1?±?1.6°C for WLD, SU and DD, respectively) than for healthy (32.6?±?1.9°C) feet. ST was higher only for WLD (33.2?±?2.0°C) compared to healthy feet (31.5?±?1.7°C). ΔT (temperature difference between CBT and ST) was higher for SU (2.1?±?0.8°C) than healthy feet (1.1?±?0.9°C). Locomotion scores (LSs) were similar between healthy cows (2.2?±?0.7) and DD (2.4?±?0.7) but greater for SU and WLD cows (3.0?±?0.9, 3.0?±?0.8) than healthy cows. The threshold values established for CBT and ST were 33.5°C (sensitivity?=?77.8%, specificity?=?65.2%) and 33.7°C (sensitivity?=?44.4%, specificity?=?92.9%) for SU, and 34.4^oC (sensitivity?=?28.1%, specificity?=?88.6%) and 31.8°C (sensitivity?=?60.7%, specificity?=?55.4%) for overall lesion, respectively. These results indicate that IRT can be a useful tool for detection of SU, but not WLD and DD. In addition, CBT and ΔT were the best indicators for the detection of foot lesions.