Mycotoxin Cocktail in the Samples of Oilseed Cake from Early Maturing Cotton Varieties Associated with Cattle Feeding Problems

Cottonseed cake in South East Asia has been associated with health issues in ruminants in the recent years. The present study was carried out to investigate the health issues associated with cottonseed cake feeding in dairy animals in Pakistan. All the cake samples were confirmed to be from early maturing cotton varieties (maturing prior to or during Monsoon). A survey of the resource persons indicated that the feeding problems with cottonseed cake appeared after 4–5 months of post-production storage. All the cake samples had heavy bacterial counts, and contaminated with over a dozen different fungal genera. Screening for toxins revealed co-contamination with toxic levels of nearly a dozen mycotoxins including aflatoxin B₁ + B₂ (556 to 5574 ppb), ochratoxin A + B (47 to 2335 ppb), cyclopiazonic acid (1090 to 6706 ppb), equisetin (2226 to 12672 ppb), rubrofusarin (81 to 1125), tenuazonic acid (549 to 9882 ppb), 3-nitropropionic acid (111 to 1032 ppb), and citrinin (29 to 359 ppb). Two buffalo calves in a diagnostic feed trial also showed signs of complex toxicity. These results indicate that inappropriate processing and storage of the cake, in the typical conditions of the subcontinent, could be the main contributory factors regarding the low quality of cottonseed cake.     

一株牛源约翰逊不动杆菌的分离鉴定

目的分离并鉴定1株致2018年7月四川省某肉牛场肉牛患呼吸道疾病并死亡的约翰逊不动杆菌。方法采集发病牛鼻腔拭子并从中分离得到一株优势菌株,对其进行形态学鉴定、生化鉴定、测定16s rRNA基因序列,用MEGA-X软件进行同源性分析、构建进化树,并进行药敏检测。结果分离菌为革兰染色阴性短杆菌,生化特性与约翰逊不动杆菌相符合,16S rRNA序列与GenBank中约翰逊不动杆菌株的同源性均达99%,因此将分离菌确定为约翰逊不动杆菌,并命名为ZZCNC-7B。8只SPF级昆明小鼠用1.4×10⁸ CFU/ml的ZZCNC-7B菌液腹腔注射(0.2 ml/只)后出现精神沉郁、腹式呼吸、眼部出现黏性分泌物、眼睑粘连、畏寒抱团等症状,有6只小鼠在16~36 h内死亡,另2只小鼠出现相同的症状但仍存活。剖检死亡小鼠,大体观察肺、肾充血肿大;肝、脾淤血肿大,肠道积气积液;组织学观察肺充血、出血,肝淤血,脾淤血、出血,肾小管坏死等病变。药敏试验显示,分离菌对四环素类药物四环素和磺胺类药物磺胺异恶唑耐药,对氨苄西林、亚胺培南、左氧氟沙星以及庆大霉素等药物均敏感。结论病牛分离菌为约翰逊不动杆菌,对小鼠具有较强的致病性和致死性,可引起肉牛呼吸道感染,甚至导致肉牛死亡,应引起高度重视。     

Carrier Status of Leptospirosis Among Cattle in Sri Lanka: A Zoonotic Threat to Public Health

Leptospirosis is a zoonotic disease of global importance and one of the notifiable diseases in Sri Lanka. Recent studies on human leptospirosis have suggested that the cattle could be one of the important reservoirs for human infection in the country. However, there is a dearth of local information on bovine leptospirosis, including its implications for human transmission. Thus, this study attempted to determine the carrier status of pathogenic Leptospira spp in cattle in Sri Lanka. A total of 164 cattle kidney samples were collected from the meat inspection hall in Colombo city during routine inspection procedures conducted by the municipal veterinary surgeons. The DNA was extracted and subjected to nested PCR for the detection of leptospiral flaB gene. Amplicons were sequenced, and phylogenic distances were calculated. Of 164 samples, 20 (12.2%) were positive for flaB‐PCR. Sequenced amplicons revealed that Leptospira species were deduced to L. borgpetersenii (10/20, 50%), L. kirschneri (7/20, 35%) and L. interrogans (3/20, 15%). The results indicate that a high proportion of the sampled cattle harbour a variety of pathogenic Leptospira spp, which can serve as important reservoirs for human disease.     

Measurement of Sterigmatocystin Concentrations in Urine for Monitoring the Contamination of Cattle Feed

This study aimed (1) at determining the levels of the fungal toxin sterigmatocystin (STC) in the feed and urine of cattle and (2) at evaluating the effects of supplementing the feed with a mycotoxin adsorbent (MA) on STC concentrations in urine. Two herds of female Japanese Black cattle were used in this study. The cattle in each herd were fed a standard ration containing rice straw from different sources and a standard concentrate; two groups of cattle from each herd (n = six per group) received the commercial MA, mixed with the concentrate or given as top-dressing, whereas a third group received no supplement and served as control. Urine and feed samples were collected at various time points throughout the experiment. STC concentrations were measured using liquid chromatography-tandem mass spectrometry (LC-TMS). STC concentrations in straw were higher in Herd 1 (range 0.15–0.24 mg/kg DM) than in Herd 2 (range <0.01–0.06 mg/kg DM). In Herd 1, STC concentrations in urine significantly declined 2 weeks after replacing the contaminated feed, whereas MA supplementation had no effect. In conclusion, mycotoxins in urine samples are useful biological markers for monitoring the systemic exposure of cattle to multiple mycotoxins, as well as evaluating the effectiveness of interventions.     

A Vaccine Based on the A/ASIA/G-VII Lineage of Foot-and-Mouth Disease Virus Offers Low Levels of Protection against Circulating Viruses from the A/ASIA/Iran-05 lineage

The recent emergence and circulation of the A/ASIA/G-VII (A/G-VII) lineage of foot-and-mouth disease virus (FMDV) in the Middle East has resulted in the development of homologous vaccines to ensure susceptible animals are sufficiently protected against clinical disease. However, a second serotype A lineage called A/ASIA/Iran-05 (A/IRN/05) continues to circulate in the region and it is therefore imperative to ensure vaccine strains used will protect against both lineages. In addition, for FMDV vaccine banks that usually hold a limited number of strains, it is necessary to include strains with a broad antigenic coverage. To assess the cross protective ability of an A/G-VII emergency vaccine (formulated at 43 (95% CI 8–230) PD₅₀/dose as determined during homologous challenge), we performed a heterologous potency test according to the European Pharmacopoeia design using a field isolate from the A/IRN/05 lineage as the challenge virus. The estimated heterologous potency in this study was 2.0 (95% CI 0.4–6.0) PD₅₀/dose, which is below the minimum potency recommended by the World Organisation for Animal Health (OIE). Furthermore, the cross-reactive antibody titres against the heterologous challenge virus were poor (≤log₁₀ 0.9), even in those cattle that had received the full dose of vaccine. The geometric mean r₁-value was 0.2 (95% CI 0.03–0.8), similar to the potency ratio of 0.04 (95% CI 0.004–0.3). Vaccination decreased viraemia and virus excretion compared to the unvaccinated controls. Our results indicate that this A/G-VII vaccine does not provide sufficient protection against viruses belonging to the A/IRN/05 lineage and therefore the A/G-VII vaccine strain cannot replace the A/IRN/05 vaccine strain but could be considered an additional strain for use in vaccines and antigen banks.     

贵州思南黄牛线粒体DNA D-loop区全序列多态性分析

为了解贵州思南黄牛的遗传多样性及遗传背景,我们测定了21个个体线粒体DNA D-loop区序列。检测到8种单倍型,4种为普通牛血统的单倍型,4种为瘤牛血统的单倍型,表明思南黄牛同时受普通牛和瘤牛的影响。这对于思南黄牛的保种及持续利用有着重要的理论指导意义。     

Practical Application of Urinary Zearalenone Monitoring System for Feed Hygiene Management of a Japanese Black Cattle Breeding Herd—The Relationship between Monthly Anti-Müllerian Hormone and Serum Amyloid A Concentrations

This study addresses an advantageous application of a urinary zearalenone (ZEN) monitoring system not only for surveillance of ZEN exposure at the production site of breeding cows but also for follow-up monitoring after improvement of feeds provided to the herd. As biomarkers of effect, serum levels of the anti-Müllerian hormone (AMH) and serum amyloid A (SAA) concentrations were used. Based on the results of urinary ZEN measurement, two cows from one herd had urinary ZEN concentrations which were two orders of magnitude higher (ZEN: 1.34 mg/kg, sterigmatocystin (STC): 0.08 mg/kg in roughages) than the levels of all cows from three other herds (ZEN: not detected, STC: not detected in roughages). For the follow-up monitoring of the herd with positive ZEN and STC exposure, urine, blood, and roughage samples were collected from five cows monthly for one year. A monitoring series in the breeding cattle herd indicated that feed concentrations were not necessarily reflected in urinary concentrations; urinary monitoring assay by ELISA may be a simple and accurate method that reflects the exposure/absorption of ZEN. Additionally, although the ZEN exposure level appeared not to be critical compared with the Japanese ZEN limitation in dietary feeds, a negative regression trend between the ZEN and AMH concentrations was observed, indicating that only at extremely universal mycotoxin exposure levels, ZEN exposure may affect the number of antral follicles in cattle. A negative regression trend between the ZEN and SAA concentrations could also be demonstrated, possibly indicating the innate immune suppression caused by low-level chronic ZEN exposure. Finally, significant differences (p = 0.0487) in calving intervals between pre-ZEN monitoring (mean ± SEM: 439.0 ± 41.2) and post-ZEN monitoring (349.9 ± 6.9) periods were observed in the monitored five cows. These preliminary results indicate that the urinary ZEN monitoring system may be a useful practical tool not only for detecting contaminated herds under field conditions but also provides an initial look at the effects of long-term chronic ZEN/STC (or other co-existing mycotoxins) exposure on herd productivity and fertility.     

广西地区家畜牛、羊体表硬蜱情况调查及种类鉴定

目的 掌握广西地区牛羊场硬蜱种类及其分子特征,了解该地区蜱类的分类地位,为养殖户防控硬蜱及蜱媒传染病提供参考依据。方法 本实验于2019年1月至2021年11月,采用动物体表法采集寄生的蜱类;提取蜱基因组,PCR扩增3种硬蜱的线粒体16S rDNA和COI基因片段,并进行同源性分析。基于邻接法,用MEGA6.0软件分别构建系统发生树,进行遗传进化分析。结果 牛羊体表上共采集蜱2 030只,隶属1科2属3种,其中微小扇头蜱1 968只,长角血蜱49只,具角血蜱13只。PCR扩增微小扇头蜱、长角血蜱和具角血蜱16S rDNA和COI基因片段长度分别是460 bp和710 bp左右,分别与GenBank中已登录的相应种类相似较高且在一个进化分支上。结论 广西地区牛羊场优势蜱种是微小扇头蜱且存在长角血蜱和具角血蜱。三蜱种16S rDNA和COI序列存在多样性和地域差异性。     

First detection and molecular identification of Neospora caninum from naturally infected cattle and sheep in North Africa

Neosporosis, caused by the protozoan Neospora caninum , is a major cause of reproductive failure in ruminants causing enormous economic losses. The objective of this study was to estimate the infection rate and molecular identification of N. caninum in Tunisian cattle and sheep. A total number of 348 meat samples were collected from 150 cows and 198 ewes slaughtered in the regional slaughterhouse of Béja (North‐west Tunisia) and tested for the presence of N. caninum ITS 1 gene using PCR followed by sequencing of some PCR products. A phylogenetic tree was then constructed to compare the partial sequences of the ITS 1 gene with GenBank sequences. The overall molecular infection prevalence of N. caninum was significantly higher in cattle than in sheep (22 and 10.6%, respectively, p  = .003). In sheep, the highest prevalence was observed in the northern Béja locality (31.2 ± 16.1), with the Noire de Thibar breed as the most infected sheep breed (31.7 ± 14.2%) (p  < .001). In cattle, there were no differences in the molecular prevalence of N. caninum according to breeds and localities. The association between age and N. caninum molecular prevalence was statistically significant in both species; the highest prevalence was observed in sheep of more than one year of age (19.4 ± 9.1%), and in cattle between two and eight years of age (28.8 ± 10.9%). Comparison of the partial sequences of the ITS 1 gene revealed 96%–100% similarity among our N. caninum amplicon and those deposited in GenBank. To our knowledge, this is the first detection and molecular identification of N. caninum in sheep and cattle in North Africa. This information is pertinent in designing control programmes that would reduce economic losses in the livestock industry.