Abstract：
This case report investigated the outbreak of aflatoxicosis in a dairy herd in Pakistan, which resulted in 30 abortions of 40 confirmed (75%) pregnant cows in a period of 35 days and in 18.8% depression of farm average milk production for the entire herd. The analysis of the concentrate feed of the total mixed ration (TMR), using enzyme-linked immunosorbent assay (ELISA) procedures from two different local laboratories, indicated concentrations of 60 μg/kg dry matter (DM) of aflatoxin B1 (AFB1) and 100 μg/kg DM of total aflatoxins (AFs: sum of B1, B2, G1 and G2). Subsequently, a confirmatory analysis with a more sensitive and validated multi-metabolite liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was performed. This analysis detected a concentration of total AFs in the TMR of 166 μg/kg DM ± 3.5 (AFB1:134, AFB2:17.4 and AFM1:14.9 μg/kg DM). The concentrate feed (55% of the TMR DM) was confirmed as a source of contamination, presenting a concentration >29 times higher than the EU-maximum limit value (5.68 μg/kg DM). Additionally, the multi-mycotoxin analysis evidenced the co-occurrence of 81 other toxic and potentially toxic fungal metabolites in the fed TMR. After replacing the contaminated concentrate feed with feedstuffs of the same formulation but from a new charge of ingredients, the abortion episodes ceased, and milk production increased significantly. In conclusion, the data of this case report suggest that AFs may be associated with pregnancy losses in dairy cattle and milk production depression. From the public health perspective, the data also indicate the need for a more careful examination of dairy animal feed in Pakistan. Since the high concentration of AFB1 detected in feed and considering the literature-reported transfer rates (1-6%) of this toxin to AFM1 (carcinogen for humans) in milk, the milk produced during the outbreak period is expected to be contaminated with AFM1, which raises public health concerns.
摘要：
本病例报告调查了巴基斯坦一个奶牛群黄曲霉毒素病的爆发，这导致40头确认（75％）怀孕母牛的30例流产35天，整个牛群的农场平均产奶量降低了18.8％。总混合日粮（TMR）的精矿饲料分析，使用来自两个不同当地实验室的酶联免疫吸附测定（ELISA）程序，指示黄曲霉毒素B1（AFB1）的60μg/kg干物质（DM）和总黄曲霉毒素100μg/kgDM的浓度（AFs：B1，B2，G1和G2的总和）。随后，采用更灵敏和有效的多代谢物液相色谱-串联质谱(LC-MS/MS)方法进行了验证性分析.该分析检测到TMR中总AF的浓度为166μg/kgDM±3.5(AFB1:134,AFB2:17.4和AFM1:14.9μg/kgDM)。浓缩物进料（占TMRDM的55％）被确认为污染源，浓度高于EU最大限值（5.68μg/kgDM）的29倍。此外,多霉菌毒素分析表明,在饲喂的TMR中同时存在81种其他毒性和潜在毒性真菌代谢物.用相同配方但新配料的饲料代替受污染的浓缩饲料后，堕胎事件停止了,牛奶产量大幅增加。总之,该病例报告的数据表明，AFs可能与奶牛的妊娠损失和产奶量下降有关。从公共卫生的角度来看，数据还表明，巴基斯坦需要对奶牛饲料进行更仔细的检查。由于在饲料中检测到高浓度的AFB1，并且考虑到文献报道的这种毒素向牛奶中AFM1（致癌物）的转移率（1-6％），疫情期间生产的牛奶预计会受到AFM1的污染，这引起了公众的健康担忧。
