Battacone G, Nudda A, Cannas A, Cappio Borlino A, Bomboi G, Pulina G
Dipartimento di Scienze Zootecniche, Università degli Studi di Sassari, Via E. De Nicola 9, 07100 Sassari, Italy.
J Dairy Sci. 2003 Aug;86(8):2667-75. doi: 10.3168/jds.s0022-0302(03)73862-4.
Two experiments were conducted to study the amount of aflatoxin M1 (AFM1) in milk in response to feeding aflatoxin B1 (AFB1). In experiment 1, four dairy ewes in early lactation received a single dose of pure AFB1 (2 mg). Individual milk samples were collected during the following 5 d to measure AFM1 concentration. The average excretion of AFM1 in milk followed an exponential decreasing pattern, with two intermediate peaks at 24 and 48 h. No AFM1 was detected in milk at 96 h after dosing. The mean rate of transfer of AFB1 into AFM1 in milk was 0.032%, with a high individual variability (SD = 0.017%). In experiment 2, 16 dairy ewes in midlactation were divided into four groups that received different daily doses of AFB1 (0, 32, 64, and 128 microgram for control and groups T1, T2, and T3, respectively) for 14 d. Pure AFB1 was administered to each animal divided in two daily doses. Individual milk samples were collected at 12, 24, 36, 48, 72, 96, 144, 216, and 312 h after the first AFB1 administration, during the intoxication period, and every 24 h for 7 d after the withdrawal of AFB1. AFM1 was detected in the milk of all animals of the treated groups at 12 h after the administration of AFB1. In all treated groups, milk AFM1 concentration increased from 12 to 144 h after the beginning of administration. It then decreased, reaching a stable concentration at 216 and 312 h after the first administration. No AFM1 was detected in milk 3 d after the last administration of AFB1. Milk AFM1 concentration measured at steady-state condition was significantly affected by the AFB1 dose (0.031, 0.095, and 0.166 in T1, T2, and T3 groups, respectively), with a linear relationship between AFB1 dose and milk AFM1 concentration (R2 = 77.2%). The carryover (AFM1/AFB1 ratio) was not significantly affected by treatment, and its mean value was 0.112% (SE = 0.011). The carryover was lower than that reported for dairy cattle and goats, suggesting a better ability of sheep to degrade AFB1.
进行了两项实验，以研究饲喂黄曲霉毒素B1（AFB1）后牛奶中黄曲霉毒素M1（AFM1）的含量。在实验1中，四只处于泌乳早期的母羊接受了单剂量的纯AFB1（2毫克）。在接下来的5天内收集个体牛奶样本，以测量AFM1浓度。牛奶中AFM1的平均排泄呈指数下降模式，在24小时和48小时出现两个中间峰值。给药后96小时牛奶中未检测到AFM1。AFB1向牛奶中AFM1的平均转移率为0.032%，个体差异较大（标准差=0.017%）。在实验2中，16只处于泌乳中期的母羊被分为四组，分别接受不同日剂量的AFB1（对照组、T1组、T2组和T3组分别为0、32、64和128微克），持续14天。将纯AFB1分两次每日剂量给每只动物给药。在首次给予AFB1后的12、24、36、48、72、96、144、216和312小时收集个体牛奶样本，在中毒期间以及停用AFB1后7天内每24小时收集一次。给药后12小时，在所有处理组动物的牛奶中检测到AFM1。在所有处理组中，给药开始后牛奶中AFM1浓度从12小时到144小时升高。然后下降，在首次给药后216小时和312小时达到稳定浓度。最后一次给予AFB1后3天牛奶中未检测到AFM1。稳态条件下测量的牛奶AFM1浓度受AFB1剂量显著影响（T1组、T2组和T3组分别为0.031、0.095和0.166），AFB1剂量与牛奶AFM1浓度之间存在线性关系（R2=77.2%）。残留量（AFM1/AFB1比值）不受处理的显著影响，其平均值为0.112%（标准误=0.011）。残留量低于奶牛和山羊的报告值，表明绵羊降解AFB1的能力更强。
