Bertilsson J, Andersson I, Johanson K J
Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala.
Health Phys. 1988 Dec;55(6):855-62. doi: 10.1097/00004032-198812000-00001.
Grass contaminated by radioactive fallout from the Chernobyl accident was cut with 150 mm (Treatment 1) and 50 mm (Treatment 2) stubble height and fed to 20 dairy cows. The transfer of 137Cs and 131I from the greencut forage to milk was studied during a four-week and a two-week period, respectively. The four-week period was followed by a three-week period with nearly uncontaminated feeds. Cutting with high stubble height significantly reduced the activity concentration in forage compared with low stubble cutting, the average contents kg-1 dry matter being 385 Bq 137Cs and 24 Bq 131I in Treatment 1 versus 6656 Bq 137Cs and 249 Bq 131I in Treatment 2. Apparent treatment effects were also demonstrated by the 137Cs concentration in milk, with maximum weekly means of 23 Bq kg-1 (Treatment 1) and 92 Bq kg-1 (Treatment 2). Single day maximum concentrations of 131I in milk were 4 Bq kg-1 (Treatment 1) and 9 Bq kg-1 (Treatment 2). The mean transfer coefficients (d kg-1) were calculated to be 0.67 X 10(-2) and 0.19 X 10(-2) for 137Cs (weeks 2-4) and 1.8 X 10(-2) and 0.2 X 10(-2) for 131I (week 2) in Treatments 1 and 2, respectively. The lower value for 137Cs might possibly be associated with an enhanced ash content of the forage. Feeding nearly uncontaminated rations rapidly decreased the 137Cs levels in milk in both treatments with calculated effective half-times over the three-week period of 10 and 7 d, respectively.
切尔诺贝利事故产生的放射性沉降物污染的草，被分别以150毫米（处理1）和50毫米（处理2）的茬高割下，并喂给20头奶牛。分别在为期四周和两周的时间内研究了137铯和131碘从青贮饲料向牛奶中的转移情况。在这四周之后是为期三周的几乎未受污染饲料喂养期。与低茬收割相比，高茬收割显著降低了饲料中的活度浓度，处理1中每千克干物质的平均含量为137铯385贝克勒尔和131碘24贝克勒尔，而处理2中分别为137铯6656贝克勒尔和131碘249贝克勒尔。牛奶中137铯的浓度也显示出明显的处理效果，每周最高平均值分别为每千克23贝克勒尔（处理1）和每千克92贝克勒尔（处理2）。牛奶中131碘的单日最高浓度分别为每千克4贝克勒尔（处理1）和每千克9贝克勒尔（处理2）。处理1和处理2中，137铯（第2 - 4周）的平均转移系数（每天每千克）经计算分别为0.67×10⁻²和0.19×10⁻²，131碘（第2周）的平均转移系数分别为1.8×10⁻²和0.2×10⁻²。137铯的较低值可能与饲料中灰分含量增加有关。在两种处理中，投喂几乎未受污染的日粮都迅速降低了牛奶中的137铯水平，在为期三周的时间内计算出的有效半衰期分别为10天和7天。
