How knowledge of the gastrointestinal absorption of elements could be used to predict transfer to milk

Abstract

The quality and quantity of data used to derive transfer parameter values for milk are variable and there are many data gaps for elements/radionuclides which may need to be considered for risk assessment of the agricultural foodchain. There has been a recent focus on critically evaluating current methods to fill data gaps and on identifying extrapolation methods to derive suitable values for the elements, and particularly radioisotopes, with no or sparse data. The relationship between fractional absorption of elements in the ruminant gastrointestinal tract and transfer to milk has been explored to determine whether knowledge of the former can be used to predict the latter. A relationship has been derived between fractional absorption of elements and two empirical ratios commonly used to quantify transfer to milk; transfer coefficients (element concentration in milk divided by element daily intake) and concentrations ratios (concentration in milk divided by concentration in feed). We propose that fractional absorption may be used to predict the order of magnitude of the transfer to milk of elements/radionuclides for which no relevant data have yet been identified or collated.

Environmental Pathways of Radionuclides to Animal Products in Different Farming and Harvesting Systems

“…Fractional absorption values for the most well-studied radionuclide elements are given in Table 5.2. The number of data available on F a in ruminants for different radionuclides varies, and, therefore, so does the confidence attributable to each Howard et al (2016a) value. The F a values vary from almost negligible, in the case of actinides such as plutonium, to 100% for radioiodine (Howard et al 2009a(Howard et al , 2016a.…”

“…The extent of transfer of radionuclides into cow, sheep and goat milk has been reported as both F m and CR values in the IAEA publications TECDOC 1616 and TRS 472 (IAEA 2009(IAEA , 2010. The data for cow and goat milk has recently been updated during the IAEA MODARIA programme (Howard et al 2016a(Howard et al , b, 2017. F m and CR values for selected radionuclide elements that are most relevant for NRE in the MODARIA tables are shown in Tables 5.10 and 5.11 for cow milk and Tables 5.12 and 5.13 for goat milk, respectively.…”

Evaluation of Hematological and Metabolic Parameters in Small Ruminants with Trace Elements Deficiency under Different Biogeochemical Conditions.

“…Most plants of the region had Co and I deficiency (Ermakov, 2017). These trace elements deficiencies in the animal's diet would be a stress factor leading to metabolic disorders, as well as decreasing productivity and reproductive function (Howard et al, 2016). Different species of small ruminants were known to have some differences in the accumulation of trace elements in the conditions of their biogeochemical deficit (Howard et al, 2016).…”

“…These trace elements deficiencies in the animal's diet would be a stress factor leading to metabolic disorders, as well as decreasing productivity and reproductive function (Howard et al, 2016). Different species of small ruminants were known to have some differences in the accumulation of trace elements in the conditions of their biogeochemical deficit (Howard et al, 2016). According to Howard et al (2016), differences in Cupper (Cu), Zink (Zn), and Manganese (Mn) content in milk of sheep and goats grazed on the same semi-desert pastures in Pakistan revealed the deficient in these elements.…”

“…Different species of small ruminants were known to have some differences in the accumulation of trace elements in the conditions of their biogeochemical deficit (Howard et al, 2016). According to Howard et al (2016), differences in Cupper (Cu), Zink (Zn), and Manganese (Mn) content in milk of sheep and goats grazed on the same semi-desert pastures in Pakistan revealed the deficient in these elements. Meanwhile, they did not found any differences in Co and Se content in the milk of these animals.…”