Extremes of Environmental Temperature and the Transfer of Radioiodine Into Milk

Abstract

Tw goats were kept at 33°C and 5°C to determine the amount of radioiodine transferred to milk after an oral dose. At 3YC, 16.8% of the oral '*'I was in the milk as opposed to 2.6% at 5°C. This is a 6.5-fold difference and suggests difficulties for prediction equations based upon actual amounts of radioiodine secreted into milk. Using F values it was judged that the shape of the milk secretion curve was relatively the same between goats and temperatures. This suggests that prediction procedures based on the shape of the milk transfer curve could be more precise.

The Importance of Source-Dependent Bioavailability in Determining the Transfer of Ingested Radionuclides to Ruminant-Derived Food Products

“…Therefore, it is unlikely that the source of radioiodine ingested by lactating ruminants will be a major factor in determining its activity concentration in milk. However, many other environmental and physiological factors such as temperature (57), milk yield (39), stable iodine status (58), and the presence of goitrogens in the diet (59) will influence the activity concentration of radioiodine in milk.…”

Scientific Opinion on the safety and efficacy of Iodine compounds (E2) as feed additives for all species: calcium iodate anhydrous (coated granulated preparation), based on a dossier submitted by Doxal Italia S.p.A.

“…Differences in feeding practices in summer and winter may contribute to the differences in iodine concentration in milk in summer and winter. Previous findings indicate that ambient temperatures also influences the iodine concentration in milk (which increases with increasing environmental temperature: Lengemann, 1979;Lengemann and Wentworth, 1979). The use of iodine as a disinfectant (udder hygiene, teat dipping, disinfection of the milking machine and other equipment) may also influence iodine content in milk (reviewed in EFSA, 2005;; see also Table E3 in Appendix E).…”

Scientific Opinion on the safety and efficacy of iodine compounds (E2) as feed additives for all animal species: calcium iodate anhydrous and potassium iodide, based on a dossier submitted by Ajay Europe SARL

“…Differences in feeding practices in summer and winter may contribute to the differences in iodine concentration in milk in summer and winter. Previous findings indicate that ambient temperatures also influences the iodine concentration in milk (which increases with increasing environmental temperature: Lengemann, 1979;Lengemann and Wentworth, 1979). The use of iodine as a disinfectant (udder hygiene, teat dipping, disinfection of the milking machine and other equipment) may also influence iodine content in milk (reviewed in EFSA, 2005;; see also Table D3 in Appendix D).…”