Fission products and the dairy cow. 2. Some aspects of the metabolism of the alkaline-earth elements calcium, strontium and barium

Gastrointestinal fractional absorption of radionuclides in adult domestic ruminants

“…The true absorption value for barium of 5.5 Â 10 À2 was based on two experimental studies with cows orally administered 140 BaCl 2 reported in the review of Sirotkin (1991) and in an oral/intravenous study by Garner et al (1960). The recent review by Thorne (2003) gave a higher value of 0.2 based on the premise that the value for Sr can be applied to Ba.…”

Review of Russian language studies on radionuclide behaviour in agricultural animals: part 2. Transfer to milk

“…A slightly larger range in values was reported by Squire et al (1958) in an experiment with a single dose to five cows, from which F m values with a mean of (1.0 AE 0.27) Â 10 À4 d L À1 and a range of 7.1 Â 10 À5 e 1.4 Â 10 À4 d L À1 can be derived. The data in Garner et al (1960a), which result from a single oral administration of 140 Ba to one cow, can be used to derive an F m value of 6.2 Â 10 À4 d L À1 , if a milk yield of 9.1 L d À1 is assumed (based on feeding levels per unit volume milk production given in the paper and an associated similar experiment by the same authors, Garner et al, 1960b). For stable Ba, Ng et al (1982) reported an F m value of 9.9 Â 10 À4 d L À1 based on stable milk concentrations and unassociated plant concentrations, assuming 10 kg d À1 (DW) intake.…”

“…An experiment by Garner et al (1960a) in which a single dose of 45 Ca was given to two cows milked for 8 days gives an F m value of 1.8 Â 10 À2 d L À1 (using milk yields derived from feeding levels per unit volume milk production given in the paper and information in Garner et al, 1960b). Similar values of 6.5 Â 10 À3 d L À1 and 8.0 Â 10 À3 d L À1 can be derived from an experiment performed by Sansom and Garner (1966) in which a single administration of 45 Ca was given to two cows (milked over 8 days).…”

Study of calcium absorption in man: a kinetic analysis and physiologic model

“…More recently this time-consuming and cumbersome approach has been avoided by analysis of the fraction of radioactivity excreted in urine (5,6) or appearing in the forearm as determined by external monitoring (7) after oral and intravenous administrations of the isotope. This technique is based on the assumption (8) that fractional loss of the absorbed portion of the oral dose is identical with that of the intravenous dose and also permits quantification of the fraction of dose absorbed. The relative rate of appearance of the isotope in the circulation by serial blood samples (4,(9)(10)(11) or by external monitoring of the forearm (12) after oral administration alone has been used as a rough and rapid means to estimate relative calcium absorption in various states of altered calcium metabolism.…”