Blood and tissue selenium concentrations in calves treated with inorganic or organic selenium compounds - A comparison

Abstract

Selenium concentrations were investigated in 5 calves treated parenterally with inorganic selenium (Group II), 5 calves treated orally with organic selenium (Group III), and 5 untreated control calves (Group I). Blood samples for analyses were collected at the beginning and at the end of the treatment period and tissue samples (liver, kidney, striated muscle, myocardium) after slaughter. Selenium was determined in the samples after microwave mineralisation using the hydride technique of AAS. Both treated groups showed highly significant increases in whole blood selenium concentrations (Group II from 53.4 ± 10.5 to 75.9 ± 4.0 μg.l-1; Group III from 70.25 ± 12.07 to 127.5 ± 16.7 μg.l-1). The comparison of tissue concentrations showed highly significant differences (P < 0.01) in the liver (213.3 ± 56.8, 206.5 ± 36.2 and 424.7 ± 88.4 μg.kg-1 wet tissue for the Groups I, II, and III, respectively), striated muscles (92.4 ± 29.2, 81.4 ± 12.1, and 263.4 ± 47.4 μg.kg-1 wet tissue for the Groups I, II and III, respectively), and myocardium (121.5 ± 31.8, 108.3 ± 9.6, and 251.4 ± 51.0 μg.kg-1 wet tissue for the Groups I, II and III, respectively) not only between Groups I and II, but also between Groups II and III. The among-group differences in selenium concentrations in the kidney (991.9 ± 49.1, 960.6 ± 36.3, and 1050.5 ± 336.8 μg.kg-1 wet tissue in the Groups I, II and III, respectively) were nonsignificant. It is apparent that oral administration of organic selenium resulted in higher tissue concentrations than parenteral administration of inorganic selenium. Highly significant (P < 0.01) correlations were found between selenium concentrations in the liver and striated muscles, in the liver and the myocardium, and in striated muscles and the myocardium (r = 0.78, 0.85, and 0.94, respectively). No relations were found between selenium concentrations in the kidney and other tissues. Highly significant (P < 0.01) correlations were also between the concentrations of selenium in the blood and in the liver, striated muscles, and the myocardium (r = 0.85, 0.80, and 0.77, respectively).