Influence of Iodine and Selenium Deficiency on the Milk Production, Macro and Trace Element Content of Ewe's Milk (Blackhead x Avassi)
L. ANGELOW, N. PETROVA, D. DOCHEVSKI and D. TODOROVA
Research Institute of Animal Science, BG-2232 Kostinbrod, Bulgaria
ANGELOW, L., N. PETROVA, D. DOCHEVSKI and D. TODOROVA, 2000. Influence of iodine and selenium deficiency on the milk production, macro and trace element content of ewe's milk (Blackhead x Avassi). Bulg. J. Agric. Sci., 6: 83-88
The Se-I-supplementation of a ewe ration with 0.15 mg Se/day and 0.20 mg I/day had a positive effect on the milk production, macro and trace element content of milk. The chronic Se- and marginal I-deficiency led to decrease of the daily milk production by 27%. The Se and I content of milk were also negatively influenced. The daily Se and I secretion were decreased by 67.6% (Se) and 82% (I). The low levels of Se and I had an antagonistic effect on the Zn-transfer into milk. The milk of control group contained twice more Zn in comparison to the deficient group milk.
The same effect was established for Ca and Mg content of milk, but in a smaller degree (35.4% and 28.4%).
The average daily trace element secretion of the control ewe's contained 3,1-times more Se, 5,6-times I and 2.1-times more Zn in comparison to the deficient animals.
Key words: lactating sheep, selenium-iodine deficiency, macro and trace content of milk