Selenium and iodine status relationship in calves and heifers from selenium and iodine deficient areas in Serbia

Abstract

The selenium and iodine status was determined in calves (3, 6 and 9 months old) and heifers (12 months) on two farms (A-Kovin, and B-Vrbas) in iodine and selenium deficient areas of Serbia. Selenium concentrations in feedstuffs on the territories surrounding farm A and B were lower than 0.1 ppm in more than 90% of the samples and lower than 0.05 ppm in more than 67% of the samples. Plasma selenium concentrations in calves and heifers from both farms were very low, ranging from 1.58 to 9.42 µg/L. Plasma GSH-Px activity was very low in 3 month old calves: 8.4 ± 5.2 and 16.1 ± 4.3 µkat/L on farm A and B, respectively, and significantly higher in 12 month old heifers: 39.0 ± 6.2 and 40.8 ± 9.8 µkat/L on farm A and B, respectively. Mean plasma T4 levels in all groups of calves and heifers were relatively high, ranging between 57.1 and 102.9 nmol/L. Mean plasma T3 levels in calves and heifers from both farms ranged from 2.72 to 3.51 nmol/L, and did not vary significantly, except for the 3-month-old calves on farm B, where the level was significantly higher than in the other groups. A significant correlation was found between plasma GSH-Px activity and T3:T4 ratio in the 6- month-old calves from farm A (r2 = 0.80), as well as in the combined groups of 6-and 9-month old calves from farm B (r2 = 0.68).

Cilj ovog rada bio je da se odredi status selena i joda kod teladi (3,6 i 9 meseci starosti) i junica (12 meseci starosti) sa područja Srbije koja su deficitarna sa jodom i selenom. Ogled je izveden na ukupno na 64 životinje podeljene na 8 grupa (8 jedinki po grupi), na dve farme u različitim delovima Srbije (farma AKovin, farma B-Vrbas). Koncentracija selena u hranivima dobijenim sa područja oko farmi A i B bila je niža od 0.1 ppm u više od 90% uzoraka, i niža od 0.05 ppm u više od 67% uzoraka hraniva. Koncentracija selena u plazmi kod teladi i junica sa obe farme bila je veoma niska, i kretala se u intervalu od 1.58 do 9.42 µg/L. Aktivnost enzima glutation-peroksidaze (GSH-Px) u plazmi kod teladi starosti 3 meseca je bila niska i iznosila je 8.4±5.2 µkat/L na farmi A i 16.1±4.3 µkat/L na farmi B dok je kod junica starosti 12 meseci ustanovljena statistički značajno viša vrednost, koja je iznosila 39.0 ± 6.2 µkat/L na farmi A i 40.0 ± 9.8 µkat/L na farmi B. Koncentracija tiroksina (T4) u krvnoj plazmi kod svih grupa teladi i junica bila je relativno visoka i kretala se u intervalu od 57.1 do 102.9 nmol/L. Koncentracija trijodtironina (T3) u krvnoj plazmi svih teladi i junica kretala se u intervalu od 2.72 do 3.51 nmol/L, i samo je kod teladi starosti 3 meseca na farmi B koncentracija T3 bila statistički značajno viša u odnosu na ostale grupe. Takođe je ustanovljena statistički značajna korelacija između aktivnosti enzima GSH-Px u plazmi i odnosa T3:T4 kod teladi starosti 6 meseci na farmi A (r2=0.80), kao i kod kombinovanih grupa teladi starosti 6 i 9 meseci na farmi B (r2=0.68).