Status of selenium in sheep and dairy cow blood in Western Balkan countries

Biofortification of Silage Maize with Zinc, Iron and Selenium as Affected by Nitrogen Fertilization

Agronomic biofortification is one of the main strategies for alleviation of micronutrient deficiencies in human populations and promoting sustainable production of food and feed. The aim of this study was to investigate the effect of nitrogen (N)fertilization on biofortification of maize crop (Zea mays L.) with zinc (Zn), iron (Fe) and selenium (Se) grown on a micronutrient deficient soil under greenhouse conditions. Factorial design experiment was set under greenhouse conditions. The experiment consisted of two levels of each N, Zn, Fe and Se. The levels for N were 125 and 250 mg N kg^-1 soil; Zn were 1 and 5 mg Zn kg^-1 soil; levels of Fe were 0 and 10 mg Fe kg^-1 soil; levels of Se were 0 and 0.02 mg Se kg^-1 soil. An additional experiment was also conducted to study the effect of the Zn form applied as a ZnO or ZnSO₄ on shoot growth, shoot Zn concentration and total shoot Zn uptake per plant. Shoot Zn concentrations increased by increasing soil Zn application both with ZnSO₄ and ZnO treatments, but the shoot Zn concentration and total Zn uptake were much greater with ZnSO₄ than the ZnO application. Under given experimental conditions, increasing soil N supply improved shoot N concentration; but had little effect on shoot dry matter production. The concentrations of Zn and Fe in shoots were significantly increased by increasing N application. In case of total uptake of Zn and Fe, the positive effect of N nutrition was more pronounced. Although Se soil treatment had significant effect, N application showed no effect on Se concentration and accumulation in maize shoots. The obtained results show that N fertilization is an effective tool in improving the Zn and Fe status of silage maize and contribute to the better-quality feed.

Productive traits, selenium status and blood metabolic status in fattening lambs affected by selenium biofortified corn

The widespread selenium (Se) deficiency in soil and in feedstuffs from such soil, needs to be prevented by various methods. Recently, biofortification of Se has been carried out by soil fertilization and foliar application of crops. The aim of this study was evaluate the productive traits, Se status and blood metabolic profile in fattening lambs affected by Se biofortified corn. The research was conducted with 20 Merinolandschaf lambs of the average age of 70 days, during 30 days of fattening. The feed mixture of the control group contained corn (0.014 mg Se/kg dry matter, DM); in the experimental group (Se-BC), corn was biofortified (0.278 mg Se/kg DM). The feed mixture, hay and water were offered to lambs ad libitum. Blood was collected from the jugular vein on days 0 and 30 of experiment. Haematological indices were determined in whole blood, whereas concentrations of biochemical indices, enzyme activities, and concentrations of metabolic hormones were determined in serum. After the slaughter, samples of musculus semimembranosus, liver, kidney, lungs, spleen, peritoneum and heart tissues were taken. No significant differences were obtained in productive traits when feeding lambs with Se-BC. Higher concentrations of Se in lungs and liver (control: 0.26 and 0.75 mg/kg, respectively; Se-BC: 0.33 and 0.92 mg/kg, respectively) was determined in Se-BC compared to control. Higher activity of glutathione peroxidase enzyme in serum, higher erythrocyte count, higher content of haemoglobin and haematocrit in whole blood of Se-BC lambs were determined. The results of the study indicate the posibility of using Se-BC in lambs’ diets.