hrvatski

Utjecaj stajanja silaže visokovlažnog zrna kukuruza na koncentraciju karotenoida, tokola i retinola u plazmi junica

Maize grain has the highest content of carotenoids among cereals, including β- cryptoxanthin and β-carotene, provitamins of vitamin A, and tocols, compounds of vitamin E activity. Acidic conditions created during fermentation may reduce the content of these compounds during prolonged storage high- moisture maize grain. However, these conditions can also increase their bioavailability. The aim of this study was to determine the effect of high-moisture maize silage storage on the concentration of carotenoids, tocols and retinol in the plasma of heifers fed the same ration during the four-month period. A total of 10 Belgian blue×Holstein heifers were fed rations containing high-moisture maize grain (25%) and maize silage (56%). Blood was taken from each heifer once a month, and concentration of retinol, tocols and carotenoid was determined in plasma using HPLC method. These compounds were also determined in maize silage, high-moisture maize grain and ration sampled on the same day. Significant changes in carotenoid and tocol concentrations in silages and ration were not determined during the trial, however, there were considerable changes in maize silage and ration after the third month. The most abundant carotenoid in heifers’ plasma was β-carotene (0.33 – 0.59 μg/mL) while β-cryptoxanthin, lutein and zeaxanthin were in low concentrations (> 0.05 μg/mL). α-tocopherol concentration in plasma was from 0.99 to 1.48 μg/mL while concentration of retinol was from 0.29 to 0.53 μg/mL. Concentration of determined compounds in plasma varied during four-month trial, however, these changes were not a result of changes in high-moisture maize grain caused by acidic silage conditions.

silaža visokovlažnog zrna kukuruza ; junice ; karotenoidi ; retinol ; tokoli

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