Effect of high levels of organic selenium on glutation-peroxidase (GSH-Px) activity in blood plasma of broilers

Abstract

An experiment lasting 45 days was performed on 125 Hybro broilers divided into five groups. All compounds for broiler feed mixes used in the experiment contained 0.15 mg Se/kg, in the form of sodium selenite. The control group (K-group) of broilers was fed mixes without added organic selenium, and the experimental groups with mixes to which selenium, in the form of selenized-yeast, was added in quantities of 2, 5, 10, or 15 mg/kg. Selenized yeast (ICN - Gaienika) was obtained from beer yeast and contained 1.51, or 1.45 mg/g total, or organically bound selenium. At the beginning of the fattening period, GSH-Px plasma activity in broilers of the K-group ranged around 16.55 μkat/L, while GSH-Px plasma activity in broilers of experimental groups was statistically significantly higher, but without any major differences among the individual groups (on the average 25.53fjkat/L). In the blood plasma of K-group, GSH-Px activity dropped already in the second week of life and was maintained at a relatively constant level (about 10 μkat/L) until the end of the experiment. The same phenomenon was observed in the experimental groups, but the trend of declining GSH-Px activity in blood plasma was more expressed, and, contrary to the control group, was expressed also in the later phases of the experiment. In the 3rd week of the fattening period, GSH-Px plasma activity in broilers of the control and experimental groups was relatively equal, and then the plasma activity of GSH-Px in broilers of the experimental groups decreased, but there were no major differences among the individual groups.

Ogled je izveden na 125 hibro brojlera podeljenih u pet grupa. Ogled je trajao 42 dana. Sve smeše za ishranu brojlera u ogledu sadržavale su 0,15 mg Se/kg, u formi natrijum selenita. Brojleri kontrolne grupe hranjeni su smešama bez dodatog organskog selena, a brojleri oglednih grupa dobijale su smeše u koje je selen, u obliku selenizovanog kvasca, dodat u količini od 2, 5, 10 ili 15 mg/kg. Selenizovani kvasac (ICN – Galenika) dobijen je od pivskog kvasca i sadržao je 1,51, odnosno 1,45 mg/g ukupnog, odnosno organski vezanog selena. Na početku tova, aktivnost GSH-Px u plazmi brojlera K-grupe kretala se oko 16,55 μkat/L, dok je aktivnost GSH-Px u plazmi brojlera oglednih grupa bila statistički značajno viša, ali bez većih razlika između pojedinih grupa (prosečno 25,53 kat/L). U krvnoj plazmi K-grupe aktivnost GSH-Px pada već u drugoj nedelji života i održava se relativno konstantnom (oko 10 μkat/L) do kraja ogleda. U oglednim grupama zapaža se isti fenomen, ali je trend smanjivanja aktivnosti GSH-Px u krvnoj plazmi izrazitiji, pri čemu je, za razliku od kontrolne grupe, izražen i u kasnijim fazama ogleda. U trećoj nedelji tova aktivnost GSH-Px u krvnoj plazmi brojlera kontrolne i oglednih grupa je relativno jednaka, a zatim je aktivnost GSH-Px u plazmi brojlera oglednih grupa bila niža bez većih razlika između pojedinih grupa.