INFLUENCE OF SELENIUM CONTENT AND OIL SOURCES IN FEED ON CONCENTRATION OF THYROID GLAND HORMONES AND ELECTROLYTE IN BROILER BLOOD

Cilj rada bio je prikazati utjecaj dizajniranih smjesa korištenih u tovu pilića na kon-centraciju elektrolita i hormona štitaste žlijezde u krvi. U istraživanju je korišteno 120 muških pilića hibrida Ross 308. Tov pilića trajao je 42 dana. U prva tri tjedna tova pilići su konzumirali standardnu starter smjesu s 22% sirovih bjelančevina i 13,90 MJ/kg ME. U zadnja tri tjedna tova pilići su podijeljeni u 6 pokusnih skupina, a svaka skupina dobi¬vala je posebno pripremljenu finišer smjesu (P1=6% suncokretovog ulja+0,0 mg Se/ kg hrane, P2=6% lanenog ulja+0,0 mg Se/kg hrane, P3=6% suncokretovog ulja+0,3 mg Se/kg hrane, P4=6% lanenog ulja+0,3 mg Se/kg hrane, P5=6% suncokretovog ulja+0,5 mg Se/kg hrane, P6=6% lanenog ulja+0,5 mg Se/kg hrane). Finišer smjesa bila je izbalansirana na 18,02% sirovih bjelančevina i 14,40 MJ/kg ME. Utvrđeno je da vrsta ulja u hrani za piliće ima utjecaja na pH krvi (P<0,001), dok razina selena (P=0,014) u hrani, kao i interakcija vrste ulja i razine selena (P<0,001) utječe na koncentraciju kalija u krvi. Vrsta ulja (P=0,037) imala je utjecaja na koncentraciju fT3, koja je kod pilića hranjenih smjesama s dodatkom lanenog ulja bila niža u odnosu na piliće koji su hranjeni smjesama s dodatkom ulja suncokreta. Na razlike u koncentraciji fT4, kao i omjera fT3/fT4, utjecaj je imala interakcija razine selena i vrste ulja (P<0,001 odnosno P=0,021). Iz rezultata istraživanja uočljivo je da korištena ulja u smjesama u kombinaciji s različitim razinama organskoga selena utječu na pH, koncentraciju nekih elektrolita i hormona štitnjače u krvi pilića. Međutim, treba istaknuti da se sve dobivene vrijednosti nalaze u granicama referentnih vrijednosti za perad.The research aimed to elaborate the influence of designed mixtures used in broilers fattening on the concentration of electrolytes and thyroid gland hormones in the blood.. The research was carried out on 120 male Ross 308 hybrid broilers. The fattening lasted for 42 days. During the first three weeks of fattening broilers were fed standard starter diet containing 22% crude protein and 13.90 MJ/kg ME. During the last three weeks of fattening, broilers were divided into 6 experimental groups, each fed specially prepared finisher diets (P1=6% sunflower oil+0.0 mg Se/kg of feed, P2=6% linseed oil+0.0 mg Se/kg of feed, P3=6% sunflower oil+0.3 mg Se/kg of feed, P4=6% linseed oil+0.3 mg Se/kg of feed, P5=6% sunflower oil+0.5 mg Se/kg of feed, P6=6% linseed oil+0.5 mg Se/kg of feed). Finisher diet was balanced at 18.02% crude protein and 14.40 MJ/kg ME. It was found out that the type of oil in chicken feed influenced to blood pH (P <0.001), whereas selenium level (P=0.014) in the feed, as well as the oil type and selenium level interaction (P<0.001) influenced the concentration of potassium in the blood. Oil type (P=0.037) influenced the concentration of fT3, which was lower in chickens fed mixtures with addition of linseed oil than in the chickens fed sunflower oil added mixtures. Interaction of selenium content and oil type had influence on differences in concentration of fT4 as well as on the ratio of fT3/fT4, (P