| Abstract | Kvaliteta ljuske jajeta jedan je od najvažnijih čimbenika u peradarskoj industriji. Procjenjuje se da jaja s oštećenom ljuskom čine 6–10% ukupno proizvedenih jaja, što uzrokuje velike ekonomske gubitke. Drugi problem, posebice u alternativnoj proizvodnji jaja, je nedovoljna čvrstoća kostiju. Ona uglavnom rezultira lomovima prsnih kostiju te predstavlja jedan od najvećih problema dobrobiti kokoši nesilica i komercijalne proizvodnje jaja. Organski mineralni izvori imaju nekoliko prednosti u odnosu na anorganske, a to su: zaštita od neželjenih kemijskih reakcija u gastrointestinalnom traktu, lak prolazak kroz netaknuti zid tankog crijeva,bolja mogućnost apsorpcije i dr.Cilj ovog rada bio je proučiti utjecaj organskih i anorganskih izvora mikroelemenata: cinka, mangana, bakra, željeza i selena u hranidbi kokoši nesilica na nesivost, kvalitetu jaja i parametre kvalitete kostiju. Istraživanje je provedeno na 30 kokoši nesilica linijskih hibrida TETRA – SL Brown u dobi od 35 do 50 tjedana, podijeljenih slučajnim odabirom u dva pokusna hranidbena tretmana: kontrolna skupina (K) i pokusna skupina (P). Svaki tretman primijenjen je na 15 kokoši, držanih pojedinačno kavezno na podu od žičane mreže. Sve kokoši hranjene su istom krmnom smjesom, pri čemu je u hranu kontrolne skupne (K) dodano: 50 ppm Zn, 75 ppm Mn, 36 ppm Fe, 4 ppm Cu i 0,15 ppm Se u obliku neorganskih soli – ZnO, MnO, CuSO4, FeSO4 i Na2SeO3, koji su u hrani pokusne skupine (P) u potpunosti zamijenjeni mikroelementima u obliku proteinata, odnosno seleniziranog kvasca, u razinama: 30 ppm Zn, 30 ppm Mn, 5 ppm Fe, 5 ppm Cu i 0,2 ppm Se. Na kraju eksperimentalnog dijela rada žrtvovano je po 10 kokoši iz svake skupine u svrhu izdvajanja kostiju tibija za analizu. Izdvojene su: lijeve tibije za analizu pepela i desne tibije za analizu mehaničkih svojstava u ispitivanju savijanja od tri točke. Hranidbeni tretman nije pokazao utjecaja na: nesivost, težinu jaja, konzumaciju i konverziju hrane (P > 0,05). Uvođenje organskih mikroelemenata u hranidbu poboljšalo je (P<0,05) čvrstoću ljuske jajeta i boju žutanjka te dovelo do višeg sadržaja Ca u pepelu tibija; 184,48 g/kg u skupini (P) u odnosu na 179,77 g/kg u skupini (K). Isto tako u skupini (P) bila je veća (P < 0,05) otpornost na lom kostiju u odnosu na skupinu (K); 155,90 N vs 108,66 N. Dobiveni rezultati upućuju na to da bi korištenje organskih kompleksa mikroelemenata moglo ublažiti negativan učinak dobi kokoši na čvrstoću ljuske jaja i čvrstoću kostiju. |
| Abstract (english) | The quality of egg shell is one of the most important factors in the poultry industry. It is estimated that eggs with damaged shell make up 6 – 10%of the total produced eggs, causing great economic losses. Another problem, especially in alternative egg production, is insufficient bone strength. It mostly results in fractures of the chest and represents one of the biggest problems of the welfare of hens and commercial egg production. Organic mineral sources have several advantages over inorganic, namely protection against unwanted chemical reactions in the gastrointestinal tract, easy passage through the suppressive wall of the small intestine, better apsorption ability etc. The aim of this thesis was to study the influence of organic and inorganic sources of microelements: zinc, manganese, copper, iron and selenium in feeding chickens to unevenness, egg quality and bone quality parameters. TETRA – SLBrown at 35 to 50 weeks of age was divided randomly into two experimental nutrition treatments: control group (C) and test group (T). Each treatment was applied to 15 chickens, held individually caged on the floor of the wire mesh. All mixtures were grown with the same feed mixture, with 50 ppm Zn, 75 ppm Mn, 36 ppm Fe, 4 ppm Cu and 0,15 ppm in the control group (C).In the form of inorganic salts – ZnO, MnO, CuSO4, FeS04 and Na2SeO3, in the feed of the experimental group (E), were completely replaced by microelements in the form of protein or selenised yeast in the levels: 30 ppm Zn, 30 ppm Mn, 5 ppm Fe, 5 ppm Cu and 0,2 ppm Se. At the end of the experimental part of the work, 10 chickens from each group were sacrificed for the purpose of extracting the bones of the tibia for analysis. The following are included: left tibia for the analysis of ash and right tibia for the analysis of mechanical properties in the three point bending test. Nutritional treatment did not show any effect on insecurity, egg weight, consumption and food conversion (P> 0,05). The introduction of organic microelements in nutrition has improved (P < 0,05) eggshell strength, yolk color and resulted in higher Ca content in the ashes of the tibia; 184,48 g/kg in the group (P) compared to 179,77 g/kg in the groups (K). Also in groups (P) was greater (P < 0,05) resistance to bone fracture in relation to group (K); 155,90 N vs 108,66 N. The obtained results indicate that the organic complexes usage could alleviate the pullets’ age negative effect in terms of bone and eggshell solidity. |
