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Reja perutnine je močno odvisna od podnebnih razmer. Vročinski stres je eden izmed pomembnejših dejavnikov, ki vplivajo na prirejo živali. Večja prireja ima za posledico spremembe prehranskih potreb, ki vključujejo tudi večje potrebe po antioksidantih. Glavna cilja magistrskega dela sta bila preučiti ali ima obogatitev krme z vitaminoma E (VE) in C ter selenom (Se) antioksidativne učinke ter če ti dodatki vplivajo na histološko zgradbo prebavil pri pitovnih piščancih, ki so bili izpostavljeni vročinskemu stresu. V prehranski poskus je bilo vključenih 100 dan starih pitovnih piščancev moškega spola, razdeljenih v pet skupin glede na prehranski tretma in izpostavljenost vročinskemu stresu. Skupine so bile NNRC (nevtralen hlev, priporočila NRC), VNRC (stres, priporočila NRC), VNRC + PUFA (stres, priporočila NRC, dodano olje), VECSe (stres, priporočila ROSS, dodan VE, C in Se), VECSe + PUFA (stres, priporočila ROSS, dodan VE, C, Se in olje). Tekom poskusa smo jih tehtali, merili zauživanje krme in beležili pogin. Žrtvovali smo 60 piščancev, v vsaki skupini po 12. Izmerili smo jim maso posameznih delov prebavil, viskoznost v vsebini tankega črevesa in pH vsebine tankega, debelega in slepega črevesa, določili smo koncentracijo hlapnih maščobnih kislin (HMK) v vsebini tankega in slepega črevesa in opravili histološke meritve na dveh delih prebavil, višino resic in globino kript v teščem črevesu ter globino kript v slepem črevesu. Ugotovili smo, da je dodatek različnih antioksidantov le delno vplival na priraste živali in na koncentracijo HMK v slepem črevesu, ni pa vplival na koncentracijo HMK v tankem črevesu in histološko zgradbo prebavil. Heat stress is one of the most important factors affecting the productivity of poultry farming. Higher productivity also means different nutritional requirements for the animals. This results in changes in nutritional requirements, which include a higher amount of antioxidants. The main objectives of the M.Sc. thesis were to investigate whether the addition of feed additives such as vitamin E (VE), vitamin C and selenium (Se) has an antioxidant effect and whether these additives affect the histological structure of the gastrointestinal tract in broilers exposed to heat stress. The nutritional experiment included 100 one-day-old male broilers divided into five groups according to nutritional and heat exposure treatment. The groups were NNRC (neutral barn, NRC recommendations), VNRC (stress, NRC recommendations), VNRC + PUFA (stress, NRC recommendations, added oil), VECSe (stress, ROSS recommendations, added VE, C and Se), VECSe + PUFA (stress, ROSS recommendations, added VE, C, Se and oil). During the experiment, we weighed broilers, measured feed intake, and recorded mortality. We slaughtered 60 birds, 12 from each experimental group. We measured the mass of each part of the gastrointestinal tract, the viscosity in small intestinal content, and the pH of the small intestine, colon and caecum, determined the concentration of volatile fatty acids (VFA) in the content of small intestine and caecum, and performed histological measurements in two parts of the gastrointestinal tract: the height of villi and the depth of crypts in the jejunum of the small intestine and the depth of crypts in the caecum. We can conclude that the addition of various antioxidants only partially affected the growth of animals and the concentration of VFA in the caecum, but had no effect on the concentration of VFA in the small intestine and the histological structure of the gastrointestinal tract. |
