EFFECTS OF SUPPLEMENTING THE DIET OF ENTIRE MALES WITH SWEET CHESTNUTS TANNINS ON INTESTINAL AND LIVER HISTOMORPHOLOGICAL AND IMMUNOHISTOCHEMICAL CHARACTERISTICS AND BOAR TAINT COMPOUNDS

V doktorski disertaciji smo proučevali vplive hidroliziranega tanina (izvleček sladkega kostanja) na histomorfološke in imunohistokemične lastnosti tankega in debelega črevesja ter jeter, v povezavi z vonjem po merjascu. Disertacija je osredotočena tudi na tvorbo skatola v debelem črevesju, njegovo razgradnjo v jetrih in nalaganje skatola v maščobne tkivu merjascev. Doktorsko nalogo sestavljata dva poskusa, v prvi je bilo vključenih 24 merjascev (Landrace x Large White), živali so bile razdeljene v štiri skupine (T0, n=6, krmna mešanica s 13,2 MJ/kg, 15,6% surovih proteinov) in pa tri z dodatkom tanina 1% (T1, n=6), 2% (T2, n=6) in 3% (T3, n=6). Dodajanje tanina v obrok merjascev je vplival na nekatere morfološke lastnosti tankega črevesja (duodenum) in sicer na povečano velikost resice, njen perimeter in debelino mukoznega tkiva. Dodatek tanina je zmanjšal velikost mitotske aktivnosti v cekumu in delu debelega črevesja (colon descendens) in apoptotsko aktivnost v delu debelega črevesja (colon ascendens). V jetrnem tkivu nismo zasledili nobenih histoloških sprememb, ki bi nastale kot posledica dodanega tanina. V drugi poskus je bilo vključenih 51 merjascev, ki so bili razdeljeni v štiri skupine: kontrolno skupino (BEK-2, 12,9 MJ/kg, 15% surovih proteinov brez dodanih taninov, T0, n=12) in v tri skupine, ki so imele v krmno mešanico dodane tanine različnih koncentracij in sicer 1% (T1, n=13), 2% (T2, n=13) in 3% (T3, n=13). Dodatek tanina v obroku je imel vpliv na zmanjšanje koncentracije skatola v debelem črevesju (colon descendens), ob tem smo zasledili tudi povečano katalitično aktivnostjo citokrom encima CYP2E1. Dodajanje taninov se je pokazalo kot tendenca na zmanjšanje aktivnosti encimov CYP2A19 in CYP1A. V maščobnem tkivu merjascev se je prav tako pokazal trend zmanjševanja koncentracije androstenona ob povečani koncentraciji dodanega tanina v krmi merjascev. Na vsebnost skatola v maščobnem tkivu merjascev dodani tanin ni imel vpliva.This doctoral dissertation is aimed at evaluating the effects of hydrolysable (wood extract of sweet chestnut) tannins on histomorphological and immunohistochemical characteristics of the small and large intestine and liver, in relation to boar taint, in particular the skatole production in the large intestine, degradation in the liver and deposition in fat tissue in entire male pigs. The doctoral thesis consists of two experiments, in the first, a total of 24 boars (Landrace x Large White) were put into four treatment groups (C, n=6, fed mixture with 13.2 MJ/kg, 15.6% crude proteins) and three experimental groups fed the same diet supplemented with 1% (T1, n=6), 2% (T2, n=6), and 3% (T3, n=6). Supplementing the diet of entire male pigs with tannins affected the morphometric traits of the small intestine (duodenum) as demonstrated by the increased villus height, villus perimeter and mucosa thickness. Tannin supplementation reduced mitosis in caecum and colon descendens, and apoptosis in colon ascendens. No effect of tannin supplementation was observed on liver characteristics. The second experiment was comprised of 51 boars, which were divided into four groups: a control group (BEK-2, 12.9 MJ ME/kg, 15 % crude proteins no tannin supplement, T0, n=12), and three groups fed with the same diet supplemented with 1 % (T1, n=13), 2 % (T2, n=13) and 3 % tannin extract (T3, n=13). Supplementing the boars’ diets with tannins resulted in a progressive reduction of skatole concentration in colon descendens, which was accompanied by an increased catalytic activity of the cytochrome enzyme CYP2E1, while the activity of CYP2A19 and CYP1A tended to be reduced by the increased supplementation of tannins. Although not statistically significant, a reduction of the androstenone level in fat tissue was quite notable with an increased tannin supplementation, while there was no effect observed on the fat tissue skatole concentration