Abstract | Zrno kukuruza najvažniji je izvor energije u obliku škroba i najzastupljenije krmivo u potpunoj hrani svinja. Kada se zbog vremenskih (ne)prilika i nedostatka mehanizacije zrno ubire poslije optimalnog roka ono gubi vodu i neprikladno je za siliranje. Rehidriranjem se podiže sadržaj vode na optimalnu koncentraciju za siliranje. S obzirom da je malo podataka o kinetici probavljivosti škroba rehidriranog pa siliranog zrna, cilj ovog istraživanja je bio, koristeći model za svinje, ispitati kinetiku in vitro ilealne probavljivosti škroba rehidriranog zrna različitih hibrida kukuruza tijekom siliranja i skladištenja (0., 21. i 95. dan). Zrno hibrida Bc 344, Bc 418b, Bc 424, Bc 525, Bc 572, Kekec i Pajdaš ubrano je nakon fiziološke zrelosti, rehidrirano do 32 % vlage i silirano uz dodatak komercijalnog inokulanta u vakuum vrećicama na sobnoj temperaturi. In vitro procedura provedena je u kontroliranim uvjetima u dva koraka koji oponašaju probavu u želucu i tankom crijevu svinja, a koeficijenti probavljivosti izračunati su za 0,25, 0,5, 0,75, 1, 2, 3, 4 i 5 sati inkubiranja pri čemu je brzina probavljivosti škroba izračunata prema kinetici prvog reda. Koeficijenti probavljivosti i brzina probavljivosti škroba se razlikovala između hibrida te je rasla s vremenom siliranja (P<0,05). Sav škrob svježe mase za siliranje probavio se nakon četiri sata dok je u silažama probavljen nakon tri sata i 21. i 95. dana siliranja. Brzina probavljivosti škroba kretala se u prosjeku od 0,5881 1/h (0. dan) do 1,1792 1/h (95. dan). Probavljivost suhe tvari prosječno je iznosila od 80,81 % (0. dan) do 89,57 % (95. dan). Siliranje značajno povećava brzinu probavljivosti što je potrebno uzeti u obzirom prilikom sastavljanja obroka. |
Abstract (english) | Maize kernel is the most important source of energy in the form of starch and most commonly used feed in complete pig diets. When grain is harvested after the optimal period due to the (un)favorable weather conditions and lack of mechanization, it loses water and is unsuitable for ensiling. Rehydrating increases water content to the optimal concentration for ensiling. Since data about digestibility kinetics of starch from rehydrated and ensiled grain is scarce, the aim of this study, using the pig model, was to investigate the in vitro ileal digestibility kinetics of starch in rehydrated kernel from different maize hybrids during ensiling and storage (0th, 21st and 95th day). Grain of hybrids Bc 344, Bc 418b, Bc 424, Bc 525, Bc 572, Kekec and Pajdaš was harvested after physiological maturity, rehydrated to 32% moisture content and ensiled with the addition of a commercial inoculant in vacuum bags at room temperature. The in vitro procedure was performed under controlled conditions in two steps mimicking digestion in the stomach and the small intestine of pigs, and the starch digestibility coefficients were calculated for 0,25, 0,5, 0,75, 1, 2, 3, 4 and 5 hours of incubation and starch digestibility rate was calculated according to the first order kinetics. The starch digestibility coefficients and the starch digestibility rate differed between the hybrids and increased with the time of ensiling (P<0,05). All starch of fresh silage mass was digested after four hours, while it was digested after three hours in silages from both 21st and 95th day of ensiling. Starch digestibility rate ranged from 0,5881 l/h (0th day) to 1,1792 l/h (95th day). Dry matter digestibility averaged from 80,81 % (0th day) to 89,57 % (95th day). Ensiling significantly increase starch digestibility rate which should be considered when formulating diets. |