Cilj ovih istraživanja bio je utvrditi ad libitum konzumaciju i in vivo probavljivost silaže travno-djetelinskih smjesa (TDS) košenim u različitim stadijima fenološke zrelosti. TDS-a je spremljena u tri različite faze fenološkog razvoja klupčaste oštrice (Dactylis glomerata L.) kao dominantne trave u tratini: kasno vlatanje (TDS 1), metličanje (TDS 2) i cvatnja (TDS 3). Udio suhe tvari (ST) u TDS 1, TDS 2 i TDS 3 iznosio je 396, 408 i 463 g kg-1 svježeg uzorka, respektivno, a sirovih proteina (SP) 119,6, 98,0, i 90,3 g kg-1 ST respektivno. Odgađanjem roka košnje TDS-a za proizvodnju silaže statistički značajno (P<0,001) povećao se udio ST u TDS 3, kao i organske tvari (P<0,001), neutralnih detergent vlakana (NDF) (P<0,05) i kiselih detergent vlakana (ADF) (P<0,001) u odnosu na TDS 1. Silaža ranog roka košnje sadržavala je više sirovih proteina (P<0,001) u odnosu na silažu srednjeg i kasnog roka košnje. Odgađanjem roka košnje TDS-a došlo je do linearnog smanjenja (PL<0,01) ad libitum konzumacije ST, organske tvari (OT) i NDF, kao i do linearnog smanjenja (PL<0,01) probavljivosti ST, OT, SP, NDF i ADF. Zaključeno je da rok košnje TDS značajno utječe na kemijski sastav, ad libitum konzumaciju, in vivo probavljivost i balans dušika silaže. Ukoliko stočarska proizvodnja zahtijeva voluminoznu krmu visoke kakvoće, TDS je potrebno kositi u ranijoj fazi fenološke zrelosti.The objective of this experiment was to study the effects of grass maturity at harvest on silage ad libitum intake, in vivo digestibility and N retention in wether sheep. The sward was harvested at the stem elongation, tasseling and flowering growth stages of orchardgrass (Dactylis glomerata). Three silages were offered to four Charolais wether sheep in an incomplete change over design with four periods. As the crop matured, there was an increase (P<0.001) in dry matter (DM), organic matter (OM) and acid detergent fiber (ADF) concentration and a decrease in crude protein (CP) concentration (P<0.001). Increasing maturity of grass ensiled showed a linear decrease (P<0.01) in voluntary silage intake of DM, OM, neutral detergent fiber (NDF), a linear decrease (P<0.01) in digestibility of silage DM, OM, NDF, ADF, CP, and a linear decrease in nitrogen balance (P<0.01). No quadratic response was recorded in silage intake, digestibility or N balance. The results suggest that grass maturity at harvest influences the nutritive value of grass silage, in terms of ad libitum intake, in vivo digestibility and N retention in sheep, as a result of changes in chemical composition
