Istraživanje je provedeno s po 24 svinje iz otvorenoga (ekstenzivnoga) i poluotvorenoga (poluintenzivnoga) sustava, od kojih su 12 muških kastrata i 12 nazimica. Svinje u oba sustava bile su tovljene do 100 kg (n = 12) i 130 kg (n = 12) tjelesne mase. Svinje iz otvorenoga sustava hranjene su na pašnjaku i na strništima, uz minimalno prihranjivanje kukuruzom (150g/dan) tijekom zime, kada nema zelene mase. Svinje iz poluotvorenoga sustava hranjene su po volji obrokom kombiniranim od krmne smjese i zelene lucerne. Krmna smjesa u prvoj fazi tova (30 - 60 kg tjelesne mase) imala je 14% sirovih proteina i 13,37 MJ ME/kg, a u drugoj fazi tova (60 – 130 kg tjelesne mase) imala je 12% sirovih proteina i 13,34 MJ ME/kg. Disekcija ohlađenih (+4°C) desnih svinjskih polovica obavljena je prema modificiranoj metodi Wenigera i sur. (1963.). Prema ovoj modifikaciji nije disecirana glava. Kvaliteta mesa (Muscullus longissimus dorsi) istražena je u pogledu pH vrijednosti, sposobnosti vezanja vode i boje. Mesnatost svinjskih polovica bila je veća kod svinja manjih tjelesnih masa (100 kg) u odnosu na svinje većih tjelesnih masa (130 kg) u oba sustava držanja, ali su te razlike bile značajne (p<0,05) samo u poluotvorenome sustavu. Svinje iz otvorenoga sustava imale su mesnatije polovice u odnosu na svinje iz poluotvorenoga sustava i pri manjim (100 kg) i pri većim (130 kg) tjelesnim masama, ali ne i statistički značajno (p>0,05) (49,23% i 44.99%; 46,56% i 42,82%). Utvrđen je značajan utjecaj sustava držanja i tjelesne mase svinja na neke pokazatelje kvalitete mesa. Meso svinja manje tjelesne mase iz otvorenog sustava imalo je značajno više (p<0,01) sirovih proteina od mesa svinja istih tjelesnih masa u poluotvorenom sustavu, kao i meso svinja veće tjelesne mase u odnosu na meso svinja manje tjelesne mase u poluotvorenome sustavu.; The research was carried out on 24 pigs kept in the outdoor (extensive) and 24 pigs kept in the semi-outdoor (semi-intensive) keeping system. In each group there were 12 barrows and 12 gilts. Pigs in both systems were fattened up to 100kg (n=12) and 130kg (n=12) body weight. The pigs from the indoor system were grazing on pastures and stubble-fields, with minimum addition of corn (150 g/day) during winter, when there is no green forage, whereas the pigs kept in the semi-outdoor system were fed ad libitum a combination of feed mixture and green alfalfa. The feed mixture used in the first fattening phase (30 - 60 kg body weight) contained 14% crude protein and 13.37MJ ME/kg, and in the second phase (60-130kg body weight) it contained 12% crude protein and 13.34MJ ME/kg. Dissection of cooled (+4°C) right half-carcasses was carried out according to modified Weniger et al. method (1963). Meat quality (Muscullus longissimus dorsi) was examined in terms of the pH value, water binding capacity and colour. The pH1 value of meat was determined 45 minutes post mortem and pH2 value 24 hours post mortem, by means of the pH-meter Mettler Toledo. Water binding capacity was determined according to Grau and Hamm (1952), and colour (CIE – L, a and b values) by means of a Minolta CR-410 chroma meter. Statistical processing of research results, variance analysis, was carried out by means of Stat. Soft. Inc. 2012. Meatiness of half-carcasses in both production systems was higher in pigs of lower body weight (100kg), compared to pigs of higher body weight (130kg). However, these differences were significant (p<0.05) only in the pigs kept in the semi-outdoor system. Pigs from the indoor system had meatier carcasses in relation to pigs from the semi-outdoor system both at lower (100 kg) and higher (130 kg) body weights, but it was not statistically significant (p>0.05) (49.23% and 44.99% : 46.56% and 42.82%).