Effects of a fattening system on meat performance of crossbred bulls and steers sired by Gascon and Charolais bulls

Fattening performance, carcass composition and meat quality were investigat ed in 44 crosses sired by Gascon (GS) and Charolais (CH) bulls. The animals were allocated to three groups. Indoor bulls (IB) and indoor steers (IS) w ere finished indoors on a diet consisting of maize silage and grass haylage , fodder straw and concentrates and slaughtered at 530 and 500 kg respectiv ely After 78 days of winter housing on a low energy diet extensive steers ( ES) were turned out to pasture for 181 days. It was followed by a finishing period (70 days) in which the animals were offered a high energy diet. Thr oughout the whale experimental period, the weight gains of IB bulls amounte d to 1.101 kg/day while those of IS and ES steers were 0.819 and 0.632 kg/d ay respectively (P < 0.001). The IB bulls had the highest dressing percenta ge (60.12 vs. 59.37 and 58.35% resp.; P < 0.05) and the most favourable car cass conformation (2.14, vs. 2.64 and 2.41; P < 0.05). Internal fat product ion, fatness score, separable fat proportion, fat thickness and lipid conte nt in lean tissue were highest in the IS group. Total meat proportion was h ighest (P < 0.05) in the TB group (80.81 vs. 79.44 and 79.62% resp.) while grade I meat proportions were higher in both the IS and ES steers (P < 0.01 ). The lowest (P < 0.001) protein content in lean tissue and the highest (P < 0.001) pH measured 24 hours after slaughter were found in the ES group. Breed differences were displayed particularly in lower daily gains, higher production of internal fat and less favourable fatness score of the GS cros ses.