The marbling fatty acid profile and the meat quality of cull cows feedlot finished receiving diets without or with sodic monensin (200mg animal-1 day-1) were evaluated. The diet contained 12.5% of crude protein and 2.99 Mcal of digestible energy kg-1 of dry matter, composed of 48% of roughage (corn silage) and 52% of concentrate. The monensin presence didn’t have significant effect on the color, texture and marbling, presenting medium values of 3.55, 3.29 and 6.38 points, respectively. Concerning the sensorial characteristics, the meat of the animals fed with monensin it demonstrated to be less palatable (P<.10). The monensin inclusion caused the increase (P<.10) of the participation of saturated fatty acids and reduction of the unsaturated in the fat intramuscular of the Longissimus dorsi. Among the fatty acids saturated, the use of monensin increased heptadecanóico (17:0) proportion and, among the unsaturated group, the trans isomer (C18:1 n9t) increased, and the cis isomer of oleate (C18:1 n9c) decreased (P<.10). The monounsaturated fatty acids proportion was reduced by monensin inclusion (P<.10). Monensin addition decreased the meat quality by decrease its palatability of the meat of cull cows. As regards the profile of fatty acids total, the monensin provides larger participation of saturated fatty acid in detriments to the unsaturated in the fat marbling of the muscle Longissimus dorsi.
composition fat; females; intramuscular fat; ionophore; palatability
