The objective of this trial was to evaluate the carcass physical composition and meat quality of crossbred cull cows, from the second (G2- 3/4Charolais (C) Nellore (N) and 3/4NC) and third (G3 - 5/8CN and 5/8NC) generations of Charolais - Nellore rotational crossbreeding, feedlot finished and slaughtered at 465, 507 and 566 kg. At the beginning of the experiment, the average age, weight and body condition were, respectively, 8.5 years, 388.6 kg and 2.35 points. The diet, with 48:52 roughage:concentrate ratio, contained 12.5% crude protein and 2.99 Mcal of digestible energy per kg of dry matter. Carcass bone (16.55, 15.84 and 12.72%) and muscle percentages (63.5, 60.05 and 60.69%) decreased, whereas fat percentage increased (19.85; 24.32; 28.08%, respectively) as slaughter weight increased. The weight gain of the carcass edible portion between the extreme slaughter weights was 77.36 kg, being 37.32 kg of muscle (48.24%) and 40.04 kg of fat (51.76%). Meat tenderness evaluated by shear force, was significantly improved in animals slaughter at higher weight (4.94, 4.89 and 3.89 kgf/cm³, respectively). Meat color of 5/8NC cows was darker (2.87 points) in relation to 5/8CN cows (4.0 points). Meat of G3 animals was tender than G2 (4.16 vs 4.99 kgf/cm³). Higher juiciness was observed for 5/8NC meat than for 5/8CN (6.49 vs 4.16 points), as result of lower cooking loss of 5/8NC meat (17.61% vs 23.33%). Increasing cull cows slaughter weight is a method to increase rapidly beef meat production, inclusively improving their quality.
Charolais; crossbreeding; cull females; marbling; Nellore; tenderness
