The study was conducted at the "Departamento de Zootecnia, Universidade Federal de Santa Maria, RS", from June to October, 1995. The objective was to evaluate the performance of steers beginning the feedlot with 270kg ( kept on native pasture during the growth period from twelve to twenty months) or 340kg (kept on cultived pasture during the growth period), submitted to two levels of concentrate 45% (high) or 30% (low) in the diet (DM basis). The treatments were: T1 Steers from native pasture, roughage:concentrate relation 70:30 (low); T2 Steers from native pasture, roughage:concentrate relation 55:45 (high); T3 Steers from cultivated pasture, roughage:concentrate relation 70:30 (low); T4 Steers from cultivated pasture, roughage:concentrate relation 55:45 (high). The roughage was corn silage. The concentrate included grinded corn, soybean meal, salt and limestone. The diets of the four treatments contained 14% of crude protein. Thirty-four Charolais, Nellore steers and their crosses with an average age of 20 months were used. The animals were taken from the herd of the "Departamento de Zootecnia". The experimental design was the completely randomized, with four treatmens in a factorial scheme 2x2 (two initial weights x two concentrate levels). The average daily dry matter intake (ADMI), average daily weight gain (ADG) and feed conversion (FC) were evaluated. ADMI expressed in percentage of live weight was higher for steers from native pasture (2.48%) than from cultivated pasture (2.17%). Steers that came from native pasture had 20% higher ADG than those from cultivated pasture (1.30 vs 1.08kg). ADG was also higher for steers with high level of concentrate (1.30kg) than for those with low level (1.08kg). FC of steers from native or cultivated pasture were, respectively, 6.57 and 7.98, while for the low and high levels of concentrate the values were, respectively, 7.8 and 6.75.
feedlot; beef cattle; compensatory growth; concentrate levels
