Calf production by Angus-Hereford and Brahman-Hereford cows on two native rangeland forage systems. 
Calf birth weights, weaning weights, and preweaning gain of Simmental-sired calves from Angus-Hereford (AH) and Brahman-Hereford (BH) F1 cows grazing native rangeland (NR) or native rangeland-complementary forage (NRCF) systems in the southern Great Plains mixed prairie were evaluated.  Calves from AH dams were heavier (P < .001) at birth than calves from BH dams in both forage systems (40 and 37 kg, respectively).  However, birth weights of calves from BH dams were 2 kg heavier (P < .001) in the NRCF fall-calving system.  Calves in the NRCF system were 122 d older and heavier (P < .001) than the NR calves at weaning (343 and 256 kg, respectively).  During the preweaning period, the NR calves gained faster (P < .001) than the NRCF calves.  When calves from both systems were evaluated at 200 d of age, NR calves were heavier (P < .001) than NRCF calves.  Calves from BH cows were 8 to 16 kg heavier (P < .001) that calves from AH cows at 200 d of age and at weaning.  The increased age at weaning associated with the NRCF did not reduce reproductive efficiency.  The NRCF system requires less land than a traditional NR system to support a cow-calf pair and seems to be more economically efficient.