Effects of processing treated corn stover and distillers grains on total-tract digestion and performance of growing cattle1

Two studies evaluated replacing traditional growing diets with pelleted feed. In Exp. 1, 6 steers were used in a 4 × 6 Youden square evaluating pelleting and harvest method of corn stover on total-tract digestion. Treatments included 2 control diets containing 18% modified distillers grains plus solubles, 18% solubles, and either 60% untreated (NEGCON) or alkaline treated (POSCON) corn stover. Remaining treatments were 1 of 2 pelleted diets containing alkaline treated corn stover, dry distillers grains, solubles, and supplement. Corn stover was harvested by raking and baling (CONV) or a baler pulled behind the combine (MOG). In Exp. 2, a 92-d study used 360 (initial BW = 316 kg) steers to evaluate replacing the NEGCON with CONV pellets on performance. Pellets were either pair fed (PELPF) to NEGCON or fed ad libitum (PELAL). In Exp. 1, MOG had the greatest OM and NDF digestion (75.55 and 63.93%, respectively), whereas NEGCON had the least (67.58 and 54.36%, respectively; P < 0.01). In Exp. 2, there were no differences (P > 0.50) between NEGCON and PELPF treatments in ending BW, DMI, or ADG (1.29 and 1.27 kg/d, respectively). The PELAL treatment had the greatest (P < 0.01) DMI (12.18 kg/d) and ADG (1.63 kg/d). The PELAL (G:F = 0.134) had reduced G:F (P = 0.05) compared with CON and PELPF treatments (G:F = 0.143 and 0.140, respectively). Replacing a traditional growing diet with a complete pelleted feed resulted in comparable or improved digestibility but decreased G:F when cattle were fed ad libitum.