Improving the use of fiber and alternative fiber sources in beef cattle diets

Six studies were conducted to evaluate the use of different technologies to improve the use of fiber and alternative fiber sources in beef cattle diets. Experiments 1 and 2 evaluated the impact of feeding a complete pelleted feed containing alkaline treated corn stover, dry distillers grains plus solubles, and distillers solubles on total tract digestion and performance of growing cattle. Experiments 3 and 4 evaluated the effects of partially replacing corn with the pellet used in Exp. 1 and 2 on total tract digestion and performance of finishing cattle. The remaining 2 experiments, Exp. 5 and 6, evaluated the impact of treating feeds with a fibrolytic enzyme on in vitro and in vivo digestibility. In Exp. 1, replacing a traditional growing diet with the complete pelleted feed resulted in similar or improved digestibility depending on the corn stover harvest method. However in Exp. 2, feeding the complete pelleted diet increased DMI and ADG if cattle were fed ad libitum, but decreased G:F in the performance study. In Exp. 3, replacing 25% of corn in a finishing diet containing 40% modified distillers grains plus solubles (MDGS) had no impact on total tract digestion. In Exp. 4, replacing up 30% of corn (DM basis) with the pelleted feed in diets containing 40% MDGS had minimal impact on performance. However, replacing more than 20% of corn (DM basis) in diets containing 20% MDGS caused a decrease in HCW. Feeding an exogenous enzyme showed minimal improvements on in vitro DM digestibility and gas production in Exp. 5. Furthermore, supplementing an exogenous enzyme to cattle on a finishing diet had no impact on in vivo digestion in Exp. 6. In conclusion, commercially treating harvested corn residue with CaO and pelleting it with distillers by-products produces a pellet that could be used as a completed pelleted feed in growing diet or a partial corn replaced in finishing diets. However, incorporation of the pellet into diets will depend on its price. In addition, these data do not support the use of exogenous enzymes to improve the digestibility of fibrous feedstuffs in beef cattle diet