Partial Substitution of Corn Grain in the Diet with Beet Pulp Reveals Increased Ruminal Acetate Proportion and Circulating Insulin Levels in Korean Cattle Steers

Abstract

We investigated the effects of the partial substitution of corn grain in the diet with beet pulp on growth performance, ruminal fermentation characteristics, microbial profiles, and blood lipogenic parameters in fattening steers. Twelve Korean cattle steers (body weight, 485 ± 19.32 kg; age, 18.0 ± 0.17 months) were equally divided into corn grain (CG) and beet pulp (BP) groups. Approximately 75% of dry matter of the requirement was offered as a concentrate portion, and the remaining 25% was offered as oat straw. Eighty percent of the concentrate portion was provided by a pelleted basal concentrate, and the remaining 20% with corn grain for the CG group, or 18% beet pulp plus 2.0% rumen-protected fat for the BP group, respectively, by top dressing. The experiment was conducted for 14 weeks, including a 2-week acclimation period. Growth rate was not affected by beet pulp feeding (p = 0.55). The molar proportions of ruminal acetate (p Fibrobacter succinogenes (p = 0.01) and Ruminococcus albus (p = 0.04) on wk 12, and serum insulin concentrations (p p p < 0.05) on wk 12 were lower in the BP group. Beet pulp could be used as a lipogenic energy source without affecting growth performance during the fattening period of cattle.

Keywords

• acetate
• byproduct
• beef cattle
• lipogenic potential
• microbial population
• rumen fermentation