Effects of rumen-protected Capsicum oleoresin on dry matter intake, average daily gain, and carcass characteristics of finishing beef steers

Objective: Our objective was to evaluate growth per-formance and carcass characteristics of finishing steers fed rumen-protected Capsicum oleoresin supplements differing in the extent of ruminal protection and when provided at 2 dose rates.Materials and Methods: A total of 450 steers were stratified by BW into 1 of 30 pens (15 steers per pen), and pens were randomly assigned to 1 of 5 treatments in a 2 x 2 + 1 factorial arrangement: no additive (CON); a low or high dose of rumen-protected Capsicum oleoresin (77 mg/d for RPLO and 250 mg/d for RPHI); or a low or high dose of Capsicum oleoresin that was rumen protected to a greater extent (100 mg/d for HPLO or 322 mg/d for HPHI). Both products were delivered in the vitamin and mineral supplement. All steers received the same basal diet of (DM basis) barley grain (86.2%), barley silage (6.0%), canola meal (6.2%), and a vitamin and mineral supplement (1.6%).Results and Discussion: Although BW at the start of the study did not differ (P > 0.19), there was an inter-action between supplement and dose (P = 0.034) where increasing the dose from HPLO to HPHI numerically re-duced BW, whereas increasing dose from RPLO to RPHI numerically increased BW. Inclusion of Capsicum, rumen protection, and dose did not affect DMI, ADG, or G:F whether reported on a live-weight or carcass-adjusted ba-sis. Hot carcass weight, DP, and rib-eye area were not affected (P >= 0.11). The proportion of carcasses grad-ing Canadian YG 3 were not affected by Capsicum but were reduced (P = 0.005) for the high versus low inclusion rates. Use of Capsicum did not affect QG, but feeding the high versus low doses decreased (P = 0.016) the propor-tion of steers grading AAA and increased (P = 0.009) the proportion grading AA. Marbling score was increased with the low versus high dose of Capsicum (P = 0.032). There were no differences for liver scores.Implications and Applications: Dietary supplemen-tation of rumen-protected Capsicum did not affect DMI, growth, or carcass weight for finishing steers. However, increasing the dose of Capsicum may negatively affect car-cass yield, QG, and marbling score.