PSI-4 Effect of rumen protected capsaicin on dry matter intake, average daily gain, and carcass characteristics in finishing beef cattle

Abstract

Abstract The objective was to evaluate growth performance and carcass characteristics for feedlot cattle fed two sources of rumen protected capsaicin at two dose rates. A total of 450 steers, stratified by BW, were assigned into 30 pens. Pens were randomly assigned to receive 1 of 5 treatments containing (DM basis) of 86.2% barley grain, 6.0% barley silage, 6.2% canola meal, and 1.6% vitamin and mineral supplement. Treatments contained no additive (CON) or included a low or high dose of Nexulin (100 mg/d for NEXLO and 330 mg/d for NEXHI) or CapsXL (77 mg/d CAPLO or 250 mg/d for CAPHI). Steers averaged 507 kg BW at the start of the study and 686 kg at the end of the study (69 days on feed) with no differences among treatments (P > 0.28). Dry matter intake, ADG, gain:feed, dressing percentage, backfat thickness, and rib-eye area were not affected by treatment (P > 0.33). Steers fed CAPLO and NEXLO tended (P = 0.07) to have lesser marbling scores than CON, CAPHI and NEXHI. The proportion of steers in Canadian yield grades 1 and 2 did not differ among treatments, while those in yield grade 3 were greater (P = 0.03) in NEXLO (29%) than the CON (10.0%) and NEXHI (12.2%) treatments, with those fed CAPLO (20%) and CAPHI (19%) being intermediate but not different. Treatment did not affect the proportion of steers in quality grades B4, A, or prime, but tended to increase the proportion of steers grading AAA (P = 0.08) and decrease the proportion grading AA (P = 0.06). Overall, the data from this experiment suggest the potential for capsaicin to affect carcass yield grade, marbling score and quality grades without affecting DMI, ADG, or dressing percentage.