Effects of byproduct-based diets or grain-based diets on performance and carcass quality of beef steers finished on pasture

Objective

A study was conducted to evaluate effects of 2 pasture-based finishing systems, compared with a conventional finishing method, on live performance and carcass quality of steers.

Materials and Methods

Sixty-three crossbred beef steers (363.9 ± 28.7 kg) were blocked by BW and randomly assigned to one of either 7 pens or 14 pasture paddocks. Treatments consisted of conventional finishing diet (FDLT), or 2 pasture-based diets fed at 2% to 2.25% of BW of either grain-based (STCH) or byproduct-based diets (BYPD). In addition to their diet, steers on the pasture-based treatments were able to graze warm-season perennial forages. Steers were fed their respective diets once daily for 161 d and were harvested at a commercial slaughter facility in Arkansas City, Kansas. Performance and carcass data were analyzed using PROC GLIMMIX and PROC MIXED (SAS 9.4); pen and pasture were the experimental units, treatment was a fixed effect, and block was considered a random effect.

Results and Discussion

Cattle fed FDLT and BYPD had greater BW on d 112 and 140 (P ≤ 0.02), and greater overall carcass-adjusted BW (P = 0.03) compared with STCH. Due to the limit-fed nature of the treatments, both STCH and BYPD had more efficient nonpasture-only feed conversion through d 56, between d 85 and 140, and between d 0 and 161 (P ≤ 0.05). Hot carcass weight tended (P = 0.13) to be greater for BYPD and FDLT compared with STCH. Marbling score tended (P = 0.14) to be greater for BYPD compared with FDLT and STCH. No differences (P ≥ 0.34) were noted in other carcass characteristics.

Implications and Applications

Data from this study suggest that feeding byproduct feed mixtures to beef cattle grazing pasture could successfully be used as an alternative finishing method without affecting carcass quality.