This study examined how different timing strategies of Ascophyllum nodosum supplementation affect carcass quality in implanted feedlot cattle.
While supplementation did not impact growth performance, feed efficiency, or carcass weight, it significantly improved carcass quality. All supplemented groups showed higher marbling scores compared to controls, though a significant impact on quality grade varied by treatment time.
The most effective strategy was feeding seaweed during the mid-feeding period (days 36–50), which produced the highest marbling scores and significantly increase the quality grade, resulting the greatest proportion of cattle grading Choice. Overall, supplementation increased the proportion of higher-grade carcasses. These results suggest that mid-period seaweed supplementation can effectively enhance marbling and carcass value in implanted cattle without compromising growth performance.