<p>This study evaluated the growth performance, carcass attributes, and meat quality of steers raised under organic and conventional agricultural systems. In the conventional system, steers were divided into two feeding groups. The first group, comprising Kampaeng Saen steers (KPS-Rf) and crossbred dairy steers (CDS-Rf), received a restricted concentrate diet (8&#xa0;kg/head/day) along with unlimited Napier grass silage. The second group, consisting of Kampaeng Saen steers (KPS-Ab) and crossbred Wagyu steers (WC-Ab), was fed ad libitum concentrate and Napier grass silage. The conventional system resulted in significantly higher weight gain, final weight, average daily gain, and a more favorable feed conversion ratio compared to the organic system (<i>P</i> &lt; 0.05). Within the conventional system, no significant differences were found between the limited and ad libitum concentrate feeding groups for final weight, weight gain, or average daily gain (P &gt; 0.05). Significant differences (<i>P</i> &lt; 0.05) were observed for hot and cold carcass weights, with the conventional system generally outperforming the organic system. Meat from the conventional system exhibited lower pH levels and lighter color (higher L* values) compared to the organic system (<i>P</i> &lt; 0.05). Regarding nutritional composition, meat from the organic system contained higher crude protein and lower fat content compared to the conventional system (<i>P</i> &lt; 0.05). Additionally, significant differences were observed in the fatty acid profiles, with organic meat showing higher levels of polyunsaturated fatty acids and omega-3 fatty acids (<i>P</i> &lt; 0.05). KPS-Rf exhibited better growth performance and feed conversion efficiency than the other breeds in both conventional and organic systems.</p>