Abstract
This study compared growth, carcass traits, and meat nutritional characteristics of Dumont and Mongolian lambs fed alfalfa hay (AH) or corn stalk (CS) in a completely randomized 2 × 2 factorial design (n = 24). AH increased average daily feed intake and gain. Because initial body weight differed between breeds, body weight on day 90 (BW90), live weight before slaughter (LWBS), and carcass weight were analyzed by ANCOVA. After adjustment, breed and roughage source affected BW90 and LWBS, while carcass weight showed a significant breed × roughage interaction, with a greater AH-CS difference in Dumont lambs. After Benjamini-Hochberg correction, AH increased C18:3n3 and total n-3 PUFA concentrations and reduced the n-6/n-3 PUFA ratio in longissimus dorsi muscle. Amino acid differences were mostly exploratory. Overall, roughage source mainly affected growth, carcass traits, and selected n-3 characteristics, whereas breed influenced feed intake, adjusted body size, carcass weight, and meat redness.