Growth performance, carcass traits, and physicochemical characteristics of Longissimus thoracis of fattening lambs feeding milk thistle (Silybum mariamum) seed powder

Abstract

This study investigated the effect of supplementing diet with milk thistle seed powder (MTSP) on performance and carcass characteristics of Romanov×Shawl crossbred lambs. Thirty Romanov×Shawl crossbred lambs (six-month-old) were fed diets containing zero (without MTSP), 1 % and 2 % MTSP (wheat bran substitute) in a completely randomized design for 90 days. Lambs fed diet containing 2 % MTSP had higher dry matter intake, final body weight, and daily weight gain (P < 0.05). The best feed conversion ratio was observed for the 2 % MTSP treatment (P < 0.05). The weights of lean meat, warm and cold carcasses, percentage of bone, and ratio of meat to bone were higher in lambs fed with 2 % MTSP diet (P < 0.05) compared with other groups. Eye muscle weight was higher in lambs fed 1 % and 2 % MTSP diets than that of the control group (P < 0.05). The highest perirenal fat was observed in the lambs fed the control diet (P < 0.05). The heart fat weight was decreased linearly with the addition of MTSP diet (P < 0.05). Spleen weight increased linearly by feeding 2 % MTSP compared to other groups. Feeding diet containing MTSP increased meat protein and decreased the concentration of malondialdehyde in Longissimus thoracis (P < 0.05). The results indicated that feeding the diet containing MTSP, especially at the level of 2 %, improved performance, carcass characteristics, and physicochemical parameters of Longissimus thoracis in lambs.