Response in Growth Performance, Carcass Traits, Physicochemical Properties, and Fatty Acid Composition of Dohne Merino Rams Fed Different Levels of Canola Meal

Abstract This study aimed to assess the effects of different inclusion levels of canola meal (CM) on growth performance, carcass characteristics, physicochemical properties, and fatty acid composition of Dohne Merino rams (DMRs). Forty DMRs, weighing 24±2.63 kg and aged 8–9 months, were individually housed and randomly assigned to one of four isonitrogenous and isoenergetic diets. The experimental diets contained 5% oil cake meal, soybean meal (SBM) or CM, CM replaced SBM at 0% (T1), 50% (T2), 75% (T3) and 100% (T4). The results revealed a quadratic increase in average daily feed intake as CM levels increase. Average daily gain and feed conversion ratio decreased. Blood urea nitrogen and total cholesterol showed a significant linear decline with increasing CM levels, while glucose-fasting, total protein, and albumin did not exhibit significant relationships. The carcass traits such as warm and cold dressing percentages, pH and temperature measurements, demonstrated a quadratic decrease with increasing CM inclusion levels. The physicochemical properties of the meat did not show significant relations, except for fat-free dry matter, which decreased quadratically. Fatty acids like capric, oleic, and eicosapentaenoic acids decreased significantly with CM levels, while margaric acid decreased linearly, and alpha-linolenic acid increased linearly. These findings suggest that restricting CM inclusion in sheep diets to below 5% could help mitigate adverse effects on growth performance. The possible antagonistic interaction between SBM and CM highlights the recommendation against combining CM with SBM in rations.