Effects of different dietary inclusion levels of macadamia oil cake on growth performance and carcass characteristics in South African mutton merino lambs

Growth performance and carcass characteristics of South African mutton merino fed graded levels of macadamia oil cake were assessed. A total of 60 South African mutton merino lambs were used in the experiment (initial live weight 25.0 ± 0.45 kg). Five diets with different inclusion levels of macadamia oil cake (MOC) were formulated: T1 (0% MOC, control), T2 (5% MOC), T3 (10% MOC), T4 (15% MOC) and T5 (20% MOC). Effects of inclusion level of MOC on average daily gain (ADG) and average daily feed intake (ADFI) were not significant (P > 0.05). Effects of inclusion levels of MOC on feed conversion ratio (FCR) of sheep were significant (P < 0.05). Highest proportion (71.2%) of sheep in the study had a carcass fat classification of 2, followed by a proportion of 17.3% sheep with a carcass fat classification of 3 and lastly 11.5% sheep had carcass fat classification of 4. Warm and cold carcass mass, chest circumference, carcass length and dressing percentage were higher in sheep fed on 5% MOC compared to other treatment diets (0, 10, 15 and 20% MOC) (P < 0.05). Fat rib eye had a greater area in sheep fed on 5% MOC (P < 0.05). It was concluded that 5% MOC provided the best results in terms of carcass characteristic measurements in sheep.