Different Production Systems and Their Impacts on Growth Performance and Carcass Quality of Lohi Lambs In Pakistan

This study aimed to evaluate the impact of different production systems on the growth performance and carcass composition of male Lohi lambs. A total of 64 male Lohi lambs were assigned to two main groups (A and B) of 32 lambs each, with each group further divided into subgroups of eight per pen. Half of the lambs in each group were castrated. Group A received a concentrate diet at 85 g of dry matter (DM) per kg of metabolic body weight per day, containing 15% crude protein (CP) and 3010 kcal/kg metabolizable energy (ME), along with hay at 100 g per lamb per day. Group B was fed fresh green forage ad libitum and supplemented with 400 g of concentrate per lamb per day containing 20% CP and 2940 kcal/kg ME. Feed composition (offered and refused), daily feed intake, and weekly body weights were recorded throughout the study. At the end of the trial, all lambs were slaughtered, and half carcasses were sampled from each pen for composition analysis. Results showed that lambs in the concentrate-fed group exhibited significantly lower daily dry matter intake (DDMI; P=0.001) and feed conversion ratio (FCR; P<0.05) but demonstrated superior growth performance (GP; P<0.05), higher carcass weight (CW; P<0.001), dressing percentage (DP; P<0.001), and conformation scores (CS; P<0.05). In conclusion, a concentrate-based diet enhanced growth rates, carcass characteristics, and overall performance metrics compared to a forage-based diet supplemented with concentrate, suggesting its effectiveness for optimized lamb production.