Nutrient intake, digestibility, growth performance and carcass characteristics of Farta sheep fed urea-treated rice straw supplemented with graded levels of dried Sesbania sesban leaves

BACKGROUND: The experiment was conducted using twenty-five Farta sheep to investigate the response of supplementing dried Sesbania sesban leaves (SSL) on feed intake, digestibility, growth performance and carcass characteristics of Farta sheep fed urea-treated rice straw. Twenty-five male Farta sheep with initial body weight of 18.9 ± 1.7 kg (mean ± SD) were used in randomized complete block design with five replications. The treatments were 0 g Sesbania sesban leaves (SSL) (control T₁), 100 g SSL (T₂), 200 g SSL (T₃), 300 g SSL (T₄) and 400 g SSL (T₅). The experiment lasted 90 days of growth and 7 days of digestibility period. All experimental sheep were given urea-treated rice straw ad libitum as basal diet. Chemical composition of diets and refusals, feed intake, digestibility of dry matter and nutrients, carcass yield and quality were recorded. All collected data were analyzed using general linear model (GLM) procedure of SAS version 9.1.3. Means were separated using Duncan’s multiple-range test. Correlations among nutrient intakes, weight gain and digestibility of nutrients were analyzed using Pearson linear correlation test. RESULTS: Results showed that supplementation of SSL significantly increased (P < 0.001) total dry matter, crude protein and organic matter intakes. Supplementation of SSL improved the digestibility of dry matter, organic matter (P < 0.05), crude protein (P < 0.01). Final body weight (P < 0.01), average daily gain and feed conversion efficiency (P < 0.001) for T₅ were higher for supplement groups, while sheep fed sole UTRS (T₁) lost body weight. Slaughter weight (P < 0.01), empty body weight (P < 0.01) and hot carcass weight (P < 0.001) increase with increase in the level of supplementation. Dressing percentage on slaughter BW basis and EBW basis was higher (P < 0.05) for T₅ than control. The partial budge analysis result indicated that sheep fed UTRS alone had the lowest net return (− 92.22 ETB), while sheep supplemented with 400 g SSL (T₅) had better net return (144.6 ETB) with marginal rate (1.7) compared to the other supplemented treatments. CONCLUSION: From the study it could be concluded that SSL could serve as alternative CP supplement in urea-treated-based crop residues feeding of growing Farta sheep to improve the biological performance and economic feasibility in the study area.