Effect of bitter vetch (Vicia ervilia) seeds as a replacement protein source of soybean meal on performance and carcass characteristics of finishing Awassi lambs

The objective of this study was to evaluate the effects of replacing the protein source of soybean meal (SBM) with different levels of bitter vetch seeds (BVS) in the diets of finishing Awassi ram lambs on performance, and carcass characteristics. Diets were designed based on replacing SBM with BVS as a percentage of the diet. Diets were: control (0% BVS), substituting 5% of SBM (5% BVS), 10% of SBM (10% BVS) and the entire SBM in the ration with BVS (15% BVS). Forty eight lambs (18.74 ± 3.95 kg initial body weight and 70 days of age) were randomly assigned to 4 treatment diets (12 lambs/treatment). Lambs were given an adaptation period of 10 days and the experiment lasted for 84 days. At the end of the trial, a digestibility experiment was performed and 6 lambs from each treatment were slaughtered to evaluate carcass characteristics. Average daily gain tended (P = 0.07) to be higher for lambs fed 10% BVS when compared to the other diets. Neutral detergent fiber digestibility was higher (P < 0.01) in control diet compared to the other diets. Fat depth (C) and leg fat depth (L3) tended (0.05 < P < 0.1) to be affected by BVS levels in the diet. Leg total lean % was the highest (P < 0.05) in 5% BVS and 10% BVS diets. These results suggest that substituting SBM with BVS in the diets did not influence performance or carcass characteristics of lambs. However, the cost of ration formulation decreases since SBM is a very expensive component of the ration.