Background and Aim: The high price of conventional diet ingredients led livestock producers to search for alternative feed sources such as faba beans (Vicia faba L.; FB). This study aimed to evaluate the effect of feeding FB on the growth performance of lambs.

Materials and Methods: A total of 24 male lambs were distributed randomly into two groups and fed a control diet (CON; n=12) and 200 g/kg FB (FB200; n=12) dietary dry matter (DM). The study lasted for 70 days. The first 7 days were used for acclimatization, followed by 63 days of data collection (i.e., nutrient intake and digestibility and growth performance). A complete randomized design was used for the statistical analysis.

Results: The average initial body weight (BW) (20.54±0.798 kg) was similar between the diet treatment groups. Lambs fed the FB200 diet demonstrated higher (p≤0.008) nutrient intake than lambs fed the CON diet. The FB200 diet tended to improve the digestibility of DM, crude protein, and acid detergent fiber more than the CON diet (p≤0.072). Neutral detergent fiber and ether extract digestibility were higher (p<0.05) in lambs fed the FB200 diet than those fed the CON diet. Next, nitrogen retention increased (p<0.05) in lambs fed the FB200 diet compared with the CON diet. Final BW did not differ (p=0.221) between the two groups. However, the average daily gain was higher (p=0.028) in lambs fed the FB200 diet than in lambs fed the CON diet. Furthermore, the cost of gain decreased more (p=0.04) with the FB200 diet than with the CON diet.

Conclusion: The results obtained in this study demonstrate the feasibility of using FB in feeding growing lambs, as it was shown to improve growth performance and reduce the cost of diet and gain.

Keywords: Awassi lambs, faba beans, growth performance, nutrient intake and digestibility.