Effect of Graded Levels of Pigeon Pea (Cajanus cajan L.) Foliage Supplementation on Feed Intake, Nutrient Digestibility, and Growth Performance of Gumuz Sheep Fed Napier Grass

Abstract This study evaluated the effects of supplementing Napier grass ( Pennisetum purpureum Schumach.) with graded levels of wilted pigeon pea ( Cajanus cajan L.) foliage versus a conventional concentrate mixture on feed intake, nutrient digestibility, growth performance, and feed conversion efficiency (FCE) of indigenous Gumuz sheep. Twenty intact male Gumuz sheep with an initial body weight of 18.48 ± 1.20 kg were arranged in a randomized complete block design across four treatments: Napier grass ad libitum + 350 g DM/day concentrate mixture (T1, control); Napier grass ad libitum plus 200 g DM/day (T2); 300 g DM/day (T3); and 400 g DM/day pigeon pea foliage (T4). Daily dry matter intake (DMI) and crude protein (CP) intake differed significantly among treatments, with T1 recording the highest intakes, followed by a linear increase across pigeon pea levels from T2 to T4. Apparent digestibility of DM, organic matter (OM), and CP was highest in T1. Among the pigeon pea treatments, DM, OM, and neutral detergent fiber (NDF) digestibility increased as pigeon pea level increased, reaching 72.64% DM digestibility in T4. Final body weight, body weight change (BWC), and average daily gain (ADG) were highest in T1, whereas differences among the pigeon pea treatments for these growth parameters were not significant. However, FCE differed significantly, with T2 recording the highest biological efficiency compared to T3, T1, and T4. Supplementing Napier grass with pigeon pea foliage effectively supported positive nutrient balance and daily weight gains (74.22–83.89 g/day) in Gumuz sheep. Among the legume supplementation levels evaluated, 200 g DM/day achieved the highest feed conversion efficiency, demonstrating that low-level pigeon pea supplementation provides a practical, high-quality forage-legume alternative to commercial concentrates for smallholder sheep production systems in western Ethiopia.