Partial replacement of dried Leucaena leucocephala (Lam.) de Wit leaves for noug (Guizotia abyssinica) (L.f.) Cass. seed cake in the diet of highland sheep fed on wheat straw.

This study investigated the effect of replacing noug (Guizotia abyssinica) (L.f.) Cass. seed cake by dried Leucaena leucocephala (Lam.) de Wit leaves on feed intake, live weight gain, nutrient digestibility, and nitrogen balance of highland sheep in Tigray Region in northern Ethiopia. Twenty intact yearling male highland sheep weighing 16.9 ± 1.62 kg were used in a randomized complete block design and included the following four treatments: T1 (control, wheat straw ad libitum + 200 g noug seed cake (NSC) + 150 g wheat bran (WB)); T2 (wheat straw ad libitum + 170 g NSC + 44.3 g dried L. leucocephala (DLL) + 150 g WB); T3 (wheat straw ad libitum + 140 g NSC + 87.3 g DLL + 150 g WB); and T4 (wheat straw ad libitum + 110 g NSC + 130.2 g DLL + 150 g WB). Sheep fed on T4 diet consumed higher total dry matter (658 g/head/day) and recorded the highest average daily weight gain (59 g/head/day). Sheep fed on T4 diet had higher dry matter (61 %), organic matter (63 %), and crude protein (75 %) digestibility values than the other treatments. Sheep fed on T3 diet demonstrated higher feed conversion ratio (11.93) than sheep kept on the other treatments. All sheep exhibited positive nitrogen balance, with the highest nitrogen retention being measured in T4 (12 g/head/day). It is concluded that partially replacing NSC by DLL can improve total dry matter intake, digestibility of nutrients, and body weight gain in highland sheep fed on wheat straw as the basal diet.