Intake, digestibility and passage rate in Menz sheep fed tef (Eragrostis tef) straw supplemented with dried leaves of selected multipurpose trees, their mixtures or wheat bran

Abstract

A digestibility trial was conducted with the objectives to evaluate the effects of supplementing single or mixtures of selected MPTs or wheat bran on feed intake, digestibility, and passage rate in Menz sheep offered a basal feed of tef (Eragrostis tef) straw. The study was conducted using 36 male Menz sheep with a mean BW of 16.45 ± 0.25 kg in a completely randomized design at Debre Zeit Research Station of the International Livestock Research Institute in Ethiopia. The nine treatments consisted of supplementing sheep fed chopped tef straw with wheat bran (positive control) or dried foliage of the multipurpose trees (MPTs), Sesbania sesban 1198 (SS1), Sesbania sesban 15019 (SS2), Acacia angustissima 15132 (AA), Leucaena pallida 14203 (LP), or mixtures of SS1 + LP; SS2 + LP; SS1 + AA; SS2 + AA at a ratio of 2:1 each. The supplement feeds were offered at 0.9% of BW on DM basis. The supplement MPTs contained low NDF (18–32%) and high CP (21.7–27.5%), whereas tef straw contained high NDF (72.8%) and low CP (4.5%). Soluble phenolics and condensed tannins were higher in the MPTs than in tef straw. Mixtures of LP with either SS1 or SS2 promoted higher (P < 0.05) intake of tef straw and total DM, N and ADF than the control treatment. However, no such differences (P > 0.05) were observed in the digestibility of DM, OM, NDF and ADF between mixtures of LP with SS1 and SS2 and the control treatment. Digestibility of N was higher (P < 0.05) in animals supplemented with the control feed than those supplemented with the mixture of LP and SS2. Supplementation with the mixtures of AA and both accessions of S. Sesban promoted higher (P < 0.05) OM, N, supplement and total feed DM intake, N digestibility and feed passage rate compared to single AA. Supplementation with the mixture of SS and LP resulted in higher (P < 0.05) digestibility of DM, OM, N, NDF and ADF compared to single LP. Feed passage rate was positively correlated (P < 0.01) with DM and N intake. It is concluded that the limitations imposed on N digestibility by high content of soluble phenolics in AA and condensed tannins in LP can be alleviated by supplementing them as mixtures with SS1.