Vernonia amygdalina as a supplement to teff straw (Eragrostis tef) fed to Ethiopian Menz sheep

Agroforestry Systems;31(3): 229-241

Sixteen rumen fistulated Ethiopian Menz type sheep were used in a completely randomized block design in experiment 1. Unchopped teff straw was fed alone or supplemented with either 100, 150 or 200 g/d of sun-dried vernonia leaves. The chemical composition of fresh, boiled, water-soaked and sun-dried vernonia and soluble carbohydrate (SC) loss by boiling were determined. In experiment 2, 25 growing Ethiopian Menz type sheep, were fed teff straw alone or supplemented with 120 g (DM) of either boiled (B) or soaked (S) fresh vernonia with or without molasses (M) (50 g). SC lost by boiling fresh vernonia for 15, 30, 45 or 60 min was determined. In experiment 1, boiling increased the nitrogen (N) concentration in vernonia but sun-drying reduced it. N bound to fibre (NDF-N) was reduced by boiling but not by soaking. SC loss increased with boiling time. Supplementation did not affect the degradation constants (a, b, PD, c) of teff straw, but DM disappearance was increased at 76 and 120 h of incubation. Intake of sun-dried vernonia was poor but increased with quantity offered. Intake and digestibilities of DM, OM and the fibre fractions were marginally higher in the supplemented diets was low due to increased faecal and urinary excretion. In experiment 2, rumen NH3-N was higher for the boiled treatments compared to the soaked treatments. Acceptability at both 2 and 4 h was highest for BM, followed by SM, B and S. Boiling for 30 min, but not soaking, enhanced the acceptability of vernonia, suggesting that a pretreatment may enhance the feed value of vernonia.