Utilization of concentrate diets containing acorns (Quercus aegilops and Quercus coccifera) and urea by growing Awassi lambs

Thirty individually penned Awassi lambs (mean BW 25.3 +/- 0.45 kg and 4-5 months of age) were used in a growth experiment. This was followed by a digestion and nitrogen balance experiment using 12 lambs (mean BW 35.5 +/- 0.43 kg and 6 months of age). Lambs in both experiments were divided into three equal groups and fed one of the three concentrate mixes, two of which contained ground acorns (Quercus aegilops and Quercus coccifera) at 25% and 50% levels of DM (% dry weight). The aim of the work was to evaluate the usefulness of acorns as an alternative energy source for growing lambs. Concentrates were given according to BW (restricted to 3.5% of BW). Daily weight gain (DWG) of lambs fed the control diet or 25% acorn diet was similar (186 and 189 g) but higher (P < 0.01) than lambs on the 50% acorn diet (142 g). Feed conversion ratio (kg DM/kg LW gain) was lower (P < 0.01) for the 50% acorn diet. Digestibility coefficients of dietary constituents (DM, OM, ash, NDF, ADF, and N) were reduced (P < 0.001 and P < 0.01) as a result of acorn substitution for barley. Nitrogen retention (g/day) was also lower(P < 0.05) for acorn diets, but similar(P > 0.05) across treatments when expressed as percentage (%) of apparently digested N. The low cost of acorns compared with barley suggest that substitution of acorns for barley at a maximum level of 25% would be economically advantageous. (C) 1998 Elsevier Science B.V. All rights reserved.