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 B W 35.5 +/- 0.43 kg and 6 months of age). Lambs in both experiments wer e divided into three equal groups and fed one of the three concentrate mixes, two of which contained ground acorns (Quercus aegilops and Que rcus 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 e nergy source for growing lambs. Concentrates were given according to B W (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 ba rley at a maximum level of 25% would be economically advantageous. (C) 1998 Elsevier Science B.V. All rights reserved.