TOMATO POMACE AS A PROTEIN-SUPPLEMENT FOR GROWING LAMBS

A barley-based diet (B) with 115 g CP/kg DM was supplemented, on DM ba sis, with 1 00 (T1), 200 (T2) or 300 (T3) g tomato pomace/kg to achiev e final CP contents of 136, 156 and 172 g/kg DM, respectively, and fed to four growing lambs each. DM intake was adjusted to achieve the sam e energy intake for all diets (50 g DOM/kg BW0.75). N retention increa sed from 0.50 to 0.69 g/kg BW0.75 between diets B and TI, but higher l evels of supplementation did not improve N retention. In a second bala nce trial, a barley-based diet (B) with 122 g CP/kg DM was supplemente d, per kg ration DM, with 200 g tomato pomace untreated (TU) or treate d with 50 g NaOH/kg DM (TT). The supplemented diets, containing 155 an d 151 g CP/kg DM, respectively, were compared to an isonitrogenous soy bean meal diet (SL. 145 g CP/kg DM). and a higher protein soybean meal diet (SH; 163 g CP/kg DM). All diets were fed ad libitum to four lamb s per treatment. There were no differences in DM or DOM intake, mean v alues being 99.1 +/- 1.66 and 65.3 +/- 1.24 g/kg BW0.75, respectively. N retention (g/kg BW0.75) increased significantly from 0.84 on diet B to 1.07 on diets TU, 17 and SL, but diet SH did not promote a signifi cantly higher N retention. In a growth trial, diets TU, TT, SL and SH were fed to seven lambs each for an experimental period of 6 wk. Mean live weight increased from 15.5 +/- 0.56 to 28.2 +/- 0.44 kg final wei ght. DM intake (g/kg BW0.75) was not affected by dietary treatment and was 95.4, 97.1, 102.3 and 97.0 for TU, TT, SL and SH, respectively. G rowth rates (g/d) and feed conversion rates (kg DM/kg gain) were 304, 318, 337, 329 and 3.20, 2.95, 3.10 and 2.95 for the same diets. It was concluded that supplementation of barley-based diets with tomato poma ce at a rate of 200 g/kg ration DM promote similar N retentions and gr owth performances to soybean protein in young lambs up to 28 kg BW.