Nutritional Evaluation of Wheat Straw Upgraded by Pleurotus ostreatus in Growing Lambs

Abstract

Wheat straw left after harvesting of edible mushroom Pleurotus ostreatus was evaluated as feed for growing lambs. Twenty four weaned lambs (25.75±5 kg) were randomly assigned to two treatments: 70% of wheat straw, either raw (US) or upgraded by Pleurotus ostreatus (TS) plus 30% of a concentrate mixture. Lambs were fed the diets for 60d. Feed intake, BW gain and feed conversion (FC) were measured. In situ digestibility of DM, NDF, ADF, and in vivo DM digestibility were also evaluated. The results showed no difference (P>0.05) in feed intake (1.65 and 1.59 kg day−1 for US and TS, respectively), with a lower (P<0.05) BW gain for TS (4.75±0.406 kg) than for US (6.06±0.401 kg) accompanying a poorer FC (US 16.91; TS 22.18). In vivo digestibility of DM was similar (P>0.05) for both treatments (76.43% US, 76.16% TS), as were the data on in situ digestibility of DM, NDF, and ADF after 12, 24, 36, 48, and 72h of incubation in the rumen. In conclusion, it could be said that wheat straw treated by Pleurotus ostreatus did not improve its nutritional value when fed to growing lambs.