Determination of nutritive value of citrus tree leaves for sheep using in vitro gas production technique.

摘要

The nutritive value of Citrus grandis, C. aurantium, C. oranges, C. limon and C. deliciosa leaves was evaluated by chemical composition and in vitro gas production techniques. Significant (p<0.001) differences were observed among Citrus species in terms of chemical composition. The crude protein (CP) contents ranged from 123.0 to 148.3 g/kg DM. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents varied among species and ranged from 219.4-355.4 and 215.0-278.8 g/kg DM, respectively. The condensed tannin (CT) contents ranged from 5.9 to 10.2 g/kg DM. The PEG addition significantly (p<0.001) increased the gas production and some estimated parameters of Citrus tree leaves. However, species showed variable responses to polyethylene glycol (PEG) treatment. There were also significant (p<0.001) differences among species in terms of gas production and estimated parameters. The OMD and ME contents of Citrus leaves without PEG supplementation ranged from 66.5-73.3% and 9.8-10.9 MJ/kg DM, respectively. The improvement in gas production, organic matter digestibility (OMD) and metabolizable energy (ME) with PEG emphasized the negative effect of tannins on digestibility. The increase in the estimated OMD and ME contents ranged from 5.5-9.8% and 5.7-10.2%, respectively. All Citrus tree leaves studied in this experiment had potential nutritive values indicated by high CP content, OMD, ME and low fibre values..