Abstract
This study was conducted to determine the potential nutritive value and in vitro gas production (IVGP) parameters of Olea europaea L. (Olive = OL), Morus alba L. (Mulberry = ML) and Citrus aurantium L. (Sour orange = SOL) tree leaves. Hohenheim gas test was used to determine the in vitro gas productions of the leaves. The gas production of samples over time was recorded for 3, 6, 9, 12, 24, 48, 72 and 96 h after incubation. Completely Randomized Design was used to compare gas production, and gas production kinetics of samples. The findings of the present study suggested that there were differences among the tree leaves in terms of crude protein, NDF, in vitro gas productions, organic matter digestibility (OMD), metabolisable energy (ME), net energy lactation (NE(L)) and relative feed values (RFV) (P<0.01). ML had the highest condensed tannin contents (P<0.05), in vitro gas production (IVGP), OMD and energy values (P<0.01). SOL had highest RFV values. OL showed the lowest IVGP when compared to SOL and ML. Low NDF and ADF contents of SOL would probably increase the voluntary intake, digestibility and relative feed values of these leaves by ruminants. In conclusion, it was determined that OL, ML and SOL used in the study have low in vitro gas production and can be utilized as alternative roughage feed in ruminants. However, it is recommended that the results obtained from this research should be tested in in vivo studies.