Determination of in vitro rumen digestibility and potential feed value of tiger nut varieties
Tiger nut (Cyperus esculentus L.), or chufa, is a plant that is found in nature and is cultivated for its edible tubers. The purpose of this study was to determine the chemical composition, nutritive value, and in vitro digestibility of three tiger nut varieties using the in vitro gas production technique. These varieties were Sarışeker (yellow), Introduction 1, and Balyumru (brown). Rumen fluid was obtained from two cannulated Holstein animals. Time-dependent in vitro gas production was monitored at 3, 6, 9, 12, 24, 48, 72, and 96 hours of incubation. The varieties differed in dry matter (DM), crude ash (CA), ether extract (EE), neutral detergent fibre (NDF), and non-fibre carbohydrate (NFC) content (P <0.05). They also differed in the instantaneous volume of gas produced and in time-dependent gas production. Balyumru produced more gas at the onset of incubation than Introduction 1 and Sarışeker. However, over time, the gas produced by digestion of Introduction 1 exceeded the other two varieties. The amounts of gas produced at each time-point were intercorrelated. It is recommended that these results should lead to further evaluation in in vivo studies.
Keywords: chemical composition, energy content, in vitro gas production