Assessing nutritional value and in vitro digestibility of Mediterranean pasture species using yak (Bos grunniens) faeces as alternative microbial inoculum in a DaisyII incubator

The aim of this study was to assess faecal extract as microbial inoculum compared to rumen fluid for an in vitro technique in order to estimate the digestibility of browse species collected in a pasture of Central Italy. The main plants represented in the pasture area were: two grasses (Bromus hordeaceus L. and Hordeum murinum L.), five forbs (Capsella bursa-pastoris L., Crepis sancta L., Erodium malacoides L., Geranium dissectum L. and Geranium molle L.) and one legumes (Medicago arabica L.). Nutrients and mineral composition showed a high variability among browse species collected. Rumen liquor and faecal samples were collected from adult healthy yak (Bos grunniens). The DaisyII incubator system was used to evaluate the nutrient digestibility of forages using rumen liquor as control and faecal extract as alternative microbial inoculum sources. Then, filter bags containing plant samples were added to the four digestion vessels along with their respective inoculum, incubated for 48 h and dry matter (DM), organic matter (OM), crude protein (CP) and neutral-detergent fiber (NDF) digestibility were determined. There was a significant relationship between estimates, indicating that faecal extract has the potential to be utilized instead of rumen fluid for in vitro digestibility estimation. It is concluded that DaisyII incubator is suitable for nutrients’ in vitro digestibility determination with faecal liquor to simply assess the adaptation capability of ruminant species to a pasture.