Can mulch mats made from sheep effectively deter deer browsing?

To what extent can mulch mats made from sheep wool effectively deter deer browsing, thus reducing reliance on plastic tree guards used to protect tree saplings during woodland creation in the UK?

Simon Smith, student at Bangor University, asks to what extent can mulch mats made from sheep wool effectively deter deer browsing, thus reducing reliance on plastic tree guards used to protect tree saplings during woodland creation in the UK?