The effect of wilting chicory on its voluntary feed intake and digestion by red deer

Two experiments were conducted at Palmerston North, New Zealand during 1997 , to investigate the effects of wilting chicory to reduce its bulkiness upo n voluntary intake of fresh feed and dry matter (DM), apparent digestibilit y and voluntary water intake. In Expt 1 fresh chicory was cut and wilted fo r 48 h to determine the drying rate; wilting for 24 h increased DM content from 87 to 173 g/kg, reduced in vitro organic matter digestibility (OMD) by 0.016 (P < 0.05) and was selected for use in Expt 2. In Expt 2, chicory wa s fed either fresh (113 g/kg DM) or wilted (250 g/kg DM) to castrated male red deer kept indoors over two time periods, late autumn and early spring. Chemical analyses showed that wilting slightly lowered the concentration of water-soluble carbohydrate from 185 to 158 g/kg DM, but did not change any other aspect of composition. There were no significant differences between fresh and wilted chicory in apparent digestibility of DM, organic matter ( OM), hemicellulose and cellulose. Wilting significantly lowered voluntary i ntake of fresh feed (P < 0.01), but significantly increased voluntary DM in take from 49 to 57 g DM/kg W-0.75/day (P < 0.05). Wilting chicory lowered f eed water intake (P < 0.01) but increased drinking water consumed (P < 0.00 1), with total water intake still being slightly lower (P < 0.05) for deer fed wilted chicory. It was concluded that wilting chicory increased DM intake by reducing its b ulkiness, without seriously affecting digestibility, and it is suggested th at the feasibility of breeding forage chicory for higher leaf DM content sh ould be investigated. A comparison with literature values showed that DM co ntents of fresh forages < c. 150 g/kg are likely to restrict the voluntary DM intake of ruminants.