A rotational grazing experiment using weaner deer was conducted at Palmerston North, New
Zealand, during the autumn, winter and spring, to compare the voluntary feed intake (VFI),
liveweight gain (LWG) and carcass production of deer grazing chicory with those grazing perennial
ryegrass/white clover pasture. Deer were either treated with anthelmintic at 3-weekly intervals (T) or
anthelmintic was withheld until trigger-treatment (TT) criteria were attained. Pure red and 0·75
red: 0·25 elk hybrid stags and hinds were given forage allowances of 5 kg DM/deer/day in autumn
and early-mid winter, 6 kg DM/deer/day in late winter and 7 kg DM/deer/day in spring. Deer
grazed chicory or pasture in autumn and spring, with all deer combined on pasture during winter
when chicory was dormant. Organic matter digestibility of diet selected was greater for chicory than
for pasture in both autumn and spring.
Anthelmintic-treated deer grazing pasture in autumn had significantly higher VFI and LWG,
contributing to higher carcass weights, than TT deer. Anthelmintic treatment had no effect on these
measures for deer grazing chicory in autumn. Clinical signs of lungworm infection were evident in
pasture TT deer during autumn and winter, and in chicory TT deer grazing pasture during winter.
Faecal egg counts (FEC) were significantly greater for pasture TT deer during autumn and early
winter than all other groups. Faecal lungworm larval counts (FLC) were significantly greater for
chicory TT deer following transfer to pasture, than for all other groups in early winter, although both
FEC and FLC were low. Faecal larval counts were poorly related to clinical signs of lungworm
infection during autumn, but were a better guide in winter. Plasma pepsinogen concentrations
appeared unrelated to gastrointestinal parasite infection. Trigger-treated deer grazing pasture
required five anthelmintic treatments during autumn and winter. The chicory TT group required no
anthelmintic treatment when grazing chicory during autumn, but required two treatments after
transfer from chicory to pasture during winter.
There was no effect of anthelmintic regime on VFI and LWG in spring, and LWG was greater for
deer grazing chicory than those grazing pasture. Hybrid deer had greater spring LWG and carcass
weights than red deer when grazing chicory, but similar LWG and carcass weights when grazing
It was concluded that grazing chicory offers the potential for reducing anthelmintic use in farmed
weaner deer, particularly during autumn.