Nutrient supply for lamb growth from Grasslands Puna chicory
((Cichorium intybus) and Wana cocksfoot (Dactylis glomerata)
K. Komolong, A.M. Nicol, D.P. Poppi, T.J. Frazer, S. Kirsopp
Department of Animal Science, Lincoln University, Canterbury,
New Zealand
Proceedings of the New Zealand Society of Animal Production.
1992, 52: 85-88
Two groups of 10 intact Border Leicester ram lambs (10 weeks
old; 22.7±0.59 kgLW) were grazed on either Grasslands Puna chicory
(Puna) or Wana cocksfoot (Wana) over a six week period in late spring,
to relate liveweight gain (LWG) to nutrient intake and supply at the
duodenum from the 2 forages. Both pastures were in a vegetative state
and offered at a high allowance (12.5 to 15 kgDM/lamb/d). Chemical
composition (%DM) of oesophageal extrusa sample was 81.5 and 89.4 OM,
34.9 and 48.1 neutral detergent fibre (NDF) and 2.6 and 3.6 N and the
in vitro OM digestibility was 72.6 and 74.2% for Puna and Wana
respectively. Liveweight was recorded weekly and intake estimated in
week 3 by reference to dilution of two faecal markers, Cr2)3 and Yb
acetate. Digestion characteristics in the rumen and nutrient supply at
the duodenum was measured in companion lambs (n=6) fitted with rumen and
duodenal cannulae using Cr-EDTA and Yb acetate as the solute and
particulate phase digesta markers, respectively.
LWG (g/d) was 268±20.9 on Puna and 205±19.1 on Wana. Digestible OM
intake (DOMI) and nitrogen intake (NI) was lower on Puna (16.10 and 0.71
g/kgLW/d) mainly due to variable N loss as ammonia across the rumen. It
appears that the disparity in LWG of lambs grazing Puna and Wana may be
related to differences in the balance of nutrients rather than the
quantitative intake or supply of any one nutrient. This is shown in the
ratio of duodenal NAN:DOMI which for Puna (43.5) was similar to legumes
but the ratio for Wana (31.9) was lower than for other grasses. It is
concluded tentatively that the nutritive value of Puna and Wana for lamb
growth is best described by the NAN:DOMI ratio.
Keywords: NZSAPAB;
Lamb growth; chicory; cocksfoot; liveweight gain; nutritive
value; intake; digestibility.
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Last Updated 25-01-1997
