Proceedings of the New Zealand Society of Animal Production.
1985, 45: 113-116
Proceedings of the New Zealand Society of Animal Production.
1985, 45: 113-116
Lambs were weaned at 6 weeks of age and measurements made at 8 and 12 weeks of age. Live-weight gain (LWG) measured over 6 weeks after weaning was higher for lambs grazing on legumes (308 ± 25, 321 ± 18 for L and W) than on grasses (230 ± 8, 227 ± 9 for P and R).
No differences were observed within species in duodenal NAN flow between measurements made at 8 and 12 weeks of age. Duodenal NAN flow (g NAN/kg LW/d) was significantly higher for legumes (1.24 ± 0.11, 1.20 ± 0.09 for L and W) than for grasses (0.87 ± 0.006, 0.96 ± 0.06 for P and R). Duodenal NAN flow, expressed as g NAN/kg DOMI, showed a similar pattern (44.9 ± 2.1, 45.0 ± 1.3, 42.8 ± 2.2), 39.3 ± 2.2 respectively for L, W, P and R) though differences between species were lower than when expressed /kg LW.
The rumen retention time (h) of a dry matter marker (103 Ru-P) was lower for legumes (8.4 ± 0.43, 9.5 ± 0.74 for L and W) than for grasses (11.5 ± 0.73, 15.1 ± 0.98 for P and R).
Intake (g OM/kg LW/d) was 30% higher for legumes than for grasses.
It was concluded that the higher LWG observed in lambs grazing legumes was associated more with a higher organic matter intake than with an increase in the duodenal NAN/DOMI ratio.
Keywords: NZSAPAB; sheep; early-weaning; grazing intake; duodenal protein flow; pure pasture species
