Performance of lambs from a clean grazing system subsequently grazed on contaminated pasture
Whitelaw, A.; Fawcett, A.R.
Veterinary Record 111(11): 224-225
1982
ISSN/ISBN: 0042-4900 PMID: 7135776 Document Number: 195654
When transferred to a permanent pasture continuously grazed by sheep in Scotland, lambs that had been reared under a clean grazing system gained less weight (107 g/day) over 78 days than did lambs that had grazed contaminated pasture from birth to weaning (138 g/day). At slaughter the lambs from clean grazing had a mean intestinal worm burden of 36 025 (including 24 140 Nematodirus) whereas the other group had only 10 790 (4135 Nematodirus); this difference reflects the different immune status of the 2 groups of animals. Genetic factors could have also contributed to the differences in growth rates.