Selecting for resilience in Romney sheep under nematode parasite challenge, 1994–2007
Autor: | A. Vlassoff, Alec D. Mackay, B. P. Devantier, C. J. West, M. Wheeler, C. A. Morris, S.A. Bisset |
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Rok vydání: | 2010 |
Předmět: | |
Zdroj: | New Zealand Journal of Agricultural Research. 53:245-261 |
ISSN: | 1175-8775 0028-8233 |
DOI: | 10.1080/00288233.2010.500714 |
Popis: | Selective breeding for increased resilience to nematode parasite challenge in New Zealand Romney sheep is reported for the period 1994–2007. Resilience was defined as the age at which a first post-weaning anthelmintic treatment was required to maintain acceptable growth in lambs grazing nematode-contaminated pasture. An experimental line selected for resilience (Rsl) was established in 1994. This was expanded in 1997 for a study comparing animal performance under conventional and low-chemical management systems. An elite resilient line (ER) was re-established in 1999. Selection increased the average ‘age-at-first-drench’ in ER lambs by 23.6 days relative to their control line counterparts. This was accompanied by a 4.5 kg increase in 6-month live weight, and a significant reduction in breech-soiling at 5 months of age. No significant change in faecal worm egg count occurred. Although the Rsl lambs still required some anthelmintic intervention under low-chemical management, the study nevertheless ... |
Databáze: | OpenAIRE |
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