Abstract

This study investigated the role of suckling on the resistance and resilience of lambs during the period - six to 20 weeks after lambing. Eighty, 42-day old twin-born lambs were allocated to four treatment groups in which lambs continued to suckle (S-) or were weaned (W-), while concurrently infected with either 0 (-N) or 1000 (-I) L3 Teladorsagia circumcincta larvae d-1. Faecal egg counts peaked at 680, 1600, 260, and 225 eggs g-1 of fresh faeces in SI, WI, SN and WN lambs, respectively. Live weight gain was reduced from day 98 of age as a consequence of weaning (p<0.001) and infection (p=0.008). Serial slaughter on days 84, 112, and 140 indicated that suckling reduced the number of adult worms in SI compared with WI lambs though significantly so only on day 112 (p<0.05). In vitro larval establishment decreased (p<0.001) with slaughter age but was not influenced by suckling or infection (p>0.05). These results suggest that suckling may inhibit nematode development at a later stage than the immediate entry of incoming L3 larvae. In addition, suckling does not appear to confer greater resilience during T. circumcincta infection in young lambs.

SO, Iposu, AW Greer, RW McAnulty, M Stankiewicz, and AR Sykes

Proceedings of the New Zealand Society of Animal Production, Volume 66, Napier, 187-192, 2006