Abstract

This study investigated the importance of suckling for the resistance and/or resilience of very young lambs to Teladorsagia circumcincta nematode infection. Thirty, 6-week old twin-born lambs were allocated to four treatment groups in a 2 x 2 factorial design in which groups continued to suckle (S-) or were weaned (W-), and concurrently not infected (-N) or infected (-I) with 1000 L3 larvae of T. circumcincta per day while grazing ‘clean’ pasture for six weeks, and then slaughtered. There was a significant infection by time interaction on faecal egg counts (FEC; P < 0.001). Suckling/weaning had no effect on FEC. Worm burdens were similar in suckled-infected (SI) and weaned-infected (WI) lambs (8029 + 1502 vs 12228 + 1704 worms, SEM; P > 0.05), respectively. Eggs per utero were significantly greater (29 + 6 vs 15 + 1 eggs, SEM; P < 0.05) in SI than WI lambs, while length of female worms was similar in both groups (10.2 + 0.2 vs 9.7+0.3mm, SEM; P > 0.05), respectively. The two suckled groups progressively gained more weight (P<0.001), while uninfected lambs of both groups were heavier (P < 0.05) from day 28 onwards. Weight gain averaged 122, 282, 98, and 240g day-1 for the WN, SN, WI, and SI lambs, respectively. The study has not shown any advantage of suckling while grazing for lambs’ resistance or resilience to larval intake within the 12-week post lambing period. KEYWORDS: Teladorsagia circumcincta; suckled lambs; resistance; resilience.

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

Proceedings of the New Zealand Society of Animal Production, Volume 65, Christchurch, 182-185, 2005