Autumn-born lambs - responses to use of anthelmintics and selenium

Authors: Killen WJ
Publication: New Zealand Veterinary Journal, Volume 35, Issue 10, pp 178-179, Oct 1987
Publisher: Taylor and Francis

Animal type: Livestock, Production animal, Ruminant, Sheep
Subject Terms: Animal remedies/veterinary medicines, Anthelmintics, Parasite control, Parasites - internal, Diet/rations/food, Environment, Growth/development, Nutrition/metabolism, Parturition, Reproduction, Reproduction - female, Seasonality/photoperiod, Selenium, Trace elements, Treatment/therapy
Article class: Correspondence

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Abstract: Out of season (autumn/winter) lambing is expanding in northern areas. These lambs need to grow at moderate rates through the late winter feed trough so they can fully utilise the spring flush to reach heavy weights before summer. Autumn-born lambs are likely to face high parasite roundworm challenge pre and post-weaning. Strongyle faecal egg counts of autumn and spring-born lambs at weaning averaged 2000 and 400 eggs/g respectively (n=30) under an all-sheep, split season lambing policy near Kaikohe. Roundworm infestation can also reduce selenium concentration in the Iiver.(2) Although Se level in pasture tends to be higher in autumn/ winter than in spring/summer this could be offset by lower pasture availability. Better winter growth rates have been recorded in weaned calves from a combination anthelmintic/ selenium drench than from either of these alone. In three successive years, autumn-born Dorset x Perendale lambsweaned and drenched in July were allocated in late July (14+2% weeks of age) to four drench treatments…

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