Supplementary feeding and gastrointestinal nematode parasitism in young grazing sheep

M.F.J. Van Houtert, I.A. Barger and J.W. Steel

CSIRO Division of Animal Production, Armidale, NSW 2350, Australia.

Proceedings of the New Zealand Society of Animal Production, 1996, 56: 94-98

Young Merino wethers (n=240) were allocated to 1 of 8 treatments in a replicated field experiment. Animals grazed semi-improved pasture and received supplements for 14 or 28 weeks based on fish meal (F14, F28), sunflower meal (S14, S28) or oat grain (O14, O28). Unsupplemented parasite-free (C-) and parasitised animals (C+) were included as controls. Animal performance and parasite status were evaluated.

During weeks 1-14 faecal egg counts (FEC) were below 120 eggs per gram (epg), due to low larval intake from pasture. Cumulative live-weight gain (LWG) over this period was increased as a result of supplementary feeding from 8.6 (mean C- and C+) to 11.4 kg (F14; P<0.01) or 9.9 or 9.7 kg (S14 and O14 respectively; P>0.05).

From week 15 animals were dosed fortnightly with 6000 Trichostrongylus colubriformis and 2000 Haemonchus contortus larvae. Lucerne hay was fed twice weekly from week 17 onwards (2 kg/sheep/week). The FEC increased to about 5900 epg in week 28 for groups C+, F14, S14, O14 and O28 and about 3000 epg for groups F28 and S28 (P<0.05). Cumulative LWG from weeks 15-28 for groups C-, F28, S28 and O28 (0.9, 1.1, 0.6 and 1.4 kg respectively) was higher than for groups C+, F14, S14 or O14 (-1.2, -1.7, - 2.2 and -0.9 kg respectively; P<0.05).

Supplementation with F, S and O during parasite infection enhanced the resilience of grazing sheep to gastrointestinal nematodes, while supplementation with F and S appear to have reduced peak FEC.

Keywords: NZSAPAB; Nutrition; sheep; Trichostrongylus colubriformis; Haemonchus contortus.

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Last Updated 18-03-1997