Dagginess and flystrike in lambs grazed on Lotus corniculatus or ryegrass

D.M. Leathwick, D.S. Atkinson

AgResearch, Flock House Agricultural Centre, Private Bag 1900, Bulls, New Zealand

Proceedings of the New Zealand Society of Animal Production. 1995, 55: 196-198

Lambs grazing the tannin containing pasture species Lotus corniculatus (cv Goldie) were compared with lambs grazing a high endophyte ryegrass (cv Nui) in order to assess the effectiveness of lotus at reducing dags and flystrike. Two trials of the same design were run consecutively, between January and April 1994. Each of 4 paddocks, 2 of lotus and 2 of ryegrass, were set stocked for 32 and 42 days (respectively for trials 1 and 2) with 62 lambs. Half of the lambs in each paddock were drenched fortnightly with a combination anthelmintic. Lambs were examined for flystrike three times each week and samples were collected for fly identification before strikes were treated with insecticide.

Lambs which grazed lotus suffered less flystrike than those grazed on ryegrass in both trials (32% of 51%; P<0.01 and 1.5% cf 7.4%; P<0.05 for trials 1 and 2 respectively). Drenching reduced flystrike in trial 1 (from 57% to 26%; P<0.01), but not in trial 2 (4.8% cf 4.1%; NS). Flystrike was strongly correlated with dagginess (R2=97%). Mean dry weight of dags was reduced by grazing lotus rather than ryegrass (79g cf 108g; P<0.01 in trial 1 and 9.7g cf 14.3g; NS in trial 2) and by drenching (68g cf 118g; P<0.01 in trial 1 and 8.8g cf 15.2g; NS in trial 2). Lambs grazing lotus had significantly (P<0.01) higher faecal dry matter content than those grazing ryegrass. We conclude that lotus has considerable potential for a future role in the integrated management of flystrike and dags.

Keywords: NZSAPAB; Lotus corniculatus; ryegrass; white clover; dags; flystrike

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Last Updated 25-01-1997