caa a22 4500 388060441 CHVBK 20180307125119.0 cr unu---uuuuu 161130e199808 xx s 000 0 eng 10.1017/S1357729800009838 doi S1357729800009838 pii (NATIONALLICENCE)cambridge-10.1017/S1357729800009838 Behavioural strategies used by parasitized and non-parasitized sheep to avoid ingestion of gastro-intestinal nematodes associated with faeces [Elektronische Daten] A study was instigated to test whether grazing herbivores have evolved effective strategies to reduce parasite ingestion and to assess the effects of parasitism on these strategies. Two choice trials, each using five animals parasitized with O. circumcincta and five parasite naive animals, were conducted to investigate cues used by sheep to avoid grazing swards contaminated with faeces. Animals were presented with pairs of artificial swards (36 × 21 cm) and allowed to graze for short periods. In the first trial, four quantities (0 g, 5 g, 15 g and 25 g), and in the second trial a control (no faeces) and three age classes (0, 10 and 21 days old), of faeces were tested against each other. Increasing amount offaeces per sward tray was associated with a reduced proportion of bites taken from the sward and reduced bite depth and mass. The minimum amount of faeces at which sheep showed significant levels of rejection was 15 g. Decreasing age of faeces was associated with a reduced proportion of bites taken from the sward, reduced bite depth and mass. This presented the paradox that grazing swards contaminated with young faeces presented least risk of parasitism, yet fresh faeces presented the strongest stimulus for sward rejection. Parasitism altered animal grazing behaviour with parasitized animals becoming more selective when avoiding contaminated swards, taking smaller bites at reduced bite rates compared with non-infected animals. The enhancement of faeces avoidance behaviours shown by parasitized animals could act to reduce further intake of parasites and suggests that grazing behaviour is affected by nematode infection. Copyright © British Society of Animal Science 1998 nematoda nationallicence Ostertagia circumcincta nationallicence parasitism nationallicence selective grazing nationallicence sheep nationallicence Hutchings M. R. Animal Biology Division, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG Kyriazakis I. Animal Biology Division, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG Anderson D. H. Animal Biology Division, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG Gordon I. J. Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH Coop R. L. Moredun Research Institute, 408 Gilmerton Road, Edinburgh EH17 7JH Animal Science Cambridge University Press 67/1(1998-08), 97-106 1357-7298 67:1<97 1998 67 ASC https://doi.org/10.1017/S1357729800009838 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S1357729800009838 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hutchings M. R. Animal Biology Division, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG NATIONALLICENCE 700 1- Kyriazakis I. Animal Biology Division, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG NATIONALLICENCE 700 1- Anderson D. H. Animal Biology Division, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG NATIONALLICENCE 700 1- Gordon I. J. Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH NATIONALLICENCE 700 1- Coop R. L. Moredun Research Institute, 408 Gilmerton Road, Edinburgh EH17 7JH NATIONALLICENCE 773 0- Animal Science Cambridge University Press 67/1(1998-08), 97-106 1357-7298 67:1<97 1998 67 ASC CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge