| dc.description.abstract | Individualavstanden mellom dyr påvirkes av faktorer knyttet til individet, forskjellige aktiviteter og miljøet. Forskjellige individer bruker ulike typer atferdstrategier for å håndtere det sosiale miljøet i ei gruppe. Formålet med dette forsøket var å undersøke effekten av sosiale strategier (offensive/defensive) og ressursfordeling på individualavstand når geitene spiser og hviler, ved tilnærmet fri tilgang på plass (10,8m2 / geit). Kriteriet for utvalg av dyr var hvorvidt geitene i en blandingssituasjon tok initiativ til aggressive konflikter (offensive dyr) eller hvorvidt de trakk seg unna (defensive dyr). Det ble valgt ut 32 avhornede, drektige geiter (i 13-16 drektighetsuke ved innsett), hvorav 20 var offensive og 12 var defensive. Dette gav 2 defensive grupper, 4 offensive grupper og 2 blandete grupper, med 4 geiter i hver gruppe. Hver gruppe ble testet for tre ulike fordelinger av fôr (ingen ressurs, fri fordeling og begrenset fordeling) over 6 dager, og rekkefølgen ble systematisk rotert. Videoopptak ble gjort av alle gruppene og ressursfordelingene i seks timer fra kl. 10.00 -16.00, etter en dags tilvenning. Individualavstanden mellom alle parene ble registrert hvert 10 minutt, samtidig som det ble registrert om geitene hvilte eller spiste.
Som forventet ble det funnet en større individualavstand blant geitene når de spiste enn når de hvilte (5,80 ±0,25 m spise; 3,23 ±0,14 m hvile; F1,154= 54,36, P < 0,0001). Individualavstanden ble signifikant påvirket av strategien til geitene, og den var minst i de blandede grupper og størst i gruppene med bare defensive geiter (Off: 4,24 ± 0,11m;
Def: 4,76 ± 0,28 m; Off-Def: 3,72 ±0,21 m; F2,90 = 6,67; P < 0,01). Individualavstanden i de blandede grupper lå ikke som forventet midt i mellom, men var lavest av alle gruppene. De ulike ressursfordelingene gav en signifikant forskjellig individualavstand (ingen ressurs:3,51±0,13m; fri fordeling: 4,55±0,16m; begrenset fordeling: 4,67±0,21m; F2,90 = 18,83; P < 0,0001). Individualavstanden var kortere når geitene ikke hadde tilgang på fôr enn når fôr var tilgjengelig. Det ble funnet en positiv samspillseffekt mellom strategi og ressursfordeling (F4,90 = 3,05, P < 0,05). I samsvar med prediksjonen ble det funnet en større individualavstand ved fri fordeling enn ved begrenset fordeling i de defensive gruppene, men ikke i de offensive og blandede gruppene. Resultatene bekrefter at geitenes behov for plass er større når de spiser enn når de hviler, og at geitenes sosiale plasskrav er større enn det arealet som er praksis i dagens geitedrift.
The individual distance between animals is affected by factors related to individual, different behavioural activities, and the environment. Individuals use different coping strategies to deal with the social environment in a group. The aim of this study was to investigate the effect of coping strategies (offensive and defensive) and resource distribution on the individual distance during feeding and resting, at near free access in place (10,8 m2 / goat). The criteria for selection of animals were whether the goats in a mixed situation took the initiative to aggressive conflicts (offensive), or if they withdraw from the situation (defensive). Thirty-two dehorned goats (13-16 weeks pregnant) were selected, of which 20 were offensive and 12 were defensive. The goats were divided into four offensive groups, two defensive groups and two mixed groups, with four goats in each group. Each group was tested for three different distributions of feed (no feed, free feed and limited feed distribution) over a period of 6 days. The order of the distributions was systematically rotated. All groups and distributions were videotaped for 6 hours, between 10.00 and 16.00 h, after the goats were accustomed to the distributions for one day. The individual distance between all pairs was scored using instantaneous sampling with 10 min intervals. At the same time it was registered if the goats were resting or feeding.
As predicted there was a higher individual distance between the goats when they were feeding than when resting (feeding: 5,80 ±0,25 m; resting: 3,23 ±0,14 m; F1,154= 54,36, P <0.0001). The individual distance was significantly affected by the strategy of the goats, where the individual distance were smallest in the mix group and largest in the homogeneous defensive groups (Off:4,24 ±0,11 m; Def: 4,76 ± 0,28 m; Off-Def: 3,72 ±0,21 m; F2,90 = 6,67; P < 0,01). The individual distance in the mix group was smallest and not in between as expected. The different resource distributions gave a significantly different individual distance, as was shorter when the goats had no access to feed than when feed resources were available (no feed:3,51 ± 0,13 m; free feed: 4,55 ± 0,16 m; limited feed: 4,67 ± 0,21 m; F2,90 = 18,83; P < 0,0001). We found a positive interaction effect between strategy and resource distribution (F4, 90 = 3,05, P < 0,05). In accordance with the prediction it was found greater individual separation when there was free distribution, than when there was limited distribution in the defensive groups, but not in the offensive or mixed groups. The results confirmed that goats' need for space is greater when they are feeding than when they are resting, and that the goats’ need for social space is larger than the area that is practised in today’s housing system for goats. | en_US |
