A study was conducted to test whether the effects of space allowance on social interactions, activity patterns and growth rates of hinds reared at pasture in single-species groups, were modified by mixing them with ewes. 30 red deer hinds (10 months old) from the same breeding group and 30 ewes (8 months old) were assigned to 2 single-species groups of 10 (hinds: H1 and H2, ewes: E1 and E2) and to 2 mixed-species groups of 5 hinds and 5 ewes (M1 and M2). For 28 days, H1, E1 and M1 were kept at high space allowance (HSA: 267 msuperscript 2/animal) and H2, E2 and M2 at low space allowance (LSA: 67 msuperscript 2/animal) and for the following 28 days, the space allowance was reversed. Mean interindividual distances in single-species groups were lower at LSA than at HSA (hinds: 10.0+or-0.3 vs. 15.4+or-4.8 m, P<0.05; ewes: 7.9+or-0.5 vs. 11.0+or-2.5 m, NS). In mixed-species groups, distances between standing individuals of the same species were less than between individuals of a different species (hinds: 8.8+or-1.6 vs. 11.0+or-1.0 m, NS: ewes: 5.3+or-1.1 vs. 7.5+or-2.3 m, NS: hinds-ewes: 14.6+or-0.9 vs. 20.6+or-1.0, P<0.05, at LSA and HSA, respectively). Agonistic encounters between hinds were more frequent at LSA than at HSA when reared in single-species groups (median number of agonistic interactions/h: 10.0 (9.6-12.8) vs. 5.0 (1.9-11.6), P<0.05). When reared in single-species groups, hinds were less synchronised during grazing at LSA than at HSA and they had shorter and more frequent meals. Such effects were not observed for ewes. Rearing the animals in mixed-species groups increased the effects of a restricted space allowance on grazing meals of hinds with a tendency to increase the number of meals and to reduce meal duration. In mixed-species groups, the effect of space allowance on ewes was more marked than when in single-species groups with ewes eating shorter and more frequent meals. Hinds reared in single-species groups grew slower at LSA than at HSA (185+or-63 vs. 225+or-42 g daily, P<0.01), whereas ewes grew at the same rates regardless of space allowance (175+or-53 vs. 185+or-54 g daily, at LSA and HSA, respectively, NS). In mixed-species groups, growth of both hinds and ewes was lower when space was restricted (hinds: 141+or-42 vs. 211+56 g daily, ewes: 170+or-47 vs. 202+or-32 g daily, at LSA and HSA, respectively, all P<0.05). It is concluded that restricting the space allowance resulted in behavioural changes and lower performance which were intensified by mixed-species stocking.
|Publication Title||Applied Animal Behaviour Science|
|Author Address||Laboratoire Adaptation des Herbivores aux Milieux, INRA de Theix, 63122 St-Genes-Champanelle, France.|
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