Social recognition in gilts mixed into a dynamic group of 30 sows

Abstract

The need to continuously re-establish the social structure in dynamic groups of sows gives rise to higher levels of aggression compared to stable groups. Previous familiarity of animals could shorten the time it takes to reorganise the social structure, but relies on the animal's social memory.

Sorting by parity to reduce aggression toward first-parity sows in group-gestation housing systems1

“…Because familiarity to each other affects aggression among sows and gilts at mixing (Strawford et al, 2008), each pen had approximately two-thirds unfamiliar dyads (unfamiliar pairs of animals), and the proportion of unfamiliar dyads was similar between control and treatment pens. Unfamiliar is defi ned as sows and gilts that had not been housed in the same group at least during the last 4 wk (Spoolder et al, 1996;Hoy and Bauer, 2005). In this study, unfamiliar sows and gilts originated from different farrowing rooms or gestation pens, and housing during previous gestation was not considered in defi ning familiarity.…”

Group housing of sows in early pregnancy: A review of success and risk factors

“…Spoolder et al (1996) looked at pairs of gilts introduced at intervals of two weeks into a large dynamic group. Pairs from an original subgroup of six recognised each other without fail, and had significant less aggression among each other compared to aggression with other gilts introduced in pairs during the same period.…”

Comportamento bioclimático de matrizes suínas em gestação e o uso de sistemas inteligentes na caracterização do ambiente produtivo: suinocultura de precisão

“…A estabilidade social relativa é alcançada depois de 2 (Bauer & Hoy, 2002), 3 (Oldigs et al, 1993) ou 10 dias (Van Putten & Van de Burgwal, 1990) entre matrizes alojadas em baias coletivas. Uma vez um grupo estabelecido, as matrizes podem se lembrar de indivíduos durante mais de 1 semana (Olsson & Svendsen, 1995) até 4 semanas (Spoolder et al, 1996) e talvez até mesmo 6 semanas, no caso de indivíduos de posição dominante (Ewbank & Meese, 1971).…”

“…O período necessário para a redução da agressividade entre os animais e o estabelecimento de uma hierarquia social relativamente estável é de 3 a 10 dias (Van Putten & Van de Burgwal, 1990;Oldigs et al, 1993). Porém, outros estudos relataram períodos maiores de tempo, até 6 semanas, para que as matrizes se tornassem completamente integradas, quando inseridas em novos grupos (Moore et al, 1993;Spoolder et al, 1996;Arey, 1999). Manifestações severas de tensão social podem conduzir a atraso no estro, aborto, aumento no período de gestação e fracasso na lactação (Hansen & Vestergaard, 1984;Bokma, 1990;Te Brake & Bressers, 1990;Varley & Stedman, 1993).…”

“…às 13 e das 16 às 17 horas, permitindo observação individual de seis animais selecionados em cada tratamento (Rudkin & Stewart, 2003 Burgwal, 1990;Olsson & Svendsen, 1995;Spoolder et al, 1996).…”