The effect of group size and stocking density on the welfare and performance of hens housed in furnished cages during summer

Abstract

The aim of this study was to investigate the effect of group size and stocking density on the welfare and performance of hens housed in furnished cage systems during summer. A total of 924 Hy-Line Brown hens were assigned to three housing systems: a standard battery cage system (control, 4 hens per cage and 398 cm 2 per hen), two furnished systems (including perches and nest); one with a small (SFC, 21 hens per cage; 586 cm 2 per hen) and one with a large group size (LFC, 48 hens per cage; 543 cm 2 per hen). The results showed that hens housed in SFC and LFC had a higher feed intake and a poorer feed efficiency compared to control hens. Laying rate and egg weight were not significantly affected by housing systems. Hens housed in LFC and SFC systems showed less sitting and more walking behaviours than control hens. SFC hens showed more nesting and less perching behaviours than LFC hens. Hens kept in SFC systems showed fewer signs of heat stress during summer, with less panting activity than LFC or control hens, and a relatively lower rectal temperature than controls. The rectal temperature of LFC hens did not differ from the SFC hens and controls. Blood concentrations of luteinising hormone, follicle-stimulating hormone and oestradiol were not significantly influenced. In conclusion, group size and stocking density in furnished cages have an effect on behaviour and performance of hens. The furnished cage systems with small group sizes were favourable for hen welfare without markedly affecting performance. Group size should be considered in the development of furnished cage systems.

Effect of Group Size on Performance and Egg Quality of Laying Hens During 20 to 36 Weeks of Age

“…Our results are partly in accordance with findings by Guo et al (2012). The authors, comparing two flocks of laying hens consisting of 21 and 48 birds along 4 weeks, observed no differences in feed intake.…”

“…In general, the hens were highly motivated to lay in the nest (Cooper and Appleby, 1996), but the most of eggs were laid in the first hours after lights were turned on (Barnett et al, 2009) and this behaviour can be responsible of competitions for the nest (Shimmura et al, 2008) more detectable in the S25 group in which the allowance of nesting space was reduced. On the other hand, in a study on the effect of group size on welfare of laying hens, Guo et al (2012) observed that birds in small group size (21 animals) significantly spent more time in nesting activity with respect to the hens from large group size (48 birds). Appleby et al (2004) suggested that the ratio of nest space per bird needed to avoid crowding declines with group size.…”

“…So, feed intake but also laying rate were not different among groups during hot weeks, the higher energy expenditure induced a decrease of BW and an increase of FCR. Guo et al (2012) concluded that furnished cage systems with small group sizes (around 20 hens) were more favourable than large group size for the thermal balance during summer. However, after the hot climate, there is a compensatory growth in hens as BW rapidly increases and FCR is not different from S25 group.…”

Comportamento de poedeiras criadas a diferentes densidades e tamanhos de grupo em ambiente enriquecido

“…Guo et al (2012) O teste de χ 2 , para os comportamentos empoleirar e perseguir, mostrou que as ocorrências desses comportamentos nos vídeos dependem da interação entre o tamanho dos grupos e as densidades de criação, e que, para a condição de 6 aves e maior densidade (774 cm² por ave), houve mais perseguições e os animais empoleiraram-se menos (Tabela 4). É esperado que, em grupos maiores, comportamentos agressivos sejam menos frequentes (D'Eath & Kelling, 2003;Rodenburg et al, 2005).…”

“…Entre esses sistemas, destacam-se o de gaiolas enriquecidas, que permite às aves a expressão de comportamentos mais próximos aos naturais (Tactacan et al, 2009). Há relatos de que a densidade de criação e o tamanho dos grupos influenciam diretamente o comportamento e desempenho de poedeiras, em gaiolas enriquecidas (Guo et al, 2012 Os galpões foram divididos em baias com ambiente enriquecido, com uso de ninho e poleiro, além da cama de maravalha em toda a área. Nas baias que receberam os grupos menores de aves (6 aves), foram dispostos dois bebedouros tipo nipple, 50 cm de comedouro, um ninho de 40x40 cm e 60 cm de poleiro.…”