The behaviour and use of space of the domestic fowl in alternative meat and egg production systems

Resumen

Alternative poultry production is characterized by a large space availability provided to the birds as compared to intensive systems. A better space availability increased the behavioural and movement opportunities and, therefore, alternative poultry production is commonly associated with high animal welfare. However, in practice, it is commonly found that birds do not use the available space in a homogeneous way, and that the use of the outdoor area is lower than expected. In addition, increased freedom of movements and behavioural opportunities may raise the incidence of problematic behaviours such as aggressive interactions. Increasing the complexity of the environment (environmental enrichment) has been proposed to manage uneven spatial distribution and social interactions, but only in few instances implementation has been conducted under commercial conditions. The focus of this work was to investigate the way that egg and meat producing domestic fowl use the available space in alternative commercial production systems and their relation to behaviour and welfare indicators. The first study aimed at determining the use of space patterns in free-range laying hens, analysing their association with welfare outcomes at an individual level. To this aim three flocks located at three free-range farms were studied from 20-69 weeks of age. Behavioural and spatial data were collected over 150 individually tagged hens/farm. In a second study, using video recordings, the behaviour and the inter-individual distances of laying hens prior to an agonistic interaction were analysed to determine the causal factors triggering the encounter. The third and fourth studies investigated the impact of increasing environmental complexity by providing panels and perches in four commercial free-range slow-growing meat chicken farms. In each of the three houses (with panels, perches or controls), within each farm 50 birds were tagged for individual identification and their location and behaviour registered during a production cycle (82 days). The main findings of these studies indicate that on average 32.58% of the free-range laying hens used the outdoor area regularly, while 49.45% were never observed using it. The hens¿ previous experience was identified as a primary factor affecting to the frequency of use of the outdoor area in successive age periods. The frequency of use of the outdoor area and total walked distance inside correlated with welfare indicators such as plumage condition and pododermatitis, respectively. On the other hand, the study on the inter-individual distances and behaviour prior to an aggressive encounter suggest that aggression in laying hens does not depend on the invasion of the critical distance per se, but would greatly depend on the activity level and directionality of the individuals which would be perceived as a threat by the aggressor. In free-range slow-growing meat chickens, a higher frequency of locomotive behaviours in the central area within the panel treatment was observed in comparison to controls. The size of the 50 and 100% core areas increased with age but no effect of increasing environmental complexity was detected. The effect of panels and perches in this study had a more noticeable effect on the use of the space patterns inside the house and very limited impact on their behaviour, probably because the number of devices used was limited. In this study, the environmental complexity interventions did not appeared to have a direct impact on welfare indicators assessed.