Performance, meat quality and blood parameters in four strains of organic broilers differ according to range use.

Chicken meat production in organic systems involves free-range access where animals can express foraging and locomotor behaviours. These behaviours may promote outdoor feed intake, but at the same time energy expenditure when exploring the outdoor area. More generally, the relationship of range use with metabolism, welfare including health, growth performance and meat quality needs to be better understood.

Implication of digestive functions and microbiota in the establishment of muscle glycogen differences between divergent lines for ultimate pH.

Both the quality of chicken meat and the quality of chicks are influenced by the level of breast muscle glycogen reserves. In order to study the role of digestive metabolism in establishing this muscular phenotype, we compared two divergent chicken lines for the ultimate pH (pHu) of the breast meat, a proxy for glycogen reserves. Males aged 4 weeks had twice the breast muscle glycogen content in the pHu- line (low pHu) than in the pHu +  line (high pHu).

Effects of strain and stocking density on leg health, activity, and use of enrichments in conventional broiler chicken production.

Conventional broiler production needs to evolve towards more animal-friendly production systems in order to meet increasing consumer concerns regarding animal welfare. Genetics and stocking density are 2 of the most promising leads to make this change possible. In this study, 6 strains with different growth rates (42-61 g/d) were reared at contrasting densities: 37 kg/m² (HD) and 29 kg/m² (LD).

Ontogeny of hepatic metabolism in two broiler lines divergently selected for the ultimate pH of the Pectoralis major muscle.

Background: Nutrient availability during early stages of development (embryogenesis and the first week post-hatch) can have long-term effects on physiological functions and bird metabolism. The embryo develops in a closed structure and depends entirely on the nutrients and energy available in the egg. The aim of this study was to describe the ontogeny of pathways governing hepatic metabolism that mediates many physiological functions in the pHu + and pHu- chicken lines, which are divergently selected for the ultimate pH of meat, a proxy for muscle glycogen stores, and which differ in the nutrient content and composition of eggs.

High-throughput phenotyping to characterise range use behaviour in broiler chickens.

A key characteristic of free-range chicken farming is to enable chickens to spend time outdoors. However, each chicken may use the available areas for roaming in variable ways. To check if, and how, broilers use their outdoor range at an individual level, we need to reliably characterise range use behaviour.