In conventional rearing systems, fast-growing broiler chickens commonly experience welfare issues, such as contact dermatitis, walking difficulties or a lack of expression of species-specific behaviours. Enriching their environment may be a way to improve their welfare. The objective of this study was to evaluate the benefits of elevated platforms and straw bales on the welfare of fast-growing broiler chickens reared at two different stocking densities. A total of 14,994 Ross 308 broilers were housed in 12 pens according to 4 treatments: 31 kg/m² with or without enrichments and 41 kg/m² with or without enrichments. The broilers’ walking ability, footpad dermatitis (FPD), hock burns (HB), weight, mortality and litter quality were assessed. Stocking density had a negative effect on FPD and HB, whereas enrichments reduced the occurrence of FPD and HB at both densities. There was a positive enrichment effect and a negative density effect on body weight at 25 days and on walking ability, but no effect on the litter quality or mortality rate. These results confirm that an enriched environment improves animal welfare in confined chickens, regardless of the stocking density. Reducing stocking density clearly appears to be an important means of increasing animal welfare.

In standard broiler production systems, birds do not have outdoor access and spend their entire lives in the same environment. A covered veranda can improve broilers' living conditions by providing access to different environments and to areas with varying space availability (i.e. different stocking densities), while also allowing them to experience outdoor sensory stimulations and protecting them from predators and the risk of disease. This study aimed to evaluate the welfare and health of broilers with access to a covered veranda. Redbro broilers were randomly assigned to six identical enriched rooms (with elevated platform and alfalfa bales), each containing 2,478 birds (final stocking density of 26 kg/m²). Three rooms had access to a covered veranda from 22 days of age (D22), while the other three had no such access (control). Footpad dermatitis, hock burns and gait were assessed on D36. We also measured activity levels (D34 and D37), use of the covered veranda (from D22 to slaughter), litter quality (D34 and D37), as well as feed and water consumption throughout the rearing period. Mortality and body weight were also monitored. Access to a covered veranda did not affect mortality, body weight, litter quality, or feed and water consumption. None of the broilers from either treatment group exhibited gait issues or footpad dermatitis. However, the prevalence of hock burns was lower in the broilers having access to a covered veranda. Additionally, more active behaviors were observed among broilers from the covered veranda group than from the control group. The covered verandas were frequently used, with usage increasing as the broilers aged. Within a day, use was more frequent in the morning and decreased thereafter. Providing access to a covered veranda improved bird welfare without negatively impacting zootechnical indicators.

Providing a variety of elements in the rearing environment may offer a promising way to transition conventional broiler production towards more animal-friendly production systems. This study aimed to investigate the effect of a complex and structured rearing environment on broiler welfare by comparing three complex enriched rooms (E) with visual cues and multiple elements for resting or exploration, to three control rooms (C) with minimal enrichments. Each room housed 2450 Redbro chickens and received natural light. We evaluated how the rearing environment influenced chicken behavior, emotional state, and the cecal microbiota composition at the end of the rearing period. E chickens stood, foraged and moved more often than C chickens (e.g. 38% vs. 19% walking; 4% vs. 1% foraging, P < 0.001), while dustbathing frequency did not differ. In group-based tests, E chickens were more likely to approach and peck at a novel object or human (P < 0.05), suggesting reduced fearfulness and increased curiosity. In the detour test, E chickens exited the U-shaped area more frequently (P < 0.001) and vocalized less (P = 0.004), indicating greater exploratory motivation and possibly better spatial cognition. Microbiota analysis revealed no differences in alpha diversity, but beta diversity differed significantly between treatments (P < 0.001). E chickens had higher relative abundances of Bacteroidota, while C chickens had more Bacillota. Overall, the complex environment promoted natural behaviors, reduced emotional reactivity, and altered gut microbiota composition, supporting its potential to improve broiler welfare under semi-commercial conditions.

The dust level is included in the animal welfare legislation of the European Union, implying assessment of dust levels during veterinary welfare inspections. This study aimed to develop a valid and feasible method for measuring dust levels in poultry barns. Dust levels were assessed in 11 layer barns using six methods: light scattering measurement, the dust sheet test with durations of 1 h and 2–3 h, respectively, visibility assessment, deposition assessment, and a tape test. As a reference, gravimetric measurements were obtained – a method known to be accurate but unsuitable for veterinary inspection. The dust sheet test 2–3 h showed the highest correlation with the reference method with the data points scattered closely around the regression line and the slope being highly significant (p = 0.00003). In addition, the dust sheet test 2–3 h had the highest adjusted R² (0.9192) and the lowest RMSE (0.3553), indicating a high capability of predicting the true concentration value of dust in layer barns. Thus, the dust sheet test with a test duration of 2–3 h is a valid method for assessing dust levels. A major challenge is the test duration as 2–3 h is longer than most veterinary inspections. Nevertheless, results showed that potentially, with some modifications to the scoring scale, the dust sheet test may be reduced to 1 h without losing validity.

1. This study evaluated the validity, inter-assessor reliability and intra-assessor repeatability of three visual scoring systems for litter quality, one known as the Welfare Quality Assessment Protocol (c) and two complementary systems for friability and humidity developed by the ClassyFarm initiative. 2. In 6 rooms of an experimental barn, 2450 medium-growing broiler chickens were reared on coarse sawdust litter until they reached a body weight of 2.2 kg at 43 days of age, with a stocking density of 33 kg/m(2). 3. Sixty-six litter samples were analysed for litter moisture at two different time points during the broiler chickens' production cycle, and were visually scored using the three systems, two consecutive times, by 7 assessors to analyse their validity, inter-reliability and intra-repeatability according to the litter moisture level. 4. The three resulting scores were correlated with the litter moisture (p < 0.001) and correlations were stronger when the litter moisture was above 35%. Similarly, inter-assessor reliability and intra-assessor repeatability were better for all three scoring systems when litter moisture was above 35% than when it was below 35%. 5. The ClassyFarm Friability system was the most reliable regardless of litter moisture level. The ClassyFarm Humidity system was the least reliable and repeatable when the litter moisture was below 35%. The Welfare Quality scoring system lay between the two ClassyFarm systems considering inter-assessor reliability, but was as repeatable as the ClassyFarm Friability system.