Foraging Behavior Shows Individual-Consistency Over Time, and Predicts Range Use in Slow-Growing Free-Range Male Broiler Chickens

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. We studied four strains of intermediate (JA757) to slow-growing (S757N, White Bresse and a dual-purpose strain) meat-type chickens with outdoor access. We selected 25 males high- (HR) and low-rangers (LR) per strain. Only in JA757, HR exhibited lower body weight before range access, which may have predisposed them to use the range more. Carcass weight and/or carcass yield were significantly lower in HR compared to LR, showing a negative trade-off between range use and growth performance in all strains. Breast meat yellowness was higher in HR compared to LR in JA757 and the dual-purpose strain, probably due to carotenoids intake from the grass. No relationship between range use and welfare indicators at slaughter was reported whatever the strain. Chicken metabolism differed by range use as HR and LR diverged for blood biomarkers of oxidative and metabolic status, immune and inflammatory system response.

Early and late cognitive and behavioral aspects associated with range use in free-range laying hens (Gallus gallus domesticus)

Individual differences in free-range chicken systems are important factors influencing how birds use the range (or not), even if individuals are reared in the same environmental conditions. Here, we investigated how various aspects of the birds' behavioral and cognitive tendencies, including their optimism/pessimism, cognitive flexibility, sociability, and exploration levels, are associated with range use and how they may change over time (before and after range access). To achieve this, 100 White Leghorn laying hen chicks underwent three distinct behavioral/cognitive tests-the cognitive bias test, the detour test, and the multivariate test-prior to gaining access to the range, between 9 and 39 days of age. After range access was allowed (from day 71), birds' range use was evaluated over 7 nonconsecutive days (from 74-91 days of age). Subsequently, a subset of birds, classified as high rangers (n = 15) and low rangers (n = 15) based on their range use, underwent retesting on the same three previous tests between 94 and 108 days of age. Our results unveiled a negative correlation trend between birds' evaluation of the ambiguous cue and their subsequent range use (rho = -0.19, p = 0.07). Furthermore, low rangers were faster to learn the detour task (χ2 = 7.34, df = 1, p = 0.006), coupled with increased sociability during the multivariate test (rho = -0.23, p = 0.02), contrasting with their high-ranging counterparts, who displayed more exploratory behaviors (F[1,27] = 3.64, p = 0.06). These behavioral patterns fluctuated over time (before and after range access); however, conclusively attributing these changes to birds' aging and development or the access to the range remains challenging. Overall, our results corroborate that behavioral and cognitive individual differences may be linked to range use and offer novel perspectives on the early behavioral and cognitive traits that may be linked to range use. These findings may serve as a foundation for adapting environments to meet individual needs and improve animal welfare in the future.

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. Traditional methods relying on visual scans require significant time investment and only provide discontinuous information. Passive RFID (Radio Frequency Identification) systems enable tracking individually tagged chickens' when they go through pop-holes; hence, they only provide partial information on the movements of individual chickens. Here, we describe a new method to measure chickens' range use and test its reliability on three ranges each containing a different breed. We used an active RFID system to localise chickens in their barn, or in one of nine zones of their range, every 30 seconds and assessed range-use behaviour in 600 chickens belonging to three breeds of slow- or medium-growing broilers used for outdoor production (all <40 g daily weight gain). From those real-time locations, we determined five measures to describe daily range use: time spent in the barn, number of outdoor accesses, number of zones visited in a day, gregariousness (an index that increases when birds spend time in zones where other birds are), and numbers of zone changes. Principal Component Analyses (PCAs) were performed on those measures, in each production system, to create two synthetic indicators of chickens' range use behaviour. The first two PCA axes represented over 90% of the variance of the five measures and were both consistent over time and correlated with independent visual scans. Contributions of the five measures to the PCAs were similar among breeds, except for the correlation between the number of outdoor accesses and the four other measures. PC1 correlated with time spent inside the barn and zone changes frequency, whilst PC2 was explained by exploration of the range. Taken together, PC1 and PC2 indicators showed that range use increased with age, outdoor temperature (in spring), and did not differ between males and females. Importantly, daily scores for both indicators were repeatable among individuals - particularly in PC1 - showing inter-individual variability on range-use. The characterisation of broiler behaviour around their range with these reliable and repeatable indicators provides novel tools to help understand individual variations of range-use in free-range farming.

Exploratory Study on Individual Locomotor Activity in Local Dual-Purpose and Commercial Breeder Pullets

Improving animal welfare is a prerequisite for the societal acceptance of poultry production. Support for improvements requires practical tools to quantify animal welfare and identify predispositions at the individual level, where possible. In this study, the activities and behavior of dual-purpose chickens (N = 245) and commercial breeders (N = 224) were analyzed. The general locomotor activity (GLA) data were collected using an RFID system over five days with 9-to-14-week-old animals. The results show that the animals of comparable age and stocking density differed from each other in their activity (p ≤ 0.001) according to breed, but no sex differences were observed (p = 0.159). No correlations were found between GLA and plumage condition (p > 0.05). The individual variations within the breeds are presented and discussed on an animal-by-animal level, providing new insights into the individual behavioral variability of chickens. The RFID systems can reliably generate GLA data that help to understand the potential interplay between behavior and animal welfare. The technology is also suitable for creating individual (personality) profiles that can be used for breeding. With a better understanding of the role of activity, husbandry and management practices can be adapted to improve animal welfare.

Early life access to hay does not affect later life oral behavior in feed-restricted heifers

Dairy cattle are often raised in environments that lack natural feeding opportunities, and they perform abnormal repetitive behaviors (ARBs) as a result. Early life restriction can affect later life behavior. We evaluated whether access to hay in the milk-fed period would affect later life behavior in heifers experiencing short-term feed restriction and whether individuals were consistent in behavioral expression over time. We had 2 competing ideas about how this would unfold. First, being raised with hay, which reduced early life ARBs, could lead to fewer ARBs later in life. Alternatively, heifers that were raised without hay and performed more ARBs in early life might be more prepared for a later feed-restricted environment and thus engage in fewer ARBs than those raised with hay. We studied 24 pair-housed Holstein heifers. As calves, they were fed milk and grain from 0 to 7 wk of age (control) or given additional forage (hay). Tongue rolling, tongue flicking, nonnutritive oral manipulation (NNOM) of pen fixtures, self-grooming, and water drinking were recorded for 12 h (0800-2000 h) during wk 4 and 6 of life using 1-0 sampling at 5-s intervals. At the start of weaning at d 50, all calves were fed a total mixed ration. All calves were fully weaned at d 60 and socially housed by d 65 to 70. After this point, all individuals were raised the same way, according to farm protocol, in groups that included both treatments. At 12.4 ± 0.6 mo of age (mean ± standard deviation), heifers were restricted to 50% of their ad libitum total mixed ration intake for 2 d as part of a short-term feed challenge. Using continuous video recording from 0800 to 2000 h on d 2 of feed restriction, we scored time spent performing oral behaviors: the 5 previously scored while they were calves, along with intersucking, allogrooming, drinking urine, NNOM of rice hull bedding, and NNOM of feed bins. We found that early life access to hay did not affect behavior performed by heifers experiencing short-term feed restriction 1 yr later. Most heifers performed a wide variety of behaviors that appeared abnormal. All heifers performed tongue rolling and NNOM, and at higher levels than when they were calves, while tongue flicks and self-grooming were performed less by heifers. Individual performance of NNOM and tongue rolling were not related across age classes [correlation coefficient (r) = 0.17 and 0.11, respectively], but tongue flicks tended to be correlated (r = 0.37). Intersucking was recorded in 67% of heifers, despite their not being able to suckle a conspecific or dam in early life. Oral behaviors were highly variable across heifers, particularly tongue rolling and intersucking. Outliers, or extreme performance of oral behaviors relative to the rest of the population, were present for many behaviors. Most outliers were expressed by unique heifers that were not extreme in other behaviors. Overall, feeding individually housed, milk-limited calves hay for their first 7 wk did not affect later life performance of oral behaviors. The considerable variability, inconsistency across ages, and excessive performance of some behaviors raises additional questions about how these develop in cattle across life stages and about what we label "abnormal."

Adaptability Challenges for Organic Broiler Chickens: A Commentary

Simple Summary

Organic poultry shows an increasing productive trend, rising from 3% in 2017 to 8% in 2019. Regulation EU 848/2018 puts great emphasis on the ability of broilers to adapt to outdoor systems as being essential for organic production. Organic poultry operators meet with regulatory constraints, consumer concerns, and challenges in terms of nutrition, welfare, health, and sustainability. The present commentary considers recent studies on and innovations in these topics that can affect organic production in addition to recent studies on animal adaptability to this production system. It reflects on the concept of broiler adaptability to organic systems not only as a classic genotype–environment interaction but as a necessary prerequisite for facing these relevant challenges.

Abstract

As organic and conventional poultry production increased in the last decade, so did consumers’ concerns, sustainability requirements, and animal welfare as well as health issues. According to Reg. EU 848/2008 on organic production, poultry must be adapted to organic outdoor systems and cope with all the regulatory constraints in terms of nutrition, health, and welfare. Adaptability must take into account the above challenges, constraints, and concerns. Chicken adaptability should not only mean being able to use pasture and outdoor areas, but also mean being able to overcome, or be resilient to, the challenges of organic farming without compromising welfare, performance, and product quality. This commentary identifies solutions to the new challenges that organic poultry chains must face in future productive scenarios, detects consumer viewpoints to provide a perspective on organic poultry production, and summarizes as well as defines chicken adaptability to organic production, assessing the main factors of chicken adaptability.