Investigating optimal levels of platform perch provision for windowed broiler housing

Use of an elevated platform with perforated surface and manure belt by fast-growing broilers on commercial farms

Like other members of the species Gallus gallus, fast-growing broilers are motivated to perch. However, broilers in the European Union are kept in unstructured barns, with no opportunity to sit elevated and rest undisturbed. A possible solution to this problem is elevated platforms. The aim of this study was to evaluate the use of an elevated platform with perforated surface and manure belt by fast-growing broilers. On 2 commercial farms, an elevated platform was installed in 1 barn per farm. Approximately 35,000 Ross 308 broilers were housed in each barn for 3 fattening periods. On 1 d per wk, the number of broilers per m² on the platform and the ramp was determined every 30 min from video recordings. Besides, focal animals were observed to analyze their behavior on the platform at different ages and during light and dark periods. Broilers used the elevated platform and the ramp from the first week until the end of the fattening period (platform: 9.92 broilers per m², ramp: 6.47 broilers per m²), with a peak in the fourth week of life (platform: 13.00 broilers per m²). In wk 2, 4, and 5, platform use was higher during the light period than during the dark period. Broilers stayed longer on the platform in the dark period (dark: 01:54:23 [hh:mm:ss], light: 00:19:54 [hh:mm:ss]). In every phase of the fattening period, broilers on the platform were inactive to a high proportion (on average 80.60%). This indicates that broilers used the platform also for resting behavior. Thus, the elevated platform with perforated surface and manure belt is a suitable option to structure broiler barns. It allows the broilers to sit elevated and provides additional space. Factors such as a shallow ramp incline of 20°, wide ramps, and appropriate material used for the surface and ramps may have contributed to its high use by broilers of all ages. Further research is needed to evaluate the design of platforms that allow broilers to rest undisturbed.

Welfare of broilers on farm

This Scientific Opinion considers the welfare of domestic fowl (Gallus gallus) related to the production of meat (broilers) and includes the keeping of day-old chicks, broiler breeders, and broiler chickens. Currently used husbandry systems in the EU are described. Overall, 19 highly relevant welfare consequences (WCs) were identified based on severity, duration and frequency of occurrence: 'bone lesions', 'cold stress', 'gastro-enteric disorders', 'group stress', 'handling stress', 'heat stress', 'isolation stress', 'inability to perform comfort behaviour', 'inability to perform exploratory or foraging behaviour', 'inability to avoid unwanted sexual behaviour', 'locomotory disorders', 'prolonged hunger', 'prolonged thirst', 'predation stress', 'restriction of movement', 'resting problems', 'sensory under- and overstimulation', 'soft tissue and integument damage' and 'umbilical disorders'. These WCs and their animal-based measures (ABMs) that can identify them are described in detail. A variety of hazards related to the different husbandry systems were identified as well as ABMs for assessing the different WCs. Measures to prevent or correct the hazards and/or mitigate each of the WCs are listed. Recommendations are provided on quantitative or qualitative criteria to answer specific questions on the welfare of broilers and related to genetic selection, temperature, feed and water restriction, use of cages, light, air quality and mutilations in breeders such as beak trimming, de-toeing and comb dubbing. In addition, minimal requirements (e.g. stocking density, group size, nests, provision of litter, perches and platforms, drinkers and feeders, of covered veranda and outdoor range) for an enclosure for keeping broiler chickens (fast-growing, slower-growing and broiler breeders) are recommended. Finally, 'total mortality', 'wounds', 'carcass condemnation' and 'footpad dermatitis' are proposed as indicators for monitoring at slaughter the welfare of broilers on-farm.

Enhancing their quality of life: environmental enrichment for poultry

Providing environmental enrichments that increase environmental complexity can benefit poultry welfare. This Poultry Science Association symposium paper is structured around four themes on 1) poultry preferences and affective states 2) species-specific behavior, including play behavior and the relationship between behavior, activity level and walking ability, 3) environmental enrichment and its relationship with indicators of welfare, and 4) a case study focusing on the application of enrichments in commercial broiler chicken production. For effective enrichment strategies, the birds' perspective matters most, and we need to consider individual variation, social dynamics, and previous experience when assessing these strategies. Play behavior can be a valuable indicator of positive affect, and while we do not yet know how much play would be optimal, absence of play suggests a welfare deficit. Activity levels and behavior can be improved by environmental modifications and prior research has shown that the activity level of broilers can be increased, at least temporarily, by increasing the environmental complexity. However, more research on impacts of enrichments on birds' resilience, on birds in commercial conditions, and on slow(er)-growing strains is needed. Finally, incorporating farmers' expertise can greatly benefit enrichment design and implementation on commercial farms.

Providing organic macro minerals and an elevated platform improved tibia characteristics, and increased locomotion and performance of fast- and slower-growing broilers

Improving leg health will support broiler health and welfare. Known factors to improve leg health are: replacing inorganic by organic macro minerals in the diet, providing environmental enrichments and using slower-growing broilers. However, it remains unknown how fast- and slower-growing broilers respond to a combination of providing organic macro minerals and an elevated platform as enrichment with regard to leg health. Therefore, the aim of this study was to identify whether a combined treatment of organic macro minerals and a platform affected leg health, tibia characteristics, behavior and performance of fast- and slower-growing broilers in a semicommercial setting. The experiment had a 2 × 2 factorial arrangement, with 12.800 fast-growing (Ross 308) and 12.800 slower-growing (Hubbard JA757) broilers that were randomly allocated to a control (i.e., inorganic macro minerals without enrichment) or adapted treatment (i.e., organic macro minerals and a platform). Broilers were housed in groups of 800 per pen (47.5 m²), with 8 replicates per treatment (total of 32 pens). Performance was measured weekly and over the total rearing period. Behavior was observed via scan sampling at a target weight of 0.6 and 1.9 kg for both breeds. Walking ability (gait score), footpad dermatitis, and hock burn were assessed in 10 broilers per pen just prior to slaughter weight. Leg disorders and tibia characteristics were assessed in the same broilers at slaughter weight (2.3 kg). Hardly any interaction effects between breed and treatment were found on leg health, tibia characteristics, behavior or performance, suggesting fast- and slower-growing broilers responded to the treatment similarly. The adapted treatment improved tibia characteristics, and increased locomotion and performance, but did not affect leg disorders, walking ability or contact dermatitis in both fast- and slower-growing broilers. The positive effects of the adapted treatment on tibia characteristics in both fast- and slower-growing broilers may improve leg health, although the current study did not confirm this for leg disorders, walking ability or contact dermatitis.

Positive Effects of Elevated Platforms and Straw Bales on the Welfare of Fast-Growing Broiler Chickens Reared at Two Different Stocking Densities

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.

Does Smart Farming Improve or Damage Animal Welfare? Technology and What Animals Want

“Smart” or “precision” farming has revolutionized crop agriculture but its application to livestock farming has raised ethical concerns because of its possible adverse effects on animal welfare. With rising public concern for animal welfare across the world, some people see the efficiency gains offered by the new technology as a direct threat to the animals themselves, allowing producers to get “more for less” in the interests of profit. Others see major welfare advantages through life-long health monitoring, delivery of individual care and optimization of environmental conditions. The answer to the question of whether smart farming improves or damages animal welfare is likely to depend on three main factors. Firstly, much will depend on how welfare is defined and the extent to which politicians, scientists, farmers and members of the public can agree on what welfare means and so come to a common view on how to judge how it is impacted by technology. Defining welfare as a combination of good health and what the animals themselves want provides a unifying and animal-centered way forward. It can also be directly adapted for computer recognition of welfare. A second critical factor will be whether high welfare standards are made a priority within smart farming systems. To achieve this, it will be necessary both to develop computer algorithms that can recognize welfare to the satisfaction of both the public and farmers and also to build good welfare into the control and decision-making of smart systems. What will matter most in the end, however, is a third factor, which is whether smart farming can actually deliver its promised improvements in animal welfare when applied in the real world. An ethical evaluation will only be possible when the new technologies are more widely deployed on commercial farms and their full social, environmental, financial and welfare implications become apparent.

Effect of Environmental Complexity and Stocking Density on Fear and Anxiety in Broiler Chickens

Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers' attention bias (measure of anxiety) and tonic immobility (measure of fear). In Experiment 1, individual birds were tested for attention bias (n = 60) and in Experiment 2, groups of three birds were tested (n = 144). Tonic immobility testing was performed on days 12 and 26 (n = 36) in Experiment 1, and on day 19 (n = 72) in Experiment 2. In Experiment 1, no differences were observed in the attention bias test. In Experiment 2, birds from high-complexity pens began feeding faster and more birds resumed feeding than from low-complexity pens following playback of an alarm call, suggesting that birds housed in the complex environment were less anxious. Furthermore, birds housed in high-density or high-complexity pens had shorter tonic immobility durations on day 12 compared to day 26 in Experiment 1. In Experiment 2, birds from high-density pens had shorter tonic immobility durations than birds housed in low-density pens, which is contrary to expectations. Our results suggest that birds at 3 weeks of age were less fearful under high stocking density conditions than low density conditions. In addition, results indicated that the complex environment improved welfare of broilers through reduced anxiety.

The relationship between gait and automated recordings of individual broiler activity levels

Gait, or walking ability, is an often-measured trait in broilers. Individual gait scores are generally determined manually, which can be time-consuming and subjective. Automated methods of scoring gait are available, but are often implemented at the group level. However, there is an interest in automated methods of scoring gait at the individual level. We hypothesized that locomotor activity could serve as a proxy for gait of individual broilers. Locomotor activity of 137 group-housed broilers from four crosses was recorded from approximately 16 to 32 days old, using an ultra-wideband tracking system. These birds were divided over four trials. Individual gait scores were determined at the end of the tracking period, on a scale from 0 to 5, with higher scores representing worse gait. Given the limited number of birds, birds were subsequently categorized as having a good gait (GG; scores 0–2) or a suboptimal gait (SG; scores 3–5). Relationships between activity and gait classification were studied to determine whether individual activity has the potential to serve as a proxy for gait. When comparing GG and SG birds using robust linear regression, SG birds showed a lower 1) activity around the start of tracking (estimate = −1.33 ± 0.56, P = 0.019), 2) activity near the end of tracking (estimate = −1.63 ± 0.38, P < 0.001), and 3) average activity (estimate = −1.12 ± 0.41, P = 0.007). When taking day of tracking, trial, cross and body weight category (heavy versus light at approximately 2 wk old) into account, a tendency was still observed for SG birds having lower activity levels within lightweight birds, but not within heavyweight birds. This study provides indications for activity differences between gait classifications. However, given that there was considerable overlap in activity levels between the gait classifications, future research implementing additional activity-related variables is required to allow a more complete distinction between birds with different gait classifications.