Effects of a partially perforated flooring system on animal-based welfare indicators in broiler housing

Comparative Analysis of Broiler Housing Systems: Implications for Production and Wellbeing

This study compares the effects of modern colony cage systems and traditional floor systems on the production and welfare of broiler chickens. Through two trials spanning 35 days each, we evaluated various physiological parameters, including growth performance, bone health, stress responses, and meat quality. Colony cages demonstrated superior thermal regulation and growth performance compared to traditional floor systems, but also exhibited higher frequencies of leg deformity and reduced standing ability. Conversely, the broilers in traditional floor systems experienced heat stress-related challenges, impacting the meat quality. Our findings underscore the need to balance productivity with animal welfare in broiler farming practices. By understanding the distinct impacts of different housing systems, we can work towards improving broiler rearing methods to ensure optimal welfare and production outcomes.

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.

The British Ixworth: individual growth and egg production of a purebred dual-purpose chicken

1. Killing male one-day-old chicks, especially from layer lines, is banned in some European countries. Therefore, dual-purpose chickens, where each sex is used for meat and egg production, respectively, offer an alternative production solution. This study evaluated the British purebred breed Ixworth as a dual-purpose chicken for meat and egg production.2. Ixworth chicks (n = 167) were hatched and reared mixed-sex in a floor housing system, with two groups receiving a commercial pullet diet (treatment 1) and two groups receiving a diet composed for males of layer lines (treatment 2). Individual chick performance data were recorded. Males were slaughtered at 12 weeks of age, and their growth rate and carcase variables were analysed. All hens were continuously reared on the pullet diet and kept in a free-range system from 20 weeks old for one laying period (52 weeks). In addition, group-based feed consumption and mortality were recorded.3. Cockerels in treatment 1 and 2 showed significantly different [T(88) = -2.846, P = 0.003] growth rates (25.3 vs. 27.4 g/day) and average final weights (2166 g vs. 2344 g). The hens in treatment 1 (n = 41) laid an average of 193 eggs per hen housed (mean egg weight: 56.9 g), whereas those in treatment 2 (n = 35) laid 195 eggs per hen housed (mean egg weight: 56.5 g). Nest acceptance was >97.5% and feed consumption was up to 140 g/bird/day.4. The results showed that the Ixworth may be a suitable breed for dual-purpose use and could be improved through selective breeding, offering potential for preservation of this local breed as well as general biodiversity in poultry farming.

Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness

Background

One priority for animal welfare is for animals to experience less fear, especially during human contact. For domestic animals, breeds that are less fearful may provide genetic resources to develop strains with improved welfare due to lower susceptibility to fear. Genetic predispositions inherited in these breeds might reflect the large diversity of chicken breeds. The goal of the present study was to systematically test a diverse group of chicken breeds to search for breeds that experience less fear.

Methods

Nineteen chicken breeds from commercial hybrid lines, native layer-type, meat-type and dual-purpose breeds, ornamental breeds as well as bantam breeds were tested in a standardized tonic immobility (TI) test. Chickens were manually restrained on their back, and the time to first head movement and first leg movement, the duration of TI, as well as the number of attempts needed to induce TI were measured.

Results

The TI response differed among chicken breeds (p ≤ 0.001) for naïve, mature hens. The median number of attempts required to induce TI ranged from 1 to 2 and did not differ significantly among breeds. Median durations were much more variable, with Lohmann Brown showing shortest durations (6 s, 12 s, 58 s for time to first head movement, first leg movement and total duration of TI, respectively). In contrast, medians reached the maximum of 600 s for all three measures in German Creepers. Repeated tests on the same individuals did not affect attempts needed to induce TI nor TI durations. Breeds clustered into two main groups, with layer-type native breeds and ornamental breeds having longer TI durations, and bantam, dual-purpose and meat-type native breeds having shorter TI durations.

Conclusions

Our findings provide evidence for substantial variation of fearfulness among breeds. This variation could be linked to the intended use during the breed's specific history. Knowledge and quantitative measurement of these behavioural responses provide the opportunity to improve welfare through selection and future breeding.

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.

The Impacts of Colony Cages on the Welfare of Chickens Farmed for Meat

There is growing interest in keeping meat chickens in modern colony cages (CCs) rather than conventional litter-floor barns. Suggested welfare improvements for chickens in such systems include reduced bodily lesions due to lower contact with flooring contaminated with faeces and urine, due to slatted flooring and automated faeces removal. This systematic review sought to determine the animal welfare impacts of CCs using slatted flooring, in comparison to litter-based non-cage systems. Overall, 23 relevant studies were retrieved. From one perspective, the extant research appeared mixed. Fifteen (65%) of these 23 studies identified some form of welfare concern about slatted floors, and thus CCs. Yet, when considering actual welfare indicators assessed, the tallies generated in favour of each housing system were similar. Crucially however, there were incomplete behavioural welfare measures in 100% of the empirical studies reviewed. Accordingly, significant welfare concerns exist about CCs, centring around behavioural deprivation. Given that over 70 billion chickens are farmed then slaughtered each year globally, widespread implementation of CCs would create a major animal welfare concern. Instead of implementing such CC systems, research and development is recommended into improving welfare outcomes of conventional litter barns using different forms of commercially feasible enrichment. As a minimum, a full behavioural analysis, as detailed in the Welfare Quality Assessment protocols, should form a mandatory part of any future studies aimed at assessing the welfare impacts of housing systems on farmed chickens.

Health-Based Welfare Indicators and Fear Reaction of Slower Growing Broiler Compared to Faster Growing Broiler Housed in Free Range and Conventional Deep Litter Housing Systems

This study investigated the welfare of a slow-growing broiler with a commercially available fast-growing breed housed in a free-range and conventional deep litter housing system. There were four main groups (2 genotypes x 2 housing systems), and each main group consisted of 5 replicates. Ante-mortem and postmortem health-based welfare indicators wıth fear reactıons and distribution of severity of them in 200 male chicks (100 slow growing, 100 fast growing) were investigated. All welfare parameters investigated were found to be significantly different between both broiler genotypes. No significant differences were detected for all broiler welfare parameters between the two housing systems. There were significant genotype x housing system interactions for breast dirtiness and feather cover of the birds (P < 0.001). In conclusion, it can be said that slow-growing broilers express more health-based indicators of positive welfare, and they might be more suitable for free-range broiler meat production. Planning further studies especially in commercial conditions that take into account economic efficiency as well as animal welfare and growth performance would be very beneficial.

The Influence of Different Types of Environmental Enrichment on the Performance and Welfare of Broiler Chickens and the Possibilities of Real-Time Monitoring via a Farmer-Assistant System

The aim of this study is to evaluate the influence of environmental enrichment on the growth performance, litter and/or air quality as well as animal welfare indicators of broilers. Control groups (CG) and trial groups (TG) were housed under identical conditions during six fattening runs, with the TG having three types of environmental enrichment and a Farmer-Assistant System (FAS). A representative number of 50 birds were weighed and litter samples were taken at d 14, 21 and 28. Additionally, the same broilers were examined for foot pad dermatitis (FPD) on those days. The average bodyweight of the birds in the CG was significantly lower (1671 g) only at d 28 compared to TG (1704 g); at d 14, d 21 and d 33 at the slaughterhouse, no significant differences were observed. The dry matter content in the litter did not significantly differ between CG and TG. Birds housed in CG had significantly higher FPD scores at d 14 (1.24) and d 21 (2.19) compared to those housed in TG (0.73 and 1.52, respectively). No effects on air quality parameters, such as CO2 and NH3, were seen between the groups. Overall, our study shows no negative influences of environmental enrichment on growth performance, litter and air quality.

Structuring Broiler Barns: How a Perforated Flooring System Affects Animal Behavior

Broiler chickens in Europe are usually raised in a barren environment. Elevated perforated platforms address this problem and can positively influence animal health and welfare. To evaluate the effect of an elevated perforated floor on the behavior of broiler chickens, one of two barns was equipped with a perforated flooring system under the food and water supply. The second barn was used as a control. In total, three fattening periods were observed, with 500 broiler chickens (Ross 308 breed) kept in each barn. To compare the behavior of the birds in these groups, cameras were installed in the two barns. The videos were analyzed by counting the number of birds and observing focal animals while recording their behavior. More animals were observed on the perforated floor than in the littered control area (p < 0.001), but focal animals spent less time on the perforated floor compared to the observed littered area in the control barn (p < 0.05). There were no differences in the length of the recorded behaviors between the treatments. These findings suggest that, in general, the elevated perforated floor is attractive for the animals. However, it does not promote one of the recorded behavior patterns. Our results show that an elevated perforated floor could be an option for structuring broiler barns.

Effect of Dietary L-Threonine and Toxin Binder on Performance, Blood Parameters, and Immune Response of Broilers Exposed to Aflatoxin B1

To evaluate the effect of L-Threonine (L-Thr) and Mycofix® Plus (MP) on aflatoxicosis, an experiment with a 3-way ANOVA model was carried out with 8 replicates and 640 birds. Treatments included two levels of L-Thr (100% and 125% of the requirements, Cobb 500, Cobb-Vantress), Aflatoxin B1 (AFB1) (0, 500 ppb), and MP (0, 1 g/kg). As the main effects showed, AFB1 decreased breast meat yield and carcass percentage (p < 0.001), serum urea, antibody titer against infectious bronchitis virus (IBV), and bone density (p < 0.05), while it increased the plasma concentrations of glucose and alkaline phosphatase (ALP) (p < 0.05). Mycofix Plus improved the grower feed intake (FI), tibia fresh weight, and body weight (BW) to bone weight (p < 0.05). L-Threonine increased the grower FI, breast meat yield, serum aspartate transaminase (AST), and glutathione peroxidase (GPX) (p < 0.05). There were positive interactions with breast meat yield, cholesterol, lactate dehydrogenase (LDH), and IBV titer. Of the treatments used, the combination of L-Thr and MP without AFB1 improved breast meat and carcass percentage. L-Threonine and MP significantly improved IBV titer in birds challenged with AFB1 (p < 0.001). In conclusion, L-Thr and MP were beneficial to improve immunity.

Effects of fully or partially slatted flooring designs on the performance, welfare and carcass characteristics of broiler chickens

1. The objective of this study was to evaluate the effects of fully (FSF) or partially (PSF) flooring designs on animal-based welfare indicators in a fast-growing broiler genotype. Growth performance and carcass characteristics were assessed.2. One-d-old male chicks were randomly assigned to three groups: fully slatted flooring (100% slatted floor), partially slatted flooring (50% litter floor and 50% slatted floor) and conventional floor pens with litter (control, 100% deep litter) with 5 replicates of 14 male chicks. The litter was rice hull, as is usual in practice.3. Measurements of live body weight, feed intake, feed conversion ratio, mortality and performance index were collected before depopulation at 42 d old. Welfare assessments were done by individual ante- and post-mortem carcass inspection during depopulation and after slaughter.4. Broiler live body weight (P < 0.03) and feed intake (P < 0.003) and ante-mortem welfare indicators (P < 0.001) were positively affected by FSF and PSF compared to the conventional deep litter system. Post-mortem lesion scores on wings and shoulder were similar in all floor types but there were significant differences for the lesions on breast (P < 0.003) and pygostyle (P < 0.05).5. In conclusion, FSF and PSF resulted in higher body weights, while reducing incidence of foot pad and hock joint deformations in live animals.

Use of available crop by-products as alternative bedding materials to wheat straw for rearing broilers

The provision of suitable bedding for rearing broilers is an ongoing challenge for poultry producers. The aim of the present study was to evaluate the effect of using different types of crop residues as alternative bedding materials to wheat straw on growth performance, carcass traits, health, and welfare of broilers; moreover, the effects on the bedding and air quality were analyzed. We randomly assigned 180 1-day-old chickens (Cobb 500) across six bedding groups (three replicates of 10 birds each). Chickens in all groups were reared under similar housing conditions. Chickens of one group were reared on a wheat straw bedding (control), whereas those of the remaining five groups were reared on clover straw, cornstalk chips (CS), sugarcane top chips, chopped palm spines (CPS), and corn ear husks. Cornstalk chip and chopped palm spines were associated with the lowest (P < 0.05) ammonia concentrations compared with the remaining beddings. The mean values of bedding moisture percentage (P < 0.05), caking score, and ammonia concentrations (P < 0.05) were decreased with 6-week-old broilers reared on cornstalk chips. At 6 weeks, wheat straw, clover straw, sugarcane top chips and corn ear husks resulted in higher (P < 0.0001) BW and average daily gain compared with CS and CPS. Broilers reared on clover straw bedding showed the best FCR during 4-6 weeks of age (P < 0.01), and those kept on clover straw and sugarcane top chips exhibited the best (P < 0.01) feed conversion ratio (1.61 and 1.64, respectively) during 0-6 weeks of age. The carcass dressing yield, airborne dust concentration, bedding pH, and bacterial counts did not differ among the different bedding materials. The proportions of the drumsticks, gizzards, and abdominal fat of 6-week-old broilers were affected by bedding type (P < 0.05); but the differences among the bedding treatments were small. The mean incidence of footpad dermatitis and breast blisters was significantly less using clover straw. Broilers reared on chopped palm spine had the highest (P < 0.05) heterophil/lymphocyte ratio when compared with their counterparts. Conclusively, using clover straw or cornstalks as an alternative bedding material may be a beneficial strategy and should be highly recommended for rearing broilers.

Effects of Different Swimming Pool Conditions and Floor Types on Growth Performance and Footpad Dermatitis in Indoor-Reared White Roman Geese

Simple Summary

The goose industry provides meat and down to the food and textile processing industry and is the third-largest poultry industry in Taiwan after the chicken and duck industries. After the avian influenza virus (HPAIV) pandemic in 2015, most poultry farms in Taiwan have been restricted to closed birdhouses to improve biosafety. However, indoor-raised poultry may experience footpad dermatitis problems. We studied the effects of providing a swimming pool and different floor types on the growth performance and footpad dermatitis score for indoor-reared White Roman geese to reduce the risk of footpad dermatitis. Our data indicated that the incidence of footpad dermatitis was decreased during the feeding period in geese supplied with a swimming pool. Our findings may help improve animal welfare in modern waterfowl production by having the geese express their natural behaviors with water.

Abstract

Footpad dermatitis (FPD) is a major foot disease in modern poultry production, and it affects both poultry health and animal welfare. It refers to inflammation and necrotizing lesions on the plantar surface of the footpads and toes. We investigated the effects of providing a swimming pool and different floor types on growth performance and FPD score in indoor-reared White Roman geese. Forty-eight male and 48 female White Roman geese were randomly allocated to pens with or without a swimming pool and with either mud or perforated plastic floor and reared from 15 to 84 days of age. Growth performance measurements included feed intake (FI), weight gain (WG), and feed conversion ratio (FCR). FI, WG, and FCR were significantly decreased at various growth periods in geese provided with a pool. Lower WG and bodyweight for the perforated plastic floor group were found at 15–28 and 28 days of age, respectively. The geese reared on the perforated plastic floors without a pool had higher FPD scores at 70 and 84 days of age than those with other rearing conditions. A higher incidence of FPD score 1 was observed in geese raised without a pool. In conclusion, providing a pool can improve footpad health in indoor-reared White Roman geese but may not benefit growth performance.

Effects of a Partially Perforated Flooring System on Ammonia Emissions in Broiler Housing-Conflict of Objectives between Animal Welfare and Environment?

Simple Summary

Previous studies have shown positive effects of a partially perforated flooring system on animal welfare in broiler housing. Towards the end of the fattening periods, the present study showed a higher ammonia emission rate (NH₃ ER) for a partially perforated flooring system compared with a littered control barn. Nevertheless, the measured NH₃ concentrations were below 20 ppm, except during a mechanical litter treatment in the winter fattening period. Furthermore, the system offers the possibility of applying practical solutions that were not feasible before. By using underfloor air extraction, manure belts, or acidification systems underneath the elevated perforated area, NH₃ concentrations and the resulting NH₃ ER could be reduced. Thus, with some optimization, the partially perforated flooring system could be used to contribute to an increase in animal welfare and environmental protection at the same time.

Abstract

A partially (50%) perforated flooring system showed positive effects on health- and behavior-based welfare indicators without affecting production performance. Ammonia (NH₃) is the most common air pollutant in poultry production, with effects on animal welfare and the environment. The objectives of animal welfare and environmental protection are often incompatible. Therefore, this study addresses the question of how a partially perforated flooring system affects NH₃ emissions. According to German regulations, three fattening periods were carried out with 500 Ross 308 broilers per barn (final stocking density: 39 kg m⁻²). The experimental barn was equipped with an elevated perforated area in the supply section, accessible by perforated ramps. The remaining area in the experimental barn and the control barn were equipped with wood shavings (600 g m⁻²). Besides the different floor types, management was identical. Air temperature (Temp), relative air humidity (RH), NH₃ concentration, and ventilation rate (VR) were measured continuously. Furthermore, dry matter (DM) content, pH, and litter quality were assessed. Towards the end of the fattening periods, the NH₃ emission rate (ER) of the partially perforated flooring system was higher compared with that of the littered control barn (all p < 0.001). This effect is mainly caused by the higher NH₃ concentrations, which are promoted by the lack of compaction underneath the elevated perforated area and the increase in pH value under aerobic conditions. Nevertheless, the partially perforated flooring system offers different approaches for NH₃ reduction that were previously not feasible, potentially contributing equally to animal welfare and environmental protection.

Welfare-Related Behaviors in Chickens: Characterization of Fear and Exploration in Local and Commercial Chicken Strains

Fear and exploration are crucial traits determining how animals behave in novel situations, and thus, they influence animal welfare. The aim of this study was the characterization of these behavioral traits among different strains to identify interesting alternatives for future poultry production. Whereas the Novel Object Test (NOT) focuses on fear and exploration of novel objects, the Avoidance Distance Test (ADT) addresses this in the context of humans. Here, a commercial hybrid line, a dual-purpose hybrid and a local adapted strain were tested. For the differences between strains and development of fear, Lohmann Brown (n = 714), Lohmann Dual (n = 844) and Rhinelander (n = 458) were observed weekly until maturity. Results show that fear and exploration towards unknown objects and humans are breed-specific (all p < 0.01). Additionally, development of fear in NOT and ADT differed between all three strains (both p < 0.01). The expressions of fear of humans or objects should be regarded as characteristics adapted for different husbandry systems and breeding goals, e.g., high exploratory behavior in aviary or high avoidance of predators in free-ranging husbandry or at least a balanced ratio between fear and exploration. Characterization of behavioral traits among different strains, understanding diversity and integrating these behaviors into future breeding and husbandry systems might reflect the need to preserve local strains and the potential to improve animal welfare.

Review of litter turning during a grow-out as a litter management practice to achieve dry and friable litter in poultry production

Maintaining dry litter that chickens can “work” is a key objective for successful meat chicken production as it reduces the likelihood of health and welfare issues by breaking down and working excreta and contributing to the water evaporation process. Litter turning is a practice that may help reduce moisture content within the litter by accelerating the drying process when it is combined with effective ventilation. However, information and research about the practice and the effects it could have on the health and well-being of meat chickens (broilers) are minimal. A recent survey of Australian meat chicken growers reiterated the concerns they have about its impact on chicken well-being, but it also demonstrated how growers thought it could enhance the effectiveness of their operation. The aim of this review paper is to identity information relevant to litter turning and the potential effects of this practice on litter quality, ammonia emissions, litter moisture, and animal welfare. This review demonstrates the need for additional research to validate perceptions and address potential concerns and impacts that this practice may have on broiler production. Closing this knowledge gap will improve litter turning practices leading to safer and more consistent outcomes.

Are Dual-Purpose Chickens Twice as Good? Measuring Performance and Animal Welfare throughout the Fattening Period

Chickens are the world's most widely used farm animal and have a significant genetic diversity. In the current study, we investigated three strains for their suitability as dual-purpose chickens, with a focus on the fattening ability and welfare of the cockerels: 1. layer cockerels (Lohmann Brown, LB, n = 714); 2. cockerels of a dual-purpose hybrid (Lohmann Dual, LD, n = 844); and 3. cockerels of a native breed (Rhinelander, RL, n = 458). Chicks were raised under identical conditions and marked individually to compare focus and random sampling methods for weighing birds weekly. Because chicks of dual-purpose origins are usually raised mixed-sex, cockerels and pullets were weighed and observed together until sexes the were identifiable at week 10 of their life. During the 10th to 20th week of life, investigations were continued on 100 cockerels per genotype. Key figures for growth performance, such as feed conversion ratio (FCR) and European production efficiency factor (EPEF), were also calculated at weekly intervals. LD cockerels showed considerable growth performance (p < 0.001 compared to LB, RL, 2 kg at 9 weeks), whereas LB reached a live weight of 2 kg at 13 weeks and RL at 15 weeks of age. Genotype-dependent differences were also evident, with favorable FCR and EPEF for LD, intermediate for LB, and unfavorable for RL (all p < 0.001). The results of the FCR and EPEF suggest that cockerels should be slaughtered around week 8 of life, although only the carcass of the LD might be marketable. Thus, the optimal time of slaughter based on production parameters such as FCR and EPEF is different from the time when the animal reaches a marketable 2 kg live weight. Animal-based welfare indicators revealed that the RL are not adapted to production environments, including those that are extensive. Further research aimed at adapted feed management, including better FCR, and animals adapted to the respective production environments is necessary to improve alternative poultry production in the future.