Chicken Welfare Research Articles

The impact of relaxation music (Weightless by Marconi Union) on production performance, welfare, and hematological and biochemical blood parameters in broiler chickens.

The study evaluated the impact of relaxation music on the production performance, welfare, and blood parameters of broiler chickens. Literature indicates that specific music genres, as environmental enrichment, can improve animal welfare and production outcomes. The research involved 1,200 Ross 308 chickens divided into control (C) and experimental (M) groups. The rearing period lasted 42 days, and was conducted according to the flock management guide (Aviagen, 2019). The M group was exposed to relaxation music (Weightless by Marconi Union), played for two hours daily (08:00-10:00) and for 30 minutes before slaughter, at 70 dB. Body weight, feed consumption (FCR), mortality, and rearing conditions (litter pH, harmful gases) were monitored. On day 35, excreta samples were collected to analyze cortisol concentrations and assess welfare. Blood was also collected at slaughter for analysis. Statistical analysis was performed using SPSS software (PS IMGO PRO 8.0). Significantly higher final body weights and lower FCRs were observed in the M group chickens (p ≤ 0.05). Enriching the chickens' environment with relaxation music also resulted in lower cortisol concentrations in excreta samples and improved welfare levels (p ≤ 0.01). Blood analysis of the M group showed a significant increase in the average number of red blood cells and the calcium content, while glutamate dehydrogenase (GDH) concentrations were lower (p ≤ 0.01). The hematocrit percentage, total protein, and uric acid concentrations were significantly lower in the M group compared to the C group (p ≤ 0.05). Litter pH monitoring showed significantly lower pH values for the M group on days 22 and 35 (p ≤ 0.01 and p ≤ 0.05, respectively). However, on day 10, litter pH was lower for the C group chickens (p ≤ 0.05). No significant differences were found for the other results. Relaxation music can serve as environmental enrichment for broiler chickens, potentially improving their production performance and welfare quality. However, further research is necessary to verify the mechanism behind these effects.

Effects of Different Dietary Fat Sources on Oxidative Stress Parameters in Broiler Chickens

Introduction: Certain types of dietary fats may elevate the generation of free radicals, resulting in oxidative stress and potential cellular damage. The present study aimed to investigate the impact of high-energy diets derived from various fat sources on broiler chicken welfare and production. Materials and methods: A total of 216-day-old unsexed Arbor Acre broiler chickens were assigned to four treatment groups. The groups, including control, beef tallow (high energy diet animal source, HEDAS), palm oil (high energy diet plant source, HEDPS), and low energy diet (LED), each consisting of three replicates with 18 birds, were investigated in a completely randomized design over 42 days. Results: According to the results, the HEDPS group had the highest live weight, while the HEDAS group indicated the highest dressing percentage. Significant differences were noted in alanine transaminase and alanine phosphatase in the treatment group compared to the control group. Cholesterol levels were significantly high in the HEDAS group and LDL levels were the lowest compared to the control group. The HEDAS group also exhibited the highest triglyceride level compared to other treatments. The HDL levels were higher in the LED and HEDPS groups compared to the HEDAS group. The VLDL concentration was significantly higher in the HEDAS group in comparison with other groups. Conclusion: The HEDPS diet positively affected serum biochemistry and carcass characteristics, highlighting its potential in broiler chicken welfare and production.

Evaluating the efficacy of probiotics and ascorbic acid as anti-stress agents against heat stress in broiler chickens.

Heat stress poses a substantial challenge to poultry production worldwide, highlighting the urgent need for effective management strategies. This study investigated the efficacy of probiotics (Saccharomyces cerevisiae) and ascorbic acid as antistress agents using cloacal and body surface temperatures (CT and BST) as heat stress biomarkers in broiler chickens. A total of 56 broiler chicks were used for the experiment and were divided into four distinct groups: control, probiotics (1 g/kg of feed), ascorbic acid (200 mg/kg of feed) and the combination of probiotics and ascorbic acid (1 g/kg and 200 mg/kg of feed, respectively). The study lasted 35 days; measurements were taken for ambient temperature (AT), CT, and BST. The ambient temperature in the pens consistently exceeded the thermoneutral zone (TNZ) established for broiler chickens. The CT values for broiler chickens in the probiotic group were significantly lower (p < 0.05) compared to the control group. Additionally, the BST values in the probiotic and probiotic + ascorbic acid groups were significantly lower (p < 0.05) than those in the control group. The findings suggest that incorporating probiotics, with or without ascorbic acid, can effectively reduce CT and BST values in broiler chickens thereby, enhancing thermoregulation when compared to the control group. This implies that using probiotics in poultry diets may enhance health and growth performance, potentially leading to better feed efficiency and reduced reliance on antibiotics. Implementing these dietary strategies could improve the productivity and welfare of broiler chickens in commercial settings.

The potential of decision trees as a tool to simplify broiler chicken welfare assessments

To simplify fast-growth broiler welfare assessments and use them as a benchmarking tool, decision trees were used to identify iceberg indicators discriminating flocks passing/failing welfare assessments as with the complete AWIN protocol. A dataset was constructed with data from 57 flocks and 3 previous projects. A final flock assessment score, previously not included in the dataset, was calculated and used as the benchmarking assessment classifier (pass/fail). A decision tree to classify flocks was built using the Chi-square Automatic Interaction Detection (CHAID) criterion. Cost-complexity pruning, and tenfold cross-validation were used. The final decision tree included cumulative mortality (%), immobile, lame birds (%), and birds with back wounds (%). Values were (mean ± se) 2.77 ± 0.14%, 0.16 ± 0.02%, 0.25 ± 0.02%, and 0.003 ± 0.001% for flocks passing the assessment; and 4.39 ± 0.49%, 0.24 ± 0.05%, 0.49 ± 0.09%, and 0.015 ± 0.006% for flocks failing. Cumulative mortality had the highest relative importance. The validated model correctly predicted 80.70% of benchmarking assessment outcomes. Model specificity was 0.8696; sensitivity was 0.5455. Decision trees can be useful to simplify welfare assessments. Model improvements will be possible as more information becomes available, and predictions are based on more samples.

Response of broilers to supplementation of Salvia officinalis L. essential oil in hot ambient conditions.

Heat stress has various detrimental effects on poultry production. The aim of the study was to alleviate the effects of heat stress in broiler production. For this purpose, 288 one-day-old broiler chicks (Ross 308) were obtained from a commercial hatchery and randomly allocated to one of three treatment groups; CON: corn-soybean meal based commercial diet, SEO100: CON with 100mg/kg Sage essential oil (SEO) and SEO200: CON with 200mg/kg SEO with 96 birds in each group (4 replicates each) in a completely randomized design under hot ambient temperatures for 42 days. No differences were observed in the body weight, feed intake, and feed conversion ratio at 42 days of age among groups. However, there was a significant increase in 21-day body weight in SEO200 chicks compared to CON. Furthermore, the addition of SEO significantly decreased the mortality rate under heat stress conditions. The total oxidant status value was lower in broiler chickens in which SEO was added to their diets. While the total antioxidant status value was higher in SEO100 chicks, it did not show a linear increase. Additionally, the results demonstrated that the addition of SEO to broiler diets under heat stress did not have a significant effect on inspected meat quality traits, with the exception of the b*(yellowness) value of breast muscle. In conclusion, the results of this study indicate that 200mg/kg SEO can be added to diets for the welfare of broiler chickens under heat stress conditions for struggling with oxidants and increasing viability. Further research is needed to investigate the antioxidant activity and meat quality of different levels of SEO in hot ambient conditions.

The effects of varying stocking densities during the first 10 days on the performance, welfare, slaughter and meat quality characteristics of broiler chickens in the subsequent period.

This study aimed to investigate the effects of varying stocking densities during the first 10 days on the performance, welfare, slaughter and meat quality characteristics of broiler chickens in the subsequent period (11-42 days). In the study, treatments representing 3 different stocking densities with the same group sizes were established and a total of 432 d-old chicks were used. In the first 10 days of the rearing period, treatments of 18 (SD18), 27 (SD27) and 36 (SD36) chicks per m2 were formed, and at 11 days of age, chicks in all treatments were reared at a density of 18 chicks/m2. Body weight differences in SD18, SD27 and SD36 treatments at 10 and 42 days of age were significant (P < 0.05), they were 252.6, 254.3 and 241.5g in SD18, SD27 and SD36 groups at 10 days and 2961.1, 2874.8 and 2842.7g at 42 days of age, respectively. In the first 10 days of growing period, SD36 showed a significant difference (P < 0.05) from the other groups in feed intake and feed conversion ratio, but this was not significant at slaughter age. The livability at 10 and 42 days was not different among treatments and was between 98.6 and 99.3% and 93.5-93.8%, respectively. The uniformity at 10 days was significant among the stocking density groups (P < 0.05) and the best uniformity level was obtained in the SD36 group, the differences in CV values at 42 days were not significant among the treatments. EPEF (European production efficiency factor) values were not different between the groups, the highest numerical value was determined in the SD36 group. Foot pad dermatitis, hock burn and breast burn levels were significantly higher in SD18 chickens (P < 0.05), however incidence of finger crookedness and valgus-varus deformity did not differ between the treatments. The litter moisture contents were similar between treatments, and ranged from 25.6 to 32.6%. Different stocking density treatments during the first 10 days of the experiment had no significant effect on slaughter, abdominal fat, carcass parts, color and pH values in the breast and thigh meat. In conclusion, rearing broiler chickens by dividing the poultry house area by half during the first 10 days (36 birds/m2) could help to improve the overall productivity (EPEF) by providing ease of maintenance, efficient heating and better control.

Text mining approach in chicken meat welfare

The aim of the study was to analyze the aspects affecting broiler welfare with the use of Text Mining technique. This approach converts text into numerical data and analyzes word frequency distributions, enabling the extraction of useful information and the identification of relationships between elements. Text mining has limitations, i.e. ambiguity and context sensitivity, making it difficult to capture nuanced meanings. The search was carried out with Scopus using the term "Welfare" with the keywords "Chicken", "Broiler", "Broiler chicken", and "Chicken meat", to create a database of abstracts. Text Mining and Topic Analysis were performed on the abstracts (1228 documents) using the Software R 4.3.1., analyzing also the weight of bigram and trigram. Publications on broiler welfare are present in the bibliography since 1990's, but in the last 10 years, for the interest of public opinion, the numbers of publications significantly increased (76.5% of all documents published). USA, Brazil, and Europe-27 published 60% of the documents found. The works were published in a high number of journals, but 37% of them are published in only 4 journals (Poultry Science, Animals, Applied Animal Behavior Science and Animal Welfare). Text Mining analysis identified key terms related to the slaughter phase, housing management, and environmental conditions such as light quality and quantity. Moreover, a high correlation was found between some terms, underlying the importance of the effects of rearing, slaughter phases and litter management on broiler welfare. Most of the countries focused their research on some specific topics identified by Topic Analysis, mainly genetic selection, feeding, stocking density, slaughter, and consumer perceptions. Poultry Science published the highest number of papers (18%) and the topics more investigated were growing performance, transport and slaughter, and litter management. In conclusion, the high number of publications on chicken welfare underlines the importance of broiler welfare both in Europe and in other countries, even if it is difficult to identify common research topics among the geographic areas and the evolution over the time.

Live black soldier fly larvae as environmental enrichment for native chickens: implications for bird performance, welfare, and excreta microbiota

Dietary live insect larvae were recently proposed for use in laying hens and broiler−intensive chicken farming as an innovative form of environmental enrichment, but their use in native dual-purpose chickens has never been investigated. This study aims to evaluate the effects of live black soldier fly (BSF) larvae as environmental enrichment in two autochthonous dual-purpose chicken breeds, namely Bionda Piemontese (BP) and Bianca di Saluzzo (BS), in terms of bird performance, behaviour, integument status, excreta corticosterone metabolites (ECMs), and microbiota analyses. A total of 90 BP and 90 BS hens aged 308 days old were randomly distributed between two treatment groups (three replicates/group/breed, 15 hens/replicate). For the following 90 days, the control group (C) was fed a commercial feed only, whereas the BSF group was fed the commercial diet plus BSF live larvae calculated at 6% of the expected daily feed intake (DFI). Larva ingestion time, bird performance, integument scores, and behavioural observations were assessed at regular intervals, and excreta samples were collected to evaluate ECM and microbiota. The larva ingestion time became faster over the course of the experimental trial (P < 0.001). The DFI of BSF-fed hens was lower than that of C hens independently of breed (P < 0.001), whereas only in the BS hens, the live weight of the BSF-fed group was greater than that of the C group (P < 0.01). The BSF-fed BP hens showed a higher laying rate and feed conversion ratio compared with BSF-BS (P < 0.05). Better total integument scores were observed in BSF-fed BP hens compared with C-birds (P < 0.05). The BSF-fed hens displayed higher frequencies of preening, trotting, and wing flapping than C, as well as a lower incidence of severe feather pecking (P < 0.05). An increase in allopreening was only identified in BSF-fed BS hens with respect to the C hens (P < 0.001). No differences in ECM and faecal microbiota were observed between treatment groups. In conclusion, the administration of BSF live larvae as environmental enrichment has the potential to positively influence the welfare of both BP and BS chickens, by enhancing the frequency of positive behaviours whilst reducing severe feather pecking, without affecting their excreta microbiota. BSF larva administration also has the potential to improve the productive performance and the plumage status of the BP breed.

Terminalia bellirica and Andrographis paniculata dietary supplementation in mitigating heat stress-induced behavioral, metabolic and genetic alterations in broiler chickens

BackgroundHeat stress (HS) is one of the most significant environmental stressors on poultry production and welfare worldwide. Identification of innovative and effective solutions is necessary. This study evaluated the effects of phytogenic feed additives (PHY) containing Terminalia bellirica and Andrographis paniculata on behavioral patterns, hematological and biochemical parameters, Oxidative stress biomarkers, and HSP70, I-FABP2, IL10, TLR4, and mTOR genes expression in different organs of broiler chickens under chronic HS conditions. A total of 208 one-day-old Avian-480 broiler chicks were randomly allocated into four treatments (4 replicate/treatment, 52 birds/treatment): Thermoneutral control treatment (TN, fed basal diet); Thermoneutral treatment (TN, fed basal diet + 1 kg/ton feed PHY); Heat stress treatment (HS, fed basal diet); Heat stress treatment (HS, fed basal diet + 1 kg/ton feed PHY).ResultsThe findings of the study indicate that HS led to a decrease in feeding, foraging, walking, and comfort behavior while increasing drinking and resting behavior, also HS increased red, and white blood cells (RBCs and WBCs) counts, and the heterophile/ lymphocyte (H/L) ratio (P < 0.05); while both mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were decreased (P < 0.05). In addition, HS negatively impacted lipid, protein, and glucose levels, liver and kidney function tests, and oxidative biomarkers by increasing malondialdehyde (MDA) levels and decreasing reduced glutathion (GSH) activity (P < 0.05). Heat stress (HS) caused the upregulation in HSP70, duodenal TLR4 gene expression, and the downregulation of I-FABP2, IL10, mTOR in all investigated tissues, and hepatic TLR4 (P < 0.05) compared with the TN treatment. Phytogenic feed additives (PHY) effectively mitigated heat stress’s negative impacts on broilers via an improvement of broilers’ behavior, hematological, biochemical, and oxidative stress biomarkers with a marked decrease in HSP70 expression levels while all tissues showed increased I-FABP2, IL10, TLR4, and mTOR (except liver) levels (P < 0.05).ConclusionPhytogenic feed additives (PHY) containing Terminalia bellirica and Andrographis paniculata have ameliorated the HS-induced oxidative stress and improved the immunity as well as the gut health and welfare of broiler chickens.

Survey of the husbandry and biosecurity practices of backyard chicken keepers in the UK.

This survey investigated the housing, feeding, health and welfare of backyard chickens kept in the UK. Information was collected via an online questionnaire active from May to July 2021. The survey asked about flock demographics, housing, diet, enrichment provision, if the flock was registered with the Animal Plant and Health Agency (APHA) and the reason, preventative health care and biosecurity, and the incidence and methods of euthanasia. The majority of flocks (48.8%) consisted of one to five birds, were located in rural areas (58%) and were kept as pets (77%) and/or for eggs (71.6%). Enrichment was provided by 78.4% of keepers. Most respondents (69%) were aware of the Animal Plant and Health Agency poultry registration scheme, with 32.8% being registered with the scheme. Kitchen scraps were fed by 29% of keepers. Veterinary services were used by 63.6% of keepers, although 4% said they struggled to find a veterinarian willing to treat backyard poultry. New additions to the flock were isolated by 70.2% of keepers. The survey was distributed through poultry-specific Facebook groups and via chicken rescue centres, so it is not a truly random sample of backyard chicken keepers. All survey-based studies have an inherent element of subjectivity. The survey identified biosecurity, humane euthanasia training, veterinary training in backyard poultry medicine, and enrichment provision as areas where improvements can be made to improve poultry health and welfare and reduce the risks of infectious disease transmission.

Impact of different range areas on behavior, welfare, and performance of Naked Neck chickens.

This study aimed to evaluate the effect of different environmental enrichment tools on behavior, welfare, productive performance, and egg quality traits of Naked Neck chickens. A total of 1080 Naked Neck female chickens (30 weeks old) were used in the present study. A completely randomized experimental design, with 3 treatments having 4 replicates of 90 birds each, was applied. Treatments consisted of 3 different range areas A (121.9 m2), B (152.4 m2), and C (190.5 m2). Behavior (walking, feeding/foraging, sitting, aggressiveness wing flapping, perching, dust bathing, and range use), welfare (foot pad dermatitis, lameness, gait score, and feather pecking), productive performance (egg weight, egg production %, egg mass, and feed intake), egg quality traits (morphometry, egg weight, shell, albumen, and yolk characteristics) were evaluated. There was no influence (P > 0.05) of different range area on bird's behavior, and egg quality traits except walking and rang usage. The range area C promoted productive performance including egg weight, egg production %, egg mass and feed intake, but it did not influence welfare traits. It might be concluded that Naked Neck chicken when reared in free range with different range enrichments did not reveal any difference regarding behavioral parameters, egg morphometry, and egg quality traits. The range area within minimum length and effectively used environmental enrichments (perching and dust bathing area) should be used for backyard poultry to obtain ideal performance.

EFFECTS OF STOCKING DENSITY AND SEASON ON THE GROWTH PERFORMANCE AND WELFARE OF BROILER CHICKENS IN IBADAN, NIGERIA.

The study was carried out to investigate the effects of season and stocking density on the growth performance and welfare of broiler chickens in Ibadan, Nigeria. In a seven-week feeding trial, a total of 96 one-week old Arbor Acre broiler chickens were randomly distributed to three stocking densities (birds/m2) of 10, 12, and 14 at the rate of 32 birds per stocking density (SD) during each season; Late Wet (LWS) and Late Dry (LDS). Total Feed Intake (TFI, g), Final Live Weight (FLW, g), Feed Conversion Rate(FCR), Live weight/m2(LW/m2), Normal Gait Score (NGS,%), Survival Rate (SR %), Heterophil: Lymphocyte(H:L) ratio, were assessed. Data were subjected to statistics analysis (ANOVA at 0.05). Birds raised during LWS had higher TFI (4756.60) than LDS birds, while SD had no effect on TFI. Birds on SD of 14 birds/m2 had lower FLW. The FCR was lower during LDS and on SD 10 and 12birds/ m2. The LW/m2 was higher in birds on SD 14birds/m2. The LWS had higher NGS and lower H:L ratio. Season and SD had no effect on SR. The NGS and H: L were not affected by SD. Broiler chickens could be raised at stocking density of 14birds/m2 during either of the seasons.

Will the white blood cells tell? A potential novel tool to assess broiler chicken welfare.

This study assessed qualitative and quantitative leukocyte evaluation as potential broiler chicken welfare indicators, contributing to the limited literature on white blood cell (WBC) morphology as a diagnostic tool for welfare. Broiler chicken welfare within four poultry houses (PH) 1 to 4, each on a different farm, was assessed using on-field indicators of affective states and health, and WBC morphology was examined. Affective states were evaluated using the Qualitative Behavior Assessment (QBA), with 25 behavioral expressions scored on a visual analogue scale (VAS) and grouped into two categories. Health indicators included assessments of lameness, footpad dermatitis, dermatitis on the breast and abdominal areas, hock burn, and feather cleaning. Blood samples were collected, differential leukocyte counts were performed, and a cell score was created for the recognition, classification, and interpretation of morphologic diversity of heterophils and lymphocytes. The heterophil to lymphocyte ratio (H/L) was also determined. Descriptive statistics and generalized linear models for binomial responses were used to analyze the results. PH4 differed from the other farms, showing a higher frequency of birds within QBA group 1 ('Attentive'to 'Desperate'), while birds in PH1, PH2, and PH3 were more frequent in QBA group 2 ('Relaxed' to 'Positively occupied'). Elevated proportions of heterophils in birds from PH4 (0.61, CI95%: 0.58; 0.64) and PH3 (0.60, CI95%: 0.57; 0.63) suggested higher stress levels and inflammatory responses. Birds in PH2 and PH4 exhibited higher frequencies of health issues such as dermatitis and lameness, and higher proportions of abnormalities in WBC number and morphology. PH3 and PH4 exhibited higher H/L ratios of 3.03 and 2.58, respectively, consistent with the on-field health and behavioral indicators. Blood samples from birds in PH2 and PH4 showed a proportion of 90% toxic change in heterophils, while in PH1 and PH3 it was 70%, indicating high levels of abnormal WBC morphology across all PHs. The findings emphasize the multifactorial nature of welfare impairments, including environmental conditions, health, and affective states. This highlights the need for indicators that reflect multiple welfare impacts, such as WBC counts and morphological alterations, which can serve as powerful tools in the complex task of assessing animal welfare.

Effect of Rearing Technology on Production Performance, Selected and Blood Parameters and Welfare Levels of Broiler Chickens During the Summer Production Cycle

Abstract The aim of the present study was to determine the effect of rearing technology (rearing system and dietary supplementation with a mixed herbal extract) on the production results, selected physiological and blood parameters, and welfare of broiler chickens during the summer production cycle. In the CON and HE groups, broiler chickens were kept on litter without access to free range; additionally, in the HE group, birds from 22 to 42 days of rearing received a mixed herbal extract (50% Melissa officinalis L. and 50% Urtica dioica L.) in the amount of 2 ml/l of water to drinkers with water. In the AP group, birds were reared on litter with access to pasture. During the experiment, production performance and body temperature of the birds were monitored. Blood was also taken from birds in each group and the H:L ratio, levels of corticosterone, glucose and thyroid hormones were determined. The application of 2 ml/l of mixed herbal extract to the drinking water did not improve the production results, nor did it affect the physiological indices of the birds studied. The addition of 2 ml/l of mixed herbal extract to the drinking water only resulted in lower corticosterone levels in the blood of the chickens on day 35 of the experiment. The free-range housing system had a negative effect on the slaughter performance of the broiler chickens. However, housing with access to the free range resulted in lower body temperature, lower mortality, as well as lower glucose, corticosterone and a narrower H:L ratio in the blood of the chickens during the period of increasing air temperature. It can therefore be concluded that housing with access to a free range reduces stress levels and thus improves the welfare of broiler chickens during the summer production cycle compared to confined housing. Comparing the rearing technologies used in the study, it was found that the free-range housing system contributed more to improving the comfort of broiler chickens during the summer than dietary supplementation with the tested herbal mixture extract.

Impact of Light Wavelength on Growth and Welfare of Broiler Chickens – Overview and Future Perspective

Abstract Lighting in poultry production holds notable importance with the advancement and modernization of the industry, as it plays a significant role in the physiology and growth of broiler chickens. Increasing attention has been paid to the impacts of lighting management on growth performance, immune status, and welfare of meat-type chickens. It is essential to have an appropriate lighting regimen that includes the light source, intensity, duration, and wavelength of light to improve broilers’ growth and behavior. By manipulating various physiological, immunological, and behavioral activities, altering the color of light has been acknowledged as a potent managerial strategy capable of mitigating an array of stressors in broiler chickens. Assessing animal welfare is necessary for animal behavior and product quality perspectives. Birds have a unique visual system, and their behavior is primarily mediated by vision. Different monochromatic light regimes can affect feed conversion ratio, modulating broiler chickens’ systematic immune response and aggressive behavior. With the advancement of lighting technology, new possibilities have emerged to enhance traditional lighting programs in poultry houses. This review integrates recent findings on the use of monochromatic light and its impact on broilers’ welfare, growth, and physiological response.

112. Study of the effects of farm eclosion on the welfare and performance of fast-growing chickens

112. Study of the effects of farm eclosion on the welfare and performance of fast-growing chickens

119. Assesment of several ways of improving broiler chicken welfare

119. Assesment of several ways of improving broiler chicken welfare

The effects of play stimulation on cognitive capacities of chickens

Play is a widespread phenomenon in the animal kingdom with observations from all vertebrate classes. The adaptive value of this behaviour, however, remains unclear. In the past century, numerous theories have been put forward, ranging from releasing surplus energy to training species-specific behaviours. However, none of these theories can fully explain the functions of play. A recent neurocognitive theory suggests that play allows the brain to encounter many different and surprising situations that provide it with opportunities to learn about the environment and form predictions about it. This theory has, however, to our knowledge, previously not been experimentally tested. To start exploring the connection between play and cognition, we compared the cognitive capacities of White Leghorn chicks that were stimulated to play in the first five weeks of their lives with chicks that did not receive any play stimulation. More specifically, we wanted to test the connection between specific types of play and cognitive domains. To achieve this, we designed two play treatments: object players that were provided with a variety of toys during their treatment, and social players that were released into an arena with plenty of space and conspecifics, as this has previously been shown to trigger social play. Subsequently, all three treatments (control, object players, social players) were tested in a cognitive test battery consisting of two experiments targeting the social domain and two targeting the physical domain. We found no improvement of cognitive capacities in either play treatment group compared to control subjects, though the social play treatment appears to have affected some behavioural variables recorded during the cognitive tests. Chicks that had played socially were in general bolder, more explorative and had more access to resources in the tests. This might subsequently allow them to exploit their environment more efficiently, which could in turn affect their welfare as they might be more resilient to stress and have more access to resources. More studies will be needed to assess the long-term effects of play on cognitive capacities and welfare of chickens.

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.

Animal-based methods for the assessment of broiler chicken welfare in organic and conventional production systems

Animal welfare is one of the pillars in organic broiler production, evident in practices such as utilizing slower-growing hybrids and maintaining lower stocking densities for the birds. However, despite these efforts, skepticism and uncertainty remain regarding the extent to which animal welfare objectives are achieved in organic farming. The primary aim of this study was to compare animal-based measures assessing positive and negative welfare between organic and conventional broiler chickens in Denmark. The selected positive welfare indicators included Qualitative Behavior Assessment (QBA) and observations of play behavior in an open-space test. An additional aim of this study was to examine the reliability of the method by having all QBA observations done by two observers. Negative welfare indicators included walking ability assessed using the 6-point Bristol gait score method and fearfulness assessed using a novel object test. Welfare assessments were conducted on-farm before slaughter at 31–33 days of age for conventional birds and at 49–55 days of age for organic birds. The results from the QBA indicated differences between organic and conventional production systems (P = 0.001). Specifically, organic broilers exhibited higher levels of active, energetic, positively occupied, happy, and agitated behaviors. Notably, the outcome of the QBA was influenced by the observer (P = 0.001); on average, one observer tended to assign higher scores specifically for depressed and distressed behaviors, while the other observer allocated higher scores to the remaining behavioral terms. Moreover, organic broilers tended to show better walking abilities than conventional broilers (P = 0.064). Fear responses were similar across both production systems. Finally, organic broilers demonstrated a lower frequency of play behavior in open spaces compared to conventional broilers (P = 0.001). Conventional birds may have expressed more play behavior due to the greater contrast between the sudden availability of open space and their typical stocking density, resulting in increased compensatory play. This presents a challenge since a higher frequency of play is often considered an indicator of positive welfare, but we speculate whether in this study, it might suggest a restriction of spontaneous play due to space limitations caused by the high stocking density in the conventional production system. As a result, when additional space becomes available, it could lead to a rebound effect. Future research should explore how stocking density influences play behavior in broiler chickens, including measures of both spontaneous play and stimulated play during controlled test situations.