Broiler Welfare Research Articles

Red Color Light at Different Intensities Affects the Performance, Behavioral Activities and Welfare of Broilers.

Red light (RL) marked higher weight gain (WG) and preference of broilers compared to other light colors. This study aimed to investigate how different intensities of RL affect the performance, behavior and welfare of broilers. RL treatments were T1 = high intensity (320 lux), T2 = medium intensity (20 lux); T3 = dim intensity (5 lux), T4 = control/white light at (20 lux) provided on 20L:4D schedule and T5 = negative control; 12 hours dark: 12 hours day light. Cobb strain broilers were used in a Complete Randomize Design with 6 replicates. WG, water/feed intake, feed conversion ratio (FCR), mortality, behavior and welfare were assessed. At 35 d, significantly (p<0.05) highest body weight (2,147.06 g±99) was recorded by T3. Lowest body weight (1,640.55 g±56) and FCR (1.34) were recorded by T5. Skin weight was the only carcass parameter showed a significant (p<0.05) influence giving the highest (56.2 g) and the lowest (12.6 g) values for T5 and T1 respectively. Reduced welfare status indicated by significantly (p<0.05) higher foot pad lesions, hock burns and breast blisters was found under T3, due to reduced expression of behavior. Highest walking (2.08%±1%) was performed under T1 in the evening during 29 to 35 days. Highest dust bathing (3.01%±2%) was performed in the morning during 22 to 28 days and highest bird interaction (BI) (4.87%±4%) was observed in the evening by T5 during 14 to 21 days. Light intensity×day session×age interaction was significantly (p<0.05) affected walking, dust bathing and BI. Light intensity significantly (p<0.05) affected certain behaviors such as lying, eating, drinking, standing, walking, preening while lying, wing/leg stretching, sleeping, dozing, BI, vocalization, idling. In conclusion, birds essentially required provision of light in the night for better performance. Exposed to 5 lux contributed to higher WG, potentially indicating compromised welfare status. Further researches are suggested to investigate RL intensity based lighting regimen that favors for both production and welfare of Broilers.

Using sound technology to automatically detect the short-term feeding behaviours of broiler chickens

This paper describes a novel monitoring system to accurately detect the short-term feeding behaviours (meal size, meal duration, meals per day and feeding rate) of broiler chickens at group level by a real-time sound processing technology. In this research, the pecking sounds of 10 male, 39days old, broiler chickens were recorded by a microphone that was attached to the feeder. Simultaneously, the appearances of broilers around feeder were recorded by a camera that was positioned at the top of the feeding pen. At the same time, a weighing system was used to automatically record feed uptake of broilers as a reference method. Moreover, an existing algorithm was used to detect the pecking sounds of 10 broiler chickens while the birds were all eating together. The feeding behaviours of broiler chickens were obtained by pecking sound analysis. The results of the algorithm were compared to reference feeding behaviours through weighing system measurements and video observations. The relationship between feeding behaviours obtained by algorithm and feeding behaviours recorded by a weighing scale and video camera was investigated and a strong positive correlation was found between these methods. Furthermore, the linear regression tests which were performed which were performed resulted in the following coefficients of determination R2=0.965 for meal size, 0.938 for meal duration, 0.896 for the number of meals per day and 0.888 for feeding rate. Additionally, the estimated accuracy of the method showed that, 90% of meal size, 95% of meal duration, 94% of the number of meals per day and 89% of feeding rate were correctly monitored using sound analysis. The results suggest that this automated continuous measurement system has the potential to be used as a tool to monitor the short-term feeding behaviours of broiler chickens at group level. The most important advantage of this system is that the measurements can be made continuously throughout the life span of a flock, in a fully automated, completely non-invasive and non-intrusive way. It is proposed to test this system in commercial conditions due to its low costs and in order to evaluate its applicability under these conditions. Future researches should be focused on sound technology to assess the health and welfare of broilers by automatically and continuously monitoring the feeding behaviours.

The effects of food-related environmental complexity on litter directed behaviour, fear and exploration of novel stimuli in young broiler chickens

Stimulation of foraging behaviour during the first weeks of life by increasing environmental complexity such as scattering food items on the litter may be one way of preventing leg disorders, reducing fear and improving broiler welfare. However, studies on effects of access to various food based enrichment are inconclusive. Motivation of animals to search for resources in the litter may be driven by the motivational significance of the provided food resource. This study was conducted to test whether the motivational significance of food enrichment differentially affects activity, litter directed behaviours and fearfulness in broiler chickens. Chickens (120 chickens in three batches of 40 animals) were divided into four groups according to type of food-related enrichment: (1) mealworms (highly attractive), (2) whole wheat (less attractive), (3) wood shavings (no nutritional value), and (4) no enrichment. Enrichment materials were scattered on the litter daily for 12 days starting on day 6. On days 6, 9, 12 and 15 of age the chickens were video-recorded from 10min before to 30min after scattering. Duration and frequency of physical activity (time spent on legs), litter directed behaviour (litter pecking and scratching) and leg stretching were analysed from videos in 10-min intervals. All birds were subjected to a tonic immobility test (day 16) and a novel object test (day 17). Mealworm treatment induced a significant increase in activity, litter pecking and litter scratching (p<0.001) during the first 10min interval after the treatment. There were no effects on activity, litter directed behaviour, and on any of the parameters in the tonic immobility test and novel object test. In conclusion, motivational significance of the food items scattered on the litter affect litter directed behaviours in broiler chickens. More studies are needed to develop feasible attractive food enrichments and complex distribution methods that would increase time spent in activity.

Preference for different intensities of red light as affected by the age, temporal variation and behaviour of broiler birds

The red light (RD) marks high preference (PR), weight gain and welfare of broilers. A study was conducted to determine the PR for high (HI; 320 lux), medium (MI; 20 lux), dim (DI; 5 lux) intensities of RD and to investigate whether such PRs are influenced by age (AG), temporal variation (TV) and behaviour. The PR-chambers consisting of three identical compartments were provided with ad libitum feed, water and illumination from 5W incandescent bulbs (20 lux, 20 L:4D). A randomized complete block design was used with six replicates. Five birds were initially confined to the centre of each experimental unit (24 hrs.) and then allowed to move freely. Their presence under respective light intensity (LI) was recorded with behaviour adopting scan sampling. Data were analyzed using ANOVA procedure (a=0.05). The PR was significantly affected by AG, TV and behaviour, i.e. walking [Wk] and lying [Ly]. At the week 2 (wk 2) the highest (87%) and the lowest (3%) PRs were marked for HI and DI, respectively, in the night (NT). Young birds (14 d) preferred HI to DI, and the opposite was recorded with AG advancement. Irrespective of the AG, the highest PR was recorded for DI in the morning (MN) and HI in the NT. The reason could be that low intensities are associated with the cooling effect. The LI*TV*AG significantly affected on Ly and Wk. The highest Wk (87.29 % ± 0.05) was observed in the NT under HI at wk 2 and the highest Ly (39.95 % ± 0.08) was performed in the evening in DI at wk4. At the wk 2, all activities occurred mostly in HI; whereas at wk 5, Ly and sleeping (Sl) were dominant in DI. It is concluded that PR for different intensities of RD varies with AG advancement, temporal variation of the day, and certain behaviours (mainly Wk and Ly) of broiler birds. Older birds were inactive and preferred to perform Ly and Sl under DI. Tropical Agricultural Research Vol. 25 (2): 146 – 157 (2014)

A comparison of post-mortem findings in broilers dead-on-farm and broilers dead-on-arrival at the abattoir

Broiler mortality during transport to abattoirs (dead-on-arrival/DOA) evokes concern due to compromised animal welfare and associated economic losses. The general aim of this study was to characterize pathological lesions associated with mortality in broilers close to slaughter. The specific aim was to investigate whether disease at the end of the growth period may be a predisposing factor for DOA by describing and comparing the pathological findings in broilers dead-on-farm (DOF) in the final days of the production cycle and in broilers DOA from the same flocks. Gross post-mortem examinations were performed on 607 broilers from 32 flocks, either DOF (371) or DOA (236). In DOF broilers, the most common pathological lesions were lung congestion (37.7%), endocarditis (29.4%), and ascites (24.0%), whereas the most common findings in broilers DOA were lung congestion (57.2%) and trauma (24.6%). Lung congestion was more prevalent among DOA broilers compared to DOF broilers (P-value of > 0.001). A possible cause behind the pathological finding lung congestion is sudden death syndrome (SDS). The study indicates that steps in the transportation process per se cause the majority of pathological lesions such as lung congestion and trauma that may have led to the mortalities registered. Pre-existing diseases such as ascites and osteomyelitis may also predispose for DOA. Thus, factors relating to on-farm health, catching, and transportation are all areas of future investigation in order to reduce transport mortalities and to enhance welfare in broilers.

Effects of catching and transportation versus pre-slaughter handling at the abattoir on the prevalence of wing fractures in broilers

AbstractFractures occurring in conscious broiler chickens are painful and severely compromise animal welfare. The aim of this study was to investigate the effects of pre-slaughter handling procedures on the frequency of wing fractures. Wings were examined for fractures in 11,609 broilers, from 12 different flocks, slaughtered in two abattoirs: one using bi-phasic CO2stunning (CS); and one using electric water-bath stunning (ES). The same broilers were examined: i) in lairage, representing fractures attributed to catching and transportation; ii) after evacuation of transport containers and shackling (only ES); and iii) post-stunning. The mean frequencies of wing fractures were: in the lairage; 0.8% (CS 0.73%, ES 0.88%); after shackling prior to stunning; 2.90% (only ES); and after stunning; 2.35% (CS 1.80%, ES 2.90%). Regardless of stunning method, significantly more fractures occurred during pre-slaughter handling at the abattoirs than during catching/transportation. The difference in prevalence between CS and ES was not significant. All fractures observed in the ES occurred in conscious animals, whereas in the CS it was not possible to distinguish between fractures occurring in conscious or stunned broilers. From a welfare perspective, fractures occurring on-farm/transport result in prolonged suffering and are thus considered more serious in risk assessments of broiler welfare, even though more fractures occur at the abattoir. Monitoring of wing fractures at abattoirs should be included as an indicator of broiler welfare.

Automatic classification of measures of lying to assess the lameness of broilers

AbstractLeg disorders are a major cause of poor welfare in broilers. Previous studies have shown that at slaughter age at least 90% of chickens experienced some degree of gait problems and approximately 30% were seriously lame. In this study, a new and non-invasive technique was developed to automatically assess the lameness of the birds. For this purpose, video surveillance images of broilers with five different pre-defined gait scores were recorded as they walked along a test corridor. Afterwards, the image-processing algorithm was applied to detect the number of lying events (NOL) and latency to lie down (LTL) of broiler chickens. Then, the results of the algorithm were compared with visually assessed manual labelling data (reference method) and the relation between these measures and lameness was investigated. Eighty-three percent of NOL were correctly classified by the automatic monitoring system when compared to manual labelling using a data set collected from 250 broiler chickens. The results also showed a positive significant correlation between NOL and gait score and a significant negative correlation between LTL and gait-score level of broilers. Since strong correlations were found, on the one hand, between two measures and gait-score level of broiler chickens and, on the other, between the results of algorithm and manual labelling, the results suggest this automatic monitoring system may have the potential to be used as a tool for assessing lameness of broiler chickens.

Effects of color of light on preferences, performance, and welfare in broilers

Broiler houses are mainly lit by fluorescent light. With the expected continued increase in energy prices, the interest in less energy consuming light sources is growing. The light-emitting diode (LED) is an energy-saving alternative. The aims of the present 2 studies were to examine 1) the preference for LED color temperature and effects on behavior, and 2) effects of LED color temperature on performance and welfare of male broilers (Ross 308). Two color temperatures were investigated: neutral-white (4,100 K) and cold-white (6,065 K). First, 6 groups of 6-day-old chicks were housed in pens consisting of 2 lightproof compartments with a pop-hole between allowing chicks to move freely between compartments. Number of broilers in each compartment and their behavior were recorded every 15 min on 6 d. A preference for 6,065 K was found (P < 0.001). On d 16, 28, and 34, more time was spent in the 6,065 K treatment (P < 0.03), whereas indifference between treatments was found on d 4, 10, and 22 (P > 0.07). Second, each of the 2 light conditions was applied to 6 groups of 75 chicks. BW and feed consumption were registered weekly. On d 34, we scored gait, foot pad dermatitis, and hock burns in 15 individuals/pen. At slaughter (d 35), cold carcass weight was recorded from all individuals, while yields of different body parts were collected from 9 individuals/group. Broilers from the 6,065 K treatment were 67.4 ± 19.2 g heavier on the day of slaughter (P = 0.0009), whereas no difference was found at other ages (P > 0.12). Feed intake was found to be similar for the 2 treatments (P = 0.52). Pectoralis minor was 4.1 ± 1.9 g heavier in the 6,065 K treatment (P = 0.03). There was no difference between the light treatments in any of the welfare parameters. We conclude from the results that of the 2 color temperatures examined, the most suitable for use in commercial broiler houses is 6,065 K.

Assessment of welfare of Brazilian and Belgian broiler flocks using the Welfare Quality protocol

The Welfare Quality consortium has proposed a science-based protocol for assessing broiler chicken welfare on farms. Innovative features make the protocols particularly suited for comparative studies, such as the focus on animal-based welfare measures and an integration procedure for calculating an overall welfare status. These protocols reflect the scientific status up to 2009 but are meant to be updated on the basis of inter alia implementation studies. Because only few such studies have been done, we applied the Welfare Quality protocol to compare the welfare of broiler flocks in Belgium (representing a typical European Union (EU) country which implies stringent animal welfare legislation) versus Brazil (the major broiler meat exporter to the EU and with minimal animal welfare legislation). Two trained observers performed broiler Welfare Quality assessments on a total of 22 farms in Belgium and south Brazil. All of the farms produced for the EU market. Although the overall welfare was categorized as ‘acceptable’ on all farms, many country differences were observed at the level of the welfare principles, criteria, and measures. Brazilian farms obtained higher scores for 3 of the 4 welfare principles: ‘good feeding’ (P = 0.007), ‘good housing’ (P < 0.001), and ‘good health’ (P = 0.005). Four of the 10 welfare criteria scores were, or tended to be, higher on Brazilian than Belgian farms: ‘absence of prolonged thirst’ (P < 0.001), ‘ease of movement’ (P < 0.001), ‘absence of injuries’ (P = 0.002), and ‘positive emotional state’ (P = 0.055). The only criteria with a higher score for the Belgian farms than their Brazilian counterparts were ‘absence of prolonged hunger’ (P = 0.048) and ‘good human–animal relationship’ (P = 0.002). Application of the Welfare Quality protocol has raised several concerns about the validity, reliability, and discriminatory potential of the protocol. The results also call for more research into the effect of animal welfare legislation as broiler welfare on the south Brazilian farms appeared to be superior to that on the Belgian farms. Animal-based welfare assessments on a larger sample of farms are needed to evaluate to what extent these findings may be generalized.

Towards real-time control of chicken activity in a ventilated chamber

Monitoring and controlling some behavioural responses such as the activity level and position of broiler chickens in broiler houses could provide an inexpensive tool with the potential to improve broiler welfare, health, energy consumption and product quality. The main objective of this paper is to examine the possibility of controlling chickens' activity level and position in a small chamber via controlling the surrounding micro-environment. A small ventilated test chamber was used. In this study real-time modelling was used to predict the dynamic activity index of broilers in relation to variations in the inlet temperature and ventilation rate. Step inputs in both ventilation rate and inlet air temperature were applied and temperature at 30 sensor locations was recorded. The chamber was populated with 9 chickens (age 7 days). A digital CCD camera that was mounted on the top of the chamber was used to capture the birds' positions and motion. Images were captured with a resolution of 640 by 480 pixels at a 1 Hz frame rate. The airflow pattern inside the chamber was investigated by conducting a set of smoke experiments. Software was developed to calculate the activity level of all chickens in real-time. The dynamic variation of activity index of chickens was compared to the two-dimensional spatial profile of temperature and the airflow pattern inside the chamber. Real-time models are defined to describe the dynamic responses of the chickens' activity to changes in the micro-environmental temperature. The resulting models are the basis for a model-based predictive controller of chickens' activity. The mathematical basis for a model-based predictive control system is defined in this paper.

Effects of Light Sources and Intensity on Blood Physiological Variables of Broilers Grown to Heavy Weights

Most governments around the world including the USA have passed measures to phase out incandescent light in favor of energy-efficient lighting alternatives. The research is limited on blood physiological variables of broilers grown to heavy weights (> 3 kg) under these new light sources to ensure welfare of broilers. We investigated the effects of light sources and intensity on blood physiological variables of broilers grown to heavy weights. In each trial with 2 replicates of 4 trials, 1-d-old 960 Ross × Ross 708 chicks were randomly distributed into 16 rooms (30 male and 30 female chicks/room). A 4 × 2 factorial treatment structure was evaluated that consisted of 4 light sources [incandescent (ICD, standard), compact fluorescent (CFL), light emitting diode (LED), poultry specific filtered LED (PSF-LED)] from d 0 to d 56 and 2 levels of light intensities (5 lx, 20 lx) from d 22 to d 56 at 50 % RH. Each of the 4 light source treatments was paired with one of the two light intensity. Feed and water were provided ad libitum. Venous blood samples were collected on d 21, 28, 42, and d 56 and analyzed immediately. Light sources, age, and sex had significant (P < 0.05) effects on BW, Hb, Hct, electrolytes, angap, and mOsm. However, all these changes were still within the normal acid-base homeostasis and physiological ranges. There was no main effect of light intensity on any examined variables. There were interactions of light sources and intensity in some of the examined variables. Plasma corticosterone was not affected by treatments. It was concluded that the 3 light sources evaluated in this study are suitable for replacement of ICD light source in commercial poultry facilities to reduce energy cost and optimize production efficiency without compromising welfare of broilers.

Incidence of Footpad Dermatitis and Hock Burns in Broilers as Affected by Genotype, Lighting Program and Litter Type

Abstract The aim of this study was to define the conditions for improving broiler leg health, thus ultimately promoting broiler welfare and greater economic efficiency of production, by investigating the effects of litter type, lighting program, or genetic predisposition on the incidence and severity of footpad dermatitis and hock burns. The study was conducted on broiler genotypes (G) Hubbard Classic and Ross 308. Litter (L) was either chopped straw or wood shavings. Lighting programs (LP) were applied when broilers were eight days old. One lighting program (LP1) was designed so that chicks between 8 to 39 days of age were exposed to 16L:4D:2L:2D, and received 23L:1D between 40 to 42 days of age. The other lighting program (LP2) was a gradual extension of photoperiod after restrictions in the second week: 16L:8D (8-14 days), 16L:3D:2L:3D (15-21 days), 16L:2D:4L:2D (22-28 days), 16L:1D:6L:1D (29-35 days) and 23L:1D (36-42 days). Evaluations of footpad lesions and hock burn, according to the method described by Thomas et al. (2004), were carried out individually for each bird, on days 21 and 42. Based on the average score and the frequency of the worst forms of footpad dermatitis, better growing conditions for broilers were found when wood shavings were used as litter material rather than the chopped straw (P&lt;0.01), and when a lighting program with gradual lengthening of photoperiod and with intermittent light/ dark periods (LP2) was applied, compared to a moderate-constant photoperiod lighting program (LP1) (P&lt;0.01). The Ross 308 broiler genotype, despite its lower body weight, showed a greater tendency to develop footpad dermatitis and hock burns. Hock burns developed more slowly than footpad dermatitis, and thereby, would be likely to exhibit a smaller adverse effect on broiler welfare and quality of chicken feet.

II. Evaluation of the impact of alternative light technology on male broiler chicken stress

This study evaluates the impact of light-emitting diodes (LEDs), cold cathode fluorescent lamps (CCFLs), and incandescent lamps on broiler welfare in response to recent interest in the agriculture industry to transition to more energy-efficient lighting technologies. Male Ross 708 broilers (n = 672) were raised to 6 wk age in 8 light-tight modified large colony houses under identical intermittent lighting conditions using 4 unique types of lamps, which were gradually dimmed throughout the study. Incandescent lamps served as the control; experimental technologies tested were a CCFL, and 2 different LED lamps. Each technology was tested in duplicate for each of the 4 trials (8 replications total per technology) conducted across the course of one year to account for seasonal variance. Birds were removed from each house at days 7, 14, 35, and 42 to be humanely euthanized and weighed for necropsy evaluation and comparison of body mass. Blood collection via cardiac puncture was performed to obtain heterophil to lymphocyte (H:L) ratios for evaluation of environmental stress. Birds raised under CCFLs had significantly lower body weights (2,871 g ± 53) than the control (3,000 ± 33 g) by 42 d. Birds raised under CCFLs additionally had significantly higher H:L ratios (0.68 ± 0.06) than the control (0.53 ± 0.03), indicating that these birds may have been chronically stressed (P = 0.03). There were not significant differences in the H:L ratio between LED technologies at α = 0.05. A significant age and seasonal correlation in H:L ratios was observed across all technologies, along with significant differences among birds raised under the experimental technologies. This study indicates that variation in broiler body weight and stress may be attributed in part to lighting technologies implemented in broiler houses.

Effect of dietary supplementation of medium-chain fatty acids on growth performance and prevalence of carcass defects in broiler chickens raised in different stocking densities

A 3 × 3 factorial experiment was conducted to examine the effect of medium-chain fatty acids (MCFA) on performance and occurrence of carcass defects in broiler chickens raised in stocking densities of 14, 16, and 18 birds/m2. A total number of 720 Ross 308 broiler chicks that were 1 d old were reared up to 49 d of age. Corn- and soybean meal (SBM)–based starter and grower diets were supplemented with 0, 1.5, and 2 g/kg Aromabiotic and provided to the birds ad libitum. Inclusion of 2 g/kg Aromabiotic in the diet significantly improved weight gain of the birds during 1 to 21 d of age compared with control birds (P< 0.001). A significant reduction in mortality (P= 0.004) and a significant increase in European performance efficiency index (EPEI;P= 0.036) were noted in the birds that received diets containing 2 g/kg Aromabiotic compared with control birds at 49 d of age. The birds grown in a placement density of 18 birds/m2had significantly improved FCR along with reduced feed intake (FI) during 1 to 49 d of age compared with those reared in a density of 14 birds/m2. The mean EPEI was significantly greater in the birds raised in a density of 16 birds/m2(P< 0.001). At 48 d of age, litter caking was significantly increased in the birds raised in a density of 18 birds/m2and decreased in the birds that received dietary supplementation of Aromabiotic (P< 0.05). The influence of dietary Aromabiotic was significant related to reduced incidence and severity of footpad lesions and hock burns (P< 0.01). Frequency of lesions with a score of 2 to 5 on footpad and hock significantly increased for the birds raised in densities higher than 14 birds/m2. It was concluded that dietary supplementation of 2 g/kg Aromabiotic improved early productive performance of broiler chickens and enhanced the PEI mainly due to decreased mortality. Dietary Aromabiotic improved broiler welfare as indicated by reduced foot defects in the birds raised in placement densities of 16 and 18 birds/m2.

Incubation temperature profiles affect broiler feathering

Two experiments were conducted to assess the effects of incubation temperature profiles, breeder feed restriction programs, and litter conditions on progeny feather follicle (FF) density and skin layer thickness. In the first experiment, Cobb 500 fast feathering breeders were subjected to 2 feed restriction programs during rearing: skip-a-day (SAD) and every-day feeding (EDF). Eggs from each group were incubated according to 2 incubation temperature profiles: standard (S) and early-low late-high (LH). A total of 72 chicks per treatment combination were placed in Petersime cages (6/cage) and sampled for skin in the breast, dorsum, and thigh areas at 22 d. Additional samples were collected from the thigh and measured for epidermal and dermal thickness. For the second experiment, 2,475 eggs from a commercial flock of Cobb 500 fast feathering breeders were subjected to 3 incubation temperature profiles: S, LH, and standard-high (SH). At hatch, 1,260 chickens were placed in floor pens (14/pen) that contained either used litter or new wood shavings. At 28 d of age, 2 chickens per pen were sampled for skin in the breast, dorsum, and thigh areas. In both experiments, FF were counted in 4.5 cm2. It was concluded that incubation temperature affected feathering development in both experiments, especially in the breast. This effect may be stronger in progeny from breeders restricted under SAD programs. Moreover, litter conditions impacted FF numbers. These findings may be applied to minimize carcass scratches and improve broiler welfare.

Broiler chicken welfare assessment in GLOBALGAP®certified and non-certified farms in Brazil

AbstractRegarding broilers, Brazil is the third largest producer and the leading chicken meat exporter in the world. Independent certifications are required by some importers in the European Union (EU) to guarantee compliance with minimum welfare requirements. Our objective was to compare broiler chicken welfare in GLOBALGAP®certified (C) and non-certified (N) intensive farms in the State of Paraná, Brazil, using the Welfare Quality®protocol. Ten farms in each group were evaluated and data were transformed using scores that ranged from 0 to 100, where 100 is the best condition. Results suggested that farms adhered to minimum welfare standards, regardless of certification and that the adoption of standards based on overseas rules may have limitations for the improvement of animal welfare. In order to further improve broiler welfare in Brazil, more rigorous standards should be developed.

Geoestatística para a avaliação do controle ambiental do sistema de ventilação em instalações comerciais para frangos de corte

O sistema de ventilação e de resfriamento utilizado em instalações para frangos de corte desempenha um papel importante no controle ambiental, possibilitando que a ave expresse seu potencial máximo de produção. Nesse sentido, o objetivo deste trabalho foi avaliar, por meio da geoestatística, a influência do sistema de ventilação e das diferentes tipologias construtivas em relação ao ambiente térmico e aéreo em aviários de frangos de corte na fase final de criação. Os aviários avaliados com sistema de ventilação artificial de pressão negativa, por meio de exaustores, foram: Blue House com nebulizadores na entrada de ar e vedação de cortinas; Dark House com painel evaporativo (tijolo cerâmico) e vedação de cortinas e Solid Wall com painel evaporativo (celulose) e vedação de alvenaria. Os atributos avaliados foram: temperatura, umidade relativa, velocidade do ar, concentração de dióxido de carbono e amônia, durante o período de verão às 14h, em 52 pontos equidistantes, no interior do aviário. Os dados foram avaliados pela análise estatística e geoestatística. A análise geoestatística apresentou-se como ferramenta eficiente para a avaliação da distribuição das condições ambientais nos aviários, e a presença ou não do painel evaporativo influenciou na condição padrão de funcionamento do sistema de ventilação.

Feather corticosterone evaluated by ELISA in broilers: A potential tool to evaluate broiler welfare

The measure of corticosterone (CORT) in feathers has been recently recognized as a valid and easily obtainable measure of chronic glucocorticoids secretion in avian species. This measure provides meaningful interpretations of how individuals respond to environmental perturbations. The growing interest of the public toward animal-food production welfare shows the need for improving and expanding objective tools to evaluate this issue. The present study evaluates whether it is possible to detect CORT in broiler feathers, and thus, assess if it would be a useful measure to study broiler welfare. Twenty-two broilers were randomly selected from an intensive farm. Four to 6 dorsal feathers were collected from each bird, and sex, weight, and morphological aspects of feather status were recorded. We tested the feasibility for detecting CORT in broiler feathers by ELISA, which had never been done before, and an assay validation test was performed. No significant relationships were found between feather CORT concentrations and physiological variables such as sex, weight, and fault bars in broilers. To our knowledge, this is the first study that uses broiler feathers as a matrix that provides a retrospective record of their hypothalamic-pituitary-adrenal activity. Results indicate that ELISA is a valid tool to detect feather CORT levels in broilers.

Effects of dietary tryptophan and stocking density on the performance, meat quality, and metabolic status of broilers.

BackgroundHighly automated cage-rearing systems are becoming increasingly popular in China. However, a high stocking density can cause oxidative stress and decrease broiler performance. The tryptophan (TRP) derivative 5-hydroxytryptophan (5-HT) has been shown to preserve membrane fluidity in birds suffering from oxidative stress. Therefore, this experiment was conducted to determine the effects of dietary TRP supplementation on performance, breast meat quality and oxidative stress in broilers reared in cages with a high or low stocking density.MethodsFemale Arbor Acres broilers (25-d-old, n = 144) were randomly allocated to 1 of 4 treatments. The birds were fed a diet based on corn, soybean meal, cottonseed meal and corn gluten meal containing either 0.18 or 0.27% TRP and were housed with stocking densities of 11 or 15.4 birds/m2 in a 2 × 2 factorial experiment. Broiler performance was evaluated from d 25 to 42. Eight birds from each treatment were slaughtered on d 42 and plasma and breast muscle samples were collected to measure biochemical indices.ResultsA higher stocking density tended to be associated with reduced weight gain (P < 0.10), and significantly increased plasma glutamic-pyruvic transaminase (GPT) activity (P < 0.001). Increased dietary TRP significantly reduced the activities of lactic dehydrogenase and GPT while increasing total cholesterol in the plasma (P < 0.01), reducing drip loss of breast muscle (P < 0.10) and improving feed efficiency (P < 0.10).ConclusionsAn increase in dietary TRP, 1.5-fold higher than the standard supplementation level, can alleviate oxidative stress as well as improve welfare and feed efficiency in broilers reared in cages with a high stocking density.

Evaluation of Free-Range broilers using the welfare quality® protocol

Scientific information on the welfare of broilers reared in alternative systems is scarce. The objective of this study was to assess the welfare of free-range broilers using the Welfare Quality® protocol. Free-range broilers reared in ten farms were observed, and measures were made in broilers of five of these farms. The collected data were transformed into scores (0-100), with higher scores indicating better welfare, except for emotional states. Prevalence percentages were calculated for the remaining data. Median (min-max) scores were 81 (63-98) for lameness, 93 (83-99) for hock burn on the farm, 100 (95-100) for plumage cleanliness, 35 (8-70) for podermatitis on the farm, 56 (26-88) for density, 53 (20-53) for dust, 34 (14-67) for litter quality, 93 (41-100) for drinkers, and 100 (100-100) for birds panting or huddling on the farm. The following average (min-max) prevalence percentages were obtained: total mortality 2.0% (1.4-7.2%), culling 0.0% (0.0-2.2%), feed withdrawal time 875 min (715-945 min), water withdrawal time 220 min (170-275 min), dead on arrival at the processing plant 0.00% (0.00-0.01%), broken wings 0%, (0-0%), inefficient stunning 3.9% (1.3-6.7%), pre-stun shock 49.3% (26.7-56.8%), hepatitis 4.5% (1.8-11.0%), bruising 9.3% (6.7-16.7%), and ascites 0% (0-0%). The negative broiler welfare points detected were pododermatitis, litter quality, density, dust, culling, feed withdrawal time, inefficient stunning, pre-stun shock, and hepatitis. The positive points identified were the absence of birds panting or huddling on the farm; low prevalence of lameness, hock lesions, dead on arrival, broken wings, and ascites; good plumage cleanliness scores, and short water withdrawal time.