Skin lesions in broiler chickens measured at the slaughterhouse: relationships between lesions and between their prevalence and rearing factors

Exploring the most common lesion of Australian farmed saltwater crocodile (Crocodylus porosus) belly skin in the Northern Territory

This is the first descriptive study to characterise and identify the most common lesions on harvested Australian saltwater crocodiles (Crocodylus porosus). 88 skins were examined over a 17-month period as part of normal farming practices, 2901 lesions identified, with scale location, location of the lesion on the scale, and characteristics (contour, keratin normality, translucency and colour) recorded. The study determined that linear lesions accounted for 68.25 % of lesions followed by foci lesions 17.24 %. Lesions were distributed on the upper proportion of the belly skin (77.8 %) and along the midline (72 %). The most common lesion identified was a single translucent linear lesion across the scale that otherwise appeared normal (58.95 %). While there is extensive research into pathogenic agents, further research is recommended to explore further causation of linear lesions, and factors that may contribute to their prevention. Given the subjective nature of crocodile skin grading, it is recommended future research into lesions is required to ensure the sustainability and profitability of the industry.

Effect of litter management systems on incidence and severity of footpad dermatitis among broilers at finisher stage

Pododermatitis, or footpad dermatitis (FPD), is a welfare concern affecting broiler chickens globally. In the humid tropics, where high temperatures and humidity prevail, the impact of pododermatitis on broiler performance characteristics and behavior becomes even more significant hence this investigation. One hundred and eighty male broilers were used for this experiment out of 200 birds initially procured at day old. They were brooded and reared on deep litter and at 21 days of age, they were randomly allotted to the experimental unit. There were three treatments each with three replicates in a completely randomized design. The three litter management systems constituted the treatment groups. In the first treatment (t-A), litter materials were changed on a weekly basis and replaced with fresh ones while in the second treatment (t-B), the litter materials were turned or raked once a week, and in the third treatment (t-C), the litter materials were left untouched. The litter material used across all treatments was wood shavings and t-C served as control. The experimental birds were fed ad libitum during the trial. Data on daily feed intake, incidence and severity of paw lesions, and weekly body weights were taken while the experiment lasted 35 days. Test of mobility and aggression were carried out on the birds from each group on the last day of the experiment. The moisture content and pH of litter materials of each replicate were taken weekly from day 21 till the end of the experiment. Data were later subjected to analysis of variance statistically. The results revealed that broilers on t-A performed better (P < 0.05) than those on t-B and t-C for feed intake, live weight, weight gain, and feed utilization. However, FPD was pronounced among broilers on t-C and much more severe. A positive correlation was observed between the values of litter moisture content, litter pH, and incidence and severity of FPD. Birds on t-C were dull in appearance and inactive. In conclusion, FPD has a detrimental impact on the performance characteristics and behavior of broiler chickens in the humid tropics. However, the severity depends on the management system adopted. By adopting appropriate management practices such as weekly replacement of litter with fresh ones, it is possible to alleviate the negative consequences of FPD, improve broiler welfare, and enhance the sustainability of the poultry industry in these regions.

Xylanase and beta-glucanase improve performance parameters and footpad dermatitis and modulate intestinal microbiota in broilers under an Eimeria challenge

Coccidiosis is an enteric disease of poultry worldwide that compromises gut health and growth performance. The current research investigated the effects of 2 doses of a multienzyme preparation on broilers' performance, gut health, and footpad dermatitis (FPD) under an Eimeria challenge. A total of 512 mixed-sex day-old chicks (Cobb 500) were randomly allocated to 4 treatments of 8 replicates. Treatments were: 1) nonchallenged control (NC); 2) NC + Eimeria challenge (CC); 3) CC + recommended level of xylanase and glucanase (XG, 100 g/t feed [on top]); 4) CC + double XG (2XG, 200 g/t feed). Eimeria spp. vaccine strains were gavaged on d 9 to induce coccidiosis in chickens. Performance parameters were evaluated during starter, grower, and finisher phases, and 4 birds per pen were euthanized on d 16 for sampling, FPD was scored on d 35, and litter moisture was analyzed on d 17 and 35. The data were analyzed using 1-way ANOVA with Tukey's test to separate means, and Kruskal-Wallis test was used for non-normally distributed parameters. The results showed that the Eimeria challenge was successful based on reduced weight gain and feed intake during grower phase, and higher FITC-d concentration, lesion score (female), and oocyst counts (d 14) in CC group compared to N.C. group, while XG and 2XG increased (P < 0.001) weight gain and improved FCR compared to CC and NC groups during finisher phase. The addition of X.G. and 2XG decreased litter moisture (P = 0.003) and FPD (P < 0.001) in challenged broilers compared to the N.C. group (d 35). Supplementing XG and 2XG reestablished the population of Lactobacillus in the cecum of challenged birds to an intermediate level between the NC and CC groups (P > 0.05). The inclusion of XG tended to increase the expression of Junctional adhesion molecule 2 (JAM2), which was not different from CC and NC groups (P > 0.05). In conclusion, the combination of xylanase and glucanase (Natugrain TS) improved the performance and modulated jejunal microbiota of broilers under mild Eimeria challenge.

Consumer trust and willingness to pay for establishing a market-based animal welfare assurance scheme for broiler chickens

The aim of this study was to examine Finnish consumers' preferences and willingness to pay (WTP) for measures to improve broiler chicken welfare and to examine how familiarity with animal production farms, trust in food system actors, and views concerning the responsibility for animal welfare were associated with the WTP. A survey instrument, including a choice experiment, to study consumer preferences for food quality attributes was developed. The survey data were analyzed using a latent class model and logistic regression analysis. The results suggested that Finnish consumers tend to have a positive WTP for improvements in farm animal welfare (FAW) in broiler production, although WTP varied by consumer segment. Five different consumer groups with different levels of WTP for specific welfare attributes were identified. The highest WTP was estimated for an additional space allowance for the birds and enhanced litter quality monitoring at the farm. In conclusion, there is demand for animal welfare labeled broiler chicken among Finnish consumers. However, consumer expectations are heterogeneous, and different strategies can appeal to different segments. While one consumer segment prioritizes FAW over price, another segment emphasizes low-priced products and considers mid-market products appealing. Moreover, public policies are an important tool for enhancing FAW for a large proportion of consumers, and public actions are therefore warranted. Finally, engaging with animal protection organizations (as mediators) and being open to consumers can be an effective strategy to build confidence in premium products.

Comparison of carcass condemnation causes in two broiler hybrids differing in growth rates

Experimental studies concluded that genetic factors enabling fast growth rate might negatively affect broiler health and welfare. Recently, the proportion of slower-growing broilers has been increasing. However, studies of health in broilers with different growth rates in commercial systems are still scarce. This repeated cross-sectional study aimed to describe causes of carcass condemnations in two broiler hybrids with different growth rates, Ross 308, and Hubbard JA787, and to estimate the effect of hybrid. The study sample consisted of 63,209,415 broilers slaughtered in 4295 batches from 139 farms. All broilers were slaughtered from January 1st, 2015, to June 22nd, 2021, by the same company (Norsk Kylling). All causes of condemnation, except fractures, were more prevalent in Ross 308. The five most common causes (ascites, discolouration, hepatitis, small and skin lesions) were investigated in greater detail, and the effect of hybrid was assessed using mixed effects negative binomial models with the condemnation codes as outcome variables. For the five selected causes, variation in prevalence between slaughter batches was considerable for Ross and minor for Hubbard. The notable differences between hybrids in prevalence and causes of condemnation have important implications for animal health, welfare, economy, and sustainability in broiler production.

Performance, Egg Quality, and Immunity of Laying Hens due to Natural Carotenoid Supplementation: A Meta-Analysis

This study aimed to investigate the effectiveness of carotenoid supplementation on the performance, egg quality, and immunity of laying hens using a meta-analysis approach. The database was searched using Google Scholar and Scopus, from 2012 to 2022. The literature was published in English. 47 Articles were selected for meta-analysis. Analyses were performed using the Open Meta-analyst for Ecology and Evolution (OpenMEE) software. The heterogeneity and data validation against publication bias were analyzed using JASP 0.16.2 software. Overall, the results showed that carotenoid supplementation improved feed intake by 0.32 g/day/hen [95% confidence interval (CI)=0.02 to 0.61], final body weight by 0.33 g/hen (95% CI=0.05 to 0.60), egg production by 0.38% (95% CI=0.14 to 0.63), egg weight by 0.29 g (95% CI=0.09 to 0.5), yolk colour by 2.11 (95% CI=1.71 to 2.51), Haugh unit (HU) by 0.26 (95% CI=0.11 to 0.42), yolk carotenoids by 1.17 μg/kg (95% CI=0.59 to 1.75), immunoglobulin A (IgA) by 0.74 mg/L (95% CI=0.18 to 1.29), and lower yolk cholesterol by -0.38 mg/g (95% CI=-0.59 to -0.16). Feed conversion ratio (FCR), eggshell thickness, and white blood cells were unaffected by the application of carotenoids. The heterogeneity analysis showed variability in all studies (<0.05). In conclusion, carotenoid supplementation can elevate productivity, enhance egg quality, and improve immunity. However, based on Kendall's test, there was a publication bias in several parameters, namely FCR, egg weight, HU, yolk carotenoids, and IgA.

Fast- and slower-growing broilers respond similarly to a reduction in stocking density with regard to gait, hock burn, skin lesions, cleanliness and performance

There is an increasing trend toward broiler production systems with higher welfare requirements. Breed and stocking density are considered key factors for broiler welfare that are often specified as criteria for such higher welfare systems. However, it remains unknown how slower-growing broilers respond to a reduction in stocking density with regard to their welfare and performance, and whether this response differs from fast-growing broilers. Therefore, we compared fast- (F) and slower-growing broilers (S) housed at 4 different stocking densities (24, 30, 36, and 42 kg/m², based on slaughter weight) and measured their welfare scores (i.e., gait, footpad dermatitis, hock burn, skin lesions and cleanliness), litter quality and performance. The experiment had a 2 × 4 factorial design with 4 replicates (pens) per treatment (32 pens in total). Thinning (15%) was done in a 50/50 male/female ratio at 38 (F) and 44 (S) d of age (estimated body weight of 2.2 kg). We hypothesized that breeds would respond differently to a reduction in stocking density. Contrary to our hypothesis, only one interaction between breed and stocking density was found on footpad dermatitis, indicating that fast- and slower-growing broilers generally showed similar responses to a reduction in stocking density. F broilers showed a steeper decline in the prevalence of footpad dermatitis with reducing stocking density compared to S broilers. Broilers housed at lower stocking densities (24 and/or 30 kg/m²) showed improved welfare measures, litter quality and performance compared to those housed at higher stocking densities (36 and/or 42 kg/m²). S broilers had better welfare scores (gait, footpad dermatitis and skin lesions), litter quality and lower performance compared to F broilers. In conclusion, reducing stocking density improved welfare of both F and S broilers, but more for F broilers in case of footpad dermatitis, and using S broilers improved welfare compared to F broilers. Reducing stocking density and using slower-growing broilers benefits broiler welfare, where combining both would further improve broiler welfare.

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.

Effect of silvopasture system on fearfulness and leg health in fast-growing broiler chickens

A silvopasture system intentionally integrates trees, forages, and livestock, allowing dual land use. These systems can provide high-quality habitat for broiler chickens; however, such systems have not been widely adopted by the broiler industry in the United States. The objective of this study was to examine the effect of silvopasture versus open pasture access on fearfulness and leg health in fast-growing broiler chickens. A total of 886 mixed-sex Ross 708 chicks in Experiment 1 (Exp 1) and 648 chicks in Experiment 2 (Exp 2) were housed in coops and had access to 16 (Exp 1) or 12 (Exp 2) 125m2 silvopasture plots (x̄ = 32% canopy cover) or open pasture plots (no canopy cover) from day 24 of age. Fearfulness was measured using a tonic immobility test (tonic immobility duration), and leg health was assessed by quantifying footpad dermatitis, hock burns, gait, and performing a latency-to-lie test on days 37-39 of age. Birds in the silvopasture treatment were less fearful than birds in the open pasture treatment. Overall, birds in both silvopasture and open pasture systems had excellent leg health. Silvopasture birds had lower footpad dermatitis scores than open pasture birds. Silvopasture birds tended to have worse gait than open pasture birds in Exp 1, but not in Exp 2. Hock burn scores and latency-to-lie did not differ between treatments in Exp 1 or Exp 2. Raising birds in silvopasture reduced fear and improved footpad health compared to birds raised in open pastures, which indicates that silvopasture systems provide some benefits for affective state and leg health in fast-growing broilers.

Fast growing broiler production from genetically different pure lines in Turkey. 2. Broiler traits: growth, feed intake, feed efficiency, livability, body defects and some heterotic effects

The aim of the this study was to reveal the trends in body weight (BW), feed intake (FI), feed conversion ratio (FCR), livability, and body defects (foot pad dermatitis (FPD), hock burn (HB), and breast burn (BB)) in offspring of ANADOLU-T pure lines (PLs), their 12 four-way hybrids and ROSS-308 hybrid, and the observed heterosis values for some performance and body defect traits. A total of 2736 (1368 broilers each) broiler chickens from ANADOLU-T pure lines, their hybrids, and commercial ROSS-308 hybrid were hatched from breeder eggs at 32 and 52 weeks of age and reared for 42 days in 2 experiments. The PL eggs were generally heavier than hybrid eggs (P < 0.001) and day-old BWs (P < 0.001) were also higher in PL chicks (ranging between 44.5 and 45.8 g). The males of ROSS-308 hybrid were heavier than others at 42 d of age (P = 0.035), and the lowest BW values were determined for A1, A2, and A3 line chickens (P < 0.001). ROSS-308 (4453.8 g) showed similar 42-d FI with all of four-way ANADOLU-T hybrids except (B1 × B2) × (A1 × A2) and (B1 × B2) × (A3 × A1). The 42-d FCR was 1.473 for the ROSS-308, while it ranged between 1.654 and 1.715 for the four-way ANADOLU-T hybrids (P < 0.001). The 42-d livability of four-way ANADOLU-T hybrids and ROSS-308 ranged between 92.0 and 100.0%. All ANADOLU-T hybrids, except two, showed higher 42-d livability than ROSS-308. While both genotype and sex were important for HB and BB, only the genotype effect was significant for FPD (P < 0.001). All ANADOLU-T hybrids showed low to moderate and positive heterosis for BW after 28 d. From 14 to 42 d, the magnitudes of heterosis for FCR decreased. Heterosis for livability from 7 to 42 d were not significant between genotypes. Percentages of heterosis for resistance to FPD (- 1.56 to 1.44%), HB (- 37.03 to 18.75%), and BB (- 12.70 to 1.02%) defects were not significant among genotypes. It was concluded that mating of B1 × B2 males with A1 × A2 and A3 × A2 females seems more favorable in terms of higher chick and meat production. However, the fact that the overall performance of ANADOLU-T hybrids is lower than ROSS-308 clearly indicates that genetic selection must be maintained for enhanced body weight and feed efficiency.

Characterization of Escherichia coli and other bacteria isolated from condemned broilers at a Danish abattoir

Meat inspection is important to ensure food safety and protect public health. Visual inspection of slaughtered carcasses for pathological changes should be supported by bacteriological analysis to determine whether the entire carcass or parts of it should be condemned. The aim of this study was to determine the bacterial species present in different sample types from condemned broiler carcasses. Furthermore, we investigated the genetic characteristics, zoonotic potential, and relatedness of Escherichia coli, the predominant bacterial species isolated from the carcasses. A total of 400 broiler carcasses condemned because of cellulitis (100), scratches (100), hepatitis (100), and healthy control carcasses (100) were selected. Samples of meat, pathological lesion, and bone marrow of each carcass were obtained for microbial analysis. From the analyzed samples, 469 bacterial isolates were recovered with E. coli accounting for 45.8%, followed by Aeromonas spp. (27.9%), in particular A. veronii. The highest rate of bacterial isolation was observed in carcasses condemned with cellulitis, whereas carcasses with hepatitis had the lowest rate of bacterial isolation. Forty-four E. coli isolates originating from different sample types were selected for whole genome sequencing. A clonal relationship was shown between E. coli from different sample types of the same carcass condemned with cellulitis and scratches. A major clade of E. coli was found in carcasses condemned with cellulitis with isolates containing mdf(A), tet(A), and bla TEM-1B genes that confer resistance to macrolides, tetracycline, and ampicillin, respectively. E. coli in this clade all belonged to ST117 and clustered with E. coli isolates previously collected from dead chickens and carcasses condemned due to cellulitis in Denmark, Finland, and the United Kingdom. Bacterial evaluation results of carcasses condemned with cellulitis, scratches (moderate to severe skin lesion), and acute hepatitis confirmed the need for total condemnation of carcasses with these pathological findings. A similar evaluation should be done for carcasses affected with chronic hepatitis, and minor scratches lesions.

Effects of a microbial muramidase on the growth performance, intestinal permeability, nutrient digestibility, and welfare of broiler chickens

The objective of these studies was to evaluate the inclusion of a microbial muramidase (MUR) in the diets of broiler chickens on the growth performance, intestinal permeability (IP), total blood carotenoid content, apparent ileal digestibility (AID), and foot pad dermatitis (FPD). In Experiment 1, a total of 1,000 one-day-old chicks were placed in floor-pens with reused litter, and randomly distributed into 4 treatments with 10 replicates each. Treatments were a basal diet (control), or basal diet supplemented with 15,000; 25,000 or 35,000 LSU (F)/kg of MUR. Feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR) were evaluated at d 21 and 43. Intestinal permeability was evaluated on d 35 by FITC-d, and FPD and AID on d 43. In Experiment 2, a total of 800 one-day-old chicks were placed in floor-pens with fresh litter, and randomly distributed into 4 treatments with 8 replicates each. Treatments were a basal diet (control), or basal diet supplemented with 25,000 or 35,000 LSU (F)/kg of MUR, and a fourth group where the basal diet was supplemented with enramycin. The birds were induced to a mild intestinal challenge. Feed intake, BWG, and FCR were evaluated on d 21 and d 42, and total blood concentration of carotenoids was evaluated on d 28. In experiment 1, 35,000 LSU (F)/kg of MUR promoted the best FCR (P < 0.05). Muramidase supplementation linearly increased the AID of dry matter, ash, and fat (P < 0.01), and regardless of the dose, MUR decreased the IP (P < 0.05). In Experiment 2, the supplementation of 35,000 LSU (F)/kg of MUR improved BWG and FCR in the entire cycle (1–42 d) and increased the concentration of carotenoids in the blood on d 28 compared to the control group (P < 0.05). These studies show that MUR improves growth performance of broilers by improving intestinal permeability, digestibility of dry matter, ash and fat, absorption of carotenoids, and reducing FPD.

Ordinal or visual analogue scales for assessing aspects of broiler chicken welfare?

When the gradation of animal welfare is scored through ordinal scales and equidistant tags are used, empirical data between tags tend to be non-equidistant. Ordinal rate scales (ORS) and visual analogue scales (VAS) were tested for the assessment of contact dermatitis on breast and abdominal areas (CD), footpad dermatitis (FP), hock burns (HB) and bird soiling (BS) in broiler chickens. Calculations regarding the inter-rater reliability, the correlation between VAS and ORS and amongst the welfare indicators measured with both scales, and the equidistance of ORS categories in relation to values measured using VAS, were made. A total of 1,303 broiler chickens from 10 flocks was assessed on-farm by three raters using both scales. Inter-rater reliabilities of CD and HB were higher when using VAS compared with ORS, but FP was lower. Correlations between scales varied between 0.90-0.97 and 0.77-0.95 (P<0.001), considering mean and individual values. Low-to-moderate correlations were observed between the four indicators using the scales. Tags on VAS that best represented ORS were non-equidistant. Results suggest both scales were reliable assessing the selected broiler chicken welfare indicators.

Effects of common litter types and their physicochemical properties on the welfare of broilers

Background and Aim:

In broiler production, the poor quality litter not only may lead to a deterioration of the welfare status but also negatively affect carcass quality, overall health and growth performance, which may result in economic losses. The effects of litter types on the welfare of broilers are known but the effects of their characteristics have been little studied. This study aimed to evaluate correlations between welfare parameters of broilers and physicochemical characteristics of five common litter types.

Materials and Methods:

Over 42 days, 600 (Cobb 700) male broiler chicks were placed within 30 pens (each 2 m²) at a density of 10 birds/m². The experiment included five treatments with six replicates per treatment. The following litter (or bedding) materials were examined: Standard quality straw, low-quality straw, wood shavings (WS), sawdust, and crop residues. Footpad condition, hock burns, and plumage cleanliness, as well as litter condition, were scored according to previously developed point scale systems. Litter quality was evaluated according to pH level, moisture, water-holding capacity, and ammonia content.

Results:

No significant differences were found among litter types in terms of pH, moisture content, or ammonia levels. WS had a significant positive effect on footpad health and plumage cleanliness. However, hock burn was not affected by different bedding types. The severity of pododermatitis was negatively correlated with litter type (r = −0.78; p < 0.001) and positively correlated with the litter scores (r = 0.67; p < 0.001). However, contact dermatitis observed (pododermatitis and hock burn) was not correlated with any of the physicochemical parameters we studied. Meanwhile, we observed a correlation between footpad lesions and hock burn (r = 0.45; p < 0.05), and between footpad lesions and plumage cleanliness (r = 0.59; p < 0.01).

Conclusion:

For all litter types examined, contact dermatitis was not correlated with any of the physicochemical components we studied. There were, however, significant correlations between litter type and footpad lesions, as well as between footpad dermatitis and hock burns.

Footpad Monitoring: Reliability of an Automated System to Assess Footpad Dermatitis in Turkeys (Meleagris gallopavo) During Slaughter

Footpad dermatitis (FPD) is an indicator of animal welfare in turkeys, giving evidence of the animals' physical integrity and providing information on husbandry management. Automated systems for assessing FPD at slaughter can present a useful tool for objective data collection. However, using automated systems requires that they reliably assess the incidence. In this study, the feet of turkeys were scored for FPD by both an automated camera system and a human observer, using a five-scale score. The observer reliability between both was calculated (Krippendorff's alpha). The results were not acceptable, with an agreement coefficient of 0.44 in the initial situation. Therefore, pictures of 3,000 feet scored by the automated system were evaluated systematically to detect deficiencies. The reference area (metatarsal footpad) was not detected correctly in 55.0% of the feet, and false detections of the alteration on the footpad (FPD) were found in 32.9% of the feet. In 41.3% of the feet, the foot was not presented straight to the camera. According to these results, the algorithm of the automated system was modified, aiming to improve color detection and the distinction of the metatarsal footpad from the background. Pictures of the feet, now scored by the modified algorithm, were evaluated again. Observer reliability could be improved (Krippendorff's alpha = 0.61). However, detection of the metatarsal footpad (50.9% incorrect detections) and alterations (27.0% incorrect detections) remained a problem. We found that the performance of the camera system was affected by the angle at which the foot was presented to the camera (skew/straight; p < 0.05). Furthermore, the laterality of the foot (left/right) was found to have a significant effect (p < 0.001). We propose that the latter depends on the slaughter process. This study also highlights a high variability in observer reliability of human observers. Depending on the respective target parameter, the reliability coefficient (Krippendorff's alpha) ranged from 0.21 to 0.82. This stresses the importance of finding an objective alternative. Therefore, it was concluded that the automated detection system could be appropriate to reliably assess FPD at the slaughterhouse. However, there is still room to improve the existing method, especially when using FPD as a welfare indicator.

Animal Welfare Assessment: Quantifying Differences Among Commercial Medium and Fast Growth Broiler Flocks

A combined welfare assessment protocol, including indicators from the Welfare Quality® and AWIN® EU funded projects, was tested on commercial fast and medium growth commercial broiler flocks to determine differences in their assessments as measured with the used of animal welfare indicators. Ten commercial fast (Ross 308, Cobb 500, or a mix of both) and 10 medium growth (Hubbard JA × Ross 308), mixed sex commercial flocks were assessed at 32 and 48 days of age, respectively. Two observers simultaneously collected data on each flock. Observations included transect walks on central and wall areas to assess the AWIN® welfare indicators, bedding quality, environmental parameters and positive behaviors, all of them collected with the i-WatchBroiler app. According to the WQ protocol, welfare assessment indicators including the human avoidance tests, gait score, body weight and hock burns were also measured on each flock. Novel object tests were also carried out. The results of the study show that fast growth flocks had a higher incidence of welfare issues shown by the higher percentage of immobile, lame, sick, featherless, and tail wounded birds. Positive behaviors such as play fighting, wing flapping and running were more frequently observed in medium growth flocks on central locations, while fast growth flocks had a more limited expression of such behaviors. Fast growth flocks also had worse gait scores. Medium growth flocks expressed a different response to behavioral tests depending on the house location, likely attributable to their better mobility and welfare state, and also to the smaller stocking densities at which they were housed, while on the other hand the behavior of fast growth broilers during tests was similar regardless house location, being likely affected by mobility problems and the higher stocking density specific to their management. These results provide quantitative evidences on the differences in animal welfare assessment outcomes in fast and medium growth broilers. Nevertheless, results also suggest that some of the test responses were associated with the physical state and movement ability of the birds and house location that limit their response capacity. Such limitations should be considered when interpreting animal welfare assessment outcomes. These results add to previously published scientific evidences showing the potential of the method and app technology for practical on-farm broiler welfare assessment, including positive indicators, with farmers, technical personnel, certification bodies or scientist as potential end-users.

Comparison of litter quality, performance, and some welfare parameters of broilers reared on the sepiolite-supplemented paper waste sludge

Waste management is the protection of the environment and the health of the population. Paper waste sludge is produced during paper production and sepiolite is a natural clay mineral. The aim of the study was to investigate the usability of sepiolite-added paper waste sludge as a bedding material in the broiler production. Two hundred eighty-eight 1-day old male broiler chicks were divided into the 6 bedding material groups (wood shavings (control), paper waste sludge, sepiolite, mix of 25% paper waste sludge and 75% sepiolite, mix of 50% paper waste sludge and 50% sepiolite, and mix of 75% paper waste sludge and 25% sepiolite) with 6 replicate pens per group. Litter quality, performance, and some welfare parameters of broilers were assessed during the 6 weeks' period. Body weight at 42 days of age and body weight gain from 0 to 42 days of broilers reared on the wood shavings and mix of 50% paper waste sludge and 50% sepiolite were found higher than those of the sepiolite and paper waste sludge groups. Feed consumption and feed to gain ratio from 0 to 42 days, yields of carcass and carcass parts, percentages of organs and abdominal fat, IgG, percentage of bursa Fabricius, burns of foot pad and breast, litter pH and meat properties of broilers reared on the wood shavings, paper waste sludge, and sepiolite litter groups were not found to be statistically different. Litter moisture was found higher in the paper waste sludge group than that in the sepiolite group at the 42 days of rearing. As a conclusion, usage of mix of 50% paper waste sludge and 50% sepiolite as a litter does not have any negative effects on performance, welfare, and litter quality. This result is important in terms of utilizing a waste product.

Necrotic enteritis in broiler chickens: disease characteristics and prevention using organic antibiotic alternatives – a comprehensive review

In line with the substantial increase in the broiler industry worldwide, Clostridium perfringens-induced necrotic enteritis (NE) became a continuous challenge leading to high economic losses, especially after banning antimicrobial growth promoters in feeds by many countries. The disease is distributed worldwide in either clinical or subclinical form, causing a reduction in body weight or body weight gain and the feed conversion ratio, impairing the European Broiler Index or European Production Efficiency Factor. There are several predisposing factors in the development of NE. Clinical signs varied from inapparent signs in case of subclinical infection (clostridiosis) to obvious enteric signs (morbidity), followed by an increase in mortality level (clostridiosis or clinical infection). Clinical and laboratory diagnoses are based on case history, clinical signs, gross and histopathological lesions, pathogenic agent identification, serological testing, and molecular identification. Drinking water treatment is the most common route for the administration of several antibiotics, such as penicillin, bacitracin, and lincomycin. Strict hygienic management practices in the farm, careful selection of feed ingredients for ration formulation, and use of alternative antibiotic feed additives are all important in maintaining broiler efficiency and help increase the profitability of broiler production. The current review highlights NE caused by C. perfringens and explains the advances in the understanding of C. perfringens virulence factors involved in the pathogenesis of NE with special emphasis on the use of available antibiotic alternatives such as herbal extracts and essential oils as well as vaccines for the control and prevention of NE in broiler chickens.

Review on skeletal disorders caused by Staphylococcus spp. in poultry

Lameness or leg weakness is the main cause of poor poultry welfare and serious economic losses in meat-type poultry production worldwide. Disorders related to the legs are often associated with multifactorial aetiology which makes diagnosis and proper treatment difficult. Among the infectious agents, bacteria of genus Staphylococcus are one of the most common causes of bone infections in poultry and are some of the oldest bacterial infections described in poultry. Staphylococci readily infect bones and joints and are associated with bacterial chondronecrosis with osteomyelitis (BCO), spondylitis, arthritis, tendinitis, tenosynovitis, osteomyelitis, turkey osteomyelitis complex (TOC), bumblefoot, dyschondroplasia with osteomyelitis and amyloid arthropathy. Overall, 61 staphylococcal species have been described so far, and 56% of them (34/61) have been isolated from clinical cases in poultry. Although Staphylococcus aureus is the principal cause of poultry staphylococcosis, other Staphylococcus species, such as S. agnetis, S. cohnii, S. epidermidis, S. hyicus, S. simulans, have also been isolated from skeletal lesions. Antimicrobial treatment of staphylococcosis is usually ineffective due to the location and type of lesion, as well as the possible occurrence of multidrug-resistant strains. Increasing demand for antibiotic-free farming has contributed to the use of alternatives to antibiotics. Other prevention methods, such as better management strategies, early feed restriction or use of slow growing broilers should be implemented to avoid rapid growth rate, which is associated with locomotor problems. This review aims to summarise and address current knowledge on skeletal disorders associated with Staphylococcus spp. infection in poultry.

Evaluation of a Precision Biotic on the Growth Performance, Welfare Indicators, Ammonia Output, and Litter Quality of Broiler Chickens

A dietary glycan-based precision biotic (Glycan PB) was evaluated on the performance, welfare indicators, and litter characteristics of broiler chickens. In Trial 1, the main effects of Glycan PB dose (0, 250 and 500 g/metric ton (MT)) and xylanase supplementation (0 or 100 g/MT) were tested, as was their interaction. In Trial 2, pens located inside a commercial house were used to test the effect of Glycan PB supplementation (500 g/MT) versus a control diet. In Trial 1, Glycan PB supplementation at 250 and 500 g/MT improved feed conversion ratio (FCR) by 7 and 11 points when compared to diets without Glycan PB (p < 0.001). At 35 d, Glycan PB reduced the pH and ammonia concentration in diets with xylanase. In Trial 1, the supplementation with 500 g of Glycan PB/MT of feed reduced litter scores (p < 0.05). In both trials, 500 g of Glycan PB/MT of feed increased the proportions of birds without footpad lesions (Trial 1: 72.2% vs. 82.7%; p < 0.001; Trial 2: 14 to 27.3% (p = 0.05) or gait defects (Trial 1: 96.1% vs. 98.4%; p < 0.001) and decreased the proportion of birds with footpad lesions (Trial 2: 86% vs. 72.7%; p = 0.05).

In Pursuit of a Better Broiler: Walking Ability and Incidence of Contact Dermatitis in Conventional and Slower-Growing Strains of Broiler Chickens

In this study, the mobility, incidence, and severity of contact dermatitis and litter moisture content were assessed in 14 strains of broiler chickens differing in growth rate. The strains encompassed 2 conventional (CONV; ADG_0-48 > 60 g/d) and 12 slower growing (SG) strains categorized as FAST (ADG_0-62 = 53-55 g/d), MOD (ADG_0-62 = 50-51 g/d), and SLOW (ADG_0-62 < 50 g/d), with 4 strains in each category. A total of 7,216 mixed-sex birds were equally allocated into 164 pens (44 birds/pen; 30 kg/m²) in a randomized incomplete block design, with each strain represented in 8 to 12 pens over 2–3 trials. From each pen, 4 to 6 birds were tested in the latency-to-lie (LTL) and group obstacle tests 1 wk prior to the birds reaching 2 target weights (TWs) of approximately 2.1 kg (TW1: 34 d for CONV and 48 d for SG strains) and 3.2 kg (TW2: 48 d for CONV and 62 d for SG strains). The incidence of footpad dermatitis (FPD) and hock burns (HB) were evaluated a day prior to each TW. Litter moisture content was determined biweekly from d 14 to d 56. At TW1, CONV and SLOW had longer LTL than FAST birds. At TW2, CONV, MOD, and FAST birds had similar LTL. At both TWs, CONV birds were lighter than FAST birds in the group obstacle test, yet their number of obstacle crossings was similar. At TW1, CONV birds had greater incidence of FPD than FAST and MOD, while at TW2, CONV birds had greater incidence than the other categories. The incidence of HB in CONV and MOD was greater than SLOW birds at TW1, while at TW2, the incidence of HB was greater in CONV and FAST birds vs. MOD and SLOW birds. Litter moisture content was high in all categories from d 28 onward. Our results indicate that both BW and growth rate influence leg strength and walking ability, whereas the overall high litter moisture content and to a lesser extent growth rate influenced the incidence of contact dermatitis.

The effects of intermittent feeding and cold water on welfare status and meat quality in broiler chickens reared under daily heat stress

This study was aimed to determine the effects of feeding type (ad libitum: AF and intermittent: IF) and water temperature (normal: NW and cold: CW) treatments on welfare status and meat quality in fast-growing broiler chickens reared under daily heat stress between 22 and 42 days of age. The chickens' panting rate and rectal temperature were determined at 4, 5, and 6 weeks of age and twice a week in 3 female and 3 male chickens in each pen. Welfare traits such as foot pad dermatitis (FPD), hock burn (HB), breast burn (BB), and leg problems (LP) were examined individually at 42 days of age. At day 43, 3 male and 3 female chickens per pen were randomly selected and slaughtered after an 8-h fasting period; pH and color (lightness (L*), redness (a*), and yellowness (b*)) of breast and thigh meat were determined. AF × C W chickens had significantly higher panting rates at all ages than the other groups (P < 0.05). While FPD and LP were not affected by feeding type and water temperature treatments, interaction effects on HB and BB were found significant (P < 0.05). The HB and BB levels were the lowest in AF × NW chickens (P < 0.05). While treatments did not change to any color traits in breast meat (P > 0.05), interactions significantly affected the yellowness (b*) value in the thigh (P < 0.05). In conclusion, management practices such as IF and CW in fast-growing broilers could not completely reduce the undesirable effects of heat stress on some welfare and meat quality traits, and in some cases, even caused more negativity.

Welfare and performance of slower growing broiler breeders during rearing

Current commercial strains of broiler breeders can only achieve an optimal reproductive performance under feed restriction. However, chronic feed restriction in broiler breeders is a welfare concern because of physiological and behavioral signs of hunger, lack of satiety, and frustrated feeding motivation. The objective of this research was to assess the welfare and performance of slower growing broiler breeders during rearing. A total of 360 broiler breeder chicks from 3 female strains (100 chicks per strain) and 2 male strains (20 and 40 chicks per strain) were raised in four identical pens per strain. Strain B and C pullets and X cockerels were slower growing strains, and strain A pullets and Y cockerels were intermediate growing strains. Birds were weighed and scored individually for footpad lesions, hock burns and feather coverage. Data were analyzed using generalized linear mixed models with pen nested in the models and age as a repeated measure. Compared to B and C pullets, strain A pullets grew faster, had poorer body weight uniformity, and started feed restriction 2 wk earlier to control growth rate. Strain A pullets also had higher feeding rate at 3 and 5 wk, higher water intake at 4 and 5 wk, and higher prevalence of footpad lesions at 6 wk than the other pullet strains. Fault bars in wing feathers (an indicator of chronic stress) were more numerous in A pullets than in B and C pullets. Our results indicate that pullets showed little feather coverage loss during early rearing and had good body weight uniformity and low cumulative feed intake at the end of rearing. Slower growing broiler breeders may still require some degree of feed restriction to control growth rate, and strains with lower feed restriction exhibited lower signs of feeding frustration and high body weight uniformity.

Can good broiler flock welfare prevent colonization by Campylobacter?

Using data on rearing and welfare metrics of multiple commercial broiler flocks, we investigate how welfare measures such as hock burn, mortality, and pododermatitis, among others, impact the likelihood of a flock becoming colonized by Campylobacter. Using both logistic regression and Bayesian networks, we show that, while some welfare metrics were weakly related to Campylobacter colonization, evidence could not be found to suggest that these metrics directly exacerbated Campylobacter colonization, rather that they were both symptoms of the same parent variable – the managing company. Observed dependency on the management of the flock suggested that yet-undiscovered differences in rearing practice were the principal factor explaining both poor bird welfare and increased risk of Campylobacter, suggesting that action can be taken to improve both these factors simultaneously.

Associations between behaviour and health outcomes in conventional and slow-growing breeds of broiler chicken

Broiler chickens are prone to a range of complex health and welfare issues. To support informed selection of welfare traits whilst minimising impact on production efficiency and to address a major gap in understanding, we systematically explored associations between health and behavioural indicators of broiler welfare. One conventional (CNV, n = 350) and two slow-growing broiler breeds (SGH and SGN, respectively n = 400) were reared from hatch in pens of 50 birds. Birds were assessed for health (gait, plumage cover and dirtiness, pododermatitis, hockburn, and leg deviations) at 2.2 kg liveweight according to the Royal Society for the Prevention of Cruelty to Animals Broiler Breed Welfare Assessment Protocol. Behaviour and resource-use of 10% of birds per pen, on days 29 (all breeds) and 43 (SGH and SGN), was (i) scan sampled every 60 min between three to six and between twelve to fifteen hours after photoperiod onset; and (ii) continuously sampled sequentially from focal birds for 3 min each in a random order, during 15 min observation periods at three and twelve hours after photoperiod onset. Binary logistic generalized linear models were used, to assess respective associations between pen prevalence of each health outcome and (i) pen mean percentage scans of behaviour, and (ii) pen mean frequency and duration per 3 min focal observation of behaviour. Better growth rate and feed conversion but poorer health outcomes (mortality, gait, pododermatitis, feather cover) were more prevalent in CNV. Strong associations between behaviour and several heath indicators revealed, (i) increases in side-lying inactive, sitting inactive, and use of the litter relative to other resources, as primary and general indicators of poorer health, and (ii) increases in standing inactive, perch use, walking, Comfort, High Energy and Exploratory behaviour as primary and general indicators of better health. Of these, changes in side-lying, standing inactive, walking, Comfort and High Energy behaviour were particularly sensitive to small differences in health outcomes important for breed acceptance in high-welfare schemes. Crucially these behavioural measures additionally represent motivational and affective aspects of welfare not captured by health measures and allow opportunity for earlier intervention. Thus, to provide a comprehensive assessment of broiler experience, behaviour should be incorporated into broiler welfare assessments.

Welfare of broiler chickens reared in two different industrial house types during the winter season in Southern Brazil

1. The following trial compared broiler chicken welfare in closed-sided (CS) versus open-sided (OS) industrial house types during the winter season in the South of Brazil.2. Ten flocks in each house type were evaluated as follows: a) bird health: contact dermatitis on the breast and abdominal areas (CDE), bird soiling (BSO), footpad dermatitis (FPD), hock burn (HBU), lameness (LAM), fractures (FRA), bruising (BRU), scratches (SCR), dead on arrival (DOA), and diseases (DIS); b) house environmental measurements: relative humidity (RHU), temperature (TEM), air velocity (AVE), illuminance (ILL), ammonia concentration (NH₃), and carbon dioxide concentration (CO₂), and c) bird behaviour and affective states: bird behaviour (BBE), touch test (TTE), and qualitative behaviour assessment (QBA).3. Statistical analyses were based on regression models for CDE, BSO, FPD, HBU, LAM and generalised linear models for DOA, FRA, BRU, SCR, and DIS. The Mann-Whitney test was used for RHU, TEM, AVE, ILL, NH₃, CO₂, and the t-test for TTE and LMO, with a specific regression model for BBE data and Principal Component Analysis for QBA.4. According to odds ratio for worse scores for CS relative to OS, birds were less likely to have severe scores for CDE (P = 0.040 and P = 0.007), BSO (P = 0.031, P = 0.016, and P = 0.038), and HBU (P = 0.017), and had higher median values for AVE (2.3, 0.0-7.8 m s^-1 vs. 0.0, 0.0-4.3 m s^-1), lower NH₃ concentration (9.0, 0.0-64.0 ppm vs. 12.0, 0.0-60.0 ppm) and TTE scores (98, 96-100 vs. 67, 25-100). Worse results were observed in CS houses for higher stocking density (13.8 ± 0.2 birds/m² vs. 12.0 ± 0.2 birds/m²), RHU (74.5, 50.7-99.9% vs 72.3, 47.4-99.9%), and TEM (23.9, 14.6-29.2°C vs. 21.7, 12.9-30.1°C), lower ILL (16.0, 1.0-60.0 lx vs. 161.0, 8.0-2380.0 lx), less drinking (P = 0.007), more inactive behaviour (P < 0.001) and lower positive emotions, according to QBA (P = 0.028).5. In the studied region and season, CS houses seemed to offer fewer welfare problems in terms of the health indicators; however, OS houses showed fewer behavioural restrictions and higher positive emotional states.

Bacillus amyloliquefaciens CECT 5940 improves performance and gut function in broilers fed different levels of protein and/or under necrotic enteritis challenge

Two studies were conducted to investigate the effect of Bacillus amyloliquefaciens CECT 5940 (BA) as a probiotic on growth performance, amino acid digestibility and bacteria population in broiler chickens under a subclinical necrotic enteritis (NE) challenge and/or fed diets with different levels of crude protein (CP). Both studies consisted of a 2 × 2 factorial arrangement of treatments with 480 Ross 308 mix-sexed broiler chickens. In study 1, treatments included 1) NE challenge (+/-), and 2) BA (1.0 × 10⁶ CFU/g of feed) supplementation (+/-). In study 2, all birds were under NE challenge, and treatments were 1) CP level (Standard/Reduced [2% less than standard]) and 2) BA (1.0 × 10⁶ CFU/g of feed) supplementation (+/-). After inducing NE infection, blood samples were taken on d 16 for uric acid evaluation, and cecal samples were collected for bacterial enumeration. In both studies, ileal digesta was collected on d 35 for nutrient digestibility evaluation. In study 1, the NE challenge reduced body weight gain (BWG), supressed feed conversion ratio (FCR) and serum uric acid levels (P < 0.001). Supplementation of BA increased BWG (P < 0.001) and reduced FCR (P = 0.043) across dietary treatments, regardless of challenge. Bacillus (P = 0.030) and Ruminococcus (P = 0.029) genomic DNA copy numbers and concentration of butyrate (P = 0.017) were higher in birds fed the diets supplemented with BA. In study 2, reduced protein (RCP) diets decreased BWG (P = 0.010) and uric acid levels in serum (P < 0.001). Supplementation of BA improved BWG (P = 0.001) and FCR (P = 0.005) and increased Ruminococcus numbers (P = 0.018) and butyrate concentration (P = 0.033) in the ceca, regardless of dietary CP level. Further, addition of BA reduced Clostridium perfringens numbers only in birds fed with RCP diets (P = 0.039). At d 35, BA supplemented diets showed higher apparent ileal digestibility of cystine (P = 0.013), valine (P = 0.020), and lysine (P = 0.014). In conclusion, this study suggests positive effects of BA supplementation in broiler diets via modulating gut microflora and improving nutrient uptake.

Potential of blended organic acids to improve performance and health of broilers infected with necrotic enteritis

Organic acids (OA) and their blends have been shown to positively affect performance and health of broilers. However, the data in the literature are not consistent. This study examined the potential of blended short-chain fatty acids (SCFA) with medium-chain fatty acids (MCFA) as alternatives to antibiotic growth promoters (AGP) on performance, health and welfare of broilers infected with necrotic enteritis (NE). The additives used were: A) a blend of SCFA, MCFA, and a phenolic compound (SMP); B) a blend of free and buffered SCFA with MCFA (SMF); C) a blend of free and buffered SCFA with a high concentration of MCFA (SHM). A total of 1,404 Ross 308 one-day-old male parental chicks were randomly distributed into 78-floor pens with 13 replicates of 18 birds each. Six treatments were the following: T1, unchallenged control (UCC); T2, challenged control (CHC); T3, challenged group plus zinc bacitracin (BAC); T4, challenged group plus additive SMP; T5, challenged group plus additive SMF; T6, challenged group plus additive SHM. Challenged birds were gavaged with Eimeria spp. on d 9 and Clostridium perfringens EHE-NE18 on d 14. Post NE challenge and cumulatively, BWG, FCR, and nutrient digestibility of birds were compromised (P < 0.05) by NE challenge indicating a successful induction of sub-clinical NE. Additive SHM had higher BWG compared to CHC and BAC groups (P = 0.001; d 10 to 24) but not different from SMP and SMF groups (P > 0.05). All the 3 additive groups had lower FCR compared to CHC (P = 0.001; d 0 to 35), and exhibited similar jejunal lesions (d 16) compared to BAC and apparent ileal protein digestibility (d 21) compared to UCC and BAC groups (P > 0.05). Birds in additive SHM group had a higher concentration of serum IgA compared to all groups (P = 0.001) except additive SMF (P > 0.05; d 21). All the additive groups had lower footpad dermatitis and hock burns compared to CHC (P < 0.05). The findings suggest the potential of blended OA as alternatives to BAC to protect broilers from NE indicated by improved FCR, immunity, digestibility, and bird welfare.

Leg health of meat chickens: impact on welfare, consumer behaviour, and the role of environmental enrichment

The Australian and global chicken meat industries have benefited from rapid improvements in the efficiency of chicken meat production that have been predominantly achieved through genetic selection, optimisation of bird nutrition and improved bird health. However, this has also resulted in morphological changes in the bird with an increase in the prevalence of leg health disorders. Compromised leg health can cause pain and lameness and bodes poorly for bird wellbeing, bird mortality, and economic returns. There are also implications for the consumer who is increasingly mindful of animal welfare and is demanding more welfare friendly products. Accurate on-farm assessment of bird leg health has challenges due to the diversity of leg disorders and the variety of techniques used to assess their severity and impact. Overall prevalence of leg disorders shows great variability between properties (farms) and flocks. Opportunities to improve bird leg health have been the focus of considerable research which has frequently included an evaluation of environmental enrichment as a means to reduce lameness and improve bird mobility. To this end, currently in Australia, 78% of chicken meat is produced under the conditions of the Australian RSPCA Approved Farming Scheme, which requires perches in the birds’ environment. However, the value of perches in providing enrichment and improving bird welfare is unclear. Therefore, this review explores animal welfare and consumer attitudes towards meat chicken welfare, describes leg disorders, outlines techniques for assessing leg health and discusses opportunities to enrich the birds’ environment to improve bird mobility and leg health.

Potential contaminants and hazards in alternative chicken bedding materials and proposed guidance levels: a review

Bedding material or litter is an important requirement of meat chicken production which can influence bird welfare, health, and food safety. A substantial increase in demand and cost of chicken bedding has stimulated interest in alternative bedding sources worldwide. However, risks arising from the use of alternative bedding materials for raising meat chickens are currently unknown. Organic chemicals, elemental, and biological contaminants, as well as physical and management hazards need to be managed in litter to protect the health of chickens and consequently that of human consumers. This requires access to information on the transfer of contaminants from litter to food to inform risk profiles and assessments to guide litter risk management. In this review, contaminants and hazards of known and potential concern in alternative bedding are described and compared with existing standards for feed. The contaminants considered in this review include organic chemical contaminants (e.g., pesticides), elemental contaminants (e.g., arsenic, cadmium, and lead), biological contaminants (phytotoxins, mycotoxins, and microorganisms), physical hazards, and management hazards. Reference is made to scientific literature for acceptable levels of the above contaminants in chicken feed that can be used for guidance by those involved in selecting and using bedding materials.

The association between meat inspection codes, footpad lesions and thinning of broiler flocks in the Danish broiler production

The foundation of the condemnation practices in Post-Mortem Inspection (PMI) of poultry should be based on up-to-date scientific evidence about the cause of infection and hence whether the lesions observed are of food safety, animal health or welfare concerns. This study aimed to investigate the association between meat inspection codes, footpad lesions, and thinning of flocks in Danish broiler production. The data set was based on the delivery of chicken flocks to one of the two larger chicken slaughterhouses in Denmark, representing 71 farms, 174 houses, and 4,068 flocks over three years from January 2016 to December 2018. Post-mortem condemnation data of slaughtered chickens recorded and stored in the Danish Quality Assurance System (KIK) database was used in the study. Five potentially causal models were developed to investigate whether there was an association between dermatitis, arthritis, systemic infection, emaciation, mortality and possible explaining factors` (footpad lesion, age at slaughter, scratches, ascites, systemic infection and thinning of the flock). These five ecological logistic regression models were analyzed with the three levels: farm, house, and flock. Data from a total number of 126,137,002 (N) slaughtered chickens recorded in KIK databases were used for modeling and analyses. The prevalence of condemned carcasses was 1.1 % (n = 1,420,812). Overall, 12 individual reasons for condemnation of carcasses were recorded. The most frequently observed reason for condemnation was skin disease (scratches and dermatitis) with a prevalence of 0.5 %. Prevalence of ascites was 0.2 %, discoloration 0.09 %, emaciation 0.09 %, hepatitis 0.09 % and arthritis 0.07 %. In the first model, dermatitis was shown to be positively associated with age at slaughter with an OR = 1.04 (CI95 %: 1.02-1.05), while arthritis was considered an intervening variable. Moreover, there was a small protective effect of thinning of the flock for first and second delivery. There was a positive association between arthritis and age at the time of slaughter with an OR = 1.13 (CI95 %: 1.12-1.15). Systemic infections were associated with scratches with an OR = 24.5 (CI95 %: 16.6-36.3) and footpad lesions with an OR = 1.007 (CI95 %: 1.006-1.008). Further modelling of emaciation and mortality was not considered because of unbalanced groups in the data probably caused by the fact that some condemnation codes were rare. We observed that the most common causal factors of condemnation in the systemic infection models were scratches and footpad lesion, therefore preventing and controlling such lesions could reduce losses. Specific management and environmental etiological factors of the main infections causing condemnation in Danish broilers should be determined.

Copper hydroxychloride is more efficacious than copper sulfate in improving broiler chicken's growth performance, both at nutritional and growth-promoting levels

This study was designed to compare the effects of nutritional and growth-promoting levels of copper hydroxychloride (CH) with copper sulfate (CuSO₄) on growth, carcass characteristics, tibia traits and mineral concentration in broilers fed a conventional wheat-soybean meal-based diet. Day-old Ross 308 male chicks (n = 864) were randomly assigned into 8 dietary treatments with 6 replicates of 18 chicks per treatment. The dietary treatments included a basal diet containing no supplemental copper (Cu) serving as the negative control (NC); basal diet supplemented with 15 or 200 mg/kg Cu as CuSO₄; basal diet supplemented with either 15, 50, 100, 150, or 200 mg/kg Cu from CH. Diets were fed over the starter (day 1-14) and grower (day 14-35) phases. Birds in the NC group gained the same body weight and had similar feed conversion ratio (FCR) to birds receiving 15 mg/kg Cu as CuSO₄, but birds receiving 15 mg/kg Cu as CH had a lower FCR than the NC birds (day 0-35; P < 0.05). Birds fed 200 mg/kg Cu as CH gained more weight (77 g/bird) and had a lower FCR (3.2 point) compared with those fed 200 mg/kg Cu as CuSO₄ (P < 0.01). Based on broken-line regression models, the optimum inclusion level of Cu as CH in the diet for optimal body weight gain and FCR were estimated to be 109.5 and 72.3 mg/kg, respectively (P < 0.001). Carcass characteristics were not affected by dietary Cu sources or levels (P > 0.05). The highest and lowest tibia ash content were observed in birds fed diet with 150 mg/kg Cu as CH and 200 mg/kg Cu as CuSO₄, respectively (P < 0.05). Supplementation with 200 mg/kg Cu as CH resulted in higher duodenal mucosa Cu content compared with the diet containing 200 mg/kg Cu as CuSO₄ (P < 0.001). In conclusion, supplementation of Cu from CH was more efficacious than CuSO₄ in promoting growth performance, both at nutritional and pharmacological levels.

Management factors influencing the occurrence of cellulitis in broiler chickens

One of the main reasons for condemning fattening broiler chickens during meat inspection is cellulitis, which demonstrates the great economic issue concerning this topic. The aim of this epidemiological study was therefore to identify risk factors in order to draw conclusions on how to prevent the occurrence of cellulitis in broilers by implementing management changes. The data were collected between April and November 2018 on conventional broiler farms (n = 100) in the north of Germany with one to fourteen poultry houses per farm. In total, data were collected from 199 broiler flocks with a total of 5,332,767 broilers. Data on the type of management (feeding- and drinking management, housing, lighting management, litter type and animal health) were collected via a questionnaire, with additional data on condemnation rates being provided by the abattoirs. It was found that litter additives like fennel, eucalyptus and probiotics as well as a moist litter quality were associated with lower cellulitis condemnation rates. Flocks fattened in windowless barns, but with relatively higher lux-values as well as those broilers examined in a lower number of housing inspections had significantly lower cellulitis condemnation rates compared to other husbandry systems. In addition, lower cellulitis rates were seen when housing capacities were smaller, regardless of stocking density. The source of the breeders and hatchery also had a significant influence on the occurrence of cellulitis. No correlation was found between the condemnation rates due to cellulitis and the performance of thinning, the water source used, the use of drinking additives, observational skills and number of herd managers monitoring the broilers, participation in an animal welfare programme, the technique of heating and ventilation systems used, the feed supplier, litter material, the broiler breed, the length of darkness periods and chick losses during the first seven days. We concluded that management decisions that lead to stress reduction in the broiler flocks are beneficial in terms of chicken welfare and occurrence of cellulitis.

Differences in performance, body conformation, and welfare of conventional and slow-growing broiler chickens raised at 2 stocking densities

Consumer concern for broiler welfare has increased interest in chicken from slower growing (SG) broiler strains. Broilers from SG strains take longer to reach market weight, which may necessitate differences in management practices, such as stocking density. This study evaluated the effects of 2 stocking densities on production performance, body conformation, and welfare of broilers from 2 strains. Broilers from strains that reach market weight at age 42 D (CONV; N = 284) and at 63 D (SG; N = 284) were exclusively stocked into pens at a density of either 29 kg/m² or 37 kg/m². Birds were provided the same starter, grower, and finisher diets with diet phase changes occurring when SG bird body weight (BW) matched CONV. Live BW, body length, pelvic width, shank length, shank width, keel length, breast width, and breast depth were collected at 4 phases: Phase 1—chick placement, Phase 2—starter, Phase 3—grower, and Phase 4—finisher. At Phase 4, footpad dermatitis (FPD), hock burn (HB), and toe damage (TD) were scored. Feed conversion ratio (FCR) and mortality for each pen were recorded throughout the study. Final BW was similar (2.68 kg) for both strains and stocking densities of birds (P > 0.05). CONV bird FCR was 35% more efficient than SG (P < 0.0001). CONV birds had shorter bodies and shanks compared with SG birds at Phases 3 and 4 (P < 0.05). Slower growing birds stocked at 37 kg/m² had the longest bodies and keel bones at Phase 4 (P < 0.01). Also at Phase 4, SG birds stocked at 29 kg/m² had the lowest prevalence of HB (4%), yet the highest prevalence of TD (28%; P < 0.01). These results indicate differences in the effects of strain and stocking density on male broiler conformation, performance, and welfare and highlight the importance of tailoring management practices to the strain of broiler raised.

Histologically validated scoring system for the assessment of hock burn in broilers

The assessment of bird-based welfare indicators plays an important role in the evaluation of bird welfare. The aim of the study was to histologically validate a visual scoring system for hock burn in broilers and to detect threshold values of a visual score to define welfare-relevant alterations in terms of mild lesions or ulcers of the hock. We collected 200 hocks of 39- to 42-day-old Ross 308 broilers after the slaughter process. Each hock was scored visually ("macro scores" 0-4) and evaluated histologically ("micro scores" 0-3), with high scores representing more severe lesions. Although we found a tendency for higher micro scores with increasing macro scores, an exact allocation of macro to micro scores was not possible. For example, macro score 1 could represent micro scores 1, 2 and 3, whereas macro scores 3 and 4 always represented micro score 3 (ulcer). The conditional probability of certain micro scores for given macro scores was estimated using a multinomial logistic regression model. Ulcer showed the highest probability at macro score 1, whereas mild lesions were not found to have an estimated highest probability at any macro score. The depth of inflammation of hock burn lesions increased with increasing macro scores up to macro score 3 with an average depth of 1019 µm. Visually more severe and deeper lesions were also histologically rated with higher scores. Thus, considering limitations, the herein validated macroscopic assessment scheme for hock burn allows an estimation of histological alterations in hocks of broilers.RESEARCH HIGHLIGHTS Histological validation of a visual assessment scheme for hock burn in broilers.Tendency for higher micro scores with increasing macro scores.Estimation of histological score via macro score possible with limitations.Histological depth of inflammation increased with an increasing macro score.

A novel environmental enrichment device improved broiler performance without sacrificing bird physiological or environmental quality measures

Modern commercial broilers have been genetically selected for fast growth and heavy breast muscling, contributing to a top-heavy phenotype and increased leg lameness. A quick-growing phenotype coupled with poor leg health fosters inactivity. The objective of this study was to stimulate broiler movement using novel environmental enrichment and determine the impact of movement on production, leg health, and environmental parameters. A total of 1,200 Ross 308 broilers were housed in 40 pens with 30 birds/pen for 6 wk in 2 separate rooms (laser enrichment or control). Each enrichment device was mounted above 2 adjoining pens, projected 2 independent, randomly moving laser beams at the floor to stimulate innate predatory behavior, and was active 4 times daily in 4-min periods. Performance outcomes were calculated by pen and averaged per bird for each performance period and overall days 0 to 42. A total of 70 randomly selected focal birds were examined for breast blisters and footpad dermatitis each week and euthanized on day 42 for tibia quality measures. Air quality and litter moisture were sampled by week. Laser-enriched pens had greater average bird feed intake in starter (P < 0.001), grower (P = 0.004), finisher periods (P = 0.004), and overall days 0 to 42 (0.19 kg/bird; P = 0.0003). Average bird weight gain was also increased in enriched pens in each performance period: starter (P = 0.043), grower (P = 0.001), finisher (P < 0.001), and overall days 0 to 42 (0.24 kg/bird; P < 0.001). Enriched pens had improved feed conversion ratio (FCR) vs. control with a decrease of 3 FCR points in the grower (P = 0.031), 18 points in the finisher (P < 0.001), and 7 points overall (P < 0.001). Enriched pens had higher ADG during starter (P = 0.048), finisher (P < 0.001), and overall (5.7 g/bird/d; P < 0.001). No differences were found in breast blister, footpad dermatitis, tibia, air, or litter quality measures (P > 0.05). In summary, a novel enrichment device based on bird visual feeding and predatory instincts positively affected performance through decreased FCR and increased ADG without sacrificing external animal-based measures, tibia quality, or air or litter quality.

Effect of low protein diets supplemented with free amino acids on growth performance, slaughter yield, litter quality, and footpad lesions of male broilers

A study with 884 Ross 308 male broilers, housed in 68 floor pens (0.75 m²) from 0 to 35 days of age was conducted to evaluate the effects of low crude protein (CP) diets, with partial replacement of soybean meal by free amino acids (AA), on performance, slaughter yields, litter quality and footpad lesions. During the first 11 d, all broilers received the same control starter diet (216 g/kg CP, 11.5 g/kg apparent fecal digestible (AFD) lysine, and 2900 kcal/kg AMEn). Thereafter, four experimental feeding programs with different levels of dietary CP (control and control with 1% (CP-1%), 2% (CP-2%) and 3% (CP-3%) less CP units) were provided in both the grower and finisher phase. In the control grower and finisher diet, the CP content was 208 and 198 g/kg, respectively. All diets were formulated to meet or exceed the recommendations concerning AFD AA, and to be iso-caloric within each feeding phase. Feed and water were provided for ad libitum intake during the entire experimental period.

None of the low CP feeding programs affected body weight gain, feed intake or mortality from 0 to 35 d. However, CP conversion was improved with the reduction of CP content of the diet. Broilers fed the CP-2% or CP-3% feeding program had an improved feed conversion ratio. Broilers fed the low CP protein feeding programs had a better litter quality and less footpad lesions, compared to broilers fed the control feeding program. Broilers fed the CP-3% feeding program had a lower breast meat yield than broilers fed the control feeding program. Slaughter yields of broilers fed CP-1% or CP-2% feeding program did not differ from the control feeding program. This study demonstrated that the CP content of grower and finisher diets can be reduced by 2.2–2.3% units without adverse effects on growth performance of broilers, while CP reduction seems promising to reduce nitrogen excretion from broiler houses, improve bird welfare, and reduces dependence on vegetable protein sources.

Associations between carcass weight uniformity and production measures on farm and at slaughter in commercial broiler flocks

In poultry flocks, flock weight uniformity is often defined as the percent individuals within 10% of the mean body weight (BW) and the variability of this uniformity can be expressed as the CV of BW. Flock weight uniformity is a standardized and objective measured, and could potentially be used as a welfare indicator; however, little is known about the relationship between flock uniformity and other production measures on-farm or at slaughter. The aim of this study was to investigate the associations between carcass weight uniformity (CV of BW) and production measures on-farm and at slaughter in Norwegian commercial broiler flocks. A total of 45 randomly selected mixed-sex Ross 308 broiler flocks were visited prior to slaughter at 28 to 30 D of age (average slaughter age 30.6 D). All flocks were raised under similar farm management systems. The Welfare Quality protocol for broilers was used to assess different animal welfare indicators in each flock. All production data from the slaughterhouse were collected for each flock, including carcass weight uniformity (%), mortality (%), growth rate (g), feed conversion ratio (FCR), and rejected birds (%) in different rejection categories. Univariable and multivariable linear regression models were used to investigate the associations between flock weight uniformity and production and welfare measures. The results showed that flock uniformity varied from 11% to 18% between flocks within the same hybrid, similar management standards, and similar slaughter age (day 29 to 32). Poorer uniformity (i.e., high CV) was associated with increased first week mortality (P < 0.004, r = 1.48, increased total mortality (P < 0.013, r = 0.01), increased FCR (i.e., less efficient growth) (P < 0.024, r = 0.06), reduced growth rate (P < 0.0012, r = −0.01), and a reduced rejection rate at slaughter (P < 0.006, r = −0.01). The results show that flock uniformity varies across broiler flocks, and is associated with several production measures.

Development and Validation of Broiler Welfare Assessment Methods for Research and On-farm Audits

Required auditing of on-farm broiler welfare in the United States has increased; however, a lack of validated tools exists for assessment of enrichment. National Chicken Council (NCC) guidelines were used on a subset of 300 Ross 308 broilers out of 1200 to validate and adapt welfare measures. Half of the broilers were exposed to environmental enrichment, hence these measures were used to evaluate the enrichment within the context of behavior and welfare, although the nature of the enrichment is not described in detail here as the aim is to serve solely as a description and validation of methods using a subset of example data. Birds were recorded in repeated 4-min periods to quantify behavior and walking distance. Outcomes were categorized to improve auditing and make recommendations to producers and researchers. Bone mineral density, content, and breaking strength were successful in determining numerical differences. Quantifying lameness using an enclosed walkway and measuring footpad dermatitis weekly are recommended on-farm. We recommend including additional measures not required by the NCC: monitoring breast condition in the flock and including a behavior component with a scoring ethogram.

Characterisation of footpad lesions in organic and conventional broilers

Recent data suggest that organic broilers often score worse on footpad lesions than conventional broilers but also that the current scoring of organic broiler feet may be misleading. In order to characterise footpad lesions in organic broilers, this study assessed and compared footpad lesions in a sample of 2987 conventional and 3578 organic broiler feet obtained from a large Danish abattoir during summer and winter. The feet were scored according to two scoring systems: the modified Danish surveillance scoring system and a histopathology-based new scoring system specifically developed to target the ability to differentiate between broiler feet with hyperkeratosis and ulcers. For both systems, all broiler feet with visible lesions were cross-sectionally incised. Significant differences between the two production systems were found for both scoring systems (χ2 = 710; P < 0.001 and χ2 = 247; P < 0.001 for the new and the surveillance systems, respectively), showing that a larger proportion of the organic feet compared to conventional feet - summer and winter - exhibited signs of hyperkeratosis. In addition, a smaller fraction of the organic feet than of the conventional feet were given the outermost scores, that is, normal or ulcerated; 13.4% v. 25.3% broiler feet were given score 0 for organic v. conventional production systems, respectively (χ2 = 152; P < 0.001), and 18.4% v. 23.8% feet were given score 4 for organic v. conventional production systems, respectively (χ2 = 308; P < 0.001). Thus, the results suggest that surveillance scoring systems such as the one used in Denmark are useful for the examination of footpad lesions in broilers from both types of production systems. However, the results have also raised attention to a typical characteristic of the feet of organic broilers, that is, profound hyperkeratosis, which may underlie potential misclassifications in surveillance scoring systems like the one used in Denmark. Among the possible solutions to this challenge to the correctness and fairness of the scoring system are improved procedures (such as mandatory incision), training of technicians and calibration of results (especially for the organic footpads).

Animal-based welfare indicators of 4 slow-growing broiler genotypes for the approval in an animal welfare label program

For broiler genotypes to be merchandized under the animal welfare label of the German Animal Welfare Federation, several animal-based welfare indicators with upper limits are listed in a criteria catalog. We compared the prevalence of animal-based welfare indicators in 4 slow-growing broiler genotypes [Ranger Classic (RC), Ranger Gold (RG), Rowan Ranger (RoR), and Rambler Ranger (RaR)] in terms of potential approval of these genotypes for a German animal welfare label program. Chicks were housed in 16 floor pens, of which 8 had access to a winter garden. With 4 replications of each genotype, animal-based welfare indicators were assessed in 160 broilers (10 broilers per pen) on fattening days (FD) 36 and 44. The body weight of the 4 broiler genotypes differed on both examination days in decreasing order for RC, RG, RoR, and RaR (P < 0.001). The walking ability was within the scope of the animal welfare label in all genotypes; it was better in genotypes with a lower mean body weight and correlated positively with the body weight in RG, RoR, RaR, and in the pooled data of the 4 genotypes. Hock burns were only observed at a low severity score, with male broilers being affected more often than female broilers. A positive correlation of the development of hock burn with the weight of the broilers was observed on FD 44 when data of all genotypes were pooled. The footpads of all examined broilers were without lesions at both examinations. Skin scratches were observed in all genotypes at both examinations, and RC broilers differed on FD 36 from the other 3 genotypes by showing a higher prevalence of more severe scratches. Broilers of pens with access to a winter garden were affected by skin scratches more often than broilers without. With the exception of weight gain in 2 genotypes, the investigated indicators showed that all genotypes met the requirements of the animal welfare label.

Husbandry Practices, Health, and Welfare Status of Organic Broilers in France

Simple Summary

Organic poultry production has grown rapidly in Europe for the past several years in the context of sustainable development within farming. The authors carried out a field study in France between 2014 and 2015 concerning 85 organic broiler flocks that showed a wide diversity of farming management systems from independent farmers set up for direct sales of poultry to farmers under contract with a company for product sales. Health and welfare characteristics did not significantly differ between these two farming systems, except slightly dirtier feathers and more footpad dermatitis on the independent farms, related to the poultry housing conditions in mobile houses. A mortality rate of 2.8% was found, with digestive problems mainly being observed. Better knowledge of husbandry practices, health, and the welfare status of organic poultry is of primary importance to improve the management of organic production and to help in characterizing farming sustainability.

Abstract

Organic poultry production has increased sharply with growing consumer demand in the context of sustainable development. A study was conducted in 85 organic broiler flocks between 2014 and 2015 to describe the husbandry practices and the health and welfare status of organic broilers in France, and to study farming diversity by comparing independent farms (Ind farms, n = 15) with direct sales to farms working with companies (Comp farms, n = 70). Each flock was visited at 3 and 11 weeks of age to collect data on farming conditions, health disorders, and mortality. Welfare notation of 30 broilers per flock and parasitic examination of 5 broilers per flock was also performed. Findings showed significantly different farming management between Ind farms and Comp farms, with smaller flocks on the Ind farms (476 broilers/house vs. 3062 broilers/house, p < 0.01) more frequently in mobile houses. The mean mortality rate was 2.8%, mainly involving digestive disorders. Helminths were detected in 58.8% of the flocks. On average, 21.9% and 5.8% of broilers in a flock had footpad dermatitis and dirty feathers, respectively. The health and welfare characteristics of organic broilers on Ind farms vs. Comp farms were not significantly different, except dirtier feathers and more footpad dermatitis on Ind farms (19.1% vs. 2.9%, p = 0.03 and 39.6% vs. 18.1%, p = 0.02, respectively), associated with poultry housing conditions in mobile houses (p < 0.01). This study provides greater insight into farming sustainability aspects related to the husbandry practices, and the health and welfare of organic broilers in France.

Effect of pH-lowering litter amendment on animal-based welfare indicators and litter quality in a European commercial broiler husbandry

Several studies have shown that litter moisture is a major reason for foot pad lesions (FPD) and promotes microbial growth of nitrifying bacteria. The aim of the current study was to determine the possible effects of a sodium bisulfate complex (SBS) as a litter additive on FPD, hock burn (HB), and litter parameters. Two application rates of SBS were examined in 2 experiments on a commercial farm. Two groups of about 30,000 broiler chicks each were introduced on spelt granulate spread at 700 g/m² and kept for 36 d. In the first experiment (TRT1), 250 g/m² SBS was spread on top of litter 20 h before chick placement; in the second experiment (TRT2), SBS was reduced to 150 g/m². Each experiment consisted of 1 treatment group (SBS) and a control group without treatment (CON). Both experiments were repeated once. Litter parameters (pH, percentage of dry matter), foot pad, hock condition and body weight of randomly sampled birds (n = 60 per group) were recorded weekly. Mortality rate was higher in SBS groups compared to CON groups (TRT1 2.79 vs. CON 2.03%, TRT2 2.88 vs. CON 2.27%). SBS had no effect on body weight averaged over the whole production period (P > 0.05). Incidence of FPD was significantly reduced in both groups treated with SBS compared to CON (P < 0.05), with group TRT1 showing the best results. Incidence of HB was not affected by SBS (P > 0.05) but by dry matter content (P < 0.05). At the beginning, SBS reduced litter pH to 1.7 and 2.0 in TRT1 and TRT2, respectively, compared to 6.5 and 6.7 in CON. Litter pH in TRT groups increased over time and approached pH of control groups by day 15. Results of the current study indicate that SBS treatment may be beneficial regarding foot pad health in broilers. However, further studies are needed to investigate alternative SBS application rates, and to verify the results.

A review of the financial impact of production diseases in poultry production systems

While the academic literature widely asserts that production diseases have a significant financial impact on poultry production, these claims are rarely supported by empirical evidence. There is a risk, therefore, that the information needs of poultry producers regarding the costs associated with particular diseases are not being adequately met. A systematic literature review of poultry production diseases was undertaken, first, to scope the availability of studies that estimate the financial impacts of production diseases on poultry systems and, second, on the basis of these studies, estimates were generated of the magnitude of these impacts. Nine production diseases, selected by a panel of stakeholders as being economically important in the EU, were examined. The review found that the poultry disease literature has primarily an epidemiological focus, with very few publications providing estimates of the financial impacts of diseases. However, some publications have quantified the physical impacts of production diseases and control interventions, for example, using measures such as output volumes, mortality rates and bacterial counts. Using these data in standard financial models, partial financial analyses were possible for some poultry production diseases. Coccidiosis and clostridiosis were found to be the most common production diseases in broiler flocks, with salpingoperitonitis being the most common in layers. While the financial impact of untreated diseases varied, most uncontrolled diseases were estimated to make flocks loss-making. However, in all cases, interventions were available that signficantly reduced these losses. The review reinforces the concern that the available academic literature is not providing sufficient information for poultry producers to decide on financially optimal disease-prevention and treatment measures.

Influence of sepiolite additions to different litter materials on performance and some welfare parameters of broilers and litter characteristics

The litter quality is an important factor affecting the performance, welfare and carcass quality of the broilers. Depending on the progress of the fattening duration, some materials may be added to the litter in order to keep the pH, moisture and ammonia levels in the litter under control. Sepiolite is a natural material and it has strong absorbing ability to the water. Therefore, the aim of this study was to determine the effects of sepiolite additions to different litter materials on performance and some welfare parameters of broilers and litter characteristics. A total of 288 1-d-old male broiler chicks (ROSS-308) were used. Birds were randomly allocated to 2 litters (wood shavings and rice hull) and 3 sepiolite groups (0, 25, 50%) with 6 replication, and each pen contains 8 chicks. Fattening performance, IgG, tonic immobility period, feather score, skin injures, breast burns, and footpad burns of broilers were not affected significantly by sepiolite additions to the litter. However, sepiolite addition to the litter can improve litter quality. There was no significant difference between 2 litter materials because both have same color. There were no significant interactions in examined parameters. In conclusion, addition of sepiolite at 25 and 50% levels to litter materials may be used as a litter material in the broiler production without adverse welfare and performance problem.

Animal- and management-based welfare indicators for a conventional broiler strain in 2 barn types (Louisiana barn and closed barn)

The aim of this observational study was to describe health- and management-related welfare indicators for a conventional broiler strain housed in 2 barn types (Louisiana barn and closed barn) on the same farm and to assess the impact of age and housing conditions on these indicators. Broilers were examined 4 times in each of 7 fattening periods. Their weight gain, gait score, and further animal-based indicators did not differ between the barn types. On average 46% showed no sign, 51% a minor but visible, and 3% a profound lameness at the end of the fattening period (fattening day 39). Soiling of the plumage, skin scratches, foot pad dermatitis, and hock burns worsened with increasing age. Soiling of the plumage was correlated negatively with litter depth (Pearson, r = -0.549, P = 0.042) and positively with litter quality (Pearson, r = 0.641, P = 0.013). Skin scratches occurred in 89% of the broilers (32% deep with penetration of dermis) on fattening day 39 and were correlated positively with cumulative mortality (Pearson, r = 0.615, P = 0.019), indicating a severe animal welfare impact. Foot pad dermatitis did not correlate with health- or management-related indicators, whereas hock burn correlated positively with the broilers' weight (Pearson, r = 0.853, P < 0.001) and with ammonia concentrations (Pearson, r = 0.577, P = 0.031). Management-related indicators (antibiotic treatments, dead on arrival) and cumulative mortality did not differ between the barn types. At the end of the fattening period, the litter quality was worse and concentrations of ammonia and peaks of high carbon dioxide concentrations were higher in the Louisiana than in the closed barn. The light intensity was on average 20 times higher in the Louisiana than in the closed barn without any negative impact. Summarizing, the barn type did not seem to influence the investigated welfare indicators, but Louisiana barns might need a more precise management to maintain the required ranges of noxious gases and litter quality.