Hock Burn Research Articles

Modern aspects of contact dermatitis in industrial poultry farming

Contact dermatitis is a lesion of the skin of broilers, which leads to a decrease in the quality of the carcass by 15-30 %. It is described as brown-black erosions and ulcers that occur on the breast (breast blisters, BB), hock burns (HB) and on the skin of the central pulp of the foot (food pad dermatitis, FPD). The most commonly affected is the pulp of the foot, followed by the hocks and chest. There are a number of factors that lead to crumb dermatitis. These include: the density of planting birds; type of troughs and the order of their use; feeding; the level of temperature and humidity in the room; type of litter, its quality and quantity; intestinal health. Birds are kept at a density of 8 individuals/m2 suffered less from dermatitis than those kept at a density of 13 individuals/m2 . Moreover, the harmful effects of high density were particularly pronounced at 18 individuals/m2 . The prevalence and severity of this pathology in broilers increases at later stages of fattening. Pododermatitis spread to several layers of skin. The condition of the crumbs worsened when the bird reached slaughter age with up to 64 % of the carcasses affected. In this case, lesions of the hocks and chest were rare. Wet litter (> 30 % moisture) is associated with an increase in the incidence and severity of contact dermatitis in broiler and turkey housing systems. This state of litter is most often registered in the winter-spring and autumn seasons. The quality of the litter, especially taking into account its humidity, has been identified as an important issue of well-being, which has a great negative impact on the condition of feathers, limb health and the frequency of contact dermatitis. Litter temperature is also important. With its growth, the degree of contact dermatitis increases. The reason for the increase in litter temperature is the increase in planting density and the accumulation of more manure, which enhances bacterial fermentation. With wet litter, bird feathers become wet or contaminated with litter, feces and dirt. It loses its protective properties. The level of bird welfare is declining sharply. Diagnosis of contact dermatitis in poultry is based on characteristic clinical signs. These are lameness, impaired mobility and discoloration of the skin, which often develops into an ulcer. The lesions are clearly separated from the intact tissue and often appear as ulcers surrounded by a deep hemorrhagic shaft. Contact dermatitis can develop in less than a week. Characteristic signs at the beginning of the disease are swelling, redness and increase in local temperature, thickening of the skin. Deep ulcers usually lead to abscesses in the underlying tissues and structures. Often the affected area is covered with crusts. If large ulcers develop, they can cause pain, slow growth, obstruct gait, and open bacteria to underlying tissues. Key words: broilers, contact dermatitis, dermatitis of the central pulp of the finger, dermatitis in the area of the hocks, dermatitis in the chest.

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 of broiler chickens in Brazilian free-range versus intensive indoor production systems

ABSTRACT We compared broiler chicken welfare in free-range (FR) and intensive indoor (IN) systems using the Welfare Quality® Protocol. Ten FR and 11 IN farms in Brazil were assessed. Results are shown as either scores ranging from 0 to 100, where higher scores indicate better welfare, or prevalence, where lower prevalence indicates better welfare. In FR, the median prevalence was lower than in IN for mortality (2.0% vs. 4.7%, p = 0.0262), culling (0.0% vs. 0.6%, p = 0.0168), ascites (0.0% vs. 0.17%, p = 0.0431). Median welfare scores on FR farms were better for plumage cleanliness (100 vs. 59, p = 0.0001), panting or huddling (100 vs. 29, p = 0.0001), lameness (81 vs. 19, p = 0.0001), hock burn (93 vs. 37, p = 0.0001), footpad dermatitis (35 vs. 26, p = 0.0018). However, FR scores were worse for litter quality (34 vs. 100, p = 0.0003), dust (53 vs. 78, p = 0.0002), breast blisters (90 vs. 100, p = 0.0077), touch test (70 vs. 99, p = 0.0082). Better emotional states were observed in FR (p < 0.001). Even though there is room for welfare improvement in both systems, the number of welfare indicators with better results was superior in FR than in IN farms.

Evaluation of Light Color Manipulation on Behavior and Welfare of Broiler Chickens

ABSTRACT This experiment evaluated the effect of light manipulation on the behavior and welfare of broilers using 280-day-old Arbor-Acre chicks, which were weighed and assigned to 7 treatments having 4 replicates and 10 birds per replicate. The light treatments were as follows: white light (WH), blue light (BL), green (GR), blue light switched to green light at 14 days (2BG), green light switched to blue at 14 days (2GB), blue light switched to green light at 28 days (4BG), and green light switched to blue light at 28 days (4GB). Feeding, drinking, resting, standing, walking, foraging and preening behaviors were observed using the scan sampling method. Behavior and welfare parameters such as footpad dermatitis and hock burn were evaluated and analyzed in a Completely Randomized Design. The results showed that feeding behavior of birds of BL, 2BG, and 2GB treatment groups was significantly higher (P < 0.05) than those of WH and GR at the starter phase. At the finisher phase, resting behavior of birds of 4GB was similar to those of 2GB but higher than those of the other treatments. It was concluded that switching of light from green to blue (4GB) at four weeks of age fostered ideal behavior and stimulated growth in broilers but had no effect on welfare parameters.

Animal Welfare Assessment in Antibiotic-Free and Conventional Broiler Chicken.

Simple SummaryAntibiotic resistance in the veterinary field, other than making the control of infectious diseases in farm animals progressively more difficult, can increase the risk that resistant microorganisms are transferred from animals to humans either directly—by contact or from food of animal origin—or indirectly due to environmental contamination. The poultry sector is now moving towards antibiotic-free production in order to meet the rising market demand, but this could affect the health and welfare of chickens. In this study, we compared the welfare of broiler chickens raised with and without the use antibiotics on a commercial scale. We found no correlation between the absence of antibiotics and poor animal health. There is no necessary correlation between the absence of antibiotics at farms and poor health of the animals, given that adequate animal-welfare-friendly management tools and methodologies are in place. These should be, however, adequately standardised in specific guidelines. In this way, it will be possible to reduce the dependence of the livestock sector on antimicrobials with regard to animal welfare and human health.The poultry sector is moving towards antibiotic-free production, both to challenge the increasing spread of the antibiotic resistance phenomenon and to meet market demands. This could negatively impact the health and welfare of the animals. In this study, the welfare of 14 batches of 41–47-day-old broilers raised by the same integrated company with and without antibiotics was assessed using the Welfare Quality® protocol. The total welfare score did not significantly differ between the two systems: the good-feeding principle was, on average, higher in the conventional batches, with statistical significance (t = −2.45; p = 0.024), while the other welfare principles (good housing, good health and appropriate behaviour) were slightly better in the antibiotic-free batches. Despite stocking densities averagely higher in the antibiotic-free batches, the absence of antibiotics did not seem to impact the good-health principle; in particular, hock burns, foot pad dermatitis and lameness were significantly less severe in the antibiotic-free batches (p < 0.0001, p = 0.018, p < 0.0001, respectively), which showed also a lower death rate (2.34% vs. 2.50%). Better management of antibiotic-free batches was reported, particularly concerning litter conditions. Further studies would be required to identify and standardise a set of managerial methodologies in order to improve the health of broilers raised without antibiotics.

Effects of barrier perch access and early dietary protein and energy dilution on some welfare parameters, tibiotarsus measurements, fear and mobility level in broiler chickens

ABSTRACT 1. This experiment determined the effect of increasing mobility in broiler chickens by placing barrier perches between feeders and drinkers. In addition, the limitation of early weight gain by dietary energy and protein dilution on some welfare parameters, tibiotarsus measurements, fear and mobility level was examined. 2. A total of 504 male, one-day-old broiler chickens (Ross 308) were randomly allocated to four treatments with three replicate pens per treatment and 42 broiler chickens per pen as a 2 × 2 factorial arrangement. Treatments included feeding the basal control diet between 0–42 days or a diet diluted by 10% energy and 20% crude protein fed between 0–21 d, with the control diet fed between 22–42 d. The second factor was the presence or absence of barrier perches. All treatments were allocated as a completely randomised design. Welfare parameters (foot pad dermatitis, hock burn, gait score, feather score, breast blister), tibiotarsus measurements (bone mineral content, bone mineral density, fluctuating asymmetry and relative fluctuating asymmetry), tonic immobility and mobility level were recorded. 3. Results showed that access to a barrier perch and the diluted diet increased the mobility in broiler chickens. However, access to a barrier perch had no significant effect on tibiotarsus and welfare parameters. Broiler chickens had better gait scores (P < 0.05) and lower foot pad dermatitis incidence (P < 0.01) in groups fed the diluted diet. The diluted diet had no significant effect on bone mineral density but reduced the tibiotarsus bone mineral content (P < 0.05). 4. In conclusion, the diluted diet provided positive effects in terms of leg health due to weight gain limitations in the early period, thus improving broiler chicken welfare.

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.

Welfare of broiler chickens reared under two different types of housing

AbstractWe compared closed- and open-sided industrial houses with respect to the welfare of broiler chickens in southern Brazil. Ten flocks from each design were evaluated and measures divided into the following categories: i) bird health: contact dermatitis on the breast and abdominal areas, bird soiling, foot-pad dermatitis, hock burn, lameness, fractures, bruising, scratches, dead on arrival, diseases; ii) environmental measurements: relative humidity, temperature, air velocity, ammonia (NH3), carbon dioxide (CO2), light intensity, litter moisture; iii) behaviour: bird behaviour, touch test; and iv) affective states: qualitative behaviour assessment. Closed-sided houses showed worse contact dermatitis on the breast and abdominal areas, lower exploratory behaviour prevalence, higher NH3(11.2 [± 6.8] vs 7.5 [± 3.9] ppm) and CO2(1,124.9 [± 561.5] vs 841.0 [± 158.0] ppm), lower light intensity (6.9 [± 6.3] vs 274.2 [± 241.9] lux), while open-sided houses had a higher prevalence for scratches and panting behaviour, and lower air velocity (2.1 [± 0.7] vs 1.1 [± 1.0] m s−1). Stocking densities of 13.9 (± 0.4) and 12.0 (± 0.3) per m2for closed- and open-sided houses, respectively, likely influenced some results. All values shown are means (± SD). Even though open-sided houses presented fewer animal welfare restrictions (according to five indicators as opposed to three for closed-sided houses), both revealed important welfare problems, evidenced by poor environmental indicators, behavioural restrictions and injuries.

Providing environmental enrichments affects activity and performance, but not leg health in fast- and slower-growing broiler chickens

Effects of environmental enrichment on activity, behaviour, walking ability, contact dermatitis and performance were investigated in fast- and slower-growing broiler chickens. A total of 840 day-old male broilers, 420 of a fast-growing strain (Ross 308) and 420 of a slower-growing strain (Hubbard JA757), were housed in a 2 × 2 factorial arrangement, using a complete randomized design. Broilers were housed in 28 pens of 3 m2 in one climate-controlled room. Half of the pens per strain were enriched (EE) with barrier perches, ramps, platforms and a dustbathing area, and the other half of the pens were not enriched (NE). In the EE pens, also black soldier fly larvae were provided daily in the dustbathing area and broilers in NE pens received an additional protein-fat mix, to achieve similar energy and nutrient intake compared to the EE treatment. Behaviour was observed by scan sampling and focal sampling in weeks 2, 4, 5 and 7. Walking ability, footpad dermatitis and hock burn were measured in three broilers per pen at a body weight of 1.7 and 2.6 kg. Performance was determined weekly. Results showed that in the enriched environment, at the same age slower-growing broilers made more use of provided enrichment materials than fast-growing broilers (P < 0.001; Δ = +13.5 %). Providing enrichment decreased the proportion of slower-growing chickens standing idle, whereas this effect was not found for fast-growing broiler chickens (P = 0.006; Δ = -2.8 % for slower-growing broilers). Furthermore, at the same age, more slower-growing broilers were active (Δ = +4.5 %) compared to fast-growing broilers, whereas fast-growing broilers showed more sitting idle (Δ = +4.2 %) and ingestion behaviour (Δ = +2.8 %) than slower-growing broilers in both EE and NE pens (P < 0.05). Broilers of both strains in EE pens showed longer duration of activity (P < 0.05; Δ = +11.3 %) compared to broilers in NE pens. No effects of enrichment or strain were observed for walking ability and contact dermatitis. Fast-growing broilers and broilers in NE pens had a higher average body weight, a higher average daily gain and a higher feed intake than slower-growing broilers and broilers in EE pens, respectively. In conclusion, environmental enrichment was most used by slower-growing broilers and providing enrichments increased activity to a similar extent in both strains. However, providing enrichments did not improve walking ability and had an adverse effect on performance in both strains.

Dual-purpose production of eggs and meat \u2014 Part 1: cockerels of crosses between layer and meat breeds achieve moderate growth rates while showing unimpaired animal welfare

The use of modern chicken genotypes with high egg or meat performance results in the ethically unacceptable practice of culling day-old male layer chicks because of their inefficient fattening performance. Dual-purpose genotypes with a balanced performance profile for both eggs and meat are one option to avoid this practice. In this study, four chicken crosses of a layer breed (White Rock or New Hampshire) and the meat breed Bresse Gauloise were compared under the conditions of organic agriculture. Purebred Bresse Gauloise and the layer hybrid Lohmann Sandy served as controls. Part 1 of this study focused on the fattening performance of the cockerels, which were reared together with the pullets. The birds were housed in a floor system (9.9–20.7 kg live weight per m2 at the end of week 15) with access to a green outdoor run. Live weight of the crosses before slaughter at the age of 15 weeks ranged between 2355 and 2447 g and did not differ significantly between the genotypes. With average daily gains of 22.1–22.8 g, the crosses grew slower than Bresse Gauloise males (26.1 g) but faster than Lohmann Sandy males (15.9 g). Welfare assessment indicated a generally high level of welfare with no foot pad lesions or hock burns on any of the cockerels. Fattening dual-purpose cockerels can therefore be an ethically desirable option with a high level of animal welfare and a better fattening performance than in male layer chicks, but still requires more resources than the fattening of specialised broilers.

In-barn heterogeneity of broiler chicken welfare in two industrial house designs and two seasons in Southern Brazilian subtropical climate

The science of animal welfare is key to improving the life quality of billions of chickens, by supporting decisions through the assessment of environmental and animal-based indicators in different conditions. Our goal was to assess the variation of bird welfare within the same barn and whether this variation depends on barn type or season. We described and compared the in-barn heterogeneity of broiler chicken welfare in four closed-sided (CS) and 13 open-sided (OS) industrial poultry houses, during two different seasons (summer/autumn and winter). The measures were divided into two categories: 1) environmental indicators: relative humidity, temperature, air velocity, ammonia (NH3) and carbon dioxide (CO2) concentrations, and illuminance; 2) animal-based indicators: contact dermatitis on the breast and abdominal areas, bird soiling, footpad dermatitis, hock burn, and lameness. The results of assessments in 30 equidistant locations, covering the whole inside area of each barn, were organized into kriging maps. Linear regression and generalized models were fitted, considering predictor variables and the interaction effect between them; the Tukey test was used for the multiple comparisons of means. We used geostatistical modelling for continuous and discrete data for environmental and animal-based measurements, respectively. In-barn heterogeneity was observed for the prevalence of environmental and animal-based problems. There was a pattern for the spatial distribution, heading from the house centre to the West end of both house types, with worse results for three environmental indicators (higher temperature, and NH3 and CO2 concentrations) and three animal-based indicators (higher prevalence of hock burn, bird soiling and footpad dermatitis). In CS, illuminance was very restrictive (4.4 to 6.7 lx) when compared to OS houses (119.8 to 145.3 lx); in both house types the prevalence of lameness was high (50.9 to 78.0%), even though both illuminance and lameness prevalence were evenly distributed inside all houses. The kriging maps allowed for the identification of worse welfare problems in the West direction, which in CS means near exhaust fans and in OS houses the direction of positive-pressure mechanical ventilation by fans. Our results show that attention is needed for the variation of bird welfare conditions inside each barn, and allow for the adoption of strategies to spread best conditions throughout the internal barn area in both house designs. Principally, the original findings on in-barn bird welfare heterogeneity suggest the relevance of constant bird welfare monitoring in key locations within the barns, minimally for the indicators with known different in-barn spatial distributions.

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

ABSTRACT 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.

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.

Over-processed meat and bone meal and phytase effects on broilers challenged with subclinical necrotic enteritis: Part 3. Bone mineralization and litter quality.

This study was conducted to determine the effect of necrotic enteritis (NE), phytase level and meat and bone meal (MBM) processing on bone mineralization of broilers and litter quality. Ross 308 male broiler chicks (n = 768) were allotted to 48 pens with 16 birds each. There were 8 dietary treatments in a 2 × 2 × 2 factorial arrangement. Factors were NE challenge (no or yes), phytase level (500 or 5,000 FTU/kg), and MBM (as-received or over-processed). Half of the birds were challenged with field strains of Eimeria spp. at d 9 and 108 CFU per mL of Clostridium perfringens strain EHE-NE18 on d 14 and 15. The middle toe, tibia and femur of 2 birds per pen were excised at d 16 and 29 for determination of ash, breaking strength (BS) and bone mineralization. At d 42, all were assessed for hock burns and litter was scored and assessed for dry matter (DM). At d 16, challenged birds had lower toe ash (P < 0.01), femur ash (P < 0.001), tibia ash (P < 0.001) and tibial BS (P < 0.001) than unchallenged birds. At d 16, challenged birds fed high phytase and over-processed MBM had higher toe Mn than those fed low phytase and as-received MBM. At d 29 unchallenged birds fed high phytase and as-received MBM had a higher toe Mn than those fed over-processed MBM. At d 16, a phytase × MBM interaction was detected for femur Zn concentration (P < 0.05), where a higher level of Zn was observed in the high phytase group fed over-processed MBM. At d 16, tibial Ca (P < 0.05) and P (P < 0.05) were lower in the challenged whereas the femur K (P < 0.001), Mn (P < 0.01) and Na (P < 0.001) were higher in the challenged at d 16. At d 42, challenged birds had higher litter DM (P = 0.058) and fewer hock burns than those unchallenged (P < 0.05). In conclusion, NE impaired bone traits but high phytase and over-processed MBM increased bone mineral contents. Cases of hock burns may be lower under NE incidences due to lower livability of birds reducing litter wetness.

Effects of hatching system on the welfare of broiler chickens in early and later life

Broiler chicks usually hatch in the hatchery without access to feed and water until placement at the farm. This can affect their health and welfare negatively. Therefore, alternative strategies have been developed, for instance providing chicks with early nutrition in the hatchery or hatching eggs directly on-farm. However, information on the physical and mental welfare of chicks hatched in these systems compared to conventionally hatched chicks is limited. The aim of this study was to investigate the effects of alternative hatching systems on the welfare of broiler chickens in early and later life. A system comparison was performed with chickens that hatched conventionally in a hatchery (HH), in a system which provided light, feed, and water in a hatcher (hatchery-fed, HF), or on-farm (on-farm hatched, OH, where feed and water were available and transport of day-old chicks from the hatchery to the farm was not necessary). Chickens were reared in 3 batches, in 12 floor pens per batch (approximately 1,155 animals per pen), with a total of 12 replicates per treatment. Animal-based welfare indicators were assessed following standard protocols: plumage cleanliness, footpad dermatitis (FPD), hock burn, skin lesions (all at day 21 and 35 of age), and gait score (day 35). Furthermore, a set of behavioral tests was carried out: novel environment (day 1 and 21), tonic immobility, novel object, and avoidance distance test (day 4 and 35). Plumage cleanliness, hock burn, and skin lesions were affected by age but not by hatching system, with older broilers scoring worse than younger ones (P < 0.05). An effect of hatching system was only found for FPD, with the highest prevalence in HH chickens, followed by HF and OH chickens (P < 0.05). All responses measured in the behavioral tests were affected by age but not by hatching system. In later life, chickens were significantly less fearful than during the first days of life. The results indicate that conventionally hatched chickens scored significantly worse for FPD, whereas, in general, hatching system seemed to have minor effects on other broiler welfare indicators.

Influence of a raised slatted area in front of the nest on leg health, mating behaviour and floor eggs in broiler breeders

European farms for broiler breeders often have raised slatted areas in front of the nests, but in other regions of the world no raised slatted areas are provided. This study aimed to investigate the effects of a raised slatted area on leg health, mating behaviour and floor laying behaviour. Ten groups of 33 broiler breeder hens and three males were housed in two pen types: with or without a raised slatted area in front of the nests. Each pen had one plastic and one wooden nest. Between 25 and 31 weeks of age, ten marked hens per pen were weighed and assessed weekly on foot pad dermatitis, hock burn and wounds. At the end of week 31, animals were euthanized and bone strength of the tibia and humerus of these individuals was assessed. At 24, 27 and 30 weeks of age, mating behaviour was observed for an hour per pen, noting both numbers of successful and unsuccessful copulations. The number of eggs laid in the nests and on the floor was recorded daily between 20 and 31 weeks of age. Foot pad dermatitis scores were affected by age, but not by pen type. Generally, there were only minor issues with foot pad dermatitis (scores <11 on a 0–100 scale), probably due to the young age of the hens. Body weight was not affected by pen type, while the prevalence of hock burns was too low to analyse and no difference in bone strength was found for the tibia and the humerus. Overall, mating behaviour was less frequent in pens with raised slats than in pens without raised slats (29 ± 2 vs 35 ± 3 times/h) and more frequent at 27 weeks of age than at 24 and 30 weeks of age (38 ± 1 vs 31 ± 4 and 27 ± 2 times/h). The pens with raised slats had a lower percentage of floor eggs than pens without raised slats (11.2 ± 0.4 vs 19.3 ± 0.5%). The wooden nest was preferred over the plastic nest as on average 63% of the eggs were laid in the wooden nest. This study shows that providing raised slats decreases mating behaviour and percentage of floor eggs, although its effects on leg health remain inconclusive.

Effects of dietary supplementation of a probiotic (Bacillus subtilis) on bone mass and meat quality of broiler chickens

The aim of this study was to investigate the effect of a dietary probiotic supplement on bone mass and meat quality of broiler chickens. Two hundred ten 1-day-old male Ross 708 broiler chicks were divided among 21 floor pens (10 chicks per pen). The pens were randomly distributed to 1 of 3 dietary treatments containing a probiotic, Bacillus subtilis, at 0 (control), 0.25 (0.25X), and 0.5 (0.5X) g/kg (n = 7). Gait score, footpad dermatitis (FPD), leg straightness, and hock burn (HB) were examined at day 33, and a latency-to-lie test was performed at day 34. At the end of the experiment (day 35), plasma, right leg, and litter samples were collected for mineral contents, meat quality, bone morphometric parameters, and litter quality assessments. The results indicated that probiotic-fed birds stood much longer during the latency-to-lie test with a greater tibial length, weight, and strength as well as higher plasma levels of calcium and phosphorus compared with the controls. In addition, probiotic-fed birds' leg muscle had higher color lightness at both 30 min and 5 h postmortem and greater water-holding capacity with a trend for less cooking loss (P = 0.056) and lower pH values (P < 0.05) at 5 h postmortem. Probiotic-fed birds' leg meat was tastier (P < 0.05) at 24 h after slaughter. These probiotic effects were greater in the 0.5X group than in the 0.25X group. There were no treatment effects on other measured parameters including gait score, HB, FPD, tibial lateral and medial wall thickness, diaphysis and medullary canal diameters, robusticity and tibiotarsal indexes, plasma magnesium concentrations, and litter moisture and pH values (P > 0.05). These findings indicate that the probiotic supplement could be a useful management tool for improving broiler production and welfare by enhanced bone mass and meat quality.

Silicon supplementation affects mineral metabolism but not bone density or strength in male broilers.

Because leg injuries produce welfare concerns and impact production for broilers, numerous interventions have been suggested as potential solutions. One mineral which may affect bone quality is silicon. The objective of this study was to determine if supplementing bioavailable silicon could affect bone morphology, mineralization, and strength without negatively influencing welfare and meat quality. Male broilers were raised from d 1 after hatching until 42 d of age and randomly assigned to treatment groups for silicon supplementation in water: Control (no supplement, C; n = 125), Normal (0.011 ml supplement/kg bodyweight, N; n = 125) and High (0.063 ml supplement/kg bodyweight, H; n = 125). Toe damage, footpad dermatitis, hock burn, and keel blisters were assessed on d 42. Blood samples were collected from wing veins for serum osteocalcin, pyridinoline cross-links, and mineral analysis. Clinical QCT scans and analysis were conducted immediately before four-point bending tests of tibias. Texture analysis was performed on cooked fillets. Silicon supplementation tended to increase daily water consumption in N and H as compared to C (P = 0.07). Footpad dermatitis and hock burn scores were higher in H than in N or C (P < 0.05 for both comparisons). Supplementation altered serum minerals (P < 0.001), but bone density, morphology, and strength measures were similar among groups. The highest level of supplementation in the current study on a kg bodyweight basis was above recommended intakes but below previous amounts demonstrating silicon’s positive influence on bone, indicating that previously suggested minimum thresholds need to be reevaluated. Factors such as growth rate and mechanical loading likely play a greater role in developing bone quality than trying to supplement on top of good basic nutrition alone.

Bird Health, Housing and Management Routines on Swedish Organic Broiler Chicken Farms.

Simple SummaryKnowledge of bird welfare and management on Swedish organic broiler farms is limited, since the number of farms began to increase only recently when two slower-growing hybrids became commercially available in Sweden. The aim of the study was to obtain information about chicken health and other welfare aspects, along with details of housing and management routines, in order to increase the knowledge and describe the current situation of these farms. Clinical examinations revealed no severe remarks, however minor to moderate plumage dirtiness, food pad dermatitis and hock burns were found in 47%, 21% and 13% of the birds, respectively. Higher body weights were significantly correlated to an increased prevalence of hock burns and dirty plumages. Although no severe walking impairments were observed, minor to moderate gait abnormalities were seen in almost two-thirds of all birds assessed. Gait in chickens assessed outdoors was significantly better than in those observed indoors. Flock body weight uniformity was low in all flocks. The study provides new knowledge of two slower-growing hybrids on Swedish organic farms. Further research should be focused on investigating other important aspects related to bird welfare, such as the low flock body weight uniformity and the high mortality rates observed.Slower-growing broilers on organic farms have replaced fast-growing hybrids to increase bird welfare. Due to limited knowledge of broiler welfare and management on organic farms in Sweden, the study aim was to gather information regarding health, housing and management routines, in order to describe the current situation on these. Farm visits performed in 2018 included 8 out of 12 established organic farms, on which either Rowan Ranger or HubbardJA57/HubbardJA87 were reared. Chickens in the observed flocks were 55 ± 6 (44–62) days of age. Observations included farmer interviews, indoor environment assessments, clinical examinations and gait scoring. Clinical examinations revealed no severe remarks, however minor to moderate plumage dirtiness, food pad dermatitis and hock burns were found in 47%, 21% and 13% of the birds, respectively. Although no severe walking impairments were observed, minor to moderate gait abnormalities were seen in two-thirds of the birds. Gait in birds assessed outdoors was significantly better than in birds observed indoors. Body weight uniformity was low in all flocks. This study provides increased knowledge of certain chicken health and welfare aspects, housing and management on Swedish organic farms. Future research should further investigate important aspects related to bird welfare, such as the high mortality rates observed.