Influence of stocking density on behavioural, health and productivity traits of turkeys in large flocks

Towards genetic improvement of social behaviours in livestock using large-scale sensor data: data simulation and genetic analysis

BACKGROUND

Harmful social behaviours, such as injurious feather pecking in poultry and tail biting in swine, reduce animal welfare and production efficiency. While these behaviours are heritable, selective breeding is still limited due to a lack of individual phenotyping methods for large groups and proper genetic models. In the near future, large-scale longitudinal data on social behaviours will become available, e.g. through computer vision techniques, and appropriate genetic models will be needed to analyse such data. In this paper, we investigated prospects for genetic improvement of social traits recorded in large groups by (1) developing models to simulate and analyse large-scale longitudinal data on social behaviours, and (2) investigating required sample sizes to obtain reasonable accuracies of estimated genetic parameters and breeding values (EBV).

RESULTS

Latent traits were defined as representing tendencies of individuals to be engaged in social interactions by distinguishing between performer and recipient effects. Animal movement was assumed random and without genetic variation, and performer and recipient interaction effects were assumed constant over time. Based on the literature, observed-scale heritabilities ([Formula: see text]) of performer and recipient effects were both set to 0.05, 0.1, or 0.2, and the genetic correlation ([Formula: see text]) between those effects was set to - 0.5, 0, or 0.5. Using agent-based modelling, we simulated ~ 200,000 interactions for 2000 animals (~ 1000 interactions per animal) with a half-sib family structure. Variance components and breeding values were estimated with a general linear mixed model. The estimated genetic parameters did not differ significantly from the true values. When all individuals and interactions were included in the analysis, the accuracy of EBV was 0.61, 0.70, and 0.76 for [Formula: see text] = 0.05, 0.1, and 0.2, respectively (for [Formula: see text]= 0). Including 2000 individuals each with only ~ 100 interactions, already yielded promising accuracies of 0.47, 0.60, and 0.71 for [Formula: see text] = 0.05, 0.1, and 0.2, respectively (with [Formula: see text] = 0). Similar results were found with [Formula: see text] of - 0.5 or 0.5.

CONCLUSIONS

We developed models to simulate and genetically analyse social behaviours for animals that are kept in large groups, anticipating the availability of large-scale longitudinal data in the near future. We obtained promising accuracies of EBV with ~ 100 interactions per individual, which would correspond to a few weeks of recording. Therefore, we conclude that animal breeding can be a promising strategy to improve social behaviours in livestock.

Environmental Complexity and Reduced Stocking Density Promote Positive Behavioral Outcomes in Broiler Chickens

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD) or low (LD) density. Through focal-animal sampling, the frequency and duration of behaviors were recorded continuously for 5 min at two timepoints for one day in weeks 2, 4, and 7. Birds were active for 30% of the observed time, with birds showing more activity in HC compared with LC. Birds in HC pens spent more time preening and foraging than birds in LC pens, which was interpreted as a positive outcome. Dustbathing and play were not impacted by complexity, possibly due to the observation method. Birds were more frequently active at HD compared with LD, but did not spend more time being active, suggesting disturbances. Birds foraged, drank, and ate less frequently in HD compared with LD, presumably because birds had more difficulty accessing resources. Activity and active behaviors reduced as birds aged, while preening frequency increased, possibly due to frustration, but this was not confirmed. Perching was unaffected by age, showing a persistent motivation to perform the behavior. Our results indicate that a complex environment provides positive stimulation for foraging, locomotion, preening, and overall activity. Despite reduced activity, many benefits of the tested environmental complexity and low density persisted as birds aged.

Stocking density effects on turkey hen performance to 11 weeks of age

Stocking density (SD) affects economic return for turkey production and can impact performance parameters. In this study (2 experimental blocks), Nicholas Select hens (n = 3,550 poults/block) were randomly placed in 1 of 4 SD treatments of 30, 40, 50, or 60 kg/m² in open rooms (67.5 m²) with 4 replications per treatment. Feeder and drinker space were equalized on a per bird basis. Air quality was measured, and ventilation was adjusted to equalize ammonia and carbon dioxide levels across all rooms. Group BW and feed consumption were measured on d 0 and wk 3, 5, 8, and 11. BW gain and mortality corrected feed-to-gain ratio were calculated. Mortality and culls were recorded daily and necropsied for cause of death. At wk 8 and 11, flock uniformity was evaluated (30 birds/replicate). Data were analyzed using regression analyses in SAS 9.4 (Proc Reg for linear regression and Proc RSReg for quadratic regression; SD as independent variable). An ANOVA was performed for air quality (Proc Mixed; SAS 9.4) and a Tukey's range test was used to separate means. Differences were considered significant when P ≤ 0.05. Carbon dioxide and ammonia were consistent across treatments for both blocks. At wk 11, BW decreased linearly as SD increased (P = 0.05). There was a tendency for overall BW gain to decrease linearly as SD increased (P = 0.06). Feed consumption decreased as SD increased during wk 8 to 11 (linear; P < 0.01) and from wk 0 to 11 (quadratic; P = 0.04). SD had no impact on feed efficiency, mortality, or uniformity. Total aggression related mortality and culls were highest in the 30 kg/m² treatment (linear; P = 0.02). A brief economic analysis was performed utilizing commercial poult and feed costs and income at marketing. Net room income increased as SD increased (linear; P < 0.01). The results indicate that high SD negatively impacted turkey hen final BW and feed consumption, but no effect was observed on feed-to-gain ratio, percent mortality, or uniformity.

Evaluating the effects of stocking density on the behavior, health, and welfare of turkey hens to 11 weeks of age

Nicholas Select hens (n = 3,550 poults in each of 2 experimental trials) were randomly placed in 1 of 4 stocking density (SD) treatments of 30, 40, 50, or 60 kg/m² until 11 wk. Birds were housed in open rooms (67.5 m²) with 4 replications per treatment. Ventilation was adjusted in each room independently to ensure air quality measures did not differ across replicate rooms. At wk 8 and 11, footpad lesions, mobility, feather cover and cleanliness, behavior (recorded), and litter moisture were evaluated. Incidences of aggressive pecking were recorded daily. Heterophil/lymphocyte (H/L) ratios were evaluated at 3, 5, 8, and 11 wk. Data were analyzed using regression analyses in SAS 9.4 (Proc Reg and Proc RSReg; SD as independent variable). Differences were considered significant when P ≤ 0.05. Gait scores were not affected by SD. Average footpad scores worsened with increasing SD at wk 8 (linear) but were not affected at wk 11. Total feather cover scores and average feather cleanliness were poorer at high SD (linear) at wk 8 and 11. The incidence of aggressive pecking and culls for aggressive damage decreased linearly as SD increased. At 5 (linear) and 11 (quadratic) wk, H/L ratios increased as SD increased. At 8 wk, H/L ratios were highest in the 40 kg/m² treatment (quadratic). At 8 wk, the percentage of birds at the feeder, resting, and total disturbances linearly increased as SD increased. The percentage of birds standing, walking, and litter pecking decreased linearly with increasing SD, while total aggressive behaviors (sum of fighting and aggressive pecking) decreased (quadratic). At 11 wk, the percentage of birds at the drinker, and decreased with increasing SD while resting, feather pecking, and severe disturbances increased as SD increased. Litter moisture increased linearly with increasing SD (wk 11). Turkey hen health and welfare were negatively impacted by higher SD. At low SD, there was notably more aggression which may also impact welfare.

The influence of stocking density on behaviour, health, and production in commercial fattening turkeys - a review

Worldwide, there are various regulations and recommendations on the maximum stocking density. While stocking density can be determined based on the space covered by the body, a more appropriate method considers space requirements for natural behaviour.Turkeys are less likely disturbed at low stocking density as seen by increased sitting, lying, and preening behaviours, compared to animals housed at high stocking density. Furthermore, lower stocking density, together with smaller group size, species-appropriate light conditions and suitable structuring of barn housing, have been repeatedly mentioned as good strategies to prevent injurious pecking.Increased stocking density - in terms of weight and animal number per floor area - is related to increased litter moisture, which can have negative impact on animal welfare. High stocking density can lead to poor body mass gain and increased mortality, which are indicators of impaired welfare and economic losses.Based on the available scientific literature and economic aspects with regard to the above criteria, maximum stocking density for turkeys appears to be 40 kg live weight per m² of usable floor space. However, the number of animals per square space should be limited to avoid increased litter moisture and reduced health and welfare.

[Aspects to improve animal welfare in fattening turkeys: structure and occupational material - a literature review]

Conventional turkey husbandries frequently fail to provide any structural elements or occupational material apart from the feeding and drinking systems. However, these may carry numerous advantages for animal welfare (spatial separation to exercise natural behavior, retreat options, stimulation of locomotion). Hence these are increasingly discussed in conventional turkey husbandry, especially against the background of minimizing injurious pecking. Studies reported in the literature concerning the effects of structural elements or occupational materials are not exactly comparable to one another due to variations in study design. However, the described positive effects predominate across the different evaluations. Nonetheless, when using such elements consideration must be given to several variables. For example, the use and positive effects of perching options depend on the type and dimensions of their structure used as well as on sex, age and breed of the animals. Straw bales represent one option, which then may also serve as occupational material. When hay or straw is offered, appropriately sized grit must also be administered in order to prevent obstipation of the gastrointestinal tract. Different occupational materials should be offered alternately and in sufficient quantities. The outdoor-climate and run area offer climatic and optic stimuli and additional opportunities for exercise. However, various basic requirements must also be considered here. In principle, the commitment and knowledge of the breeder are of crucial importance for all of the animal welfare improvements mentioned. Therefore, regular further training for this group of people is recommended.

Evaluation of Welfare in Commercial Turkey Flocks of Both Sexes Using the Transect Walk Method

The study was conducted between March and September 2019 in six meat-type turkey flocks with similar management standard procedures using the transect walk method. The concept of the method is based on visual observation of the birds while slowly walking across the entire farm in predetermined transects. Each flock was evaluated at three different times during the fattening cycle: at 3 to 4, 12 to 13, and 19 to 20 weeks of age, and total number of males and females that were immobile or lame, had visible head, vent, or back wounds, were small, featherless, dirty, or sick, had pendulous crop, or showed aggression toward birds or humans were recorded. At each visit, NH₃ and CO₂ were measured within the facilities. In the first assessment, the most frequently observed welfare indicators were small size (0.87%) and immobility (0.08%). Males showed a significantly higher prevalence of small size (p < 0.01), sickness (p < 0.05), and dirtiness (p < 0.1) compared to females. In the second assessment, the most common findings in both sexes were dirtiness (1.65%) and poor feather condition (1.06%), followed by immobility (0.28%). Males were significantly dirtier (p < 0.001), had more immobile birds (p < 0.01) and birds with vent wounds (p < 0.1), but had fewer sick birds (p < 0.05). In the last assessment, an increase in immobile, lame, sick, and dead birds was recorded, indicating an increase in health problems. Higher CO₂ (3000 and 4433 ppm) and NH₃ (40 and 27.6 ppm) values were noted only at the first assessment in two facilities. Further analyses showed that slightly elevated NH₃ and CO₂ levels did not influence the occurrence of welfare indicators. This study is the first description of the welfare of commercial turkey flocks in Slovenia.

Influence of environmental enrichment on circulating white blood cell counts and behavior of female turkeys

Under commercial conditions turkeys are housed in large groups in poorly structured environments. This leads to stress and subsequently to pecking and cannibalism. Environmental enrichment is suggested to reduce stress and feather pecking, thus leading to an increase of the overall flock health. However, the effect of increasing age on the use of enrichment elements and on the behavior repertoire as well as its correlation with health parameters has scarcely been studied. Therefore, our objective was to investigate the influence of environmental enrichment on the behavioral repertoire and on health parameters of turkeys. In 3 consecutive trials, female turkeys were housed up to 12 wk either in an unstructured (control group) or enriched environment (EE group) featuring elevated plateaus at different levels (“turkey tree”). Behavior parameters, clinical health, and immune parameters were determined at selected time points. The percentage of birds using the turkey tree increased with age up to 55 to 77% at 22 to 30 d post hatch (dph). Thereafter, the number of birds located on the turkey tree decreased to 25 to 32% at 73 to 79 dph. Feather pecking and fighting was significantly lower in the EE group compared to the control group in 2 and 3 trials, respectively (P < 0.05). The integrity of feathers and integument, scored in the head/neck, wing, and tail regions was repeatedly better in the EE birds compared to control birds at most investigated time points (P < 0.05), suggesting a reduction in stress related aggression by the use of the turkey tree. Head pecking, running and flying activity, foraging, and preening were overall comparable between the EE and the control group (P > 0.05). Humoral immunity as determined by vaccination-induced anti-Newcastle disease virus antibody titers was not affected by the turkey tree use. The flow cytometric evaluation of blood monocyte and T-lymphocyte numbers showed no repeatable difference between control and EE groups. Interestingly, compared to the control groups, EE birds displayed significantly higher numbers of circulating MHC class II⁺ lymphocytes and lower numbers of thrombocytes at various time points compared to controls (P < 0.05). This study provides clear evidence that environmental enrichment with plateaus not only leads to an altered behavioral repertoire but also modifies some of the investigated immune parameters, implying that EE may have a modulatory effect on turkeys’ immunity and overall fitness. Further studies are needed to understand the correlation between behavior and health parameters in birds more closely.

Associations between animal-based measures at 11 wk and slaughter data at 20 wk in turkey toms (Meleagris gallopavo)

To monitor animal welfare on a commercial scale, systematic collection and evaluation of slaughterhouse data is the most feasible method. However, we need to know whether slaughterhouse data retrospectively and reliably reflect information about the birds' welfare on-farm. The aim of this study was therefore to investigate associations between animal-based welfare measures in flocks of turkey toms at 11 wk of age recorded with the transect walk and slaughter data at 20 wk of age. A total of 20 commercial flocks of turkey toms were visited, where an observer walked the transects in a random order and recorded the total number of birds per transect that were immobile, lame, with visible head, tail, or wing wounds, small, featherless, dirty, sick, terminal, or dead. Slaughterhouse data were provided for each flock. Univariate and multivariate linear regression models were used to investigate the associations between on-farm and slaughterhouse measures. Increased prevalence of immobile toms at week 11 resulted in more birds rejected at slaughter owing to leg issues (P = 0.02) and airsacculitis (P < 0.001). More lame birds on-farm were associated with an overall higher rejection rate at slaughter (P < 0.001). Flocks with more featherless birds had significantly more birds being rejected at slaughter owing to skin issues (P = 0.02). More dirty birds at week 11 resulted in more birds being rejected owing to airsacculitis at slaughter (P < 0.001). A higher mortality on-farm was associated with more birds rejected for being too small (P = 0.04). In conclusion, significant associations between animal-based measures of turkey toms as assessed by the transect walk method on-farm at 11 wk and slaughter data at 20 wk were identified.

Effects of stocking density on large white, commercial tom turkeys reared to 20 weeks of age: 1. growth and performance

Industry standards for turkey stocking densities are variable and may not represent the more rapidly growing strains currently available. Therefore, a study was completed to evaluate 4 stocking densities: a nominal density (0.3525 m²/bird), 10% tighter density (0.3169 m²/bird), 10% looser density (0.3882 m²/bird), and 20% looser density (0.4238 m²/bird) on the effects on large white, commercial male turkeys with regard to performance from 5 to 20 wk of age. Brooding stocking density was fixed for all pens of birds with 60 birds per replicate pen at 0.46 m²/bird to 5 wk of age. Density treatments were applied from 5 to 20 wk by altering pen size with pen population held constant at 60 per pen. There were 4 pens of birds per density treatment. Birds were weighed individually at 0, 5, and 20 wk of age and performance parameters were calculated. There were no differences in bird performance at 5 wk, which was expected because stocking density was fixed. From 5 to 20 wk and at 20 wk, birds that were reared at the nominal standard (0.3525 m²/bird) and 10% tighter density (0.3169 m²/bird) had significantly lower body weight compared with the 10% looser density (0.3882 m²/bird) and 20% looser density (0.4238 m²/bird) (P = 0.03 and 0.01, respectfully). The feed conversion ratio (FCR) tended (P = 0.08) to be improved for birds reared at looser density. In addition, based on linear regression, as stocking density decreased (i.e., m²/bird increased), BW (P < 0.05) increased, and FCR (P = 0.10) tended to decrease (improve) at 20 wk. It was concluded that birds reared at looser density had improved performance.

Are Turkeys (Meleagris gallopavo) Motivated to Avoid Excreta-Soiled Substrate?

Simple Summary

Commercial turkeys are raised in large barns at stocking densities that cause excreta (or feces) to quickly accrue in the turkeys’ environment. Even though commercial turkeys spend most, if not all, of their time in contact with their excreta, we do not know how turkeys perceive this soiled environment. Therefore, our study used six pens of four turkeys, dividing each pen with a barrier that contained two one-way push-doors. This created two compartments: a “home” compartment containing soiled wood shavings, and a “treatment” (T) compartment containing fresh pine and spruce wood shavings (FP), soiled pine and spruce wood shavings (SP), ammonia reductant-treated soiled pine and spruce wood shavings (TSP), no substrate (NS), or a feed treatment. To establish the turkeys’ motivation to access these resources, we weighed the door to T with 0%, 20% or 40% of the turkeys’ body weight. The number of turkeys that pushed the maximum door weight was used as an indicator for their motivation. Additionally, time spent in T and the odds of visiting T were examined to determine how the turkeys responded to increasing challenge. We found that the turkeys preferred feed over all other resources and showed equal motivation for all floor substrate treatments.

Abstract

The soiling of bedding on modern turkey farms combined with turkeys’ reduced ability and opportunity to perch and roost at elevation, forces them to spend most, if not all, of their time in contact with their excreta. To determine turkeys’ perspective on these conditions and the value they place on unsoiled bedding vs. soiled litter (collectively, substrates), we used twenty-four eleven-week-old turkey hens divided into six two-compartment pens. In the “home” compartment (H), we placed soiled wood shavings, while the “treatment” compartment (T) contained no substrate (NS), fresh pine and spruce wood shavings (FP), soiled pine and spruce wood shavings (SP), ammonia reductant-treated soiled pine and spruce wood shavings (TSP), or a feed treatment. One-way push-doors separated the two compartments. The door leading to T weighed an additional 0%, 20% or 40% of the turkeys’ body weight while the door to H remained unweighted. All birds were exposed to each resource and door weight combination in a systematic order. We measured the turkeys’ motivation based on the number of birds that pushed the maximum weight to access each resource, the amount of time spent in T, and the number of visits to T. Our findings show that turkeys worked harder to access feed compared to all the floor substrate treatments. Additionally, they were equally motivated to access all the substrate treatments.

Associations between on-farm welfare measures and slaughterhouse data in commercial flocks of turkey hens (Meleagris gallopavo)

There is a growing demand for documentation of animal welfare in meat production industry. Research on turkey welfare has mainly focused on toms at the end of production cycle, and information on the relationship between on-farm welfare and slaughterhouse recordings for turkey hens is currently lacking. The aim of this study was to investigate the relationship between routinely collected slaughterhouse data from turkey hens and their on-farm welfare measured by transect walks, to identify potential retrospective welfare indicators. The study was conducted between November 2017 and March 2018 in 20 commercial turkey flocks in Norway. On-farm welfare was evaluated using the transect walk method when the turkey hens were 11 wk old, recording the number of birds that were immobile, lame, small, featherless, dirty, sick, terminal, or dead and had visible head, tail, or wing wounds. Slaughterhouse data was provided for each flock. Univariate and multivariate linear regression models were used to investigate the associations between the variables. The results showed significant associations between several measures on farm and at slaughter. Flocks with more lameness on farm had more birds rejected at the slaughterhouse owing to leg and joint issues (P = 0.03, r = 1.01). Featherlessness and dirtiness on farm were positively associated with airsacculitis (P = 0.005; r = 0.42 and P = 0.0008; r = 0.57, respectively). The results suggest that slaughterhouse registrations may provide both practical and feasible retrospective information on the welfare of turkey hens that potentially could be implemented in future welfare assessment schemes. Further studies are needed to investigate the causal factors behind the identified relationships.

Identifying welfare issues in turkey hen and tom flocks applying the transect walk method

In commercial conditions turkey tom and hen flocks are reared under similar housing and management conditions. However, the 2 sexes differ with regard to behavioral and physiological characteristics, and are slaughtered at different ages, resulting in different growth patterns. The rearing environment and management likely have similar effects on the welfare of both sexes reared in 1 barn, as usual in commercial flocks, but this has not previously been studied. The main aim of current study was to identify on-farm health and welfare issues of commercially reared hen and tom turkeys at 11 wk of age using the transect walk method. The study was conducted between November 2017 and March 2018 in 20 commercial turkey flocks on 16 different farms in the eastern part of Norway. On each farm, 1 barn, divided into tom and hen area, was evaluated using transect walk method. An observer walked the transects in random order and recorded the total number of birds per transect that were immobile; lame, with visible head, tail, or wing wounds; small; featherless; dirty; sick; terminal or dead. To analyze the data, we applied ANOVA and Spearman correlations in SAS software (v 9.3). The most commonly observed welfare indicators across sexes were dirty and featherless birds, and birds with tail and wing wounds. Across sexes, poor litter quality resulted in more head wounds (P < 0.05). Toms had significantly more tail wounds (P < 0.001), there were more sick birds (P < 0.01) and more terminal birds (P < 0.01) compared to hens at the same age. Several of the welfare indicators were positively correlated between the sexes, including lame, head, wing- and tail-wounded, dirty, and dead birds, suggesting similar underlying environmental causes affecting animal welfare.

The effects of stocking density on turkey tom performance and environment to 16 weeks of age

Stocking density (SD) of turkey toms (n = 2,868 Nicholas Select) was evaluated in 2 16-wk trials. Poults were randomly allocated to 1 of 8 independently ventilated rooms (6.71 × 10.06 m) for each trial, to reach a final target SD of 30, 40, 50, or 60 kg/m2. Air quality was monitored (carbon dioxide and ammonia) throughout the trial, and ventilation was adjusted to balance these parameters across all rooms. Within each trial, body weight and feed consumption were recorded (0, 4, 8, 12, and 16 wk of age). Body weight gain and mortality-corrected feed-to-gain ratio (F: Gm) were calculated for each 4-wk interval. Uniformity was assessed at 12 and 16 wk of age (20 birds per replicate). Mortality and culled birds were recorded daily and necropsied to determine cause of death or illness. Room temperature was recorded hourly, and litter moisture and temperature (trial 2) were evaluated weekly from 12 to 16 wk. A 1-way ANOVA was performed to evaluate the effects of SD on room temperature. Regression analyses were performed to determine the relationship between SD and all other measured variables (linear, Proc Reg; quadratic, Proc RSReg in SAS 9.4). Differences were considered significant when P ≤ 0.05. Body weight decreased as SD increased at 12 (quadratic) and 16 wk (linear). Body weight gain decreased in the last 4 wk (12 to 16, linear) and over the course of the trial (0 to 12, quadratic; 0 to 16, linear) as SD increased. Feed consumption demonstrated a linear relationship with increasing SD, increasing from week 4 to 8 and decreasing from week 12 to 16. The F: Gm ratio increased linearly with increasing SD for all time periods beginning at week 4. Flock uniformity and total percent mortality were unaffected by SD. Litter moisture demonstrated a quadratic effect and litter temperature increased (quadratic) as SD increased. Overall, increasing SD negatively impacted aspects of bird performance, including body weight, body weight gain, and feed efficiency. Feed consumption was negatively impacted later in production (week 12 to 16). Finally, overall mortality and uniformity were not affected.

Investigation of the prevalence and severity of foot pad dermatitis at the slaughterhouse in fattening turkeys reared in organic production systems in Germany

The present study shows the prevalence and severity of foot pad dermatitis (FPD) in turkeys reared in organic production systems assessed at slaughterhouses in Germany. The investigations of altogether 1,860 turkeys of the strains Kelly Broad Breasted Bronze (Kelly BBB; 540 toms, 540 hens) and British United Turkeys (B.U.T.) 6 and the Test Product 7 (TP 7; 780 hens) showed that 97.7% of the examined turkeys were diagnosed with different degrees of FPD. Only 4.6% of the toms and 1.3% of the hens had feet without lesions. Most frequent were necrotic lesions measuring up to 2 cm in diameter (64.3% of all turkeys). Extensive necrotic lesions of the foot pads (toms: 29.8%; hens: 12.4%) and necrosis of superficial scales (toms: 11.3%; hens: 7.6%) were less frequent. Plantar abscesses were rare findings (1.9%). In general, the feet of the Kelly BBB hens were more affected by foot pad lesions than those of the Kelly BBB toms. There were significant differences between the investigated flocks concerning the occurrence of foot pad lesions. The aim in rearing turkeys must be the reduction of FPD.

Validity of Micro-Data Loggers to Determine Walking Activity of Turkeys and Effects on Turkey Gait

Accelerometers have the potential to provide objective, non-invasive methods for detecting changes in animal behavior and health. Our objectives were to: (1) determine the effects of micro-acceleration data loggers (accelerometers) and habituation to accelerometers on turkey gait and health status, (2) determine age-related changes in gait and health status, and (3) assess the validity and reliability of the accelerometers. Thirty-six male commercial turkeys were randomly assigned to one of five groups: accelerometer and habituation period (AH), accelerometer and no habituation period (AN), VetRap bandage (no accelerometer) and habituation period (VH), bandage (no accelerometer) and no habituation period (VN), and nothing on either leg (C). Health status and body condition were assessed prior to video-recording birds as they walked across a Tekscan® pressure pad at 8, 12, and 16 weeks to determine effects of treatment on number of steps, cadence, gait time, gait distance, gait velocity, impulse, gait cycle time, maximum force, peak vertical pressure, single support time, contact time, step length, step time, step velocity, stride length, total double support time, and duty factor. Accelerometer validity and reliability were determined by comparing the number of steps detected by the accelerometer to the number of steps determined from video recordings. Several age-related changes in turkey gait were found regardless of habituation including a slower cadence at 16 weeks, shorter gait distance at 8 weeks, and slower gait velocity at 16 weeks. When comparing bandaged vs. unbandaged limbs, both treatment and age-treatment interactions were found depending on the gait parameter. Accelerometer validity and reliability were affected by both age and treatment. False discovery rate increased, while accuracy and specificity decreased with age. Validity and reliability were lowest for non-habituated birds (AN and VN). Results demonstrated that micro-data loggers do not adversely affect turkey health status, but habituation to wearing accelerometers greatly affects accelerometer reliability and validity. Accelerometer validity and turkey gait are also greatly affected by the age of the turkeys.

Assessing the Effects of Stocking Density on Turkey Tom Health and Welfare to 16 Weeks of Age

Four levels of turkey tom stocking density (SD) (30, 40, 50, 60 kg/m2) were evaluated in two 16 week trials (n = 2,868 Nicholas Select). Poults were allocated to one of eight independently ventilated rooms per trial (6.71 × 10.06 m) based on final predicted body weight (two replicates per SD per trial). Room temperature, humidity, carbon dioxide and ammonia concentration were recorded throughout the trial; ventilation was adjusted to equalize air quality across treatments. Mobility (gait score, scale 0-5) was recorded at 12 and 16 weeks (20 birds per replicate). Footpad lesion score (scale 0-4), feather condition (scale 1-4), and cleanliness scores (scale 1-4) were recorded at 10 (Trial 2), 12, and 16 weeks of age (20 birds per replicate). Aggressive injury incidence was recorded daily for Trial 2. Stress (heterophil/lymphocyte ratio) was evaluated at 4, 12, and 16 weeks of age (15 birds per replicate). Behavior was recorded and scan sampled (field of view) at 12 (Trial 1), 14, and 16 weeks. Data were analyzed using regression analysis (linear, Proc Reg; quadratic, Proc RSReg) for relationships between the variables and SD. Differences were considered significant when p ≤ 0.05. Mobility and footpad lesions were negatively affected by increasing SD (linear) at 16 weeks only. Feather condition and cleanliness decreased linearly as SD increased at week 10, 12, and 16. The incidence of aggressive damage was higher as SD increased during week 4-8 (quadratic). Heterophil/lymphocyte ratios increased linearly at 4 weeks (similar trend at 12 weeks). Behavior was impacted at 12 weeks of age with standing behavior showing a quadratic response, and walking and total disturbance showing a linear decrease as SD increased. Resting, preening, and comfort behaviors increased linearly (14 weeks), while walking and strutting decreased linearly with increasing SD. Finally, at 16 weeks of age resting, standing, walking, feeding, and total disturbance responded quadratically while preening behavior increased linearly with increasing SD. Results suggest that increasing SD negatively impacts bird health and wellbeing through decreased mobility, increased footpad lesions, poorer feather condition and cleanliness, and behavioral changes, but that very low SD (30 kg/m2) may result in increased aggressive damage.

A review of the effects of stocking density on turkey behavior, welfare, and productivity

Stocking density, the amount of space available per animal, greatly affects the welfare of commercial turkeys. For example, stocking density has been found to affect behavior such as injurious pecking; production, such as growth rates and feed efficiency; and health-related aspects, such as leg health and the incidence of airsacculitis. Current industry guidelines and standards for turkey space requirements and stocking densities vary, and they are different from those that have been examined scientifically. Scientific research into stocking density effects on turkey behavior, welfare, and productivity have been conducted in experimental settings with flock sizes that are much different from those in the commercial turkey industry. There is currently little information available regarding how much space turkeys require for particular behavioral activities. This paper reviews the current industry guidelines and standards as well as scientific literature pertaining to stocking densities for commercial turkeys.

Impact of Selected Factors on the Occurrence of Contact Dermatitis in Turkeys on Commercial Farms in Germany

Simple Summary

In two extensive field studies in Germany, the influence of husbandry on health and fitness of fattening turkeys was investigated in living animals of various ages as well as carcasses shortly after slaughter. Already in the early rearing phase, contact dermatitis of foot pads was observed as a relevant problem in turkey farming. Litter quality and condition as well as management must be coordinated at all rearing stages of turkeys to prevent the appearance of high litter moisture values in order to minimize the prevalence of foot pad dermatitis.

Abstract

In a long term research project in Germany the influence of husbandry on the health of fattening turkeys (Study 1) as well as the influence of practiced rearing conditions on the health of turkey poults (Study 2) was examined in 24 farms and at the meat processing plant. In all examined rearing farms, litter samples for the determination of litter moisture were taken. This paper summarizes the results obtained by our working group from 2007 until 2012. The results elucidate the universal problem of foot pad dermatitis (FPD). Nearly 100% of the observed turkeys showed a clinically apparent FPD at the meat processing plant. Furthermore, skin lesions of the breast, especially breast buttons were diagnosed, particularly at the slaughterhouse. FPD was detected in the first week of the rearing phase. Prevalence and degree showed a progressive development up to the age of 22–35 days, whereas 63.3% of the poults had foot pad alterations. As even mild alterations in the foot pad condition can be indicators for suboptimal design of the rearing environment, especially high litter moisture, it is important to focus on the early rearing phase.

Static space requirements of male meat turkeys

The area covered by standing male meat turkeys between 11 and 21 weeks of age was measured by planimetry on photographs taken from directly above the birds. There was a strong relationship (r = 0.86) between their liveweight and the area covered, and a formula was derived for the calculation of the area covered by turkeys weighing between 7.6 and 21.8 kg. A comparison with the formula developed on theoretical grounds in 1995 by the Farm Animal Welfare Council (FAWC) showed that for heavy turkeys the FAWC formula is not valid, because it yields values which are about 50 per cent too low.

Reliability and validity of a modified gait scoring system and its use in assessing tibial dyschondroplasia in broilers

1. The gait scoring system for broilers developed by Kestin et al. (Veterinary Record, 131: 190-194, 1992) has been widely used to evaluate leg problems. The many factors and measures associated with this scale have empirically established its external (biological) validity. However, published test-retest (within-observer) reliabilities are poor, and inter-observer reliabilities are unknown. We evaluated several modifications to this scale aimed at improving its objectivity and reliability. 2. Eighteen naïve observers scored a standardised video of birds exhibiting varying degrees of lameness, either using Kestin et al.'s system, or our modified system. 3. Test-retest reliability (0.906) for Kestin et al.'s system was higher than previously reported. Inter-rater reliability was also good (0.892). The modified system offered significantly better test-retest (0.948) and inter-rater reliabilities (0.943), without incurring costs in terms of time taken or difficulty of use. The systems were consistent, assigning individual birds the same score on average. 4. It is concluded that the modified system offers the advantages of reduced error within and between studies. 5. In a second experiment, we used our modified scoring system to examine the relationship between tibial dyschondroplasia (TD) and gait score in 267 selected broilers. 6. Neither the presence nor severity of TD affected gait score, suggesting that, at least in this strain of broilers, other leg problems like slipped tendons or torsional deformities had more influence on gait impairment than did TD.

Risk factors for foot-pad dermatitis in chicken and turkey broilers in France

A prospective cohort study was conducted in the Brittany region to identify the risk factors related to foot-pad dermatitis (considered an indicator of animal well-being) in chicken and turkey broilers reared under commercial conditions. Factors related to the shed, equipment, litter management and stocking density were recorded; the dependent variable was the prevalence of lesions observed on the slaughterhouse chain. Lesions were scored from 0 (no lesion) to 3 (severe lesion). Our survey lasted from May 1999 to October 2000. Fifty flocks of chicken broilers (15 farms), 27 flocks of female turkey broilers (21 farms) and 41 flocks of male turkey broilers (27 farms) were surveyed. In chicken broilers, 10% of flocks were of high quality (80% of birds with score 0) and this was related to the use of concrete floors with a thin layer of wood shavings. In turkey broilers, 48% of female and 46% of male flocks were of bad quality (>10% of birds with score 3). A poor fan ventilation system (<150m(3)/h/kg) was a significant risk factor. Turkey flocks of high quality were not observed. Stocking density had no influence on the prevalence of foot-pad dermatitis. We concluded that it is possible under high commercial stocking densities to have flocks with a low prevalence of foot-pad dermatitis in chicken broilers, whereas it is not in turkey broilers. Hence in chicken broilers, implementing a monitoring system based on the observation of foot-pad dermatitis prevalence at slaughter appears to be more appropriate than to legislate stocking density. In turkey broilers, it would probably be necessary either to reduce the stocking density drastically or to investigate new systems of floor drainage.

Influence of environmental enrichment on injurious pecking and perching behaviour in young turkeys

1. In order to reduce injurious pecking, the influence of environmental enrichment on pecking and perching behaviour was studied in young male and female turkeys. 2. Two different types of enrichment and a control treatment (TO) were tested: T1, metal objects and straw; T2, similar to T1 + wood perches. Birds were housed in 36 m2 pens at a light intensity of 5 lux with 4 replicates per treatment in a 2x3 factorial design. 3. Pecking at objects and perching behaviour were observed weekly. Behaviour was video recorded at weeks 5 and 10. Birds were examined daily for the occurrence of injuries. At the end of the rearing period, an ACTH challenge was performed and H/L ratio was measured. 4. Objects were regularly pecked at. Perching was more common in females, peaked at week 5 (10% to 13% of birds perched) and declined to 0% by week 10. Aggressive pecking was more frequently observed in males in T0 than in T1 or T2 at week 10. Wing (in males and females), tail and head (in males) injuries were more common in T0 than in T1 or T2. T1 and T2 were similar Response to ACTH challenge and H/L ratio were not consistently influenced by treatments. 5. It is concluded that metal objects and straw reduced injurious pecking in young female and male turkeys by redirecting, pecking activity.