Gentle Feather Pecking Research Articles

Do flickering lights impact turkey hen behavior, stress, and fear?

Little is known about the effect of light-flicker frequency on poultry, particularly on turkeys. This experiment examined the impact of light-flicker frequency on the behavior, stress, and fear response of Nicholas Select turkey hens reared to 11 wk. The experiment was a randomized complete block design (2 trials), with a one-way factorial analysis evaluating 3 light-flicker frequencies (30, 90, or 195 Hertz; Hz). Birds (n = 3,276 per trial) were housed in 9 individual environmentally controlled rooms (3 replicates per treatment per trial). Data collected included: behavior (4, 8, and 10 wk), incidence of aggressive damage, heterophil-to-lymphocyte ratio, and novel object test (daily d 1-7 and at 4, 8, and 11 wk). Data were analyzed using Proc Mixed (SAS 9.4), with significance declared at P ≤ 0.05. Behavior data are presented as the percentage of time spent performing the behavior. At 4 wk, gentle feather pecking and exploratory behaviors were higher under 195 Hz compared to 30 Hz (P = 0.04 and P = 0.05, respectively). Preening was higher under 90 Hz compared to 30 Hz (P = 0.05). At 8 wk, wing flapping was lowest under 195 Hz (P < 0.01). Gentle feather pecking was higher under 90 and 195 Hz compared to 30 Hz (P = 0.02). Fighting (P = 0.05), aggressive pecking (P = 0.02), and aggressive behaviors (P = 0.01) were lower under 30 Hz compared to 90 Hz. At 10 wk, preening was decreased under 30 Hz (P = 0.03). Incidences of aggressive damage were reduced under 30 Hz compared to 90 Hz (0 d-4 wk; P = 0.01) and under 30 compared to both 90 and 195 Hz (4-8 wk; P = 0.01). At 11 wk, heterophil-to-lymphocyte ratios were lowest under 30 Hz (P = 0.04). The novel object test was unaffected by flicker treatment. In conclusion, many behaviors and the stress and fear responses were unaffected by either visible or non-visible flicker. However, visible flicker (30 Hz) reduced some comfort and exploratory behaviors early in life, and the impact on preening continued to older ages, suggesting minor negative impacts of flicker, particularly early in life.

Effects of Stocking Rate and Environmental Enrichment on the Ontogeny of Pecking Behavior of Laying Hen Pullets Confined in Aviary Compartments during the First 4 Weeks of Life.

Simple SummaryThe objective of this study was to describe the development of aggressive pecking, gentle feather pecking and severe feather pecking of non-beak-trimmed laying hen pullets during the first 4 weeks of life. The pecking behavior patterns were observed in three different experimental groups, which differed in stocking rates and the provision of enrichment material. The enrichment materials were suitable and intensely used by the pullets. The provision of pecking blocks and pecking stones is recommended as a preventive measure from the first day of life onwards for pullets housed in commercial rearing aviaries. There was no effect of reduced stocking rate, most likely due to the low variation in stocking rates.The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first 4 weeks of life (observation on 1st, 8th, 15th, 22nd, and 29th days of life) while they were kept within the compartments of a commercial rearing aviary (without access to a litter area). All chicks were placed into compartments of the middle tier of the aviary on the 1st day of life. On the 10th day of life, half of the chicks of each compartment were moved into the compartments of the lower tier. The aviary floor was covered with chick paper before the placement of the chicks and fully or partially removed from the 15th day of life onwards. The pecking behavior patterns were observed in three experimental groups (EG): NE (not enriched): group size until/after 10th day of life: 230/115; 120.8/60.4 birds/m2, no enrichment; EL (enriched, low stocking rate): group size until/after 10th day of life: 203/101, 106.6/53.6 birds/m2; and EH (enriched, high stocking rate): group size until/after 10th day of life: 230/115;120.8/60.4 birds/m2, both pecking stones and blocks as enrichment) in two rearing periods. For each pecking behavior pattern, an independent regression model with the parameters EG, chick paper, observation day, and functional area was estimated. GFP, SFP, and EP increased with age during the observation. The AP rate was highest in all EGs on the first day of life and decreased during the observation period. A pairwise comparison of NE (high stocking rate without enrichment) with EH (high stocking rate with enrichment and with EL (low stocking rate with enrichment) showed a significant effect of the EG on pecking behavior, with more SFP, AP, and GFP in NE. There were no differences between EL and EH, indicating that the provision of pecking materials had more influence than the stocking rate. However, we presumed that the difference between the stocking rates were too small to observe an effect. AP, SFP, and GFP were significantly higher on wired slats, as compared to the perches and the vicinity of the enrichment materials. The enrichment materials were suitable and intensely used by the pullets. The provision of pecking blocks and pecking stones was recommended as a preventive measure from the first day of life onwards for pullets housed in commercial rearing aviaries. There was no effect of reduced stocking rate, most likely due to the low variation in stocking rates.

Influence of different dietary fibre contents in the diet on feather pecking, locomotor activity and performance of laying hens

ABSTRACT 1. This study investigated the effects of three diets with increasing proportions of insoluble dietary fibre (3%, 6% and 9%) but with similar metabolisable energy on behaviour, plumage condition and laying performance of Lohmann Tradition hens. 2. At 21 weeks of age, four groups of 20 hens each (= four replicates/treatment) were randomly assigned to one of the three feeding treatments and exclusively fed with their assigned feed until the end of the laying period. 3. Severe feather pecking decreased with increasing fibre content (3%: 0.78 pecks/30 min/hen, 6%: 0.31, 9%: 0.12; P < 0.0001). In contrast, no effect of fibre was seen for gentle feather pecking (P = 0.19) and aggressive pecking (P = 0.84). The number of free feathers in the littered area increased with increasing fibre content (3%: 0.06 feathers/625cm2/hen, 6%: 0.09, 9%: 0.16; P = 0.0074). Over time, plumage quality worsened in all hens, but was consistently better with increasing fibre content (fibre content × sampling period; P < 0.0001). Locomotor activity was similar across all treatments, except for a slight decrease in hens fed the 3% fibre diet at the end of the experimental period. No effect of fibre content on hens’ weight (P = 0.75) was detectable. Similarly, performance did not differ between hens fed varying dietary fibre. 4. The results supported the assumption that increasing dietary fibre helps to reduce the risk for the occurrence of feather pecking in laying hens, i.e. improve well-being, while having no negative effects on performance.

Types and clinical presentation of damaging behaviour - feather pecking and cannibalism in birds

Behavioural disorders, including feather pecking and cannibalism, are a common problem in both domestic and wild birds. The consequences of this behaviour on welfare of birds incur serious economic losses. Pecking behaviour in birds is either normal or injurious. The type of normal pecking behaviour includes non-aggressive feather pecking – allopreening and autopreening. Aggressive feather pecking aimed at maintenance and establishment of hierarchy in the flock is not associated to feathering damage. Injurious pecking causes damage of individual feathers and of feathering as a whole. Two clinical presentations of feather pecking are known in birds. The gentle feather pecking causes minimum damage; it is further divided into normal and stereotyped with bouts; it could however evolve into severe feather pecking manifested with severe pecking, pulling and removal, even consumption of feathers of the victim, which experiences pain. Severe feather pecking results in bleeding from feather follicle, deterioration of plumage and appearance of denuded areas on victim’s body. Prolonged feather pecking leads to tissue damage and consequently, cannibalism. The nume­rous clinical presentations of the latter include pecking of the back, abdomen, neck and wings. Vent pecking and abdominal pecking incur important losses especially during egg-laying. In young birds, pulling and pecking of toes of legs is encountered. All forms of cannibalistic pecking increase morta­lity rates in birds. Transition of various pecking types from one into another could be seen, while the difference between gentle, severe feather pecking and cannibalism is not always distinct.

Assessment of fluralaner as a treatment in controlling Dermanyssus gallinae infestation on commercial layer farms and the potential for resulting benefits of improved bird welfare and productivity

BackgroundPoultry red mite (PRM) (Dermanyssus gallinae) infestations are a cause of anaemia, impaired productivity and stress-related behaviours linked to reduced hen welfare. A study investigated the potential health, welfare and productivity benefits following fluralaner treatment to eliminate PRM from infested hens.MethodsA PRM-infested layer house was selected on a free-range farm (5400 hens) and an aviary farm (42,400 hens). Fluralaner (Exzolt®; 0.5 mg/kg body weight) was administered twice, 7 days apart (Weeks 0 and 1), via drinking water. Mite populations were monitored by traps. Cameras recorded nighttime hen behaviours weekly, pre- and post-treatment. On the free-range farm, daytime behaviours were also recorded weekly. For pre- and post-treatment corticosterone assessments, eggs were randomly collected on both farms, and blood samples were collected from 50 randomly selected aviary farm hens. Production parameters were assessed using farm records.ResultsThroughout the post-treatment period, fluralaner efficacy against PRM was > 99% on both farms. On the aviary and free-range farms, treatment was followed by significant nighttime increases in the proportion of resting hens (P < 0.0001; P = 0.0175, respectively). Significant post-treatment versus pre-treatment nighttime reductions were observed in head shaking (aviary, P < 0.0001; free-range P = 0.0233) and preening (P = 0.0032; P = 0.0018) and on the aviary farm in bouts of body shaking (P = 0.0108), vertical wing shaking (P = 0.0002), head scratching (P = 0.0335), and gentle feather pecking (P < 0.0001). On the free-range farm there were significant daytime reductions in head scratching (P < 0.0001), head shaking (P = 0.0492) and preening (P = 0.0012). Relative to standard production parameters, no differences were detected on the aviary farm, but on the free-range farm the laying rate decline with increasing age was less than expected and the increase in egg weight greater than expected. Post-treatment increases in egg and plasma corticosterone were suggestive of stress factors in addition to mite infestation. Red blood cell counts and haematocrit increased following treatment.ConclusionFluralaner treatment eliminated mite challenge, leading to improved hen welfare and health, based on reductions in stress-related behaviours and restoration of the anaemia-inducing effects of mite blood feeding.Graphical

Self- and conspecific-directed pecking behavior of commercial Pekin ducks

Injurious pecking behavior affects commercial Pekin duck welfare, but little information is available regarding the characteristics thereof. This study investigated self- and conspecific-directed pecking behavior of ducks, including 1) the prevalence, frequency and duration, 2) age-related changes in pecking and preening behavior, and body locations affected; 3) influence of time of day and location within the barn; and 4) occurrence of feather removal and feather eating. Behavior of two commercial flocks was video-recorded at 20–22 d (Period 1), 27–29 d (Period 2), and 34–36 d (Period 3) and analyzed using scan (n = 340 ± 91 ducks/flock per observation time point) and focal (n = 144 observation periods/flock) animal sampling. The percentage of ducks performing pecking behavior (gentle feather pecking (%GFP), severe feather pecking (SFP), aggressive pecking (AGGP) and self-picking (SELFP)) was determined every 30 min (09:00 h-15:00 h). Randomly selected focal ducks were observed for 30 min (09:45 h-10:15 h and 13:45 h-14:15 h) to determine durations and frequencies of pecking and preening behavior and the occurrence of feather removal and feather eating. Scan sampling data and focal behavioral durations were analyzed using PROC MIXED; behavioral frequencies were analyzed using PROC GLIMMIX (SAS 9.4). SFP, AGGP and SELFP were combined into one category, other pecking (OP), for analysis. GFP was observed most frequently, SFP and AGGP occurred less frequently, and SELFP was rarely observed. Feather removal (13 times) and feather eating (7 times) occurred infrequently. GFP frequency, duration and GFP% increased from Period 1 to 2 (P < 0.01), then declined from Period 2 to 3 (P < 0.01). Preening frequency and duration similarly changed with age (P < 0.01). OP frequency (P = 0.03) and duration (P = 0.03) were higher in Period 2 than Period 1. Body locations affected by GFP included the tail, wings and back. Little injurious pecking was observed; GFP between conspecifics was the most frequently observed behavior. Age was a major factor affecting the performance of pecking behavior, which peaked at Period 2 and was most frequently directed at the tail, wings and back. Further research is needed to examine seasonal effects and other factors influencing injurious pecking of ducks.

Reducing feather pecking and cloacal cannibalism by providing layer breeders with nest boxes in colony cages for natural mating

Colony cages for natural mating have been applied on many layer breeder farms. However, feather pecking and cloacal cannibalism are considered as prominent problems for these systems. This study aimed to investigate the effects on feather pecking and vent pecking behaviors by providing layer breeders with nest boxes (0.90 m L × 0.40 m W × 0.60 m H) in colony cages for natural mating (4.80 m L × 1.20 m W × 0.71 m H). Video recording and artificial observation were adopted. The results showed that the usage of nest boxes gradually increased from the beginning of nest boxes providing at the age of 37 weeks to the end of the experiment at the age of 55 weeks. The utilization rates of nest boxes were 36.75%, 44.75% and 50.38% at the ages of 41 weeks, 47 weeks and 53 weeks, respectively. The hens in the cages without nest boxes showed significantly more frequent gentle feather pecks (both given and received) than hens in the cages with nest boxes at the ages of 41 weeks, 47 weeks and 53 weeks. A decreasing trend of gentle feather pecking frequency (both given and received) was found with the increasing age for both the two groups. No significant difference was found in the number of given or received severe feather pecks at the age of 41 weeks. The hens in the cages without nest boxes showed a significantly higher frequency of given and received severe feather pecks than hens in the cages with nest boxes at the ages of 47 weeks and 53 weeks (p<0.05). Both cannibalistic injury occurrence and mortality rate in the cages with nest boxes were significantly lower than those in the cages without nest boxes. In conclusion, providing nest boxes in colony cages for natural mating could decrease abnormal pecking behaviors and improve animal welfare conditions of layer breeders. Keywords: feather pecking, vent pecking, nest box, colony cage, cloacal cannibalism, layer breeder, animal welfare DOI: 10.25165/j.ijabe.20181106.3323 Citation: Shi H P, Zheng W C, Tu J, Li B M. Reducing feather pecking and cloacal cannibalism by providing layer breeders with nest boxes in colony cages for natural mating. Int J Agric & Biol Eng, 2018; 11(6): 27–32.

Comparing the behavioural organization of head pecking, severe feather pecking, and gentle feather pecking in domestic turkeys

Detection of behavioural temporal patterns (T-patterns) allows for insight into the organization of behaviours that is not apparent through quantitative analysis of the durations and frequencies of discrete behaviours. In this study, a T-pattern was defined as a reoccurring sequence of ≥2 behavioural event types22Behavioural event types: In this study, a behavioural event type was classified as each occurrence of a behavioural event and both the start and end of each occurrence of a behavioural state. linked by a non-random critical period of time and occurring more often than expected by chance. This study aimed to identify differences in the behavioural distribution and organization of two forms of injurious pecking, head pecking (HP) and severe feather pecking (SFP), and non-damaging gentle feather pecking (GFP) in domestic turkeys using two analytical methods T-pattern analysis and a conventional assessment of behavioural frequencies and durations. Video observations of pecking behaviour were obtained from focal samples of domestic male turkeys between 5 and 15 weeks of age. Each focal sampling observation recorded all behaviours shown by a single turkey 120 s (s) before and after the turkey performed HP, GFP, or SFP (241 s total observation length per pecking event). Pecking type had no effect on the number of T-patterns and the frequency of T-pattern occurrences. However, both T-pattern detection and the conventional analysis showed turkeys in observations containing HP tended to be more active with shorter lying durations (H = 7.36, df = 2, P = 0.025), less frequent standing (H = 5.61, df = 2, P = 0.061), and less structured T-patterns (total T-pattern durations: H = 5.996, df = 2, P = 0.050, mean durations: H = 5.34, df = 2, P = 0.068) than turkeys engaged in GFP or SFP. The analyses also showed that turkeys that performed SFP tended to show more frequent GFP than turkeys that performed HP (H = 5.79, df = 2, P = 0.055). However, discrepancies in organization of feeding and foraging behaviour between the two analytical methods highlighted the susceptibility of both methods to behavioural variation between individuals when using small sample sizes. Future research should use T-pattern detection to evaluate age, sex, and environmental differences in the organization of the injurious pecking behaviour in domestic turkeys.

The influence of stocking density and enrichment on the occurrence of feather pecking and aggressive pecking behavior in laying hen chicks

The housing conditions and environments experienced during the rearing period can influence the development of feather pecking in chickens during this time and in the subsequent laying period. The aim of this study was to investigate the effect of a reduced stocking density and the provision of enrichment materials on the occurrence of feather pecking in hen chicks under commercial rearing conditions. Three groups, identical in age, laying strain, and management but kept with different stocking densities and varying availability of enrichment (pecking stone, pecking block, and lucerne bale), were observed. Group 1 had a high stocking density (22.9 animals per m2) and no access to enrichment, group 2 had a lower stocking density (18.1 animals per m2) plus enrichment, and group 3 had a high stocking density (22.9 animals per m2) plus the same enrichment as group 2. Behavioral observations from video recordings were made on the occurrence of enrichment pecking, gentle feather pecking (GFP), severe feather pecking (SFP), and aggressive pecking. Furthermore, the influence of enrichment pecking on the occurrence of GFP, SFP, and aggressive pecking and the effect of SFP on the plumage condition were examined. The comparison of the 2 groups with enrichment demonstrated that the group with the higher stocking density showed a higher rate of SFP (95% confidence interval [CI] for the difference: [0.001-0.015]). The comparison of the 2 groups with and without enrichment but with equal stocking densities showed that the group with access to enrichment had significantly lower rates of GFP (95% CI: −0.019 to −0.006), SFP (95% CI: −0.036 to −0.020), and aggressive pecking (95% CI: −0.004 to −0.001). The group with a combination of a lower stocking density and enrichment had significantly lower rates of GFP (95% CI: −0.022 to −0.009), SFP (95% CI: −0.044 to −0.028), and aggressive pecking (95% CI: −0.004 to −0.001) compared to the group with a high stocking density without enrichment. Additionally, the occurrence of enrichment pecking had a significantly reducing effect on the occurrence of GFP (95% CI: −0.046 to −0.031), SFP (95% CI: −0.030 to −0.016), and aggressive pecking (95% CI: −0.003 to −0.0003). Finally, a high rate of SFP had a deteriorating effect on the plumage condition (95% CI: −0.859 to −0.084). Thus, we conclude that a lower stocking density and the provision of enrichment, such as pecking stones, pecking blocks, and lucerne bales, can reduce the prevalence of feather pecking and aggressive pecking in laying hen chicks. The evaluation of the plumage condition can be a valid indicator of feather pecking.

Provision of a resource package reduces feather pecking and improves ranging distribution on free-range layer farms

The effect of a resource package designed to reduce inter-bird pecking and increase range use was tested on fourteen free-range farms in the UK. The package comprised two types of objects intended to attract pecking behaviour: ‘pecking pans’ containing a particulate pecking block, and wind chimes; plus long, narrow shelters placed just outside the popholes, bridging a barren area 2–10m from the house, with the aim of improving bird distribution on the range. We predicted that if the resource package succeeded in these aims, overall bird welfare would also be improved. Fourteen commercial farms were enrolled for this two-year study. Flocks were assessed for pecking behaviour, range use and general indicators of welfare at 40 weeks in Year 1 without the resource package. The resource package was then added to the same houses at the start of the next flock cycle in Year 2. The new flocks were assessed in the same way at 40 weeks with additional observations taken of their use of the resource package at 25 and 40 weeks. These additional observations showed that most aspects of pecking behaviour directed at the pecking pans remained consistent from 25 to 40 weeks although a reduction in substrate pecking frequency was seen (p<0.001) and birds perched on the pan for longer (p=0.033) and more often (p=0.010) at 40 weeks. Although consistent within houses, wind chime use was very variable between houses, with pecking observed in only 8 of the 14 houses. The number of birds under the shelters increased from 25 to 40 weeks (p=0.018), as did the proportion of birds that went under a shelter within 5min of entering the range area (p=0.021). Birds were more likely to use a shelter within 5min if they exited the shed via a pophole within 10m of the shelter rather than a pophole more than 10m away at both 25 weeks (p<0.001) and 40 weeks (p=0.001).A reduction in gentle feather pecking (p=0.001) and severe feather pecking (p=0.018) behaviour was seen when the resource package was provided in Year 2. Range distribution also improved, with a greater proportion of birds seen 2–10m from the house (p=0.023). Additionally, the proportion of abnormal eggs (p=0.010), headshaking behaviour (p=0.009) and the percentage of wet/capped litter (p=0.043) decreased in Year 2.

The effects of environmental enrichment and beak-trimming during the rearing period on subsequent feather damage due to feather-pecking in laying hens

This experiment investigated effects of environmental enrichment and beak-trimming during the rearing period on behavior in rearing and plumage damage later in life. Treatments were applied in a 2 × 2 factorial arrangement. Half of the birds were beak-trimmed at 1 d of age using an infra-red laser. A follow-up light-trim was performed at 11 wk of age with a hot blade. Environmental enrichment consisted of pecking strings, whole oats in the litter, and greater litter depth. Sixteen pens of 50 ISA Brown laying hens were used. Four pullets were selected from each pen as focal birds and observed in their home pens between 3 and 14 wk of age. Plumage damage was scored at the end of the experiment in wk 43. Beak-trimmed birds performed less ground-pecking (P = 0.003), less severe feather-pecking (P = 0.021) and more gentle feather-pecking (P = 0.018) than their non-trimmed counterparts during the rearing period. These birds also exhibited less feather damage in wk 43 (P < 0.001). The results indicate that gentle feather-pecking during rearing is not related to plumage damage when older. Additionally, higher rates of ground-pecking and severe feather-pecking during rearing may be predictive of plumage damage later in life. There was no effect of enrichment on plumage damage. It was concluded that while there was no effect on enrichment, beak-trimming appeared to be effective in reducing plumage damage in wk 43.

Individual Consistency of Feather Pecking Behavior in Laying Hens: Once a Feather Pecker Always a Feather Pecker?

The pecking behavior [severe feather, gentle feather, and aggressive pecks (AP)] of individual White Shaver non-cage laying hens (n = 300) was examined at 21, 24, 27, 32, and 37 weeks. Hens were housed in 30 groups of 10 hens each and on 3 cm litter with access to a feeder, perch, and two nest boxes. The number of severe feather pecks given (SFPG) and received (SFPR) was used to categorize hens as feather peckers (P), victims (V), neutrals (N), or feather pecker-victims (PV) at each age. Hens categorized as PV exhibited pecking behaviors similar to P and received pecks similar to V. SFP given were correlated with APs given, but not with gentle feather pecks (GFP) given throughout the study. State-transition plot maps illustrated that 22.5% of P remained P, while 44% of PV remained PV throughout the duration of the study. Lifetime behavioral categories identified hens as a consistent feather pecker (5%), consistent neutral (3.9%), consistent victim (7.9%), consistent feather pecker-victim (29.4%), or inconsistent (53.8%) in their behavioral patterns throughout their life. Consistent feather peckers performed more SFP than hens of other categories, and consistent neutral hens received fewer GFP than consistent feather PV. No differences in corticosterone or whole blood serotonin levels were observed among the categories. Approximately, half of the population was classified as a feather pecker at least once during the study, while the remainder was never categorized as a feather pecker. Therefore, even if the development and cause of feather pecking may be multifactorial, once the behavior has been developed, some hens may persist in feather pecking. However, as some hens were observed to never receive or perform SFP, emphasis should be made to select for these hens in future breeding practices.

Effects of age at first access to range area on pecking behaviour and plumage quality of free-range layer chickens

Abstract. The aim of this study was to investigate the effects of age on pecking behaviour and plumage quality of free-range laying hens during first access to range. Six hundred 16-week-old layer pullets obtained from a commercial company were housed in a experimental free-range house. The experimental house consisted of a slat-and-litter floor with range area and was divided into three similar pens. The pullets were randomly assigned to a control and two experimental groups according to age at first access to range area. The birds were allowed into the range area for the first time at 18, 20 and 22 weeks of age in the groups of treatment I, treatment II and control, respectively. Pecking behaviour and plumage quality of the birds were measured for 8-week intervals from 24 to 48 weeks of age. Total feather damage significantly increased with age in all groups (P &lt; 0.040, P &lt; 0.006, P &lt; 0.001). Compared to the control group, birds allowed into the range area earlier had less feather damage. The feather score of the tail body region in all groups was significantly greater (more damage) than in the others (P &lt; 0.001). There were no significant differences for the total pecking behaviour of the birds in the groups at 24, 32, 40 and 48 weeks of age. Incidents of gentle feather pecking in every period were more frequent, while aggressive pecking was less frequent (P &lt; 0.026, P &lt; 0.007, P &lt; 0.001). It can be said that access to range area as early as possible at the beginning of the laying period may be useful to reduce the negative effect of feather pecking in free-range layer chickens.

Use of dynamic and rewarding environmental enrichment to alleviate feather pecking in non-cage laying hens

Feather pecking (FP) can cause feather loss, resulting in physical injuries, which may lead to cannibalism. FP appears to be a redirection of foraging behavior, which intensifies when hens have difficulty coping with stress and fear. Dynamic environmental enrichment (EE) may allow expression of natural foraging behavior thus reducing conspecific pecking behavior and alleviating hen injury. Three treatments (plastic box: BOX; hay bale: HAY; and no enrichment: CON) were randomly applied to 30 identical floor pens (10 hens/pen; 10 pens/trt). At the pen level, hen behavior, and the number of severe FP (SFP), gentle FP (GFP), aggressive pecks (AP), and enrichment pecks (EP) were recorded from video prior to (21wk) and after (24wk) treatment implementation, and when hens were 27, 32, and 37wk of age. A manual restraint test (MR) was performed immediately after behavioral observations and levels of blood serotonin (5-HT) and glucocorticoids (GC) measured. Short-term (ST) and long-term (LT) analyses identified the impact of EE over the ST (21 vs. 24wk of age) and LT (21 vs. all other ages) at the pen level. At the pen level, HAY (3.18±0.33) tended to reduce GFP compared to CON (4.10±0.34) over the ST (P=0.15) and LT (P=0.09), but did not impact the number of SFP, or AP over the ST or LT. More EP was observed in HAY (3.56±0.14) than BOX (1.61±0.18) throughout the study (P<0.0001). More HAY hens perched (P=0.05) at 24wk (0.28±0.12) compared to 21wk (0.19±0.11), and more HAY hens (3.69±0.25) performed dust bathing compared to CON (4.14±0.22, P=0.05) throughout the study. CON performed more struggles (1.13±0.04, P=0.04) and were quicker to vocalize (4.87±0.07s, P=0.05) during MR than HAY (latency to vocalize(s): 5.16±0.05; number of struggles: 0.96±0.05), counter-intuitively suggesting CON were less fearful. Treatment did not affect 5-HT or GC. HAY appears to be a promising EE for mitigating GFP in non-cage laying hens. Future studies should examine the impact of EE on individual, rather than group-level responses. These results suggest that the presence of a hay bale is stimulating and may reduce GFP while encouraging hens to redirect pecking towards a dynamic and manipulable EE.

The effect of rearing environment on feather pecking in young and adult laying hens

Although the rearing period has an important influence on the development of feather pecking in laying hens, few studies have quantified the risk factors operating on commercial farms during this time and identified their long-term impact. Our aim was to conduct a longitudinal study to investigate the effect of rearing environment on feather pecking in young and adult laying hens. Thirty-four flocks from 29 rearing farms were recruited and visited at the beginning, middle and end of the rearing period and once at lay (35 weeks). Twelve flocks were beak trimmed. Information on rearing environment was used to create models predicting feather pecking and plumage damage during rear and lay, using the multilevel statistical software MLwiN 2.25. Across all flocks, gentle feather pecking (GFP) was observed during 94% of the visits at both rear and lay, at 1.3 and 1.0 bouts/bird/h respectively. Severe feather pecking (SFP) was observed during 27% of the visits during rear and during 65% of the visits at lay, with a mean rate of 0.4 pecks/bird/h during rear and 1.9 pecks/bird/h at lay, across all flocks. The mean percentage of the flock with missing feathers was 12% at 16 weeks and 49% at lay. The mean individual feather score at lay was 21 (range 6–24 (best)). The study confirmed that feather pecking and feather damage occur during the rearing period. Statistical modelling further showed that the percentage of the flock with missing feathers was significantly lower and individual feather scores significantly higher (better) at lay, in flocks where feather pecking had not started at the end of rear. The three models on the effect of rearing environment on GFP, SFP and the percentage of the flock with missing feathers during rear contained 21 significant variables. Approximately a third of those related to house climate (temperature, humidity, sound, light and dust levels), while another third related to foraging. Foraging itself appeared in all three models, confirming that good foraging is one of the major factors in reducing feather pecking. The four models on the effect of rearing environment on GFP, SFP, the percentage of the flock with missing feathers and individual feather scores at lay contained 17 significant variables and sound level was significant in three of the four. The analysis further indicated that experienced rearing staff was protective against feather pecking at both rear and lay and that feather pecking increased with an increasing number of diet changes during rear.

Can substrate in early rearing prevent feather pecking in adult laying hens?

AbstractIn The Netherlands, laying hen chicks are often reared without litter on the raised slatted area of a barn system or confined in the aviary system during the first two to five weeks after hatching, with chick paper or chicken wire on the floor. In the absence of a suitable pecking substrate, chicks may redirect their pecking behaviour to other birds, which possibly increases the risk of developing feather-pecking behaviour. The aim of this study was to determine whether housing on wood-shavings (WS treatment; n = 15 groups) as compared to housing on chicken wire (CW treatment; n = 15 groups) between day 1-20 could reduce feather pecking in adult birds. After day 20, all chickens were allowed wood-shavings as litter. Behavioural observations showed that CW chicks performed significantly less ground-pecking behaviour compared with WS chicks up to day 20. More CW chicks showed gentle feather pecking at day 7 and 14 as compared to WS chicks, and more CW chicks pecked at the feeder or drinker than WS chicks up to day 20. CW chicks showed rebound behaviour: the day after they were introduced to wood-shavings they displayed more ground-pecking behaviour compared to the WS chicks. Later on in the rearing period no noticeable differences between treatments were found in frequency of gentle and severe feather-pecking bouts. During laying, more gentle feather-pecking bouts were observed in CW than in WS groups but no differences in severe feather-pecking bouts were observed, nor in feather damage at the end of the trial. The results indicate that hens can display substantial flexibility in their pecking behaviour and that, despite more gentle feather pecking in CW hens in laying, the absence of substrate in early rearing does not increase the risk of developing severe feather-pecking behaviour when adult.

The prevention and control of feather pecking in laying hens: identifying the underlying principles

Feather pecking (FP) in laying hens remains an important economic and welfare issue. This paper reviews the literature on causes of FP in laying hens. With the ban on conventional cages in the EU from 2012 and the expected future ban on beak trimming in many European countries, addressing this welfare issue has become more pressing than ever. The aim of this review paper is to provide a detailed overview of underlying principles of FP. FP is affected by many different factors and any approach to prevent or reduce FP in commercial flocks should acknowledge that fact and use a multifactorial approach to address this issue. Two forms of FP can be distinguished: gentle FP and severe FP. Severe FP causes the most welfare issues in commercial flocks. Severe FP is clearly related to feeding and foraging behaviour and its development seems to be enhanced in conditions where birds have difficulty in coping with environmental stressors. Stimulating feeding and foraging behaviour by providing high-fibre diets and suitable litter from an early age onwards, and controlling fear and stress levels through genetic selection, reducing maternal stress and improving the stockmanship skills of the farmer, together offer the best prospect for preventing or controlling FP.

The effect of dark brooders on feather pecking on commercial farms

Commercial laying hen chicks experience continuous light for up to 24h/day in the first week of life. Under these conditions, active chicks disturb, and may direct feather pecks towards resting ones. Previous experimental work with small groups showed that both problems were reduced in chicks brooded by dark brooders (heaters). The current study aimed to extend these small-scale trials by examining the use of dark brooders on two commercial rearing farms. Each farm contributed two identical houses, one of them equipped with dark brooders and the other with regular brooders. The experiment comprised five replicates, each consisting of one dark brooder flock and one control flock (total of 10 flocks). Each flock contained 2000 Columbian Blacktail chicks with intact beaks, which were reared to organic standards. Observations took place three times during the rearing period at 1, 8 and 16 weeks and three of the five replicates were also followed into lay, with observations at 25 and 35 weeks. Bird weights, the evenness of body weight, mortality at the end of rear, feather pecking, the percentage of the flock with missing feathers and individual feather scores were measured, as well as the flock's reaction to a novel object and an approaching human in selected areas of the house. Apart from mortality, which was analysed as a paired t-test in PASW Statistics 18, data were ordered in three (or four) levels (visits within (flock within) replicate within farm) and were analysed using the multilevel statistical software MLwiN 2.25. Treatment and age were entered in the model as explanatory variables. On average, across observations taken at all ages, dark brooder flocks performed significantly less severe feather pecking than control flocks (χ2=12.215, df=1, P=0.0005) and had a significantly lower percentage of birds with missing feathers (χ2=7.380, df=1, P=0.007). Individual feather condition deteriorated faster in the control treatment (treatment×age2: χ2=12.148, df=1, P=0.0005). There was also an interaction between treatment×age for weight (χ2=11.087, df=1, P=0.0009) which meant that dark brooded birds ended up slightly heavier than birds from the control treatment. Mortality at the end of rear, gentle feather pecking and evenness of the weight were not measurably affected by treatment. The novel object and human approach test gave mixed results. In conclusion we found no detrimental effects of dark brooding on commercial farms and suggest this is a promising approach to reducing problems with feather pecking and generally improving the welfare of commercial pullets.

Reduced variance of gene expression at numerous loci in a population of chickens selected for high feather pecking

Changes in gene expression in response to selection were studied by comparing microarray expression profiles among a population of domestic chickens selected for high feather pecking (FP) with a control population and a population selected for low FP. No transcripts showed significant differences among populations with respect to mean expression scores, but numerous transcripts showed reduced variance in expression scores in the high FP population in comparison to control and low FP populations. The reduction in variance in the high FP population generally involved transcripts whose expression scores had a negatively skewed distribution in the control population but not in the high FP population. A certain number of these transcripts corresponded to genes whose expression was significantly associated with either severe FP (SFP) or gentle FP. The patterns of gene expression associated with SFP and gentle FP were distinct, suggesting that very distinct underlying neural mechanisms underlie these 2 behaviors, with SFP showing more signs of an association with synaptic plasticity and with an immunosuppressive stress response.

Effect of broody hens on behaviour of chicks

The objective of the present study was to examine the details of dynamic changes of behaviour of brooded and non-brooded chicks at an early age, the effects of broody hens on the behavioural development and fearfulness of chicks and the correlation between maternal care and fearfulness of chicks, as seen in mice. Five groups of five chicks each were reared by a broody hen, and five groups of five chicks each were provided with a red heating lamp for 28 days. The behaviour of all chicks was recorded using scan sampling at 5-min intervals for 6 h per day at 1, 5, 9, 13, 17, 21 and 25 days of age. Two behavioural tests for evaluating fearfulness and familiarity with humans were conducted at 27 and 28 days of age, and the duration of freezing and latency to the first vocalisation and first step, as well as the number of vocalisations and steps during 10 min, were recorded. The data were analysed using repeated-measures analysis of variance (ANOVA) or Student's t-test. Although the brooded chicks spent 60% of their time resting under broody hens at 1 day of age, the proportion then decreased sharply during the first 2 weeks, stabilised around 10% from 13 days of age and, finally, was reduced to almost zero at 25 days of age. The brooded chicks spent more time on active behaviour ( P < 0.05), dust-bathing ( P < 0.01) and floor pecking ( P < 0.01), but less time on gentle feather pecking ( P < 0.01) than non-brooded chicks. In both behavioural tests, the total duration of freezing was shorter in brooded chicks ( P < 0.001) and the total number of vocalisations ( P < 0.001) and steps taken ( P < 0.001) were higher in brooded chicks. No correlation between resting under broody hens and fearfulness was found. In conclusion, the behavioural development of chicks was promoted and fearfulness was decreased markedly by the presence of a broody hen.