Regarding the lack of standardized methods for beak trimming to reduce feather pecking in Japanese quail, the present study aimed to compare two ages and 3 methods of beak trimming, evaluating the ...performance, egg quality and feather pecking. One-day-old Japanese quails (n = 770; 22 birds cage-1), at the initial phase, and 36-day-old (n = 630; 18 birds cage-1), at the production phase, were assigned to a completely randomized design, consisting of 7 treatments with 5 replicates. The treatments were: non-trimmed (NT), cauterization of approximately 1/3 at 14 days-of-age (CAUT 14) and at 28 days-of-age (CAUT 28), moderately trimmed to approximately 1/3 beak at 14 days-of-age (MOD 14) and at 28 days-of-age (MOD 28), severely trimmed to 1/3-1/2 beak at 14 days-of-age (SEV 14) and at 28 days-of-age (SEV 28). Data were analyzed using Minitab®. The results indicated that beak trimming methods applied did not influence the performance and egg quality. Quails subjected to MOD 28 and SEV (14 and 28) presented lower feed conversion per egg mass compared to NT. However, MOD 14 and SEV were more efficient in preventing feather pecking behavior.
Injurious pecking remains one of the biggest problems challenging free range egg producers, with both economic implications for the farmer and welfare implications for the birds. The most widespread ...form of injurious pecking is feather pecking, the most damaging form of which is severe feather pecking (SFP) which has, as yet unclear, links with gentle feather pecking (GFP). The current prospective epidemiological study investigates the development of GFP and SFP on 61 free range and organic UK farms (111 flocks). Flocks were visited at 25 (20–30) and 40 (35–45) weeks, when rates of GFP and SFP respectively and levels of feather damage were recorded. Environmental and management data were collected for each flock. Factors affecting the development of these behaviours were modelled using the multilevel modelling program, MLwiN (
Rasbash et al., 2004).
GFP was observed in 89.2% and 73% of flocks at 25 and 40 weeks, respectively, at a mean rate of 0.65
bouts/bird/h. GFP rates decreased with increased percentage range use (coeff.: −0.001
±
0.0006,
p
=
0.025) and temperature inside the laying house (coeff.: −0.005
±
0.001,
p
=
0.001). GFP was higher in flocks with soil or grass litter (
χ
2
=
13.16, df
=
4,
p
=
0.012), flocks which had no perch access (0.010
±
0.001 vs. 0.007
±
0.002
bouts/bird/min,
p
=
0.047) and flocks which were beak trimmed compared to those non-beak trimmed or retrospectively beak trimmed (0.013
±
0.002 vs. 0.003
±
0.001 and 0.002
±
0.001,
p
=
0.007). SFP was observed in 68.5% and 85.6% of flocks at the 1st and 2nd visits, respectively, at a mean rate of 1.22
bouts/bird/h. SFP rates decreased with range use (coeff.: −0.001
±
0.0003,
p
=
0.003). Mean rates were highest in non-beak trimmed compared to beak trimmed flocks (0.032
±
0.003 vs. 0.017
±
0.003
bouts/bird/min,
p
=
0.028), flocks observed to be feather pecking when they arrived on farm compared to those that were not (0.062
±
0.018 vs. 0.019
±
0.002
bouts/bird/min,
p
=
0.001), and flocks fed pelleted compared to those fed mashed food (0.042
±
0.002 vs. 0.016
±
0.002
bouts/bird/min,
p
=
0.005). Plumage damage was lower in beak trimmed compared to non-beak trimmed flocks (plumage score 1.00
±
0.0001 vs. 1.15
±
0.068,
p
=
0.040), and flocks which were fed mashed feed, and showed a quadratic relationship with severe feather pecking (
p
=
0.003) which was positive over the observed ranges of the behaviours. In commercial situations, feeding mashed feed and increasing range use may reduce severe feather pecking and therefore feather damage.
Plumage damage (PD) as a result of severe feather pecking (SFP) and skin lesions (SL) due to cannibalism (CA) is serious welfare, performance, and economic problems in commercial layer farms. ...Genetics, nutrition, and housing conditions are central complexes that contribute to the multifactorial causes of these behavioral disorders. Practical recommendations consider the quality of litter as an important criterion for the prevention of SFP, although systematic longitudinal studies providing evidence-based findings are lacking.
Therefore, the aim of this study was to investigate the effects of litter condition on the occurrence of PD and SL in the field using a longitudinal design. Integument scoring (PD and SL; 7 times), litter scoring (structure, cake formation, litter quality, and litter height; 12 times), and laboratory litter analysis (dry matter (DM), nitrogen (N), phosphorus (P) and pH value; 12 times) were performed in 28 laying hen flocks with a median flock size of 12,357 birds, in barn (n = 21) or free-range systems (n = 7), during the first laying period.
Binary logistic regression (BLR) models showed the association of housing type and animal age on PD and SL (P < 0.001), and of the hybrid type on PD (P < 0.001). Furthermore, a significant association with PD and SL was observed for several litter traits. An increase in litter height, DM, and P was associated with lower PD (P ≤ 0.022) and SL (P < 0.001). In contrast, a higher N content of the litter was associated with an increase in SL (P = 0.007). Cake formation (P < 0.001) and a low structure (P = 0.025) of the litter showed an association with higher PD.
In conclusion, this study identified caked litter with less structure, low height, and low contents of DM and P as risk factors for behavioral disorders in commercial laying flocks.
•Feather pecking (FP) in chickens can be malfunctioning and maladaptive.•Deficient 5-HT1A autoreceptor and MAO-A activity appear predisposing for FP.•Young chicks with high FP tendency have low ...central 5-HT and DA activity.•Central 5-HT and DA activity is affected in adult FP birds in specific brain regions•Peripheral 5-HT, gut microbiota, immune functioning, are related to FP.
A deficient serotonergic system is associated with psychopathological behaviors in various species, among which, feather pecking (FP) in chickens. Deficiency in the serotonergic system can predispose birds to develop FP, while the serotonergic system is affected in birds that feather peck. Serotonin (5-HT) can further influence dopamine (DA) activity. Lines with high FP tendency generally have low central 5-HT and DA turnovers at a young age, but high turnovers at an adult age in brain areas involved in somato-motor regulation and goal-directed behavior. Agonizing 5-HT1A and 5-HT1B receptors increases FP, while antagonizing D2 receptor reduces FP. Genetic associations exist between FP, 5-HT1A and 5-HT1B receptor functioning and metabolism of 5-HT and DA. Birds with deficient functioning of the somatodendritic 5-HT1A autoreceptor and 5-HT metabolism appear predisposed to develop FP. Birds which feather peck often eat feathers, have low whole-blood 5-HT, different gut-microbiota composition and immune competence compared to non-peckers. FP and feather eating likely affect the interaction between gut microbiota, immune system and serotonergic system, but this needs further investigation.
The aim of this study was to evaluate the effect of 16L:8D photoperiod with green (GREEN) or white (WHITE) lights during incubation on hatching performance, blood melatonin, corticosterone, and ...serotonin levels, hypothalamic expressions of genes related to photoreception, serotonin, and stress systems in layers in relation with feather pecking behavior. Dark incubation (DARK) was the control. Eggs (n = 1,176) from Brown Nick breeders in 2 batches (n = 588/batch) were incubated in the experiment. A total of 396 female chicks and 261 hens were used at rearing and laying periods until 40 wk. Incubation lighting did not affect hatchability, day-old chick weight, and length, but resulted in a more synchronized hatch as compared with the DARK. The effect of incubation lighting on blood hormones was not significant except for reduced serotonin in the GREEN group at the end of the experiment. There was no effect of incubation lighting on gentle, severe, and aggressive pecking of birds during the early rearing period. From 16 wk, GREEN hens showed increased gentle pecking with increasing age. WHITE hens had the highest gentle pecking frequency at 16 wk while they performed less gentle but higher severe and aggressive pecks at 24 and 32 wk. At hatching, the hypothalamic expression of CRH, 5-HTR1A, and 5-HTR1B was higher for the WHITE group compared with both GREEN and DARK, however, 5-HTT expression was higher in GREEN than WHITE which was similar to DARK. Except for the highest VA opsin expression obtained for WHITE hens at 40 wk of age, there was no change in hypothalamic expression levels of rhodopsin, VA opsin, red, and green opsins at any age. Although blood hormone levels were not consistent, results provide preliminary evidence that incubation lighting modulates the pecking tendencies of laying hens, probably through the observed changes in hypothalamic expression of genes related to the serotonin system and stress. Significant correlations among the hypothalamic gene expression levels supplied further evidence for the associations among photoreception, serotonin, and stress systems.
Oviposition in an appropriate nest is a behavioural priority in laying hens, and layer strains are known to differ in their patterns of nest use. However, besides oviposition, laying hens often show ...undesired behaviours such as aggression or gregarious nesting in colony nest boxes. The aim of the present study was to obtain basic information on the patterns of nest use and the behaviour in the nest of dual-purpose hens (Lohmann Dual, LD) by comparing them to a conventional layer strain (Lohmann Brown plus, LB+). In addition, the effect of nest location was tested for each hybrid. About 1850 untrimmed hens per genetic strain were housed in four compartments of an aviary system with colony nest boxes on the top tier. Video-based data were recorded in the first (N1) and the sixth nest (N2) in a row of nest boxes in each compartment at three times during the laying period to assess the number of hens per nest, the duration of nest visits of focal animals, and the behaviour of the hens in the nest. In general, a larger number of LD (0.87 ± 0.09–10.63 ± 0.30) than LB+ hens (0.21 ± 0.04–4.90 ± 0.24) was observed per nest box. In both hybrids, more hens were found in N1 compared to N2 (P < 0.05). Except for 43rd–48th weeks of life, the durations of nest visits did not differ between LB+ (09:51 ± 00:41–18:25 ± 00:48 mm:ss) and LD hens (07:14 ± 00:32–17:14 ± 00:32 mm:ss). However, both hybrids spent more time in N2 compared to N1 (P < 0.05). Hybrid effects (P < 0.05) were found for nearly all of the observed behaviours. In particular, LB+ hens performed more total pecking behaviour, whereas LD hens showed more piling in the nest. In the LB+ hens, nest location affected only few of the behaviours. In contrast, nest location effects were found for most of the behaviours observed in the LD hens. Particularly piling occurred to a larger extent in N1. The present results indicate that the patterns of nest use and the behaviour in the nest differed between conventional layers and dual-purpose hens. Within genetic strain, dual-purpose hens seemed to be more affected by nest location than conventional layers
Various plumage and integument scoring methods are commonly used to deduce the occurrence of severe feather pecking and cannibalism in laying hens. The aim of our study was to provide evidence of ...correlations between the occurrence of severe feather pecking and our individual plumage scoring system used under practical conditions on commercial farms with non–beak-trimmed and beak-trimmed layers (study I). In second step, we aimed to verify whether the results of the elaborate individual scoring may be predicted with a visual scoring method based on the total body scores of groups of birds (study II). For study I we observed the pecking behavior and performed an individual plumage scoring at the beginning, in the middle, and at the end of a laying period on 8 commercial farms. For study II we performed both an individual and a visual plumage scoring on 49 flocks on 45 farms at the beginning of the laying period and on 43 flocks on 41 farms at the end of the laying period. Spearman's Rho revealed a correlation of the mean feather pecking rate with the total plumage score, the neck–back plumage score, and the total cannibalism score in all observation periods. A high feather pecking rate was correlated with severe plumage damage and the frequent occurrence of skin injuries. We conclude that both the total plumage score and the neck–back plumage score constitute a reliable indicator of the occurrence of severe feather pecking in the flocks assessed in this study. The results of study II suggest that the percental assessment of plumage damage on flock level in 3 categories (“visual score”) leads to a good prognosis of the actual, individually assessed plumage score. Therefore, the application (and documentation) of the visual score on a regular basis can provide a good evaluation of the development of the plumage condition of the flock. The visual score presented in this study is suggested as a suitable instrument for self-evaluation programs on farms.
1. Within a triennial project, 34 layer flocks with untrimmed beaks were examined regularly throughout the laying period to broaden knowledge on the occurrence and development of severe feather ...pecking and cannibalism, as well as on factors influencing this non-desirable behaviour.
2. Flocks involved 850 to 27,183 hens of seven different genetics, kept in a barn or on free-range systems. Damage to the plumage and skin was assessed in individual hens during each visit and their body weights recorded. Correlations smaller than 0.8 between different body areas for damage indicated the necessity to consider them separately. Accounting for the risk of bias due to unevenly distributed factors, regression functions were used to assess associations between pecking damage, losses and performance, housing and management conditions. In addition, temporal pattern of pecking damage for flocks with severe, medium and little damage was modelled using these functions.
3. As expected, plumage damage increased with age, whereas the development of skin lesions was less consistent. From 30 weeks of age, pecking damage on the back increased remarkably in flocks with the most severe scores compared to those with medium and little damage, especially during the later laying period. Associations were found between pecking damage on the back of hens with plumage quality of pullets when entering the layer house (point of lay). Damage to the vent/cloacal region was more pronounced in white compared to brown layers. However, this did not deny the importance of factors not significant in this study.
4. The study identified factors related to genetics and status of hens when entering the layer house, particularly the influence of the rearing phase.
It is crucial to identify whether relations between immune characteristics and damaging behaviors in production animals exist, as these behaviors reduce animal welfare and productivity. Feather ...pecking (FP) is a damaging behavior in chickens, which involves hens pecking and pulling at feathers of conspecifics. To further identify relationships between the immune system and FP we characterized high FP (HFP) and low FP (LFP) selection lines with regard to nitric oxide (NO) production by monocytes, specific antibody (SpAb) titers, natural (auto)antibody (N(A)Ab) titers and immune cell subsets. NO production by monocytes was measured as indicator for innate pro-inflammatory immune functioning, SpAb titers were measured as part of the adaptive immune system and N(A)Ab titers were measured as they play an essential role in both innate and adaptive immunity. Immune cell subsets were measured to identify whether differences in immune characteristics were reflected by differences in the relative abundance of immune cell subsets.
Divergent selection on FP affected NO production by monocytes, SpAb and N(A)Ab titers, but did not affect immune cell subsets. The HFP line showed higher NO production by monocytes and higher IgG N(A)Ab titers compared to the LFP line. Furthermore the HFP line tended to have lower IgM NAAb titers, but higher IgM and IgG SpAb titers compared to the LFP line. Thus, divergent selection on FP affects the innate and adaptive immune system, where the HFP line seems to have a more responsive immune system compared to the LFP line. Although causation cannot be established in the present study, it is clear that relationships between the immune system and FP exist. Therefore, it is important to take these relationships into account when selecting on behavioral or immunological traits.
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•We studied immune characteristics of lines differing in feather pecking (FP).•High and low FP lines did not differ in relative abundance of immune cell subsets.•High FP line monocytes produced more nitric oxide ex vivo vs low FP line monocytes.•High FP line had higher specific and natural (auto)antibody titers vs low FP line.•High FP line seems to have a more responsive immune system vs low FP line.
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