Pecking Behavior Research Articles

Transcriptomic and metabolomic analysis based on different aggressive pecking phenotype in duck

Aggressive pecking is an important welfare and production efficiency issue in poultry farming. The precise mechanisms underlying the occurrence of aggressive pecking remain poorly understood. In this study, we selected Sansui ducks that performed aggressive pecking and ducks that did not perform aggressive pecking from video recordings. Transcriptomic and metabolomic analyses of the whole brains of aggressive pecking ducks and normal ducks revealed 504 differentially expressed genes and 5 differentially altered metabolites (adenosine, guanidinopropionic acid, Met-Leu, Glu-Ile and 5,6,8-trihydroxy-2-methylbenzo[g]chromen-4-one). By jointly analysing the transcriptomics and metabolomics results, we discovered 8 candidate genes (ADCYAP1, GAL, EDN2, EDN1, MC5R, S1PR4, LOC113843450, and IAPP) and one candidate metabolite (adenosine) that regulates aggressive pecking behaviour in ducks. The candidate genes and metabolites may be involved in regulating aggressive pecking behaviour by inducing neurodegeneration and disrupting neural excitatory-inhibitory homeostasis, which in turn affects central nervous system function in aggressive pecking and normal ducks. Our findings provide a new reference for revealing the underlying mechanism of aggressive pecking behaviour in ducks.

Effects of different feeding strategies on behavior and performance in broiler breeder pullets

This study examined the effects of different feeding strategies (diluted diets and feeding frequency) on the behavior and performance of broiler breeder pullets. A total of 3,200 1-day-old female pullets (Ross 308) were randomly distributed over 16 floor pens in 4 rooms and allocated to 1 of 4 treatments: (1) control diet once a day (CON), (2) 20% diluted diet once a day (20-ON), (3) 20% diluted diet twice a day (20-TW), and (4) 30% diluted diet twice a day (30-TW). All the pullets of the different treatments were fed to the same body weight (BW) profile. The 30-TW pullets had the highest and the CON pullets the lowest feed intake, with the 20-ON and 20-TW pullets showing intermediate values. Total water intake was the highest for the 30-TW pullets, followed by the 20-TW and 20-ON pullets, and was the lowest for the CON pullets (P < 0.001). The pullets fed twice a day had the highest total water-to-feed ratio, and the pullets fed once a day had the lowest ratio (P = 0.003). Feeding pullets twice a day yielded the highest average BW uniformity, while the pullets fed once a day had the lowest BW uniformity (P = 0.003). Total mortality was lower in the 20-TW and 30-TW pullets than in the 20-ON pullets, which was primarily caused by fewer dead and graded pullets. The pullets fed twice a day showed overall more eating, more drinking and less sitting, object pecking, and aggressive pecking. The behavior pattern during the daylight period was different for the pullets fed twice a day. Pullets on the diluted feeding strategies were less eager to approach the novel feeder and ate less feed (P = 0.002). In conclusion, feeding pullets with adjusted feeding strategies (feeding twice a day and up to 30% diluted diets) resulted in improved behavior and welfare expressed in decreased stereotypic pecking behavior, and lower eagerness to approach the novel feeder with lower feed intake, with improved BW uniformity and decreased mortality.

Research Note: Differences in the pecking behavior of turkey hens in proximity to the feeding pan depending on their beak condition

The present study aimed to provide further insight on different pecking behavior of beak-trimmed and untrimmed turkey hens in proximity to the feeding pan. Investigations were carried out in 4 housing compartments with female fattening turkeys where video were recorded and evaluated with regard to 4 different types of (pecking-) behavior (feeding, pecking on the ground, pecking at conspecifics, being pecked) observed in 1 focal animal in proximity to each feeding pan. Concerning the median duration, there were only small differences between the animals with different beak conditions. Pecking behavior varied in how many animals exhibited 'pecking on the ground' with more turkeys with intact beaks showing this activity in proximity to the feeding pan with a slightly increased median duration (0:06 vs. 0:04 min). Further discrepancies were observed in the maximum duration of recorded behaviors, as there were animals with intact beaks that showed "pecking on the ground" (4:09 vs. 2:54 min), "pecking at conspecifics" (3:46 vs. 1:25 min), and were "being pecked" (0:52 vs. 0:35 min) for a longer period of time. Based on this result, however, it can be assumed that especially individual animals with an intact beak forage more intensively and perform some pecking behaviors, which include injurious pecking, with longer duration in proximity to the feeding pan.

The potential of pumice as a litter material and its influence on growth performance, carcass parameters, litter quality traits, behavior, and welfare in broiler chickens.

This study evaluated the possibilities of pumice (light stones) as litter material in broiler production. Experimental treatments included wood shavings (WS), acidic pumice (AP), and basic pumice (BP) alone, and in combination; wood shaving + acidic pumice (WSAP) and wood shaving + basic pumice (WSBP) in a ratio of 1:1. Two trials were performed, one in summer, and the other in winter. Each trial involved 750 mixed-sex Ross (308) broilers. Also, there were 15 replicate pens with 50 broilers and a stocking density of 12.5 birds/m2 for each pen at the beginning of each trial. Performance, litter quality, carcass parameters, body and leg abnormalities, body temperature, fear and stress responses, proportional asymmetry, and some behavior expressions were investigated. The litter treatment influenced the final live body weight, litter moisture, ammonia concentration, footpad dermatitis, hock burn, breast blister, hot carcass yield, heart, liver, spleen, abdominal fat, wing and neck ratio, breast and back cleanliness, and the expression of dust bathing and foraging behaviors (P < 0.01; P < 0.05). Furthermore, there was a seasonal effect on live body weight, feed conversion ratio, livability, litter pH, 42-day litter moisture, hot carcass yield, back cleanliness, footpad dermatitis, hock burn, footpad temperature, heterophil-to-lymphocyte ratio, and expression of pecking behavior (P < 0.01; P < 0.05). It is suggested that acidic pumice stone alone or in a mixture with wood shavings could be used as a reliable litter material, alternative to wood shavings.

Effects of water access time and unlimited access to alfalfa straw on litter quality, performance, and behavior of breeder pullets

Between 3 and 20 wk of age (WOA), the effects of water access time and access to alfalfa during the rearing phase on the litter conditions, performance, and behavior of broiler breeder pullets was studied. A total of 480 female one-day-old chicks (Ross 308) were randomly assigned to 24 floor pens (20 pullets/pen) within a 3 × 2 factorial completely randomized block design. Between 3 and 20 WOA, pullets received water 1) between 07:30 am and 10:30 pm h (3HR), 2) in 2 periods between 07:30 am and 11:00 pm h and between 14:00 pm and 15:30 pm h (5HR), or 3) during the entire light period (8HR). Half of the pens had unlimited access to alfalfa straw (ALF+) or not (ALF-). Higher water use and water-to-feed ratios were observed in the 5HR and 8HR pullets compared to the 3HR pullets (P < 0.001), with no effect observed from unlimited alfalfa. Clear differences in water use throughout the day were observed for the different water strategies. The dry matter (DM) content in the litter was lower, and the litter friability and moisture scores were higher in the 5HR and 8HR than the 3HR pens (P < 0.001), with no differences in fresh feces DM. Alfalfa straw had no effect on litter DM content, fresh feces DM content, litter friability score, or litter moisture score. Feather cover score and feather and footpad contamination score were higher in 5HR and 8HR pullets than in 3HR pullets (P < 0.05), with no differences between the ALF+ and ALF- pullets. The 5HR and 8HR pullets showed increased pecking at alfalfa straw and drinking nipples, along with decreased foraging and perching than the 3HR pullets (P < 0.05). Additionally, ALF+ pullets showed a tendency for less object pecking behavior (P = 0.066) than ALF- pullets. In conclusion, the study demonstrated that extended access to water in breeder pullets increased water use, resulting in inferior litter quality, decreased feather cover, and decreased feather cover and footpad contamination. Moreover, unlimited access to alfalfa straw decreased object pecking behavior.

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.

Research Note: Effects of environmental sound stimulus on behavioral responses, cortisol levels, and horizontal immunity of transferred pullets

The aim of this study was to investigate the effects of prolonged exposure to varying levels of music or noise on the behavioral, physiological, and immune responses of pullets following their transfer to an egg-laying facility. A total of 240 one-day-old Hy-Line Brown pullets were randomly assigned to five groups: 0 dB sound stimulation, low-decibel music (65-75 dB), high-decibel music (85-95 dB), low-decibel noise (65-75 dB), and high-decibel noise (85-95 dB) stimuli. Pullets received music or noise stimuli 10 h per d from 1-day-old to 16-wk-old and were then transferred to the egg-laying facility. The results indicated that feeding and drinking behaviors significantly decreased (P < 0.05), whereas feather pecking, aggression, and preening behaviors significantly increased (P < 0.05) in the pullets after transfer. Pullets also had higher serum cortisol (COR) levels (P < 0.05), whereas immunoglobulin Y (IgY), tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), interleukin-1β (IL-1β), interleukin-2 (IL-2) and interleukin-6 (IL-6) levels significantly increased (P < 0.05). Low-decibel sound stimuli increased aggressive behavior and decreased pecking behavior (P < 0.05). High-decibel sound stimuli decreased feather pecking, cage pecking, aggression, and sham dustbathing behaviors (P < 0.05). In addition, a low-decibel sound stimulus decreased the serum COR content, and increased the serum IL-6 level in the transferred pullets. A high-decibel sound stimulus also induced shorter tonic immobility (TI) durations in pullets on d 7 after transport stress. Meanwhile, high-decibel sound stimulus decreased the serum IL-6 and TNF-α levels of pullets. In conclusion, the transfer has detrimental effects on the pullets. Long-term sound stimulation effectively mitigated the negative impact of transportation stress on pullets. Among them, the high-decibel sound stimulus showed more promise in relieving transport stress.

Preening cups in duck housing are associated with an increase in central dopamine activity that suggests a negative affective state

Preening cups are a form of environmental enrichment that provides Pekin ducks a semi-open water source to express their natural behaviors. We recently observed that preening cups may increase feather pecking behaviors in ducks. Thus, we set out to determine if this form of enrichment can impact the affective state of Pekin ducks. To accomplish this goal, we evaluated the effect of preening cups on serotonin (5-HT) and dopamine (DA) turnover via mass spectrometry and their respective synthetic enzyme gene expression via qRT-PCR. Our study investigated the link between aggressive pecking with levels and activity of brain 5-HT and DA. Brain 5-HT and DA levels and activity have been established for decades to be associated with affective states. Grow-out Pekin ducks (n = 260) were housed at Purdue and raised per industry standards. On day 18, brains were collected from ducks in pens before preening cups were placed (PRE, n = 6) and, again on day 43, in pens with (PC, n = 6) and without (CON, n = 6) preening cups. Brains were dissected into right and left halves, then further microdissected into 4 brain areas: caudal mesencephalon (CM), rostral mesencephalon (RM), diencephalon (DI), and forebrain (FB). The right hemisphere was used for mass spectrometry to determine the neurotransmitter concentration (ng/mg of tissue) and those concentrations were applied to neurotransmitter turnover equations. There were no differences across treatments for 5-HT turnover in any brain area. There were differences in DA turnover across age (P = 0.0067) in the CM and across treatments (P = 0.003) in the RM. The left hemisphere of the brain was used to perform qRT-PCR on the genes of 5-HT and DA production enzymes. Within the CM, day 43 duck brains had increased (P = 0.022) tryptophan hydroxylase and tyrosine hydroxylase relative mRNA levels. All other brain areas showed no differences. Our data suggest that ducks housed with preening cups and that showed increased feather pecking are associated with increased brain DA activity. The increased DA in the brain may lead to a predisposition for increased aggression in the form of feather pecking.

Formation of the Pecking Order during Small-Scale Floor Feeding in Helmeted Guinea Fowl (Numida meleagris).

Helmeted guinea fowl are social animals and only males form a hierarchy in the wild. Non-cage husbandry systems benefit the reproductive health of guinea fowl; however, there are concerns that the feeding duration of subordinate individuals is insufficient. Here, the pecking orders formed during small-scale floor feeding were investigated. There were three experimental categories: male-only (four males), female-only (four females), and mixed category (two males, two females). Each experimental category was set up three times and included different individuals. Behaviors were recorded for 130 h 52 min, 89 h 11 min, and 98 h 46 min in the male, female, and mixed categories, respectively. Male helmeted guinea fowls pecked other males, whereas females exhibited little pecking behavior. Male pecking behavior was not homogeneous within each experimental group. It has been suggested that males form a pecking order, whereas females have no hierarchy under small-scale floor-feeding conditions, as observed in the wild. In most cases, on the first day the number of pecking behaviors was low 20 min after the start of the experiment. The three subordinate individuals in the mixed category had little time to feed, whereas the other birds in the mixed category and all helmeted guinea fowl in the male- and female-only categories had longer feeding durations. We suggest that helmeted guinea fowl may be reared under small-scale floor feeding, and that the health of males should be managed. However, rearing females and males under small-scale floor feeding conditions should be avoided. This study contributes to improving the welfare of helmeted guinea fowl reared under small-scale floor feeding.

Effects of abrupt and gradual light/dark switching on growth performance, behavior, villus development, meat characteristics, and immunity of broilers.

The aim of this study is to determine the effect of abrupt and gradual light/dark switching on growth performance, behavior, villus development, meat characteristics, and immunity of broilers. A total of 270 daily male broiler chicks were used in the experiment. The study comprised three groups based on whether the transitions between light and dark periods were abrupt or gradual. No significant differences were observed among the examined groups in terms of body weight, weight gain, mortality rate, feeding, pecking, relaxing, and feather preening behaviors, carcass, and breast meat quality characteristics. Total body weight gain, total feed consumption, total feed utilization ratio, and mortality rates of broilers during the 6-week fattening period did not differ compared to the abrupt transition. Broilers in the group with gradual transition exhibited less movement, more sitting, and sleeping behaviors. It was determined that the IgG was higher in the gradual transition group. The transitions between light and dark periods influenced the characteristics of thigh meat. Villus height and crypt depth were higher in the group where a 1-h gradual transition was applied. As a conclusion, gradual transition is more appropriate in broiler rearing.

Effects of environmental enrichment on ostrich behaviours

This study was aimed to investigate the behavioural differences of ostrich (Struthio camelus) breeders reared under environmental enrichment with natural vegetation in farm conditions. The effect of enriched environment with vegetation on eating, drinking, foraging, pecking, defecation, walking, running, alert, standing, sitting, sleeping, dust bathing, preening, head shake, thermoregulation, kantel, mating, laying, threat and fight behaviours of ostriches were found similar (P &amp;gt; 0.05). The ratio of boom, courtship and displace behaviours were found higher in enriched than in gravel floor (P=0.050; P=0.028 and P=0.001). The foraging, dust bathing, boom, laying and displace behaviours of ostriches were affected by gender (P=0.029, P=0.040, P=0.050, P=0.025 and P=0.001). The eating, foraging, standing, sitting, dust bathing and laying behaviours of ostriches were affected by time of day (P=0.010, P=0.023, P=0.049, P=0.026, P=0.018 and P=0.009). There was a significant interaction of enriched environment and gender effect on eating, standing, boom and displace behaviours of ostriches (P=0.047, P=0.031, P=0.050 and P=0.001). The pecking and standing behaviours of ostriches were affected by enriched environment and time of day interaction (P=0.027 and P=0.023). As a conclusion, enriched environment with natural vegetation in paddock only affected ostriches’ courtship behaviours, also affected male and female eating and standing behaviours differently.

The effects of stocking density on growth, morphological development, behavior, and welfare parameters in pheasants (Phasianus colchicus).

In pheasants, which are generally raised in large flocks, stocking density is important for their growth and development, normal behavior and welfare. But there is still a lack of information on the optimum stocking density for game birds. This research was conducted on a total of 200 pheasants to examine the effects of low (5 pheasant/m2) and high (10 pheasant/m2) stocking density rearing practices on body weight, morphological development, behavioral characteristics and welfare parameters such as foot-pad dermatitis and plumage quality. When we look at the study results, it was determined that the density of stocking did not make a difference in the first 13 weeks of age, but pheasants reared at low density at the ages of 14-16 weeks reached higher body weight. In terms of body weight at 14, 15, and 16 weeks, the low stocking density group had an average of approximately 41, 71, and 94 g higher than the high stocking density group, respectively (p<0.05). It had been found that low density provides better morphological development. The low group was found to be significantly higher than the high group in terms of ornithological size, wingspan, back length, tail length, head length and head width, 5.9 cm, 2 cm, 1.3 cm, 7.6 cm, 1.7 mm and 1 mm, respectively (p<0.05). Since the animals in the low group had more individual space, they had the opportunity to perch and therefore exhibit more passive behavior. On the other hand, pheasants in the low group exhibited higher levels of aggressive behavior (p<0.05). More foraging behavior was observed in the higher group and the low-density group consumed more feed in the 14th week (p<0.05). But no significant differences were detected between groups in terms of feed consumption in other weeks (p>0.05). A 1.12 point higher score was calculated in the low group compared to the high group, especially in terms of tail feather quality, and as a result, pheasants reared in low stocking density had better plumage quality (p<0.05). It had been determined that as the stocking density decreases in the rearing of pheasants, they exhibit easier flight and roosting behaviors and therefore they were less affected by feather pecking behavior and had better feather quality. In addition, it had been determined that pheasants grow and develop better in this group, which had more rest opportunities. In conclusion, rearing at low stocking density is recommended for better fattening performance and better welfare conditions.

EFFECTS OF SEASON, SEX AND TIME OF DAY ON OSTRICH BREEDER (Struthio camelus) BEHAVIOR

Ambient temperature has a crucial effect on livestock production performance, behaviors and welfare. In ostrich, previous research primarily focused on survival and reproductive performance during the climatic shifts. This study was carried out to investigate the effect of seasonal variation on behavioral differences of male and female ostrich (Struthio camelus) breeders, reared in farm environment. The individual behaviors related to digestion, locomotor activities, resting, comfort and thermoregulation, reproduction, and aggressive behaviors were recorded. The higher sitting and sleeping behavior were observed in summer season (P≤0.01 and P≤0.001, respectively). The thermoregulation behaviors were observed only in summer season (P≤0.0001). The higher foraging, alertness and spot pecking behaviors were observed in females (P≤0.01, P≤0.05, and P≤0.05, respectively). The boom behavior was only observed in males (P≤0.05). The higher walking behavior was observed in the afternoon and morning (P≤0.05). The higher sleeping, dust bathing, grooming and thermoregulation behaviors were observed at noon (P≤0.001, P≤0.001, P≤0.0001 and P≤0.0001, respectively). There was a significant interaction between season and sex for displace behavior, a sign of aggressive behavior (P=0.006). There was a significant interaction between season and time of day for drinking and defecation related to digestive behaviors (P≤0.05 and P≤0.05, respectively); sleeping described as a resting behavior (P=0.0001); dust bathing and grooming which is related to comfort behaviors (P≤0.0001 and P≤0.0001); thermoregulation (P≤0.0001); copulation described as a reproductive behavior (P=0.003); displace and escape behaviors mostly a sign of aggressive behavior (P≤0.05 and P≤0.05). Ostriches are diurnal animals with a nomadic lifestyle and have higher activity during the early and late times of the day. Identification of the seasonal, sexual and time of day differences on behavior types of ostriches, provides important information for ostrich management and their welfare. Keywords: Ostrich (Struthio camelus), climate-change, behavior, animal welfare.

Social-pair judgment bias testing in slow-growing broiler chickens raised in low- or high-complexity environments

Impacts of environmental complexity on affective states in slow-growing broiler chickens (Gallus gallus domesticus) are unknown. Chickens’ performance in judgment bias tests (JBT) can be limited as they are tested individually, causing fear and anxiety. The objectives were to apply a social-pair JBT to assess the effect of environmental complexity on slow-growing broiler chickens` affective states, and assess the impact of fearfulness, anxiety, and chronic stress on JBT performance. Six-hundred Hubbard Redbro broilers were housed in six low-complexity (similar to commercial) or six high-complexity (permanent and temporary enrichments) pens. Twelve chicken pairs were trained (1 pair/pen, n = 24 chickens) using a multimodal approach (visual and spatial cues), with reward and neutral cues of opposing color and location. Three ambiguous cues were tested: near-positive, middle, and near-neutral cues. Approach and pecking behavior were recorded. Eighty-three percent of chickens (20/24) were successfully trained in 13 days. Fearfulness, anxiety, and chronic stress did not impact chickens’ performance. Chickens successfully discriminated between cues. Low-complexity chickens approached the middle cue faster than high-complexity chickens, indicating that they were in a more positive affective state. The environmental complexity provided in this study did not improve affective states in slow-growing broiler chickens compared to a control. A social-pair JBT resulted in excellent learning and testing outcomes in slow-growing broilers.

Diversity of cranial shape in European Woodpecker species (Picidae)

Abstract The woodpecker family (Picidae) includes numerous species that vary in size and plumage colouration, but which share many easily recognisable external features. These birds possess pronounced anatomical adaptions that enable them to exploit arboreal habitats and live in niches that are inaccessible to most other birds. The aim of this study was to increase our knowledge on the relationships between skull shape, habitat preference, pecking abilities and foraging habits of 10 European woodpecker species. A geometric morphometric approach was used to analyse two-dimensional cranial landmarks. We used principal component (PC) analyses on those measurements that may be related to habitat preference and foraging habits. The PCs resulted in descriptions of the relative length and width of the bill, variation in its relative size, orientation of the nostrils variation in the elongation of the neurocranium, the relative size and position of the palatine bone, length of the rostrum, and the thickness of the mandible bone. The analysis showed and confirmed the presence of some cranial elements that are strongly associated with habitat preference, pecking behaviour and excavation abilities.

Effective Strategies for Mitigating Feather Pecking and Cannibalism in Cage-Free W-36 Pullets

Pecking is one of the most concerning poultry welfare issues in the layer houses, especially in the cage-free (CF) housing system. Pecking behavior may lead to severe feather pecking (SFP) and cannibalism when birds feel frustrated, stressed, and dominant over other birds. Since pecking is caused by multi-factorial problems (e.g., hormonal influence, environment, dietary composition, and genetic differences), it is very important to find optimal strategies for reducing pecking damage. The objective of this study was to evaluate the effects of pullet age and management practices on pecking behavior and to identify the optimal pecking mitigation strategy. Four climate-controlled rooms were used, each housing 200 Hy-Line W36 pullets, for a total of 800 pullets from 0 to 16 weeks of age (WOA). Pecking mitigation strategies were tested at different ages, including an isolated chamber (IC) at 14 WOA, an IC with lotion (water, aloe vera gel, tea tree oil, calendula, and methyl anthranilate), and a pecking block from 15 to 16 WOA. Data on severe feather pecking (SFP) and mortality were collected daily from 13 to 16 WOA during the pecking block, IC, and IC with lotion treatments and from 0 to 16 WOA for the entire pullet cycle of age treatment. Results show that the SFP significantly increased with the bird’s age (p &lt; 0.01). The SFP started with 5 WOA. About 16% of birds were found with severe peck damages by 16 WOA. In this study, pecking blocks did not show a reduction in pecking order, possibly due to pecking at alarming rates. Isolating birds with SFP damages into the IC and applying lotion resulted in a significant decrease in SFP (p &lt; 0.05) and cannibalism (p &lt; 0.05). This study provides a reference for commercial CF egg producers to develop on-farm management strategies for mitigating pecking damage and cannibalism.

Malfunctioned inflammatory response and serotonin metabolism at the microbiota-gut-brain axis drive feather pecking behavior in laying hens

Feather pecking (FP) is a multifactorial abnormal behavior in laying hens where they display harmful pecks in conspecifics. FP has been associated with the altered functioning of the microbiome-gut-brain axis affecting host emotions and social behavior. The altered levels of serotonin (5-HT), a key monoaminergic neurotransmitter at both terminals of the gut-brain axis, affect the development of abnormal behavior, such as FP in laying hens. However, the underlying mechanism involving reciprocal interactions along the microbiota-gut-brain axis, particularly about the metabolism of 5-HT, remains unclear in FP phenotypes. This study examined the microbiota diversity, intestinal microbial metabolites, inflammatory responses, and 5-HT metabolism in divergently selected high (HFP; n=8) and low (LFP; n=8) FP hens to investigate the possible interconnections between FP behavior and the examined parameters. The 16S rRNA analysis revealed that compared to LFP birds, the gut microbiota of HFP birds exhibited a decrease in the abundance of phylum Firmicutes and genera Lactobacillus, while an increase in the abundance of phylum Proteobacteria and genera Escherichia Shigella and Desulfovibrio. Furthermore, the intestinal differential metabolites associated with FP phenotypes were mainly enriched in the tryptophan metabolic pathway. HFP birds had higher tryptophan metabolites and possibly a more responsive immune system compared to the LFP birds. This was indirectly supported by altered TNF-α levels in the serum and expression of inflammatory factor in the gut and brain. Moreover, HFP birds had lower serum levels of tryptophan and 5-HT compared to LFP birds, which was consistent with the downregulation of 5-HT metabolism-related genes in the brain of HFP birds. The correlation analysis revealed that genera Lactobacillus and Desulfovibrio were associated with differences in intestinal metabolites, 5-HT metabolism, and inflammatory response between the LFP and HFP birds. In conclusion, differences in the cecal microbiota profile, immune response and 5-HT metabolism drive FP phenotypes, which could be associated with the gut abundance of genera Lactobacillus and Desulfovibrio.

Tracking pecking behaviors and damages of cage-free laying hens with machine vision technologies

Feather pecking (FP) is one of the primary welfare issues in commercial cage-free hen houses as that can seriously reduce the well-being of birds and cause economic losses for egg producers. After beak trimming is highly criticized in Europe and the USA, alternative methods are needed for pecking monitoring and management. A possibility for minimizing the problem is early detection of FP behaviors and damages to prevent it from spreading or increasing as feather pecking is a learned behavior. The objectives of this study were to develop a machine vision method, testing the performance of new models in tracking the pecking behaviors of hens and potential damages in the cage-free facilities and improve the detection accuracy of the model.Two YOLOv5 based deep learning models, i.e., YOLOv5s-pecking and YOLOv5x-pecking, were developed and compared in tracking FP behaviors of laying hens cage-free facilities. According the performance based on a dataset of 1924 images (1300 for training, 324 for validation, and 300 for testing), YOLOv5x-pecking model had a 3.1 %, 5.6 %, and 5.2 % higher performance in precision, recall, and Map than YOLOv5s-pecking model, respectively. However, YOLOv5s-pecking model size is 80 % smaller, and thus used 75 % less GPU memory and 80 % less time in model training than YOLOv5x-pecking model for the same dataset. Therefore, YOLOv5s-pecking model was considered with superior performance. This study was among the first to apply YOLOv5 models to track problematic behaviors of cage-free hens. The model provides a basis for developing a real-time automatic model for tracking pecking damages in commercial cage-free houses to protect the health and welfare of hundreds of millions laying hens.

Effects of light color and intensity on discrimination of red objects in broilers.

Poultry are sensitive to red objects, such as comb and blood on the body surface, likely inducing injurious pecking in flocks. Light is an important factor that affects the pecking behavior of poultry. A wooden box was built to investigate the effects of Light Emitting Diode (LED) light color (warm white and cold white) and intensity (5 and 50 lux) of background light on the discrimination of red objects in broilers. A piece of red photographic paper (Paper 1) was used to simulate a red object and paired with another piece of paper (Paper 2 to 8) with a different color. Bigger number of the paired paper indicated greater color difference. The experiment consisted of three phases: adaptation, training, and test. In the adaptation phase, birds were selected for the adaptation to reduce the stress from the box. In the training phase, birds were trained to discriminate and peck at Paper 1 when paired with Paper 8 under one type of background light. Twenty-three birds were tested when the paired paper was changed from Paper 7 to 2. Each pair of paper included 12 trials for every bird, and response time to peck and proportion of choices of Paper 1 in the last 10 trials were collected. The results showed that broilers tested under 5 lux light had longer response times than broilers tested under 50 lux light (P < 0.05). When Paper 1 was paired with paper 7, broilers tested under warm white light had lower proportion of choices of Paper 1 than those tested under cold white light (P < 0.05). Color difference had a significant effect on response time of broilers (P < 0.05). Moreover, the proportion of choices of Paper 1 decreased to 50% (chance-level performance) when color of the paired paper was gradually similar to Paper 1. Conclusively, rearing broilers in warm white rather than cold white light with appropriate light intensity should be recommended to reduce damaging pecking behavior in broiler production.

Behaviors associated with formalin-induced pain in the Japanese quail (Coturnix coturnix japonica)

The present study aimed to investigate behaviors associated with formalin-induced nociception in the Japanese quail (Coturnix japonica). The tarsometatarsus region of the male quail's foot (shank) was injected with 40µl of formalin (0.3, 0.6, and 0.9%) solutions or normal saline. Two distinct nociceptive behaviors that is injected foot lifting and flinching/shaking behaviors were recorded over 45 minutes. Also, unstimulated preening, eye closing, and chamber wall pecking behaviors were recorded during the observation period. Subcutaneous injection of formalin 0.6 and 0.9% significantly increased the foot lifting activity in the 0-5 minutes (acute phase) and 15-45 minutes (inflammatory phase) after administration. But the injection of formalin 0.3% significantly increased foot lifting activity only in the acute phase. In the other recorded behaviors, we did not find this biphasic time course pattern. All formalin concentrations induced significant foot flinching/shaking activity only in the acute phase. Subcutaneous injection of formalin 0.9% but not 0.6 and 0.3% significantly increased the duration of eye closure behavior between 20-45 minutes after administration. Injection of all formalin concentrations caused a significant decrease in the unstimulated preening activity between the period of 10 to 45 minutes after administration. Injection of all formalin concentrations caused a significant decrease in the observation chamber wall pecking activity between the period 30 to 45 minutes after administration. These results suggest that the quail formalin test can be considered a relevant, sensitive, and specific technique that helps researchers to use it in the determination of the neurobiology and pharmacology of nociception in the avian species.