Beak trimming effects on behavior patterns, fearfulness, feathering, and mortality among three stocks of White Leghorn pullets in cages or floor pens

Beak trimming in japanese quails at initial phase is an alternative to reduce the negative effects of feather pecking

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.

Feather Pecking in Non-Beak-Trimmed and Beak-Trimmed Laying Hens on Commercial Farms with Aviaries

Simple Summary

Severe feather pecking (SFP) is a major animal welfare problem in layers. It results in pain and injuries in the affected animal. SFP is a behavioral disorder and should not be confused with aggressive pecking. The aim of our study was to observe the pecking behavior of layers on farms with flock sizes common in practice and to identify possible influencing factors. We found that SFP occurred in all flocks, but the pecking rate varied widely between flocks. A low stocking density and the provision of a winter garden or free range (or both) had a positive effect and reduced SFP. Keeping mixed flocks of brown and white layers was a risk factor for SFP. SFP occurred mainly in the litter area and only rarely on perches. This finding emphasizes the importance of providing enough litter, litter areas and environmental enrichment. Aggressive pecking and SFP were correlated, which may indicate a higher stress level in the flock. Beak trimming reduced pecking rates but did not entirely prevent SFP. Instead of subjecting chicks to this potentially painful procedure, reasons for SFP should be addressed. SFP remains a multifactorial problem, but in recent years, many risk factors have been identified and included in best-practice recommendations, allowing the housing of non-beak-trimmed layers.

Abstract

Severe feather pecking (SFP) is a major animal welfare problem in layers. It results in pain and injuries in the affected animal. It was the aim of this study to gain insight into the actual pecking behavior of laying hens kept on commercial farms with flock sizes common in practice. We observed aggressive pecking and SFP in non-beak-trimmed and beak-trimmed flocks of laying hens and investigated possible influencing factors. The study took place on eight conventional farms in Germany with aviaries, including three farms with a free range and a winter garden, one with a free range and one with a winter garden. Pecking behavior was observed during three observational periods (OPs): OP 1, at the peak of the laying period between the 28th and 33rd week of life; OP 2, in the middle of the laying period between the 42nd and 48th week of life; and OP 3, at the end of the laying period between the 63rd and 68th week of life in one laying period. Videos were analyzed using behavior sampling and continuous recording. We found that SFP occurred in all flocks, but the pecking rate differed significantly between the flocks. SFP correlated positively with the number of hens per square meter of usable area, with statistical significance in the litter area (r = 0.564; p = 0.045). The multivariate analysis revealed that access to a winter garden or free range significantly reduced the SFP rate on perches (p = 0.001). The stocking density (number of birds per usable square meter) had a significant influence on the SPF rate in the nest-box area (p = 0.001). The hybrid line had a significant effect on the SFP rate on perches and in the nest-box area (p = 0.001 each). Lohmann Brown hens in mixed flocks had a higher SFP rate (significant in OP 2) than those in homogeneous flocks, indicating that mixed flocks may be a risk factor for SFP. Lohmann Brown hens pecked significantly less than Dekalb White hens in the litter area (p = 0.010) and in the nest-box area (p = 0.025) and less than Lohmann Selected Leghorn hens in the litter area (p = 0.010). Lohmann Brown and Lohmann Selected Leghorn hens showed increasing SFP rates during the laying period. All hybrid lines had significantly higher SFP rates in the litter area, followed by the nest-box area and perches. These findings emphasize the importance of providing enough litter, litter areas and environmental enrichment. We found a significant positive correlation between aggressive pecking and SFP—in OP 1: rho (Spearman) = 0.580, p < 0.001; OP 2: rho = 0.486, p = 0.002; and OP 3: rho = 0.482, p = 0.002 (n = 39) —indicating that SFP may lead to a higher stress level in the flock. Beak trimming reduced pecking rates but did not entirely prevent SFP. Instead of subjecting chicks to this potentially painful procedure, reasons for SFP should be addressed. In conclusion, our data suggest a positive influence of a lower stocking density and the provision of a winter garden or free range for additional space. The hybrid line had a significant influence on the feather-pecking rate on perches and the nest-box area. Aggressive pecking and severe feather pecking correlated positively. We assume that vigorous and painful AP were an additional stress factor, especially in non-beak-trimmed flocks, leading to more SFP in due course. Beak trimming had a reducing effect on SFP. However, our results showed that non-beak-trimmed flocks could be kept without major outbreaks of SFP.

Effects of beak trimming on the performance, beak length, behavior, and carcass traits of a local broiler breed reared in battery cages

This study investigated the effects of beak trimming on a local broiler breed. A total of 648 one-day-old birds were randomly allocated into three treatments: no trimming (NBT), infrared beak trimming (IRBT), and hot-blade beak trimming (HBBT). The performance, beak length, behavior, carcass traits, organ percentages, and meat quality were inspected. The body weight (BW) from 7 to 35 days in the IRBT group was significantly lower than that in the NBT group, and the BW from 7 to 49 days was lower than that in the HBBT group (p < .05). Compared with untrimmed birds, birds in the IRBT group had lower average daily feed intake (ADFI) from 15 to 21 days, and higher heart percentage and L* value in the breast muscle. The upper beak length at 28 and 49 days of age were longest in untrimmed birds, intermediate in birds in the HBBT group, and shortest in the IRBT groups (p <.05). No evidence was found that HBBT caused changes in performance, behavior, carcass traits, organ percentages, and meat quality except for lower change in spleen percentage. Taken together, IRBT had more influence at inhibiting early BW, ADFI, and upper beak length than HBBT in the local broiler breed.

Effects of nest boxes in natural mating colony cages on fear, stress, and feather damage for layer breeders1,2,3

Colony cages are commonly used in China for the natural mating of layer breeders. However, feather pecking (FP) is a major problem in this system, and feather damage mainly due to FP needs to be alleviated. The objective of this study was to investigate the effects of nest boxes provided in colony cages. Each colony cage confined 10 roosters and 90 laying hens. The use of nest boxes as it relates to age, feather damage, sexual behavior, fertility, and fearfulness was evaluated. Thyroid hormones, which are considered to be physiological indicators of various forms of stress in poultry and may be correlated with the quality of feather coverage, were also tested. The control group and the nest box group each had 12 replicates, totaling 24 identical cages. Analyses were conducted using the linear mixed models procedure of SPSS Statistics 22.0. The results showed that the control group had a significantly higher proportion of hens with feather damage to 4 specific body regions (back, rump, tail, and belly) compared to the nest box group (P < 0.05). Increasing the use of the nest boxes took place from weeks 41 to 47 and at 53 wk of age, as seen by the percentage of eggs and number of sitting events in the nests, number of hens using the nests, and frequency of visits. There were no significant differences in fertility, the occurrence of mounting, or full copulation behavior between the 2 groups. Hens in the control group showed a significantly longer duration of tonic immobility at 43, 49, and 55 wk of age (P < 0.05). No significant differences were found between groups for the concentration of triiodothyronine or thyroxine, but a significantly higher concentration of corticosterone was measured in the control group than in the nest box group (P < 0.05). In conclusion, hens with access to nest boxes during the laying period had a decreased FP frequency, fewer damaged feathers, lower plasma corticosterone secretion, and were less fearful. This information contributes to the understanding of the FP behavior and stress sensitivity of layer breeders, which will provide a basis for the development and optimization of the colony cage equipment.

The influence of environmental enrichment and stocking density on the plumage and health conditions of laying hen pullets

In this study, the effects of environmental enrichment, stocking density, and microclimate on feather condition, skin injuries, and other health parameters were investigated. During 2 rearing periods (RP), non-beak-trimmed Lohmann Brown hybrid pullets were housed in an aviary system for rearing with cages and from week 5 of age onwards with access to a litter area. All pullets were reared in the same barn and under practical conditions. In total, 9,187 (RP 1) and 9,090 (RP 2) pullets were distributed in 9 units, and each unit was assigned to 1 of 3 experimental groups (EG). In the control group (EG 1), the pullets were kept without environmental enrichment and at a commonly used stocking density (22 to 23 pullets per m²). Each unit of the 2 treatment groups was provided with 3 types of environmental enrichment simultaneously (pecking stones, pecking blocks, and lucerne bales), and the pullets were kept at a lower than usual (18 pullets per m²) (EG 2) or commonly used stocking density (EG 3). In each RP, the plumage condition, injuries and health of the pullets, and the microclimate of the housing system were examined 5 times. The statistical relationships of enrichment, stocking density, and microclimate with animal health were estimated via regression models. We found that the provision of environmental enrichment had a significant increasing effect on the plumage quality in week 17. Furthermore, significant relationships were found between several predictors (temperature in the housing system, dust concentration, and age of the pullets) and response variables (plumage condition, body injuries, head injuries, bodyweight, difference to the target weight and uniformity). The results of this study showed that increasing temperature in the housing system and increasing age of the pullets are significantly associated with the occurrence of feather damage and skin injuries during rearing. With stocking densities as high as we used (all > 17 pullets per m²), no significant positive effect of a reduced stocking density could be observed.

Welfare Consequences of Omitting Beak Trimming in Barn Layers

Beak trimming is used worldwide as a method of reducing the damage to feathers and skin caused by injurious pecking in laying hens. However, beak trimming also causes some welfare issues as trimming the beak results in pain and sensory loss. Due to this dilemma, there is an ongoing discussion in several European countries about whether to ban beak trimming. In this study, we investigated the welfare consequences of keeping layers with intact beaks and examined for links between injurious pecking damage and keel bone damage on an individual level. A study was conducted on 10 commercial farms housing laying hens in the barn system. Each farm participated with a flock of beak-trimmed hens (T) and a flock of non-trimmed (NT) hens that were visited around 32 and 62 weeks of age. During visits, the condition of plumage, skin, feet, and keel bone of 100 hens was assessed. Mortality was recorded by the producers. NT flocks had a lower prevalence of hens with good plumage condition around 32 weeks of age (94.1 vs. 99.6%, P < 0.001) and a higher prevalence of hens with poor plumage condition at 62 weeks of age (63.6 vs. 15.2%, P < 0.001) compared with T flocks. The prevalence of hens with keel bone deviations, with both keel bone fractures and deviations and with body wounds, was higher in NT flocks compared with T flocks at both ages (P < 0.001). Accumulated mortality from placement to end of production tended to be higher in NT flocks compared with T flocks (14.2 vs. 8.6%; P = 0.06). The prevalence of keel bone damage was higher among hens with poor plumage condition than hens with moderate/good plumage condition (31.5 vs. 22.2%; P < 0.001). Thus, omitting beak trimming had negative consequences for the condition of plumage, skin, and keel bone, and tended to increase mortality, highlighting the risk of reduced welfare when keeping layers with intact beaks. In addition, injurious pecking damage was found to be positively linked to keel bone damage. The causal relation is unknown, but we propose that fearfulness is an important factor.

Review of rearing-related factors affecting the welfare of laying hens

Laying hens may face a number of welfare problems including: acute and chronic pain caused by beak trimming; exaggerated fearfulness that may cause stress and suffocation; difficulties in locating resources, resulting potentially in emaciation and dehydration; frustration and boredom, caused by an environment that is barren; feather pecking; cannibalism; foot lesions; and bone fractures. In Europe, a greater proportion of laying hens are housed in non-cage systems compared to the rest of the world. The extent of the different welfare problems may therefore vary between countries as the type of housing system influences the risk of suffering. More generally, many of these welfare problems are influenced by the rearing environment of the pullets. This article therefore focuses on welfare problems in laying hens that can be traced back to rearing. Factors that have been studied in relation to their effects on bird welfare include beak trimming, housing type, furnishing, enrichment, feeding, stocking density, flock size, sound and light levels, concentration of gasses, age at transfer from rearing to production facilities, similarity between rearing and production facilities, competence of staff, and interactions between bird strain and environment. The present review aims to summarize rearing-related risk factors of poor welfare in adult laying hens housed according to European Union legislation. It aims to identify gaps in current knowledge, and suggests strategies for improving bird welfare by improving rearing conditions. Two main conclusions of this work are that attempts should be made to use appropriate genetic material and that beak trimming should be limited where possible. In addition to this, the rearing system should provide constant access to appropriate substrates, perches, and mashed feed, and should be as similar as possible to the housing system used for the adult birds. Finally, young birds (pullets) should be moved to the production facilities before 16 weeks of age. The measures outlined in this review may be useful for improving the welfare of pullets and adult laying hens.

Different effects of infrared and one-half hot blade beak trimming on beak topography and growth

This study examined the effects of infrared beak treatment (IR-BT) and hot blade beak trimming (HB-BT) on beak length and production in laying hen pullets. Seventy-two 1-d-old birds were randomly assigned to the HB-BT, IR-BT, or control group. Birds were pair housed by treatment, and beak images and production indices were obtained posttreatment at fixed intervals for 10 wk. Immediately after treatment, HB-BT beaks were shorter than control or IR-BT beaks (P < 0.01), whereas control and IR-BT beaks remained comparable in length until the onset of tissue degeneration and erosion of the IR-BT beaks at 1 to 2 wk posttreatment. At wk 2 posttreatment, beaks were longest in control birds, intermediate in IR-BT birds, and shortest in HB-BT birds (P < 0.01). Thereafter, an increase in beak length in all treatments was observed over time (P < 0.01), but HB-BT beaks had the greatest regrowth. The beak length of birds in the HB-BT group was similar to that of birds in the IR-BT group from wk 3 to 8, and then grew longer at wk 9 and 10 posttreatment (P < 0.01). The effects of treatments on BW emerged at d 5 posttreatment. The BW of birds in the HB-BT group was suppressed up to and including wk 9 posttreatment compared with that of control birds (P < 0.05) and was significantly lower than that of birds in the IR-BT group between 2 and 4 wk posttreatment (P < 0.05). Birds in the IR-BT group did not differ from control birds after wk 3 posttreatment (P < 0.05). By the final week of the study, differences in BW across treatments were no longer apparent (P > 0.05). For the most part, feed intake was higher in control birds, intermediate in birds in the IR-BT group, and lowest in birds in the HB-BT group until wk 9 posttreatment (P < 0.05). Similarly, feed waste was generally higher in control birds and least in birds in the HB-BT group (P < 0.05). The IR-BT treatment appeared to be more effective at inhibiting beak regrowth, with a less pronounced effect on feed intake than the HB-BT treatment in laying hen pullets.

Effects of genetic group selection against mortality on behavior and peripheral serotonin in domestic laying hens with trimmed and intact beaks

Severe feather pecking is a maladaptive behavior in laying hens that may result in cannibalism and ultimately death of the victims. Selection methods in which the genetic effect of an animal on the survival of its group members is taken into account, i.e. 'group selection', have been shown to be very effective in reducing mortality due to feather pecking and cannibalism in laying hens. It has been suggested that fearfulness and serotonergic functioning are involved in the causation and development of feather pecking. We investigated effects of selection based on survivability in non-beak trimmed groups on fear-related behavior and peripheral 5-HT concentration and uptake in hens with trimmed or intact beaks, in a 2 x 2 factorial arrangement. Hens from the second generation of the low mortality line showed less fear-related behavior than control line hens. In addition, they displayed higher whole blood 5-HT concentrations and a lower platelet 5-HT uptake, indicating differences in functional activity of the 5-HT system. Beak trimming resulted in lowered levels of fear, and in a reduction of feather damage. Hens with trimmed and intact beaks did, however, not differ in peripheral 5-HT. The results imply that fearfulness and 5-HT activity are related to feather pecking without distinguishing between cause and effect. However, given that selection altered fear-related behaviors and peripheral 5-HT concentration and uptake, whereas beak trimming affected fearfulness and feather damage, but not 5-HT parameters, we suggest that peripheral 5-HT activity might reflect the predisposition to develop severe feather pecking under adverse conditions in laying hens.

Neurobiological basis of sensory perception: welfare implications of beak trimming

The practice of beak trimming in the poultry industry occurs to prevent excessive body pecking, cannibalism, and to avoid feed wastage. To assess the welfare implications of the procedure, an emphasis of this paper has been placed on the anatomical structures that comprise the beak and mouth parts and a representation of the structures removed following beak trimming. Five animal welfare concerns regarding the procedure have been addressed, including the following: loss of normal beak function, short-term pain and temporary debilitation, tongue and nostril damage, neuromas and scar tissue, and long-term and phantom limb pain. Because all of the concerns involve the nervous system, the current knowledge of the avian somatosensory system was summarized. The critical components include touch, pain, and thermal receptors in the buccal cavity and bill, the trigeminal system, and neural projections mapped to the pallium (cortical-like tissue in the avian forebrain). At the present time, a need remains to continue the practice of beak trimming in the poultry industry to prevent head, feather, and vent pecking in some lines of birds. The procedure, however, should involve conservative trimming and be limited to young birds. Importantly, data show that removing 50% or less of the beak of chicks can prevent the formation of neuromas and allow regeneration of keratinized tissue to prevent deformed beaks and therefore positively affect the quality of life of birds during their lifetime.

Relationship Between Body Weight and Beak Characteristics in One-Day-Old White Leghorn Chicks: Its Implications for Beak Trimming

Beak trimming is a routine practice used in laying hens to prevent feather pecking and cannibalism. The effect of beak trimming on bird well-being depends on multiple factors, including the amount of beak that is trimmed and the quality of the procedure. The aim of this work was to determine if a relationship existed between BW and beak characteristics in 1-d-old chicks, with a future aim to develop an automated system for standardizing beak trimming. Three hundred forty-four 1-d-old chicks (Hy-Line W-36) were sorted into 3 categories based on their BW (heavy, intermediate, and light), and their beaks were photographed. Dimensional measures of beaks, including the lengths of the culmen, gonys, maxillary tomia, mandibular tomia, and the width of the upper mandible and lower mandible measured at 2, 3, and 4 mm from the tip of the upper and lower beaks, were calculated using imaging software. Correlations between BW and beak measures were evaluated using Pearson product-moment, Spearman rank-order, Kendall's tau, and Hoeffding's dependency tests. Results showed there were no significant correlations between beak dimensions and BW in the light BW group. In contrast, correlations were present between BW and the width of the upper mandible measured at 4 mm from the tip of the upper beak (P < 0.05) and the width of the lower mandible measured 2 to 4 mm from the tip of the lower beak (P < 0.05) in the intermediate BW group. In the heavy BW group, BW was positively correlated with mandibular tomia, gonys, and the width of the lower mandible measured at 2 mm from the tip of the lower beak (P < 0.05). However, in general, these correlations were too low (all below 0.23) to have any practical use for predicting beak size. Overall, the data indicated that BW cannot be used as a reliable predicator of beak size in 1-d-old Hy-Line W-36 chicks.

Improving animal well-being through genetic selection

This paper reviews the possibilities of adapting laying hens to cages by means of genetic selection. By selecting separately for rate of lay and longevity using a kin selection method, a strain of laying hen has been developed that shows much less feather pecking and cannibalism than a control strain, and with no decrease in productivity. This experimental strain enjoys a higher level of welfare in cages because it does not require beak trimming.

Behavioural and anatomical consequences of two beak trimming methods in 1- and 10-d-old domestic chicks

1. To examine the effects of beak trimming on behaviour, beak anatomy, weight gain, food intake and feather condition 360 ISA Brown chicks were trimmed by hot cut or cold cut at 1 d or 10 d of age or were sham-operated controls. The experiment was a 3 x 2 factorial design, with the chicks housed in littered pens in groups of 10 and observed for 6 weeks after trimming. 2. In the first week after trimming, when trimmed birds were compared with untrimmed controls, they were less active (sat and slept more), fed less, preened less and generally engaged in less beak-related behaviour. 3. These differences waned sharply during week 2 and had disappeared by week 5. There were very few differences between hot- and cold-cut birds. 4. There were also differences in production variables: trimmed birds grew more slowly during the week after trimming, their food intake was depressed for 3 weeks and food conversion efficiency improved for 2 weeks. 5. The only significant effect on feather scores was better plumage condition in the groups trimmed at 1 d and scored at 6 weeks. 6. To examine the anatomical effects 36 ISA Brown chicks trimmed by hot or cold cut at 1 d or 10 d of age were killed at 21 and 42 d after trimming, and their beaks were processed and examined histologically. In all trimmed groups healing was very rapid and no scar tissue was seen but, unlike the controls, the regrown tips contained no afferent nerves or sensory corpuscles. 7. Beak lengths immediately after trimming were 40% to 50% shorter than controls; the anatomical consequences of both methods were identical. 8. Overall, it was judged that the effects on behaviour and beak anatomy were much less severe than previously reported for birds trimmed at older ages. If birds do have to be trimmed then the procedure should be carried out in young birds: from the birds' standpoint 1 d appears to be the most suitable.

Behavioural development in groups of pen-housed pullets in relation to genetic strain, age and food form

1. Behavioural development in groups of 8 pullets kept in pens with litter floors, and fed on either mash or pellets, was studied from 0 to 10 weeks in a White Leghorn x broiler (F2) hybrid line (experiment 1) and from 0 to 24 weeks in Hisex, White Leghorn and Brown Leghorn strains (experiment 2). The aim was to identify precursors of feather pecking and cannibalism. 2. Rates of body weight gain were consistently greater with pellets than with mash in both experiments. In experiment 2, the onset of lay was at 17 weeks of age in Hisex, 21 weeks in White Leghorns and 23 weeks in Brown Leghorns. 3. Persistent feather pecking, which was not seen in experiment 1, developed in 2 of 12 groups (one Hisex and one White Leghorn, both fed on pellets) in experiment 2, and was studied in detail at 23 and 24 weeks. The more damaging pecking in the Hisex group was followed by cannibalism in the same group. 4. Based on the (often inconsistent) effects of genetic strain, age and food form on behaviour that were observed, a working hypothesis was constructed to account for the aetiology of feather pecking and cannibalism in situations where there is floor litter. 5. An age-related decline in one or more foraging activities may coincide with increases in preening and non-damaging pecking at other birds. Consumption of litter particles and moulted feathers may be reinforcing. Dustbathing may enhance the stimulus value of litter particles when they are contrasted against background plumage colour. This may direct pecking towards the backs of birds, where feathers as well as litter particles may be removed and eaten. Regular pecking and feather removal may lead eventually, after the onset of lay, to vent pecking and cannibalism. This sequence of events may be more likely in groups where activity levels are high.

Review: welfare perspectives on hens kept for egg production

The wild ancestors of chickens, along with those of most other farm animals, were preadapted to domestication because their lack of specialized requirements allowed them to adapt to a wide variety of environments provided by humans. Currently most commercial chickens kept for table-egg production are incubated, reared, and maintained as productive adults in high-density, artificial environments. Nevertheless, there are limits to adaptability as indicated by behavioral, physiological, immunological, and individual productivity indicators when environmental conditions become extreme. However, with the exception of obvious injury, no single criterion is likely to be adequate. Multiple indicators are required to obtain reliable evaluation of whether husbandry practices and environmental conditions reduce hens' welfare significantly. Concern for the well-being of hens has led to the phasing out of cages in two European countries. Although cages are known to be associated with some problems of well-being, it is known also that they have some welfare advantages for hens over alternative systems of production and they have definite economic advantages for producers. Therefore, it is doubtful whether the use of cages should be denied without exploring further the possibilities of cage modification or genetic selection aimed at improving the well-being of hens in such environments. Ethical perspectives relative to animals have been evolving since the time of Aristotle more than 300 yr B.C. Recent developments include divergence of welfare concerns between utilitarian and animal rights based philosophies. The utilitarians generally agree that animals may be used for human benefit if unnecessary pain and suffering are avoided and humane care and management criteria are met. Fundamentally, rights-oriented groups reject such exploitation. The general public exhibits a continuum of attitudes towards animals. However, there are indications that they are moving towards a protectionist attitude toward farm animals. Many requirements for good husbandry are known. However, uncertainty prevails in some areas, particularly with the necessity of routine procedures such as beak trimming and the amount of space needed, optimal group size, and whether nests, roosts, litter, and other quality of environment features are necessities or luxuries in terms of hens' welfare. Floor and feeder space and group size seem to be of paramount importance, and space that is adequate for well-being seems to be greater than that which yields the greatest net income. Genetic solutions to several behavior-related problems that compromise hens' well-being seem to be feasible and worthy of greater emphasis by commercial poultry breeders.

Beak trimming effects on beak length and feed usage for growth and egg production

Two experiments were conducted to compare beak treatment effects on pullets of three genetic stocks. Within each stock, equal numbers were assigned to three treatments: no beak trimming (IN), beak trimming once (1X), and beak trimming twice (2X). Beak treatment, genetic stock, and age effects along with interactions among main effects were examined for production-associated traits during rearing and brief periods of early egg production. Beaks of 1X and 2X pullets remained shorter than those of IN pullets through final measurements at 36 and 32 wk of age in Experiments 1 and 2, respectively. However, differences in beak length decreased as age increased. Upper beaks of 2X pullets remained shorter than those of 1X pullets, but lower beaks of 1X and 2X pullets did not differ by 20 wk in Experiment 2. Weight gains, feed usage, and efficiency of growth were affected by beak treatments. Beak trimming reduced gains, feed eaten, feed wasted, and total feed used, and 2X pullets used their feed more efficiently for weight gain and egg production. A general decrease occurred in differences among beak treatments for weight gains, feed eaten, feed wasted, and efficiency of gains with increasing age during rearing. Nevertheless, significant differences in feed consumed, feed wasted, and efficiency of feed used for egg production indicated an economic advantage in favor of beak trimming.

Beak trimming and sex effects on behavior and performance traits of large white turkeys

The effects of beak trimming at day old on performance and behavioral activities of male and female Large White turkeys were evaluated. One hundred and twenty poults of each sex were evenly assigned to 20 treatment pens and evaluated for body weight, feed usage, and livability characteristics to 18 wk of age. Behavioral observations were conducted for feeding, drinking, sleeping, huddling, resting, and agonistic activities. Beak trimming affected body weight and feed usage levels for the sexes differently. From 6 wk, trimmed males were significantly heavier than untrimmed males, whereas untrimmed females were heavier than trimmed females from 12 wk. Similar to body weights, feed usage levels from 13 to 18 wk were higher for trimmed males compared with untrimmed males and lower for trimmed females compared with untrimmed females. Feed conversion ratios after 12 wk and survival to 18 wk were not affected by trimming treatment. Livability rates, however, were lowest for untrimmed males and highest for untrimmed females. Effects on behavioral activities were confined primarily to the brooding and early rearing phases. Beak trimming reduced feeding activity of females and drinking activity of both males and females during the first 2 wk. Sleeping, huddling, and resting activities were increased by beak trimming for both sexes during brooding. Agonistic acts were reduced by beak trimming main effect at 3 and 6 wk. Trimmed males committed fewer agonistic acts at 6 wk than untrimmed males.

Applications of behavior to poultry management

The application of poultry behavior to management is discussed with examples of behavior-management interactions relating to commercial poultry husbandry practices. Behaviors that are important for the adaptation of poultry to husbandry include: social behavior, aggression, sexual behavior, feeding, broodiness, cannibalism, nest site selection, and comfort behaviors.

Research note: genetic adaptation to multiple-bird cage environment is less evident with effective beak trimming

Selection of hens with intact beaks for high performance in multiple-bird cages has produced a stock that clearly exceeds its unselected control when hens have intact beaks but shows less advantage when comparisons involve effectively beak-trimmed birds. The selected stock performed at about the same level as a stock recently derived from a commercial source (but with two generations of relaxed selection) when birds had intact beaks but at a lower level when birds had their beaks trimmed. Relative incidences of deaths from cannibalistic pecking were partially responsible for the results obtained.

Selection and beak-trimming effects on behavior, cannibalism, and short-term production traits in White Leghorn pullets

Pullets of stocks derived from the North Central Randombred White Leghorn population without selection (C) or selected (S) on family performance when kept with beaks intact in multiple-hen cages were compared. Pullets had intact, one-fourth, or one-half of the beak removed (IN, 1/4R, and 1/2R, respectively). No stock differences were detected for behavior traits or other measures during the rearing period. However, beak-trimmed pullets were more inactive and feeding behavior was depressed in 1/2R pullets 1 wk after beak trimming. At 16 wk, 1/4R pullets' beaks had regrown but 1/2R pullets' beaks continued to be shorter than IN pullets' beaks. No differences in fearfulness were found between genetic stocks or among beak length treatments early in the laying period. Deaths from beak-inflicted injuries accumulated steadily from 18 wk until the study was ended at 40 wk. Cannibalistic deaths occurred less frequently in S as compared with C pullets within each beak treatment. As the amount of beak removal increased, beak-inflicted mortality decreased. The S pullets had earlier sexual maturity, lighter egg weights, and greater hen-housed egg production and egg mass than C pullets, and 1/2R pullets had greater egg production than 1/4R and IN pullets. Genetic stock by age and beak treatment by age interactions were present for hen-housed production and egg mass, and the interactions appeared to result primarily from increased mortality from cannibalistic pecking with increased age.