RESUMO
The prevalence of keel bone damage as well as external egg parameters of 2 pure lines divergently selected for high (H) and low (L) bone strength were investigated in 2 aviary systems under commercial conditions. A standard LSL hybrid was used as a reference group. Birds were kept mixed per genetic line (77 hens of the H and L line and 201 or 206 hens of the LSL line, respectively, per pen) in 8 pens of 2 aviary systems differing in design. Keel bone status and body mass of 20 focal hens per line and pen were assessed at 17, 18, 23, 30, 36, 43, 52, and 63 wk of age. External egg parameters (i.e., egg mass, eggshell breaking strength, thickness, and mass) were measured using 10 eggs per line at both 38 and 57 wk of age. Body parameters (i.e. tarsus and third primary wing feather length to calculate index of wing loading) were recorded at 38 wk of age and mortality per genetic line throughout the laying cycle. Bone mineral density (BMD) of 15 keel bones per genetic line was measured after slaughter to confirm assignment of the experimental lines. We found a greater BMD in the H compared with the L and LSL lines. Fewer keel bone fractures and deviations, a poorer external egg quality, as well as a lower index of wing loading were found in the H compared with the L line. Mortality was lower and production parameters (e.g., laying performance) were higher in the LSL line compared with the 2 experimental lines. Aviary design affected prevalence of keel bone damage, body mass, and mortality. We conclude that selection of specific bone traits associated with bone strength as well as the related differences in body morphology (i.e., lower index of wing loading) have potential to reduce keel bone damage in commercial settings. Also, the housing environment (i.e., aviary design) may have additive effects.
Assuntos
Densidade Óssea/genética , Galinhas/genética , Galinhas/fisiologia , Ovos/normas , Abrigo para Animais , Seleção Genética , Animais , Cruzamento , Feminino , Oviposição , Esterno/patologiaRESUMO
Keel bone damage (KBD) is a critical issue facing the laying hen industry today as a result of the likely pain leading to compromised welfare and the potential for reduced productivity. Recent reports suggest that damage, while highly variable and likely dependent on a host of factors, extends to all systems (including battery cages, furnished cages, and non-cage systems), genetic lines, and management styles. Despite the extent of the problem, the research community remains uncertain as to the causes and influencing factors of KBD. Although progress has been made investigating these factors, the overall effort is hindered by several issues related to the assessment of KBD, including quality and variation in the methods used between research groups. These issues prevent effective comparison of studies, as well as difficulties in identifying the presence of damage leading to poor accuracy and reliability. The current manuscript seeks to resolve these issues by offering precise definitions for types of KBD, reviewing methods for assessment, and providing recommendations that can improve the accuracy and reliability of those assessments.
Assuntos
Criação de Animais Domésticos/métodos , Galinhas , Fraturas Ósseas/veterinária , Doenças das Aves Domésticas/diagnóstico , Animais , Feminino , Fraturas Ósseas/diagnóstico , Fraturas Ósseas/etiologia , Doenças das Aves Domésticas/etiologia , Reprodutibilidade dos Testes , Terminologia como AssuntoRESUMO
Keel fractures in the laying hen are the most critical animal welfare issue facing the egg production industry, particularly with the increased use of extensive systems in response to the 2012 EU directive banning conventional battery cages. The current study is aimed at assessing the effects of 2 omega-3 (n3) enhanced diets on bone health, production endpoints, and behavior in free-range laying hens. Data was collected from 2 experiments over 2 laying cycles, each of which compared a (n3) supplemented diet with a control diet. Experiment 1 employed a diet supplemented with a 60:40 fish oil-linseed mixture (n3:n6 to 1.35) compared with a control diet (n3:n6 to 0.11), whereas the n3 diet in Experiment 2 was supplemented with a 40:60 fish oil-linseed (n3:n6 to 0.77) compared to the control diet (n3:n6 to 0.11). The n3 enhanced diet of Experiment 1 had a higher n3:n6 ratio, and a greater proportion of n3 in the long chain (C20/22) form (0.41 LC:SC) than that of Experiment 2 (0.12 LC:SC). Although dietary treatment was successful in reducing the frequency of fractures by approximately 27% in Experiment 2, data from Experiment 1 indicated the diet actually induced a greater likelihood of fracture (odds ratio: 1.2) and had substantial production detriment. Reduced keel breakage during Experiment 2 could be related to changes in bone health as n3-supplemented birds demonstrated greater load at failure of the keel, and tibiae and humeri that were more flexible. These results support previous findings that n3-supplemented diets can reduce fracture likely by increasing bone strength, and that this can be achieved without detriment to production. However, our findings suggest diets with excessive quantities of n3, or very high levels of C20/22, may experience health and production detriments. Further research is needed to optimize the quantity and type of n3 in terms of bone health and production variables and investigate the potential associated mechanisms.
Assuntos
Comportamento Animal/efeitos dos fármacos , Osso e Ossos/fisiologia , Ácidos Graxos Ômega-3/farmacologia , Fraturas Ósseas/veterinária , Oviposição/efeitos dos fármacos , Envelhecimento , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Galinhas , Dieta/veterinária , Suplementos Nutricionais , Ácidos Graxos Ômega-3/química , Feminino , Fraturas Ósseas/prevenção & controle , Abrigo para AnimaisRESUMO
Commercial laying hen housing is shifting from traditional cages to non-cage housing systems, such as the aviary, which has gained popularity due to potential for more species-typical behavior. However, birds housed in aviaries may have difficulties moving through the vertical tiers of the system leading to health problems such as keel bone fracture (KBF). One possible way to improve movement is to add ramps into an aviary system, allowing hens to walk between tiers rather than jump or fly. The objective of this study was to evaluate the impact of adding ramps to rearing and laying aviaries on bird health, production, and movement across vertical tiers of the aviary. Lohmann Selected Leghorn pullets were raised in 2 treatments: 4 pens (600 birds/pen) were raised with wire mesh ramps to aid movement between aviary tiers (RR) and 4 pens (600 birds/pen) were raised without ramps (RO). At 17 wk of age (WOA), birds were moved to the laying facility, in which 16 aviary pens with 225 birds/pen were populated. Half the pens (n = 8) were supplemented with wire mesh ramps (LR) and the other half were not (LO). Within each laying treatment group, 4 pens were populated with RR hens and 4 pens were populated with RO hens, creating 4 treatment combinations (RRLR, RRLO, ROLR, ROLO). From each pen, 15 focal hens were selected for radiographic imaging of their keel bones taken at 21, 36, 45, and 60 WOA and the images were subsequently scored for KBF severity. Focal hens were also scored for feather condition and footpad quality at 36 and 60 WOA using a standardized welfare assessment protocol. The number of downward transitions among aviary areas and falls were recorded at 19 to 20 and 30 to 31 WOA. Data were analyzed using (generalized) linear mixed models in R software. When ramps were available, they were used in most of the observed downward transitions (79% in ROLR and 86% in RRLR). Hens who received ramps in lay (i.e., RRLR and ROLR) showed more transitions immediately after lights on compared to midday or dusk phases (p < 0.001), performed more transitions from the first aviary tier compared to nest or top tier (p = 0.013) and had lower KBF severity than those who did not receive ramps in the laying aviaries (ROLO, RRLO; p < 0.001). At 60 WOA, hens in the RRLR treatment had greater feather coverage than those in ROLR and RRLO treatments (p < 0.001). Birds in the RRLR treatment had better foot health overall than those in treatments without ramps in lay (p = 0.018). Providing ramps to hens in aviaries appeared to be the preferred means of transitioning between aviary tiers though had positive effects on welfare parameters such as food health, feather coverage, and KBF severity, without negative impacts on production. Benefits were seen primarily when ramps were provided in lay, though their installation in rearing provided evidence of easier adaptation to the laying barn. Our study supports providing ramps throughout the lifetime of the bird to accommodate hens' preferred means of moving vertically in aviaries and deliver consequent benefits to health and welfare.
RESUMO
Lameness represents a major welfare and production issue in the poultry industry with a recent survey estimating 27% of birds lame and 3% unable to walk by 40 d of age. A variety of factors may induce lameness and are typically grouped into 2 broad classes on the basis of being infectious or skeletal in nature with the latter accounting for the majority of cases. The current work sought to build upon a large body of literature assessing the anatomical properties of bone in lame birds. Our specific objectives sought to identify relationships between relevant anatomical properties of the tibia and metatarsus using digital quantification from radiographs of legs and a measure of walking difficulty. Resulting output was statistically analyzed to assess 1) observer reliability for consistency in placing the leg during the radiograph procedure and quantification of the various measures within a radiograph, 2) the relationship between the various measurements of anatomical bone properties and sex, bird mass, and gait score, and 3) the relationship between each measurement and leg symmetry. Our anatomical bone measures were found to be reliable (intra-rater and test-retest reliabilities < 0.75) within radiograph for all measures and 8 of the 10 measures across radiographs. Several measures of bone properties in the tibia correlated to difficulty walking as measured by gait score (P < 0.05), indicating greater angulations with increasing lameness. Of the measures that manifested a gait score × bird mass interaction, heavier birds appeared to exhibit less angulation with increasing difficulty walking with lighter birds the opposite. These interactions suggest possibilities for influencing effects of activity or feed intake on bone mineralization with the bone angulation observed. Our efforts agree with that of others and indicate that angulation of the tibia may be related to lameness, though subsequent efforts involving comprehensive measures of bird activity, growth rates, and internal bone structure will be needed if the validity of the measures are to be accepted.
Assuntos
Galinhas , Marcha , Coxeadura Animal/fisiopatologia , Metatarso/diagnóstico por imagem , Doenças das Aves Domésticas/fisiopatologia , Tíbia/diagnóstico por imagem , Animais , Cadáver , Feminino , Coxeadura Animal/diagnóstico por imagem , Masculino , Metatarso/anatomia & histologia , Metatarso/patologia , Doenças das Aves Domésticas/diagnóstico por imagem , Radiografia , Reprodutibilidade dos Testes , Tíbia/anatomia & histologia , Tíbia/patologiaRESUMO
1. Previous studies found beneficial effects on the prevalence of keel fractures and bone health in laying hens receiving a short chain ω3 fatty acid diet. However, subsequent work using a mixed short and long chain ω3 diet (MCD) found little benefit to bone health and substantial production losses. 2. The current study examined commercial use of a mixed chain length ration in multiple farms and flocks and identified a detrimental effect on productivity including: mortality, number of poor quality eggs, hen daily average, feed consumption, and increased egg weight. 3. Production data were acquired from 11 flocks housed on 5 farms and modelled using MlwiN, a statistical package developed for analysis of hierarchical data. Production responses were individually modelled with duration of exposure to the diet, age of introduction, flock size and farm, included as prediction variables. 4. Analysis indicated birds receiving the MCD manifested dramatic increases in mortality, poor quality eggs, mean egg weight, feed consumption and decreased production in comparison to control flocks receiving a standard ration. Increased exposure time appeared to increase the magnitude of the diet effect. 5. Although no data were collected to explain the potential mechanisms of this diet, the authors discuss several possible scenarios including excessive long chain ω3 content overwhelming eicosanoid regulatory capacity and changes in behaviour patterns.
Assuntos
Ração Animal/análise , Galinhas/fisiologia , Ovos/normas , Ácidos Graxos Ômega-3/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Comportamento Alimentar , Feminino , Abrigo para AnimaisRESUMO
Piling behaviour of laying hens often results in smothering or death due to suffocation. Mechanisms leading to piling are not yet understood though various potential factors have been suggested. In this experimental study, we predicted that the presence of a light spot, a novel object (metal foil), or a heat area within animal pens would increase animal numbers around the stimulus leading to piling behaviour. We presented the cues in a 4â¯×â¯2 Latin-square design in eight identical experimental pens including each 55 Lohmann Selected Leghorn hens. The cues were presented in two test areas per pen, at two bouts per day in the morning, consecutively for 5â¯days, over four periods (age: 20, 22, 24, 26â¯weeks). Each pen received a cue and control condition simultaneously (test areas without cue presentation) once. For a bout, each cue was presented for 35â¯min except for the light spot where the duration was 10â¯min. Birds' responses to the cues during bout and non-bout times were video recorded and analysed for the first bout of each period. To assess the cues' attractiveness, the number of hens during bout times was counted at predefined times within the test and control areas. To assess the cues' effects on piling, we described piling behaviour (pile number, duration, animal numbers, trigger) in control and test areas during bout times. Furthermore, we described piling behaviour during bout times and non-bout times on the first day of the first period and fourth period. The best model explaining the number of hens included the interactions of treatment and bout time, and treatment and area. Over the bout's time course, more hens were attracted to the light spot compared to the control condition, and more to test areas compared to control areas. In the novel object condition, more hens were drawn to the test areas compared to the control areas. Hens were not attracted to the heat area. Piling in bout times was observed twice when hens pecked at the novel object. During non-bout times, piling behaviour occurred frequently at midday and in the late morning compared to the afternoon, mostly in corners and mainly preceded by the mutual attraction of hens. Overall, hens were attracted to light spots and less so to the novel object though neither reliably induced piling behaviour. The occurrence of piling behaviour in non-bout times shows that more work is needed to understand mechanisms eliciting piling behaviour.
Assuntos
Galinhas , Abrigo para Animais , Animais , Comportamento Animal/fisiologia , Galinhas/fisiologia , Feminino , Temperatura AltaRESUMO
European farms for broiler breeders often have raised slatted areas in front of the nests, but in other regions of the world no raised slatted areas are provided. This study aimed to investigate the effects of a raised slatted area on leg health, mating behaviour and floor laying behaviour. Ten groups of 33 broiler breeder hens and three males were housed in two pen types: with or without a raised slatted area in front of the nests. Each pen had one plastic and one wooden nest. Between 25 and 31â¯weeks of age, ten marked hens per pen were weighed and assessed weekly on foot pad dermatitis, hock burn and wounds. At the end of week 31, animals were euthanized and bone strength of the tibia and humerus of these individuals was assessed. At 24, 27 and 30â¯weeks of age, mating behaviour was observed for an hour per pen, noting both numbers of successful and unsuccessful copulations. The number of eggs laid in the nests and on the floor was recorded daily between 20 and 31â¯weeks of age. Foot pad dermatitis scores were affected by age, but not by pen type. Generally, there were only minor issues with foot pad dermatitis (scores <11 on a 0-100 scale), probably due to the young age of the hens. Body weight was not affected by pen type, while the prevalence of hock burns was too low to analyse and no difference in bone strength was found for the tibia and the humerus. Overall, mating behaviour was less frequent in pens with raised slats than in pens without raised slats (29⯱â¯2 vs 35⯱â¯3 times/h) and more frequent at 27â¯weeks of age than at 24 and 30â¯weeks of age (38⯱â¯1 vs 31⯱â¯4 and 27⯱â¯2 times/h). The pens with raised slats had a lower percentage of floor eggs than pens without raised slats (11.2⯱â¯0.4 vs 19.3⯱â¯0.5%). The wooden nest was preferred over the plastic nest as on average 63% of the eggs were laid in the wooden nest. This study shows that providing raised slats decreases mating behaviour and percentage of floor eggs, although its effects on leg health remain inconclusive.
Assuntos
Galinhas , Abrigo para Animais , Animais , Feminino , Pisos e Cobertura de Pisos , Óvulo , ReproduçãoRESUMO
1. Much evidence exists detailing how animals respond to pathogen challenge, yet information explaining how the various behavioural, immunological, and physiological systems in chickens interplay during such challenges remains limited. 2. To gain an understanding of this interplay while controlling for genetic variation, the current study collected a variety of behavioural, physiological and immunological measures from three inbred lines (P, O and N) of laying hens before and after a sub-clinical infection with Salmonella enterica Typhimurium at 56 d of age. For comparison, an equal number of control birds were inoculated with a Salmonella-free broth. To identify an underlying profile, which might result in reduced susceptibility to infection, data were also collected in the pre-infection period. Post-infection blood and faeces were collected at 1-d post infection (dpi) and faeces again at 8 dpi. Animals were killed 15 d after infection and faeces, caecal contents, and spleen were examined for the presence of Salmonella. 3. Statistical analysis was performed to identify pre- and post-infection differences between genetic lines, changes in bird behavioural patterns between the two periods, and associations between a positive test for Salmonella and the various response measures. 4. Tissues from Line P birds were more often negative for Salmonella than those from birds of other lines, though this was inconsistent and tissue-dependent. The P line was also characterised by relatively greater serum concentrations of immunoglobulins at 1 dpi and α(1)-acid glycoprotein at 15 dpi. In addition, P line birds were more timid and their growth was reduced during the pre-infection period suggesting the possibility of a profile with reduced susceptibility to the bacterial challenge. 5. The current work has identified correlations between attributes of chicken strains and improved clearance. Future work using hypothesis-based testing will be required to determine whether the identified correlations are causally related.
Assuntos
Comportamento Animal , Doenças das Aves/microbiologia , Galinhas/microbiologia , Salmonelose Animal/imunologia , Bem-Estar do Animal , Animais , Doenças das Aves/imunologia , Peso Corporal , Galinhas/imunologia , Galinhas/fisiologia , Suscetibilidade a Doenças , Feminino , Glucocorticoides/metabolismo , Imunoglobulina M/sangue , Imunoglobulinas/sangue , Masculino , Orosomucoide/metabolismoRESUMO
Aviaries provide hens with many resources, but birds must develop motor and cognitive skills to use them properly. Introducing birds to aviaries at older ages has been reported to result in less use of perches, nests, and vertical space, which can reduce productivity and hen welfare. The objectives of this study were to examine (1) how enrichment influenced distribution of hens in the aviary during the day and (2) how enrichment influenced the distribution and roosting substrate of birds at night. Hy-Line W36 pullets were raised in floor pens before moving to laying aviaries (100 hens/aviary unit × 4 units/treatments). Control (CON) pullets were placed into aviaries at 17 wk of age (WOA). Floor (FLR) and enriched (ENR) pullets remained in floor pens until 25 WOA, and ENR birds were provided with perches and nests at 17 WOA. Birds were counted in tiers and litter areas of the aviary at morning, midday and evening at 36 and 54 WOA. Data were analyzed using generalized linear mixed models in R statistical software. At 36 WOA, ENR and CON birds occupied aviary areas at similar rates but differently from FLR birds. For example, in the morning 34% of CON hens and 30% of ENR hens occupied the highest tier compared to 15% of FLR hens (P < 0.01). At midday, 57% of CON and 57% of ENR birds were counted in litter compared with 77% of FLR birds (P < 0.01). In the evening, CON and ENR hens moved to the top tier of the aviary in greater numbers than FLR hens (22 and 17%, respectively, vs. 7%, P < 0.01). At 54 WOA, differences between FLR hens and CON/ENR hens were less pronounced, suggesting FLR hens were adapting to the aviary. Overall, we conclude that birds exposed to aviaries at 25 WOA can adapt to aviary systems, but take more time to do so than birds exposed to aviaries or vertical enrichment at 17 WOA.
Assuntos
Adaptação Psicológica , Bem-Estar do Animal , Galinhas/fisiologia , Abrigo para Animais , Criação de Animais Domésticos/métodos , Animais , Feminino , Pisos e Cobertura de PisosRESUMO
In commercial flocks of laying hens, keel bone fractures (KBFs) are prevalent and associated with behavioural indicators of pain. However, whether their impact is severe enough to induce a depressive-like state of chronic stress is unknown. As chronic stress downregulates adult hippocampal neurogenesis (AHN) in mammals and birds, we employ this measure as a neural biomarker of subjective welfare state. Radiographs obtained longitudinally from Lohmann Brown laying hens housed in a commercial multi-tier aviary were used to score the severity of naturally-occurring KBFs between the ages of 21-62 weeks. Individual birds' transitions between aviary zones were also recorded. Focal hens with severe KBFs at 3-4 weeks prior to sampling (n = 15) had lower densities of immature doublecortin-positive (DCX+) multipolar and bipolar neurons in the hippocampal formation than focal hens with minimal fractures (n = 9). KBF severity scores at this time also negatively predicted DCX+ cell numbers on an individual level, while hens that acquired fractures earlier in their lives had fewer DCX+ neurons in the caudal hippocampal formation. Activity levels 3-4 weeks prior to sampling were not associated with AHN. KBFs thus lead to a negative affective state lasting at least 3-4 weeks, and management steps to reduce their occurrence are likely to have significant welfare benefits.
Assuntos
Bem-Estar do Animal/ética , Fraturas Ósseas/complicações , Hipocampo/fisiopatologia , Doenças das Aves Domésticas/psicologia , Esterno/lesões , Estresse Psicológico/etiologia , Criação de Animais Domésticos/ética , Animais , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Galinhas , Proteínas do Domínio Duplacortina , Feminino , Fraturas Ósseas/patologia , Fraturas Ósseas/psicologia , Expressão Gênica , Hipocampo/metabolismo , Abrigo para Animais/ética , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Neurônios/patologia , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Doenças das Aves Domésticas/patologia , Reprodução/genética , Estresse Psicológico/patologia , Estresse Psicológico/psicologia , Índices de Gravidade do TraumaRESUMO
OBJECTIVES: To investigate the long term reliability of clinician and owner visual analogue score (VAS) for dogs with unilateral forelimb lameness attributable to fragmented medial coronoid process (FMCP) when compared to objective gait analysis. METHODS: Nine dogs with unilateral thoracic limb lameness due to FMCP underwent inverse dynamics gait analysis at initial presentation, and at one, two, six and 12 months following diagnosis. Total support moments were calculated and a total support moment ratio (TSMR) derived as an objective assessment of thoracic limb asymmetry. A VAS questionnaire for lameness was completed by the owner of each dog for each visit. Video footage of each dog walking and trotting at each visit was compiled, assigned to random order and subjected to VAS for lameness by a specialist in small animal surgery. Data from owner and clinician VAS lameness questionnaires were compared to the thoracic limb TSMR. RESULTS: Statistical analysis demonstrated a significant negative correlation between TSMR and owner VAS at four weeks post treatment but at no other period of evaluation. There was no significant correlation between TSMR and clinician VAS score at any evaluation period. CLINICAL SIGNIFICANCE: Assessments by owner and clinicians using VAS appear to be of limited use as a long term outcome measure for dogs with unilateral lameness due to FMCP when compared to objective gait analysis. There is a tendency for owners to underestimate forelimb lameness with increasing time which is not supported by quantitative measures of gait.
Assuntos
Doenças do Cão/cirurgia , Membro Anterior/lesões , Marcha , Coxeadura Animal/etiologia , Fraturas da Ulna/veterinária , Animais , Cães , Membro Anterior/cirurgia , Humanos , Articulações/lesões , Articulações/cirurgia , Medição da Dor , Inquéritos e QuestionáriosRESUMO
Birds from Rhode Island Red (RIR) origin show a lower fear response and less feather pecking than birds from White Leghorn (WL) origin. This study investigated whether responses in fear eliciting tests were affected if RIR and WL birds were housed together. Experimental groups contained either birds from one line only ('pure' groups) or an equal number of RIR and WL birds ('mixed' groups). These arrangements were maintained from hatch onwards, throughout the rearing and laying period. Birds were subjected to open field tests at 5-6 weeks and 17-18 weeks of age and to manual restraint tests at 7-8 weeks and 24 weeks of age. RIR birds were more active in both open field tests and in the manual restraint test at 24 weeks of age as compared with WL birds. RIR birds from pure groups were more active in the open field test at 17-18 weeks and in the manual restraint test at 24 weeks of age than RIR birds from mixed groups. These results suggest that otherwise low fearful RIR birds may adopt a higher fear response if they are housed together with more fearful conspecifics. These effects do not emerge until after 8 weeks of age.
Assuntos
Comportamento Animal/fisiologia , Galinhas/fisiologia , Medo/fisiologia , Abrigo para Animais , Atividade Motora/fisiologia , Criação de Animais Domésticos , Animais , Galinhas/genética , Medo/psicologia , Plumas , Feminino , Atividade Motora/genética , Densidade Demográfica , Comportamento Social , Estresse Psicológico/genética , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologiaRESUMO
OBJECTIVES: The objectives of this study were to quantify the sensitivity and specificity of visual assessment of radiographs of the canine elbow in detecting ulnar trochlear notch sclerosis, to establish interobserver and intra-observer variation for the presence and grade of sclerosis and to quantify the effect of radiographic exposure on observer grading. METHODS: Mediolateral elbow radiographs were obtained from Labrador retrievers (n=34) aged between six and 18 months. Radiographs from dogs with an arthroscopic diagnosis of fragmented medial coronoid process (n=17) and those from a control population (n=17) were subjected to observer grading for the presence or absence of and the grade of ulnar trochlear notch sclerosis. Interobserver and intra-observer variation and observer sensitivity and specificity were calculated. Digital data from the ulnar trochlear notch were correlated with mean observer grade to quantify the effect of radiographic exposure on observer grade. RESULTS: Interobserver agreement was "fair" (kappa=0.251 to 0.369) and intra-observer agreement was "moderate" to "substantial" (kappa=0.462 to 0.667). The sensitivity of observer assessment was 72 per cent with a specificity of 22 per cent. Mean observer grade was not significantly correlated with the degree of radiographic exposure (P=0.70). CLINICAL SIGNIFICANCE: Ulnar trochlear notch sclerosis is a phenomenon associated with fragmented medial coronoid process. However, interobserver agreement in grading this feature is only fair, being identified by observers with moderate sensitivity but with relatively poor specificity. This low specificity may predispose to overdiagnosis in clinical cases. Intra-observer agreement is moderate to substantial, suggesting that individuals can reliably quantify this radiological feature on multiple occasions. The ability of observers to assess the degree of sclerotic change is not significantly affected by radiographic exposure.
Assuntos
Doenças do Cão/diagnóstico por imagem , Artropatias/veterinária , Ulna/patologia , Animais , Competência Clínica/estatística & dados numéricos , Doenças do Cão/patologia , Cães , Feminino , Artropatias/diagnóstico por imagem , Masculino , Variações Dependentes do Observador , Radiografia , Esclerose/diagnóstico por imagem , Esclerose/veterinária , Sensibilidade e Especificidade , Ulna/diagnóstico por imagem , Médicos Veterinários/normasRESUMO
We sought to objectively quantify and compare the recorded movement and location patterns of laying hens within a commercial system. Using a custom tracking system, we monitored the location within five zones of a commercial aviary for 13 hens within a flock of 225 animals for a contiguous period of 11 days. Most hens manifested a hen-specific pattern that was (visually) highly consistent across days, though, within that consistency, manifested stark differences between hens. Three different methods were used to classify individual daily datasets into groups based on their similarity: (i) Linear Discriminant Analysis based on six summary variables (transitions into each zone) and total transitions; (ii) Hierarchical Clustering, a naïve clustering analysis technique, applied to summary variables and iii) Hierarchical Clustering applied to dissimilarity matrices produced by Dynamic Time Warping. The three methods correctly classified more than 85% of the hen days and provided a unique means to assess behaviour of a system indicating a considerable degree of complexity and structure. We believe the current effort is the first to document these location and movement patterns within a large, complex commercial system with a large potential to influence the assessment of animal welfare, health, and productivity.
Assuntos
Criação de Animais Domésticos/métodos , Análise Discriminante , Bem-Estar do Animal , Animais , Comportamento Animal/fisiologia , Galinhas , Feminino , Abrigo para AnimaisRESUMO
Broiler breeders are commonly kept without perches, although perching has been shown to be a high-priority behavior in laying hens. We studied whether broiler breeders used elevated perches of different lengths during the night and how access to perches affected health and production. Using the Ross 308 hybrid, pens offering 4 different perch spaces per bird (5, 10, 14, and 20 cm) in a cross-over design were compared with pens without perches. The number of birds on perches at midnight were recorded 7 times during production. Prevalence of keel bone fractures, breast blisters, pododermatitis, and plumage quality of hens was assessed at 45 wk, and production was monitored daily. To determine subsequent effects on offspring, chicks from hens with and without perches were reared and their growth rate was assessed. Analysis found more broiler breeders perched at night when 14 cm perch length per bird was provided than with less available perch length (P = 0.0005), but there was no difference between 14 and 20 cm per bird. Perch use declined with age from about 50 to 20% (P < 0.0001). The number of eggs and hatchability were not affected by treatment. During a period of high temperatures, mortality was lower in pens with perches (P = 0.001). Keel bone fractures were present in 1/4 of hens and were not affected by the presence of perches. The growth of chicks was not affected by the parent treatment. In conclusion, our results suggest that perches were chosen for roosting by broiler breeders depending on their age and did not impair production.
Assuntos
Bem-Estar do Animal , Galinhas/fisiologia , Abrigo para Animais , Animais , Comportamento Animal , Galinhas/crescimento & desenvolvimento , Estudos Cross-Over , Feminino , MasculinoRESUMO
REASONS FOR PERFORMING STUDY: While imprint training procedures have been promoted in popular magazines, they have received limited scientific investigation. OBJECTIVES: To determine the effects of a neonatal imprint training procedure on 6-month-old foals and to determine if any one session had a greater effect than others. METHODS: Foals (n = 131) were divided into the following treatments: no imprint training, imprint training at birth, 12, 24 and 48 h after birth or imprint training only at birth, 12, 24, 48, or 72 h after birth. Foals then received minimal human handling until they were tested at 6 months. RESULTS: During training, time to complete exposure to the stimulus was significant for only 2 of 6 stimuli. Percentage change in baseline heart rate was significant for only 2 of 10 stimuli. These 4 effects were randomly spread across treatments. CONCLUSIONS: Neither the number of imprint training sessions (0, 1, or 4) nor the timing of imprint training sessions (none, birth, 12, 24, 48, or 72 h after birth) influenced the foal's behaviour at 6 months of age. POTENTIAL CLINICAL RELEVANCE: In this study, imprint training did not result in better behaved, less reactive foals.
Assuntos
Animais Recém-Nascidos/psicologia , Comportamento Animal , Cavalos/psicologia , Vínculo Humano-Animal , Fixação Psicológica Instintiva , Fatores Etários , Criação de Animais Domésticos/métodos , Animais , Feminino , Manobra Psicológica , Humanos , Masculino , Distribuição Aleatória , Socialização , Fatores de TempoRESUMO
Several studies have attempted to determine the effects of orientation on a horse's ability to maintain balance during transportation. The results have often been contradictory because of differences in trailer design and lack of simultaneous comparisons. In this study, three replications of two forward-facing and two rear-facing horses were transported at the same time over a standardized course to allow for simultaneous comparisons. Each animal's total forward and backward motion during transport was calculated to estimate the effect of orientation on the horses' ability to maintain balance. The course consisted of four laps around a 3.6-km rectangular course, each lap reversing direction, totaling 14.4km. To mimic realistic travel, the course had artificial bumps, three turns (90 degrees, 45 degrees, and 135 degrees ), five straight-aways, and a hard stop at the end of each lap. Four horses were transported over the course in 3.7mx2.4m stalls mounted in-line on a 16-m long commercial straight-deck trailer (16 wheels). At the end of the first run (four laps), the orientation of each horse, two forward and two rear-facing, was reversed for a second run. Twelve horses were transported in each of the two orientations. Movement was recorded using video cameras positioned perpendicular to the horse's side. Movement while forward-facing ranged from 4.75 to 34.48m, averaging 12.95m; when rear-facing, movement ranged from 8.13 to 35.21m, averaging 16.99m, and was not statistically influenced by orientation (P=0.1219) due to high variation. Certain horses did demonstrate a superior ability to maintain balance in a particular orientation. Thus individual characteristics and other factors may play a larger role than orientation alone in the ability of horses to maintain balance during transport.
RESUMO
The aim of this work was to study the effect of keel fractures on the extent to which free-range hens access the range through pop holes. Over two consecutive laying periods (two production years) a total of 1100 individual birds from one half of a house, divided into four separated flocks, were caught at 25, 35, 45, 55 and 65 weeks, palpated to assess the prevalence and severity of keel fractures and tagged with RFID transponders. Their use of pop holes was subsequently monitored in some cases from week 25 to end of lay at 68 to 70 weeks. At regular intervals (every 10 weeks), the tagged birds were re-caught to assess changes in keel fracture prevalence and severity. The average percentage of birds with fractured keels at 25, 35, 45, 55, 65 and at end of lay (68 to 70 weeks of age) was 5.5, 25.5, 49, 63, 66.5 and 78.5, respectively, across both production years. The effect of keel score on pop hole use was modelled statistically, adjusting for weather conditions and age of the birds. There were significant effects of most of the weather variables recorded, as well as age of the bird, on use of pop holes and also a significant effect of keel score. Higher keel scores resulted in a reduction in pop hole use. A significant statistical interaction between keel score and ambient temperature revealed an accelerated reduction in use as the temperature decreased and keel score increased. It is concluded that the occurrence of keel fractures may affect the birds' ability or willingness to utilise the outdoor range provided by free-range housing systems, thereby reducing the potential welfare advantages of this type of housing.
Assuntos
Osso e Ossos/lesões , Galinhas/fisiologia , Fraturas Ósseas/veterinária , Abrigo para Animais , Oviposição , Fatores Etários , Bem-Estar do Animal , Animais , Feminino , Fraturas Ósseas/epidemiologia , Fraturas Ósseas/etiologia , Fatores de Tempo , Tempo (Meteorologia)RESUMO
Free-range laying hens are able to move between the indoor house and range through exits termed pop holes. The aim of this study was to examine the proportion of the flock that used the pop holes and to identify patterns of movement throughout the flock cycle. Four flocks of free-range hens each of 1500 birds were studied. Ten per cent of each flock were tagged with RFID (radio-frequency identification) transponders and their pop hole activity studied throughout the production cycle. Within two weeks of tagging at 25, 35, 45, 55 and 65 weeks of age, approximately 80 per cent of the tagged birds were seen in the pop holes and 50 per cent of the tagged birds were seen on 80 per cent of the days available to them after tagging. Within the flock, subpopulations of birds could be identified: those that never ventured to the pop holes (approximately 8 per cent), those that used the pop holes very infrequently (approximately 8 per cent), those that sat in the pop holes (approximately 4 per cent), and those that used the pop holes frequently (approximately 80 per cent). There was an effect of age of the birds, time of day and daily mean temperature on pop hole usage. Additional factors affecting activity on particular days were wind speed, rainfall and hours of sunshine. The findings show that a significant proportion of the flock accesses the pop holes on a regular basis with only a very small proportion preferring to stay in the house.