The Dual-Purpose Hen as a Chance: Avoiding Injurious Pecking in Modern Laying Hen Husbandry.

Dual-purpose strains, with hens housed for egg laying and roosters kept for meat production are one alternative to the killing of male day-old chickens. However, dual-purpose hens seem to have additional advantages compared to conventional layers, for instance, a lower tendency to develop behavioral disorders, such as feather pecking and cannibalism. In the present study, three batches of about 1850 conventional layers (Lohmann Brown plus, LB+) and 1850 dual-purpose hens (Lohmann Dual, LD) each, all of them with untrimmed beaks, were observed during production (20-71 (56) weeks of life) in a semi-commercial aviary system. The aim was to investigate whether the hybrid and batch affected the occurrence of injurious pecking, and to identify a detailed time course of the damage caused by this behavior. Therefore, the hens' plumage and skin condition were assessed as an indicator by means of a visual scoring method. The LB+ hens had higher production performances and higher mortality rates compared to the LD hens. Plumage loss in the LB+ flocks started at 23 to 25 weeks of age, and deteriorated continuously. The LD hens showed only moderate feather loss on the head/neck region, which started at 34 to 41 weeks and remained almost constant until the end of the observations. Compared to feather loss, injuries occurred in the LB+ hens with a delay of several weeks, with a maximum of 8% to 12% of hens affected. In contrast, skin injuries were observed only sporadically in single LD hens. In all batches, hybrid had an effect on the occurrence of feather loss (p < 0.05). Within the LB+ strain, the proportions of hens affected by plumage loss and injuries differed among batches (p < 0.05), whereas this was not the case in the LD flocks. Thus, severe feather pecking and cannibalism seemed to occur in the conventional layer hybrids but not in the dual-purpose hens, though both genetic strains were raised and managed under the same semi-commercial conditions. Therefore, keeping dual-purpose hens should also be considered as an alternative approach to avoid injurious pecking in laying hen husbandry.

Erratum: The study of service dogs for veterans with Post-Traumatic Stress Disorder: a scoping literature review.

[This corrects the article DOI: 10.1080/20008198.2018.1503523.].

The study of service dogs for veterans with Post-Traumatic Stress Disorder: a scoping literature review.

The therapeutic application of human-animal interaction has gained interest recently. One form this interest takes is the use of service dogs as complementary treatment for veterans with Post-Traumatic Stress Disorder (PTSD). Many reports on the positive effect of PTSD Service Dogs (PSDs) on veterans exist, though most are indirect, anecdotal, or based on self-perceived welfare by veterans. They therefore only give a partial insight into PSD effect. To gain a more complete understanding of whether PSDs can be considered an effective complementary treatment for PTSD, a scoping literature review was performed on available studies of PSDs. The key search words were 'dog', 'canine', 'veteran', and 'PTSD'. This yielded 126 articles, of which 19 matched the inclusion criteria (six empirical studies). Recurrent themes in included articles were identified for discussion of methodology and/or results. It was found that results from most included studies were either applicable to human-animal interaction in general or other types of service animals. They therefore did not represent PSDs specifically. Studies which did discuss PSDs specifically only studied welfare experience in veterans, but used different methodologies. This lead us to conclude there is currently no undisputed empirical evidence that PSDs are an effective complementary treatment for veterans with PTSD other than reports on positive welfare experience. Additionally, the lack of development standardization and knowledge regarding welfare of PSDs creates risks for both human and animal welfare. It is therefore recommended that a study on the effect of PSDs be expanded to include evaluation methods besides self-perceived welfare of assisted humans. Future studies could include evaluations regarding human stress response and functioning, ideally conducted according to validated scientific methodologies using objective measurement techniques to identify the added value and mechanisms of using PSDs to assist treatment of PTSD in humans.

La aplicación terapéutica de la interacción humano-animal ha ganado interés en los últimos años. Una forma que toma este interés es el uso de perros de servicio como tratamiento complementario para veteranos con Trastorno de Estrés Postraumático (TEPT). Existen muchos reportes del efecto positivo de los Perros de Servicio en TEPT (PSDs, en su sigla en inglés) en los veteranos, aunque la mayoría son indirectos, anecdóticos o basados en la autopercepción de bienestar de los veteranos. Por lo tanto, sólo entregan una visión parcial sobre el efecto de los PSD. Para obtener una comprensión más completa sobre si los PSDs pueden ser considerados un tratamiento complementario efectivo para el TEPT, se realizó una revisión exploratoria de la literatura de los estudios disponibles de PSDs. Las palabras clave de búsqueda fueron 'perro', 'canino' 'veterano' y 'TEPT', lo que arrojó 126 artículos, de los cuales 19 cumplieron los criterios de inclusión (6 estudios empíricos). Los temas recurrentes en los artículos incluidos fueron identificados para discusión de la metodología y/o resultados. Se encontró que los resultados de la mayoría de los estudios incluídos eran aplicables a la interacción humano-animal en general o en otro tipo de animales de servicio. Por lo tanto, no representaban a los PSDs específicamente. Los estudios que discutían acerca de PSDs en forma específica solo estudiaron la experiencia de bienestar en los veteranos, aunque usaron diferentes metodologías entre ellos. Esto lleva a concluir que actualmente no hay evidencia empírica indiscutible de que los PSDs sean un tratamiento complementario efectivo para los veteranos con TEPT más allá de los reportes de una experiencia positiva de bienestar. Adicionalmente, la falta de estandarización del desarrollo y conocimiento acerca del bienestar de los PSDs genera riesgos para el bienestar de ambos, humano y animal. Por lo tanto es recomendable que el estudio del efecto de los PSDs sea ampliado para incluir métodos de evaluación mas allá del bienestar auto-percibido de los humanos asistidos. Estudios futuros podrían incluir evaluaciones en relación a la respuesta al estrés y funcionamiento humanos, idealmente conducidos de acuerdo a metodologías científicas validadas usando técnicas de medición objetivas para identificar el valor agregado, y mecanismos, del uso de PSDs para asistir el tratamiento del TEPT en humanos.

Across-line SNP association study for (innate) immune and behavioral traits in laying hens.

BACKGROUND: An association study between single nucleotide polymorphism markers (SNP) and (innate and adaptive) immune parameters but also feather condition score on the back, rump and belly of laying hens was performed. The immune parameters measured in blood samples were natural and acquired antibody titers and complement activity. Feather condition score as a measure of feather damage was determined, this parameter is closely related to feather pecking behavior in hens housed in groups.The aim of the study was to detect associations between genetic markers and immune parameters and feather condition score across nine lines of laying hens, focusing on the feather peckers as well as on the victims of feather pecking. METHODS: A novel approach based on across-line analysis and testing of the SNP-by-line interaction was performed. RESULTS: In total 59 significant associations between SNP and immune traits were detected. Previously identified QTL were confirmed and new associations of genes regulating immune function identified. The IL17A gene (chromosome 3) influences natural and acquired antibody titers and activation of classical and alternative complement pathways. The major histocompatibility complex on chromosome 16 showed significant association with natural and acquired antibody titers and classical complement activity. The IL12B and IRF1 genes on chromosome 13 were associated with natural antibody titers.The direct effect of the genotype of an individual on its feather condition and the associative effect of the genotype of the cage mates on the individual's feather condition were analyzed. The direct genetic effect can be described as the susceptibility to be pecked at, and the associative genetic effect as the propensity to perform feather pecking. Eleven significant associations were detected for the direct effect, and 81 for the associative effect. The serotonin receptor 2C (HTR2C) on chromosome 4 was highlighted in both analyses. CONCLUSIONS: Our results confirmed previously identified QTL and identified new associations of genes regulating immune function. The results for feather condition score supports existing evidence of involvement of the serotonergic system in feather pecking in laying hens. Immune regulatory genes were found to be associated to feather condition score, revealing relationships between the immune system and behavior.