Korrelationen zwischen dem Befiederungszustand, der intestinalen Mikrobiota, sowie von pathohistologischen Untersuchungen an Organen bei konventionell gehaltenen Mastputen

Beschreibung

Investigation of the relationship between feather detriments in turkeys, their pathohistological organ and intestinal-microbial status This work is centered in the context of recent animal welfare efforts to avoid beak trimming in turkey hatcheries. Beak trimming impairs the integrity of the animal and is in conflict with animal welfare principles; at the same time, it is a reliable measure to reduce the consequences of extensive aggressive behaviour such as feather pecking, which otherwise results in severe damage of the turkey and eventually death. Recent literature suggest that it may not be sufficient to improve only the housing conditions (respective stocking density, shed structuring, climate conditions and light regime) in order to abandon beak trimming; there might be additional factors. In the present study, the feather status was taken as an indicator for feather pecking. To identify probable factors that might be associated with feather detriment of turkeys, a comparative, descriptive study design was applied. From eight farms, five animals each with apparent plumage detriments were sampled and compared to five turkeys with intact plumage on a histological and bacteriological level. On the histological level, both groups showed similar levels of skin irritations in a variety of different skin regions (chest, shoulder, cloaca), ruling out skin irritations as the sole reason for feather detriments. Significantly increased skin irritations were found for turkeys with plumage detriments at the two locations “snood” and “neck”, which were, however, expected, because these two locations are the main target for agonistic behaviour. In summary, the results indicate that inflammatory changes in the skin and its adnexa may not be the sole cause of feather detriments. A detectable level of lymphatic cells was noted for the pancreas of several animals; however, without a significant difference between the two turkey groups. In the gut, similar levels of branching of gut crypts was detected. This indicates that branching processes are not a main driver of feather detriments in turkeys. On the other hand, differences between both turkey groups were found on the bacteriological level. Seven out of 40 turkeys with plumage detriments showed Clostridia in the gut regions “duodenum” and “jejunoileum”, which originated from three out of eight farms. In contrast, none of the turkeys with intact plumage showed detectable levels of Clostridia in these two gut regions. Furthermore, turkeys with plumage detriments had significantly increased Clostridia counts in the gut region “caecum”, compared to those with intact plumage. However, it has to be noted that for the positive control, the caecum, Clostridia could only be detected for 20% of all animals, which indicates methodological limitations. Furthermore, differences in the holdings have not been recorded and thus cannot be assessed for. Subject to methodological limitations and influences of the holdings, the results of this study might indicate that at least some turkeys with plumage detriments might have a less favourable status in the digestive tract than those with intact plumage. The occurrence of Clostridia in the intestine, especially in those with plumage detriments, seen in the context of previous studies, might suggest a probable correlation between the Clostridia status on the one hand and plumage status on the other. As a limitation of the descriptive study design, it is, however, not possible to decipher whether increased colonization of Clostridia in the gut are cause or consequence of plumage detriments in turkeys (i. e., dysbiotic processes in the intestine are primarily at least partly responsible for damage to the plumage, or due to the unfavorable metabolic influences associated with subdominance). Although ethiological conclusions could not be drawn due to the descriptive study design, the obtained results, especially when taking recent literature into account, indicate the direction for causal designed follow-up studies. Accordingly, the effect of the feeding regime on the gut microbiome and the extend of feather pecking should be investigated. In synopsis, those studies would enable for the definition of appropriate measures to responsibly refrain from beak trimming of turkeys, and thus establish the prerequisite for a future meat production better meeting the request for integrity as a basic principle of animal welfare in husbandry.

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Lara Elisabeth Jaeger

Themen in »Korrelationen zwischen dem Befiederungszustand, der intestinalen Mikrobiota, sowie von pathohistologischen Untersuchungen an Organen bei konventionell gehaltenen Mastputen«

Duodenum Federn Haut Histologie Pathologie Pute Tiergesundheit animal welfare caecum feathers histology jejunum pancreas pathology skin

Stimmen zu »Korrelationen zwischen dem Befiederungszustand, der intestinalen Mikrobiota, sowie von pathohistologischen Untersuchungen an Organen bei konventionell gehaltenen Mastputen«

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