Respiratory and Gut Microbiota in Commercial Turkey Flocks with Disparate Weight Gain Trajectories Display Differential Compositional Dynamics

ABSTRACT Communities of gut bacteria (microbiota) are known to play roles in resistance to pathogen infection and optimal weight gain in turkey flocks. However, knowledge of turkey respiratory microbiota and its link to gut microbiota is lacking. This study presents a 16S rRNA gene-based census of the turkey respiratory microbiota (nasal cavity and trachea) alongside gut microbiota (cecum and ileum) in two identical commercial Hybrid Converter turkey flocks raised in parallel under typical field commercial conditions. The flocks were housed in adjacent barns during the brood stage and in geographically separated farms during the grow-out stage. Several bacterial taxa, primarily Staphylococcus, that were acquired in the respiratory tract at the beginning of the brood stage persisted throughout the flock cycle. Late-emerging predominant taxa in the respiratory tract included Deinococcus and Corynebacterium. Tracheal and nasal microbiota of turkeys were identifiably distinct from one another and from gut microbiota. Nevertheless, gut and respiratory microbiota changed in parallel over time and appeared to share many taxa. During the brood stage, the two flocks generally acquired similar gut and respiratory microbiota, and their average body weights were comparable. However, there were qualitative and quantitative differences in microbial profiles and body weight gain trajectories after the flocks were transferred to geographically separated grow-out farms. Lower weight gain corresponded to the emergence of Deinococcus and Ornithobacterium in the respiratory tract and Fusobacterium and Parasutterella in gut. This study provides an overview of turkey microbiota under field conditions and suggests several hypotheses concerning the respiratory microbiome. IMPORTANCE Turkey meat is an important source of animal protein, and the industry around its production contributes significantly to the agricultural economy. The microorganisms present in the gut of turkeys are known to impact bird health and flock performance. However, the respiratory microbiota in turkeys is entirely unexplored. This study has elucidated the microbiota of respiratory tracts of turkeys from two commercial flocks raised in parallel throughout a normal flock cycle. Further, the study suggests that bacteria originating in the gut or in poultry house environments influence respiratory communities; consequently, they induce poor performance, either directly or indirectly. Future attempts to develop microbiome-based interventions for turkey health should delimit the contributions of respiratory microbiota and aim to limit disturbances to those communities.

Respiratory and Gut Microbiota in Commercial Turkey Flocks with Disparate Weight Gain Trajectories Display Differential Compositional Dynamics

ABSTRACTHost-associated communities of bacteria (microbiota) substantially contribute to the overall poultry health and performance. Gut microbiota are known to play roles in resistance to pathogen infection and optimal weight gain in turkey flocks. However, knowledge of turkey respiratory microbiota and its link to gut microbiota is lacking. This study presents a 16S rRNA gene-based census of the turkey respiratory microbiota (nasal cavity and trachea) alongside gut microbiota (cecum and ileum) in two identical commercial Hybrid Converter turkey flocks raised in parallel under typical field commercial conditions. The flocks were housed in adjacent barns during the brood stage and in geographically separated farms during the grow-out stage. Several bacterial taxa that were acquired in the respiratory tract (RT) at the beginning of the brood stage persisted throughout the flock cycle, primarily Staphylococcus. Late-emerging predominant taxa in RT included Deinococcus and Corynebacterium. Tracheal and nasal microbiota of turkeys were identifiably distinct from one another and from gut microbiota. Nevertheless, gut and RT microbiota changed in parallel over time and appeared to share many taxa. During the brood stage, the two flocks generally acquired similar gut and RT microbiota, and their average body weights were comparable. Separating the flocks during the grow-out stage resulted in divergent microbial profiles and body weight gain trajectories. Lower weight gain corresponded with emergence of Deinococcus and Ornithobacterium in RT, and Fusobacterium and Parasutterella in gut. This study provides an overview of turkey microbiota under field conditions and suggests several hypotheses concerning the respiratory microbiome.IMPORTANCETurkey meat is an important source of animal protein, and the industry around its production contributes significantly to the agricultural economy. The nonpathogenic symbionts present in the gut of turkeys are known to impact bird health and flock performance. However, the respiratory microbiota in turkeys are entirely unexplored. This study has elucidated the microbiota of respiratory tracts of turkeys from two commercial flocks raised in parallel throughout a normal flock cycle. Further, the study suggests that bacteria originating in the gut or in poultry house environments may influence respiratory communities and consequently induce poor performance, either directly or indirectly. Future attempts to develop microbiome-based interventions for turkey health should delimit the contributions of respiratory microbiota and aim to limit disturbances to those communities.

Some like it hot: the effect of temperature on brood development in the invasive crab Hemigrapsus takanoi (Decapoda: Brachyura: Varunidae)

The duration of brood development in the introduced crab, Hemigrapsus takanoi in the Oosterschelde, The Netherlands, was compared at three different water temperatures. At 12, 18 and 24°C the females took an average of 32, 11 and 8 days respectively to lay eggs, which took 86, 28 and 18 days respectively to complete development. Five stages of development were identified, with each brood stage comprising a similar proportion of the duration time at different temperatures. The duration of each brood stage was also somewhat proportional to the number of females found carrying each brood stage in the field at the beginning of the breeding season. There appears to be a trigger for the breeding season in H. takanoi in the field at around 15°C above which ovary development begins. The results suggest that an increase in water temperature as a result of climate change may result in an increased net reproductive rate in H. takanoi due to earlier onset of the breeding season and increased number of broods per inter-moult period resulting in population growth. Increased temperatures may therefore lead to increased invasiveness of H. takanoi where it is already present, and range extension into locations where its establishment is currently excluded by unsuitable temperature.

Habitat-patch occupancy in the common goldeneye (Bucephala clangula) at different stages of the breeding cycle: implications to ecological processes in patchy environments

We studied the pattern of habitat-patch occupancy of radio-tagged common goldeneye ( Bucephala clangula (L., 1758)) females in two sequential stages of the breeding season, the nest stage and the brood stage, and whether the resources needed in nesting and brood-rearing are spatially inter-related as revealed by patch occupation rate of goldeneye females in these stages. We also studied patch-specific factors potentially explaining the rate of patch occupation separately during the nest stage and the brood stage. There was no association in patch occupation rate between the nest stage and the brood stage, indicating that all the critical resources needed to complete a successful breeding cycle were not met within the same habitat patch. At the nest stage, patch occupation rate increased with nest-site availability and decreased with nest predation rate but was not affected by vegetation luxuriance or patch size. Vegetation luxuriance had a positive effect on patch occupation rate at the brood stage, whereas nesting success of the focal patch had no effect. Results suggest that nest-site selection and brood-stage habitat selection are governed by different ecological factors. We conclude that breeding-stage-specific resource requirements redistributed individuals among habitat patches across the landscape, implying dynamic distribution of ducks between nesting and brooding stage.

Individual foraging behaviour indicates resource limitation: an experiment with mallard ducklings

The linkage between individual behaviour and population processes has recently been emphasized. Within this framework we studied the effect of resource limitation on the behaviour of mallard (Anas platyrhynchos) ducklings in boreal lakes. One group of 12 human-imprinted ducklings (4-16 days old) were taken to 11 "rich" lakes, i.e., with a relatively high concentration of total phosphorus in the water, and the other group of 12 ducklings to 11 "poor" lakes to forage for a period of 6 h. During this, a time budget study lasting 5 min was done of each of the 12 ducklings. In the rich lakes, ducklings fed significantly more and moved less than in the poor ones. This difference was particularly striking in above-surface feeding. Variation in foraging performance was associated with change in body mass of the ducklings: the less distance the ducklings moved and the more they fed above water, the more they gained mass. Earlier results had suggested that at least some of the boreal wetlands that lack duck broods year after year (70% of the total in one study) do so because they do not harbour enough food. Hence, it is possible that mallard populations are resource-limited at the brood stage during the breeding season.