Across-Species Pose Estimation in Poultry Based on Images Using Deep Learning

Animal pose-estimation networks enable automated estimation of key body points in images or videos. This enables animal breeders to collect pose information repeatedly on a large number of animals. However, the success of pose-estimation networks depends in part on the availability of data to learn the representation of key body points. Especially with animals, data collection is not always easy, and data annotation is laborious and time-consuming. The available data is therefore often limited, but data from other species might be useful, either by itself or in combination with the target species. In this study, the across-species performance of animal pose-estimation networks and the performance of an animal pose-estimation network trained on multi-species data (turkeys and broilers) were investigated. Broilers and turkeys were video recorded during a walkway test representative of the situation in practice. Two single-species and one multi-species model were trained by using DeepLabCut and tested on two single-species test sets. Overall, the within-species models outperformed the multi-species model, and the models applied across species, as shown by a lower raw pixel error, normalized pixel error, and higher percentage of keypoints remaining (PKR). The multi-species model had slightly higher errors with a lower PKR than the within-species models but had less than half the number of annotated frames available from each species. Compared to the single-species broiler model, the multi-species model achieved lower errors for the head, left foot, and right knee keypoints, although with a lower PKR. Across species, keypoint predictions resulted in high errors and low to moderate PKRs and are unlikely to be of direct use for pose and gait assessments. A multi-species model may reduce annotation needs without a large impact on performance for pose assessment, however, with the recommendation to only be used if the species are comparable. If a single-species model exists it could be used as a pre-trained model for training a new model, and possibly require a limited amount of new data. Future studies should investigate the accuracy needed for pose and gait assessments and estimate genetic parameters for the new phenotypes before pose-estimation networks can be applied in practice.

Effects of ammonia and nitrite on food consumption of the Amazon River prawn Macrobrachium amazonicum (Heller, 1862) postlarvae

Experiments were carried out to study the effects of ammonia and nitrite on food consumption of Macrobrachium amazonicum postlarvae. Postlarvae (average weight of 0.0625 g) were exposed during 21 days to four concentrations of total ammonia (0, 1.05, 2.1 and 4.2 mg. NH3+NH4+ L-1) and four concentrations of nitrite (0, 0.075, 0.15 and 0.30 mg N-NO2- L-1). After the exposure period, six prawns per treatment were maintained individually in 250 mL experimental units to analyze the food consumption as a function of the amount of food offered and the leftovers during a 24 h period. The food consumption presented significant alterations for prawns exposed to all nitrite concentrations and at concentrations of twice the recommended safety level for total ammonia. According to the results obtained, high concentrations of total ammonia and nitrite affect the food consumption of M. amazonicum adversely, influencing the species performance in culture systems.

Native and alien species suffer from late arrival, while negative effects of multiple alien species on natives vary

Ongoing globalisation and climate change are causing plant species to invade new habitats and thereby alter biodiversity and ecosystem functioning. Since numbers of plant invasions continue to increase globally, it is crucial to investigate the effects of multiple co-occurring alien species on native communities. Furthermore, priority effects due to the earlier emergence of certain species affecting fitness of later arriving species can shape community structure and affect native species performance. We investigate in a common garden pot experiment the interactions among five alien-native species pairs. First we focus on the effect of growing with either one or two alien neighbour species on a native plant, second we alter the arrival time of the alien or native neighbour by 3 weeks. Generally, native species performance decreased when surrounded by two alien species compared to only one, although the magnitude of this effect varied depending on species, with one species even performing better with alien neighbours than in monoculture. Species performance greatly decreased when arriving second in the pot, for both native and alien species. In contrast, alien species tended to benefit more from arriving early. Given that we studied annual ruderal species, their potentially lower competitive ability might explain why we detected negative effects of late arrival. We highlight the need to further elucidate underlying mechanisms of small-scale invasion dynamics to achieve generalisations concerning the response of multiple alien and native plants given their species-specific differences in response to neighbour species and arrival time.

Competition in a Mixed-Species Planting With Four Contrasting Species

Background: Mixed-species systems are well-suited to smallholder and community forestry, but reliable evidence regarding and procedures to assess species performance in such systems is scarce. This study concern a field trial with a pair of clinal plots varying spacing and species composition that offered insights into competition between four species proposed for mixed-species plantings by smallholders for landscape rehabilitation in the Philippines. Results: Use of a size-distance competition index allowed an assessment of the competitive and collaborative influences between four tree species. Within the expected general trend for growth to decline with increasing competition, there were indications that Shorea palosapis is a benign competitor that may stimulate the growth of neighbouring individuals. Paraserianthes falcataria is a strong competitor that is also strongly impacted by competition, especially through antagonistic intraspecific competition. Paraserianthes falcataria appears well suited as a solitary tree in a field or village, whereas Shorea palosapis seems ideal for plantations, in both monoculture and mixed plantings. Conclusion: Pterocarpus indicus exbibits strong intraspecific, but low inter-specific competition, so appears well-suited for polyculture plantings. Of the four species, Swietenia macrophylla appears to be best-suited as a monoculture species as it exhibits the lowest intraspecific competition.

Growth, thermal preference and critical thermal maximum for Totoaba macdonaldi: effect of acclimation temperature and inclusion of soybean meal in the diet

We studied the interaction effect between temperature 23 and 26°C, and replacing fishmeal for soybean meal (SBM): 32, 43, and 56% vs. a diet control on culture performance, thermal behavior, and critical thermal maximum (CTMax) of juvenile Totoaba macdonaldi. Fish were fed to apparent satiation three times daily for 61 days. The results showed that temperature had a significant effect (P < 0.05) on weight gain, percent weight gain, and specific growth rate, which were all higher in fish acclimated at 26°C. The preferred temperature ranged between 26.4 and 27.7°C, significantly influenced by acclimation temperature (P < 0.05) but not by diet. CTMax was influenced by acclimation temperature and SBM in the diet. Fish resistance decreased when the percent SBM in the diet was higher. Information on biological indicators for T. macdonaldi adds to the knowledge of a key Mexican species. Our study demonstrated that the use of SBM as an alternative to fishmeal in the diet and the interaction with temperature as a factor could affect this species' performance.

Performance of Exterior Wood Coatings in Temperate Climates

Wood used in exposed exterior applications degrades and changes color due to weathering. Expanded use of mass timber is resulting in architects increasingly designing structures with wood in exterior exposure. Coatings can reduce the effects of weathering and prolong the visual characteristics of wood. However, coating performance depends on a variety of factors including the blend of resins, oils, pigments, and binders. Coating manufacturers often claim superior performance for products, but data directly comparing different coatings on different species is rarely publicly available. Premature coating failure increases long-term building maintenance expense while potentially enhancing biological degradation and reducing service life. This study compares the performance of 12 exterior wood coatings on 5 wood species. Performance was evaluated according to changes in the components in the International Commission on Illumination (CIE) L*a*b* color space of images taken at 6-month intervals over 18 months of the wood samples. The analysis was performed using Welch’s ANOVA, Games–Howell pairwise comparisons tests, and a clustering procedure using distances between each pair of groups means for the 18 months ΔL*, Δa*, Δb* values. Most of the coatings lost their protective effects within 1 year of exposure due to combinations of biological and ultraviolet radiation (UV) degradation illustrating the difficulty of protecting timber in exterior exposures. This study provides a guide for users wishing to specify coatings for exposed wood in mass timber structures.

Local Tree Diversity Suppresses Foliar Fungal Infestation and Decreases Morphological but Not Molecular Richness in a Young Subtropical Forest

Leaf fungal pathogens alter their host species’ performance and, thus, changes in fungal species composition can translate into effects at the tree community scale. Conversely, the functional diversity of tree species in a host tree’s local neighbourhood can affect the host’s foliar fungal infestation. Therefore, understanding the factors that affect fungal infestations is important to advance our understanding of biodiversity-ecosystem functioning (BEF) relationships. Here we make use of the largest BEF tree experiment worldwide, the BEF-China experiment, where we selected tree host species with different neighbour species. Identifying fungal taxa by microscopy and by high-throughput DNA sequencing techniques based on the internal transcribed spacer (ITS) rDNA region, we analysed the fungal richness and infestation rates of our target trees as a function of local species richness. Based on the visual microscopic assessment, we found that a higher tree diversity reduced fungal richness and host-specific fungal infestation in the host’s local neighbourhood, while molecular fungal richness was unaffected. This diversity effect was mainly explained by the decrease in host proportion. Thus, the dilution of host species in the local neighbourhood was the primary mechanism in reducing the fungal disease severity. Overall, our study suggests that diverse forests will suffer less from foliar fungal diseases compared to those with lower diversity.

Experimental warming influences species abundances in a Drosophila host community through direct effects on species performance rather than altered competition and parasitism

Global warming is expected to have direct effects on species through their sensitivity to temperature, and also via their biotic interactions, with cascading indirect effects on species, communities, and entire ecosystems. To predict the community-level consequences of global climate change we need to understand the relative roles of both the direct and indirect effects of warming. We used a laboratory experiment to investigate how warming affects a tropical community of three species of Drosophila hosts interacting with two species of parasitoids over a single generation. Our experimental design allowed us to distinguish between the direct effects of temperature on host species performance, and indirect effects through altered biotic interactions (competition among hosts and parasitism by parasitoid wasps). Although experimental warming significantly decreased parasitism for all host-parasitoid pairs, the effects of parasitism and competition on host abundances and host frequencies did not vary across temperatures. Instead, effects on host relative abundances were species-specific, with one host species dominating the community at warmer temperatures, irrespective of parasitism and competition treatments. Our results show that temperature shaped a Drosophila host community directly through differences in species’ thermal performance, and not via its influences on biotic interactions.