Diet Selection Research Articles

Dietary Niche Variation in an Invasive Omnivore: The Effects of Habitat on Feral Pig Resource Use in Hawai'i.

Invasive omnivores may have profound impacts on ecological communities through diet selection, particularly when their functional roles differ from those in their native range. While the threat of feral pigs (Sus scrofa) to native plant communities in Hawai'i is well known, their trophic dynamics and the drivers of variation in their diet remain understudied. We investigated the feral pig trophic niche on Hawai'i Island using stable isotopes (13C and 15N) and Bayesian mixing models to identify drivers of variation in resource use. We also reconstructed intra-individual variability for six subsampled individuals to understand temporal variation in resource use and individual diet specialization. Our results revealed that feral pigs on Hawai'i Island exhibit a broad trophic niche characterized by diverse diets, with substantial overlap in resource use across districts and habitats. Differences in dietary composition in the transition from forest to open habitat were driven primarily by a decline in invertebrates and an increasing reliance on resources enriched in 15N, which may reflect a shift in protein sources with habitat. Pigs in forested areas exhibited a smaller trophic niche than those in open habitats, largely driven by differences in feeding strategies and resource availability. Diets for subsampled individuals varied little, suggesting feral pig resource-use strategies in Hawai'i tend to be relatively stable through time. Individual niche width was relatively narrow compared to that of feral pigs in Hawai'i at large, indicating the relatively wide feral pig dietary niche is characterized by substantial intraspecific diet specialization, likely as a result of strong intraspecific competition. Understanding the drivers of feral pig resource use offers key information for management strategies aimed at mitigating their ecological impacts in imperiled systems like Hawai'i.

Variation of parental and chick diet in opportunistic insectivorous European Bee-eaters

Insectivorous Palaearctic bird species associated with open habitats rely on high prey abundances, which are currently declining due to habitat loss and intensive agricultural practices. The European Bee-eater (Merops apiaster) is an opportunistic insectivore of open habitats, preying mainly on medium to large-sized flying insects. Its diet composition received some attention in the past, but the current variation in diet composition of birds breeding across different habitats, and between adults and chicks remains poorly known. In this study, we determine variation in bee-eaters’ diet in colonies located in five common habitats at the Iberian Peninsula. We also assess differences in the diet composition of chicks and adults and investigate seasonal diet selectivity of adults. Finally, we explore the variability in the size of prey provided to chicks throughout their growth period. Hymenoptera and Coleoptera were the most important groups for bee-eaters, with adults and chicks consuming 58.8% and 64.1% of hymenopterans and 37.6% and 28.6% of coleopterans, respectively. The proportion of Hymenoptera (42.3–55.7%) and Coleoptera (43.3–53.5%) in the diet was similar in colonies in pasture and oak habitats. But Hymenoptera dominated (83.8% and 95.7%) in meadow and mixed forest colonies. Despite being a generally opportunistic predator, adult bee-eaters provide their progeny with an increasing proportion of larger insects through chick development. Moreover, they equally take Hymenoptera and Coleoptera for themselves and their chicks, even when the abundance of these insects decreases seasonally. Overall, these results suggest that local prey availability associated with specific habitats influences diet composition and that regional declines in certain groups may, therefore, affect insectivore species differently according to their dietary and habitat preferences.

Detrimental Effects of Diet Selection in Hospitalized Patients with ESKD

Detrimental Effects of Diet Selection in Hospitalized Patients with ESKD

Study on Rumen Degradability and Intestinal Digestibility of Mutton Sheep Diets with Different Concentrate-to-Forage Ratios and Nonfiber Carbohydrates/Neutral Detergent Fiber Ratios.

This study was conducted to investigate the rumen degradability and intestinal digestibility of mutton sheep diets different in concentrate-to-forage ratio, NFC/NDF, and ingredient combination, providing a guideline for the selection of a fattening diet for mutton sheep. Twenty-eight diets composed of four raw material combinations and seven concentrate-to-forage ratios and four three-year-old mutton sheep with permanent rumen fistulas were used in the experiments. The nutrient composition of the diets was first analyzed, and then an in situ method and in vitro three-step method were separately used to measure the rumen degradability and intestinal digestibility, mainly focusing on the effects of dietary concentrate-to-forage ratio and NFC/NDF as well as the effects of soybean meal and soybean meal replacement and peanut vine and peanut vine replacement. The results showed that a dietary concentrate-to-forage ratio of 70:30~80:20 and an NFC/NDF ratio of 1.5~2.0 are recommended for fattening mutton sheep, and low-cost cottonseed meal and rapeseed meal can be feasible alternative protein sources to soybean meal. In addition, the nutritional values of sunflower seed hulls and rice hulls for mutton sheep are lower than that of peanut vine. Such a study can provide practical guidelines for enterprises and farmers, being of important significance for the high-quality development of the mutton sheep industry.

Changes in the Fatty Acid Composition of Vegetable Oils Affect the Feeding Behavior, Feed Preference, and Thermoregulatory Responses of Sheep

This research evaluated the effects of energy supplementation on sheep’s feeding behavior, feed preference, and thermoregulatory responses using technical cashew nutshell liquid (CNSL) and different vegetable oils with different unsaturated fatty acid (UFA) compositions. The experiment was completely randomized with five treatments: a mixture of CNSL (0.5%) + vegetable oils [canola (high in monounsaturated fatty acids—MUFA), and corn, soybean, sunflower, or cottonseed oil (high in polyunsaturated fatty acids-PUFA) at 1.5%] based on total diet dry matter, with eight replications. Forty uncastrated male sheep, with an average initial BW of 24.44 ± 1.5 kg, were evaluated for 70 days. The CNSL + vegetable oil blend did not affect DM and neutral detergent fiber (aNDF) intake (p > 0.05). However, diets with canola oil resulted in higher SFA intake (p < 0.05) than other oils. The canola oil + CNSL blend led to a higher intake of UFA and MUFA and lower PUFA intake than other oil blends (p < 0.05). Sheep fed canola oil ruminated fewer boli per day than those fed soybean and sunflower oils. Using three sieves (pef1.18) reflected in higher sheep aNDF intake. Respiratory frequency and surface temperature of sheep were lower before feeding than 3 h after, without effects of the type of oil. Higher serum creatinine and cholesterol levels were observed in sheep fed CNSL with corn and canola oils compared to other oils. Serum calcium was lower in sheep fed CNSL with soybean and canola compared to sunflower and corn. Including CNSL with vegetable oils with different FA compositions did not affect physiological and thermographic variables. However, sheep showed better diet selectivity and lower bolus rumination with higher MUFA (canola oil) content. Including CNSL with canola oil in sheep diets is recommended, as it increases dietary energy content, enhances diet selectivity, reduces PUFA intake, and does not impact animal health.

Current Awareness and Knowledge of Heavy Metals

This review discusses public health hazards associated with environmental heavy metals, focusing on those that are especially toxic and persistent: lead, mercury, cadmium, arsenic, chromium, copper, nickel, and zinc. Most of the discussion in this review is devoted to identifying potential routes of exposure and the potential health effects that these metals might pose. In addition, the effectiveness of educational programs is considered, together with demographic factors influencing public knowledge. The methodology includes a detailed literature review to highlight gaps in knowledge and the impacts of the education process. The preliminary findings show very limited knowledge among the public about the risks from toxic metals, especially among children and people working in the industrial sectors. Notwithstanding the aforementioned educational initiatives, there is still a greater need for further intervention strategies to increase awareness and ensure safety. Further, the review shows a lack of concerted efforts on strategies aimed at reducing heavy metal toxicity, including chelation therapy, phytoremediation, and advanced techniques like electro sorption and nanotechnology. The text further examines the efficacy of dietary selections and supplements as natural detoxification techniques that could assist the body in expelling these harmful substances. The study thus concludes emphatically that mitigating the risks of exposure to heavy metals requires increasing public awareness and education, imposing strict regulations on emissions from industries, and involving the community. Policymakers, educators, and health professionals must be unified on a single platform to spread awareness about effective remediation and natural detoxification methodologies. Heavy metals largely threaten human health and ecosystems, so the protection of human health and the maintenance of ecosystems require a comprehensive approach.

What does it take to revolutionize Chinese diets: evidence from a choice experiment on urban Chinese consumers

PurposeThe purpose is to understand the factors affecting Chinese diet selections and propose strategies for revolutionizing Chinese diets toward healthy ones.Design/methodology/approachThis study implemented an online discrete choice experiment to identify the factors affecting diet selections among urban Chinese consumers. Four different diet patterns were used to label each of the product alternatives in the experiment, which varied in taste and cost. Specifically, implying the healthiness and sustainability of a diet, the diet alternatives included the average diet, the Chinese Food Guide Pagoda diet, the EAT-Lancet diet and the Flexitarian diet. Using consumer data from six provincial capital cities, we used random parameter logit models to estimate their preferences.FindingsDiet type and diet cost were found to be more important in urban Chinese consumers' diet selections than the ability to customize taste. The average diet, although not healthy and sustainable, was preferred most by respondents, signaling the challenges of shifting the consumer diet in China. Increasing the cost of the average diet can significantly promote sustainable healthy diet choices among urban Chinese residents. In other words, improving the affordability of sustainable healthy diets would have the potential to fuel the diet revolution in China.Originality/valueInstead of choices of a single food item, this paper focused on the individual selection of a diet, where different food products can act as substitutes or as complements for one another. We also proposed a way to assess individual preferences and valuations for several different diets.

Integrating eDNA metabarcoding and citizen science enhances avian ecological research.

Research Highlight: Bourbour etal., 2024. Feeding en route: Prey availability and traits influence prey selection by an avian predator on migration. Journal of Animal Ecology. Diet selection plays a key role in the eco-evolutionary dynamics of animals, exhibiting substantial variability across species, environments and seasons. The complex interplay between movement capability, hunting strategies, habitat use, prey traits and availability shapes the foraging patterns of avian predators. However, detailed information on how these birds exploit their extensive territories remains limited. In this study, Bourbour etal. utilised a novel integration of eDNA metabarcoding and citizen science to explore predator-prey interactions between migrating sharp-shinned hawks (Accipiter striatus) and an ephemeral avian prey community along North America's Pacific flyway. The research identified 1396 detections from the diet (65 species) of 588 migrating sharp-shinned hawks. Hawks' diet composition correlated with prey abundance indices sourced from the eBird database throughout the migration season, highlighting the significant impact of prey availability-shaped by migration tendency, flocking behaviour, and habitat-on raptor-songbird interactions. Notably, the study also found significant differences in prey size between male and female hawks, indicating that sexual dimorphism has led to diverse foraging strategies during migration. These findings underscore the potential of combining eDNA metabarcoding with citizen science to deepen our understanding of the foraging ecology of highly mobile and wide-ranging birds, as well as to monitor complex and vast ecosystems.

Influence of diet on the course and activity of Crohn's disease and ulcerative colitis - a review of available literature

Introduction: Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the digestive tract. It is a clinical entity that includes: Crohn's disease (CD) and ulcerative colitis (UC). Food intake is an important environmental factor that influences the development of IBD. This article reviews studies on different dietary options and their effects on the course and activity of Crohn's disease and ulcerative colitis. Materials and methods: A review of the literature available in the PubMed database was carried out, using the key words: ”inflammatory bowel disease”; ”Crohn disease”; ”diet”; “nutrition”; „colitis ulcerosa”. Results: Appropriate diet selection is important in the course of inflammation in the intestines. It influences disease activity. It turns out that the diet improves inflammation parameters, clinical symptoms, and quality of life. In patients with inflammatory bowel disease, one should also remember about deficiencies such as iron, vitamin D or protein deficiency, the demand of which is increased in sick patients compared to the general population. Conclusions: An individualized approach to nutritional therapy may be one of the main branches of treatment for patients with inflammatory bowel diseases. However, there is a need for further research on larger groups of patients in order to effectively implement it into treatment standards.

Conducting a successful diet trial for the diagnosis of food allergy in dogs and cats.

A limited antigen diet trial and subsequent food provocation is currently the optimal method of confirming a diagnosis of food allergy in dogs and cats. However, performing an effective diet trial can be challenging as it requires a high level of client and pet compliance, appropriate diet selection and correct interpretation of the provocative challenge. This narrative guides the clinician through the process, highlights potential pitfalls and specifies how these can be avoided to achieve a successful outcome.

Larval coregonine density and diet composition along beaches of northern Lake Michigan

Recent oligotrophication in Lake Michigan has contributed to reduced biomass of spring zooplankton and a shift in the zooplankton assemblage toward more calanoid copepods. These changes have likely altered prey availability for first feeding native fish species that hatch in early spring. While spring zooplankton densities and assemblage compositions are routinely monitored in offshore areas of Lake Michigan, zooplankton in nearshore areas such as shallow beach environments are less studied; and associated descriptions of diet characteristics among larval coregonine species are limited. In this study, we a) describe the nearshore (<1 m depth) zooplankton assemblage at four sites in northeastern Lake Michigan during early spring 2015–2019 and b) compare diets and diet selectivity of larval lake whitefish (Coregonus clupeaformis) and Cisco (C. artedi). Zooplankton composition varied among years, but calanoid copepods and copepod nauplii consistently dominated the zooplankton assemblage. Cisco and lake whitefish larvae were captured regularly, with Elk Rapids containing the highest proportion of ciscoes each year. For both species, calanoid and cyclopoid copepods were common in diets and were positively selected as prey. Although previous research has indicated high consumption of cyclopoid copepods by larval coregonines, our results provide new evidence that larval lake whitefish and Cisco in northeastern Lake Michigan will also consume and select for calanoid copepods when they are abundant. As such, should calanoid zooplankton continue to dominate the copepod community in Lake Michigan, larval coregonines appear capable of exploiting this abundant prey resource to improve their likelihood of survival to later life stages.

Association of maternal genetics with the gut microbiome and eucalypt diet selection in captive koalas.

Koalas, an Australian arboreal marsupial, depend on eucalypt tree leaves for their diet. They selectively consume only a few of the hundreds of available eucalypt species. Since the koala gut microbiome is essential for the digestion and detoxification of eucalypts, their individual differences in the gut microbiome may lead to variations in their eucalypt selection and eucalypt metabolic capacity. However, research focusing on the relationship between the gut microbiome and differences in food preferences is very limited. We aimed to determine whether individual and regional differences exist in the gut microbiome of koalas as well as the mechanism by which these differences influence eucalypt selection. Foraging data were collected from six koalas and a total of 62 feces were collected from 15 koalas of two zoos in Japan. The mitochondrial phylogenetic analysis was conducted to estimate the mitochondrial maternal origin of each koala. In addition, the 16S-based gut microbiome of 15 koalas was analyzed to determine the composition and diversity of each koala's gut microbiome. We used these data to investigate the relationship among mitochondrial maternal origin, gut microbiome and eucalypt diet selection. This research revealed that diversity and composition of the gut microbiome and that eucalypt diet selection of koalas differs among regions. We also revealed that the gut microbiome alpha diversity was correlated with foraging diversity in koalas. These individual and regional differences would result from vertical (maternal) transmission of the gut microbiome and represent an intraspecific variation in koala foraging strategies. Further, we demonstrated that certain gut bacteria were strongly correlated with both mitochondrial maternal origin and eucalypt foraging patterns. Bacteria found to be associated with mitochondrial maternal origin included bacteria involved in fiber digestion and degradation of secondary metabolites, such as the families Rikenellaceae and Synergistaceae. These bacteria may cause differences in metabolic capacity between individual and regional koalas and influence their eucalypt selection. We showed that the characteristics (composition and diversity) of the gut microbiome and eucalypt diet selection of koalas differ by individuals and regional origins as we expected. In addition, some gut bacteria that could influence eucalypt foraging of koalas showed the relationships with both mitochondrial maternal origin and eucalypt foraging pattern. These differences in the gut microbiome between regional origins may make a difference in eucalypt selection. Given the importance of the gut microbiome to koalas foraging on eucalypts and their strong symbiotic relationship, future studies should focus on the symbiotic relationship and coevolution between koalas and the gut microbiome to understand individual and regional differences in eucalypt diet selection by koalas.

The Association Between Overall, Healthy, and Unhealthy Plant-Based Diet Index and Risk of Prediabetes and Type 2 Diabetes Mellitus: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies.

The global incidence of prediabetes and type 2 diabetes mellitus (T2DM) has increased substantially in recent years. Among the established, modifiable lifestyle factors associated with favorable prediabetes and T2DM risk, healthy dietary patterns have attracted considerable attention. The association between adherence to plant-based dietary pattern indices (PDIs), including the overall PDI (O-PDI), healthy PDI (H-PDI), and unhealthy PDI (U-PDI), and the risk of prediabetes and T2DM was investigated in this study. A literature search was conducted of the PubMed/Medline, Scopus, and Web of Sciences databases from their inception to February 2024. A systematic review and meta-analysis were conducted using random effects models and dose-response analyses. The Cochran Q test and the I2 statistic were used to evaluate heterogeneity between studies. A total of 16 publications, with data on a total of 721 012 participants, were identified for the meta-analysis. According to a pooled analysis, compared with the lowest category of O-PDI and H-PDI adherence, the highest category was associated with a 14% and 19% reduction in T2DM risk, respectively, for O-PDI (effect size [ES] = 0.86; 95%CI, 0.82-0.90; I2 = 57.7) and H-PDI (ES = 0.81; 95%CI, 0.75-0.88; I2 = 82.6). Greater adherence to U-PDI was significantly associated with an 10% increase in the risk of T2DM (ES = 1.10; 95%CI, 1.04-1.16). Consistent associations were found within the predetermined subgroups. As well, there was a nonlinear inverse association between O-PDI, H-PDI, and T2DM risk. No significant association was found between adherence to O-PDI (ES = 0.87; 95%CI, 0.75-1.01; I2 = 68%), H-PDI (ES = 0.99; 95%CI, 0.87-1.13; I2 = 0.0%), and U-PDI (ES = 1.09; 95%CI, 0.94-1.21; I2 = 22.9%) and risk of prediabetes. These findings underscore the importance of dietary selections within the framework of a plant-based dietary pattern, particularly when incorporating healthful, plant-based foods, which may have potential benefits in reducing the T2DM risk. PROSPERO registration no. CRD42023459851.

The interaction of genes and environment on percent of juniper in the diet of goats divergently selected for high or low juniper consumption

Diet selection and preference by grazing animals are determined by genetic and environmental factors that interact and affect their efficacy for managing vegetation as targeted grazers and developing animals adapted to local grazing environments. The effect of the rearing environments on the consumption of juniper (Juniperus spp.) by goats that for 15 years were divergently selected for high (J+) or low (J-) percent juniper in their diet was investigated. To test the effect of rearing environment, at the end of the breeding season, pregnant does from both selection lines were grazed on either juniper-infested (JIR) or juniper-free (JFR) rangelands until their kids were weaned at about 75 days of age. Fecal samples were analyzed with fecal near-IR spectroscopy to determine the percent juniper in the diet. Fecal samples were collected from does on JIR when their offspring were 30 days of age and at weaning. Then, does that raised kids in both rearing environments grazed a common JIR pasture for a 28-day adaptation period before collecting fecal samples. After weaning, kids from both rearing environments grazed JIR for 22 days before collecting fecal samples. The J+ does always consumed more (P < 0.001) juniper than J- does, demonstrating different maternal role models for kids reared in the JIR environment. There was no effect of rearing environment (P = 0.488) or rearing environment × selection line interaction (P = 0.096) when J- and J+ does grazed a common JIR pasture. The percentage of juniper in J- kid diets (7%) was the same regardless of the rearing environment. However, the rearing environment did affect the percentage of juniper in the diet of J+ kids, resulting in a gene-environment interaction (P = 0.022). The percentage of juniper in the diet of J+ kids reared in JFR (16%) and JIR (24%) were about two and three times higher than J- kids, respectively, indicating that genetics and the rearing environment contributed about equally to the increase in the percentage of juniper in the J+ kid diets. Regardless of the rearing environment, the J+ kids had a higher percentage of juniper in their diets than J- kids (P < 0.001). Compared to males, female kids had a higher percentage of juniper in their diets (12 vs 17%, respectively; P = 0.002). The ability to select animals with specific dietary preferences holds promise for targeted grazing strategies to restore degraded rangelands, with potential applications in conservation and ecosystem management.

Using winter diet composition and forage plant availability to determine browse selection and importance for moose (Alces alces) in a landscape modified by industrial forestry

Abstract Between 2000 and 2015, moose (Alces alces L.) populations within some areas of north-central British Columbia, Canada declined by 70%. Such declines are occurring in other regions within the range of moose. One cause for mortalities of cow and calf moose in British Columbia was apparent starvation, implying a potential connection to food supply. To investigate possible connections between moose declines and industrial forestry, we examined moose winter diets relative to browse availability in six Biogeoclimatic Ecosystem Classification subzones within north-central British Columbia. In the spring of 2017, we collected moose winter pellets. To assess diet, pellets were analyzed using microhistology, a common technique for quantifying the diets of ungulates. In the summer of 2018, we used a modified point-intercept method to survey browse plant availability at pellet collection sites. We related diet composition to plant availability through indices of selection (use of a forage species relative to availability) and values of importance (the proportion of a species in the diet as a function of its occurrence in the environment) of various browse items to moose. Twenty-eight species of potential browse plants were identified in our browse availability surveys. Only 12 of these plants were found in moose pellets, with four plants [subalpine fir (Abies lasiocarpa Hooker), willow (Salix spp. Linnaeus), paper birch (Betula papyrifera Marshall), and trembling aspen (Populus tremuloides Michaux)] comprising the majority (93.3%) of the diet. We used mixed-model analyses to examine differences between these top four winter diet items, in relation to: (i) diet composition; (ii) plant availability; (iii) selection by moose; and (iv) importance to moose. Subalpine fir (mean: 45.7%) was a significantly larger diet component in pellets than aspen (5.7%) and willow (19.5%), but there was no significant difference in the proportions of subalpine fir and birch (22.4%). Birch and willow were found in significantly higher proportions than aspen, but proportions of birch and willow in pellets did not differ. The availability of the top four diet items was not significantly different between species. Subalpine fir, aspen, birch, and willow were the most selected diet items, but selection was not significantly different between them. The importance values of subalpine fir, birch, and willow were not significantly different from one another, but all three were significantly greater than the importance value for aspen. Diet composition, availability, selection, and importance did not vary between subzones surveyed. The high selection for and importance of subalpine fir, birch, willow, and aspen by moose in winter demonstrate the need to ensure these browse species are maintained on moose ranges, especially where moose populations are declining. Where industrial forestry impacts the abundance and species composition of winter browses for moose, we encourage forest planners and managers to examine browse availability in relation to moose diet, so that the browse plants important to and selected for by moose can be integrated into forest management objectives.

DNA metabarcoding analysis of the bare-nosed wombat (Vombatus ursinus) diet.

Wombats are native herbivorous grazers that have adapted to Australia's low-quality forage. Studies on diet selection by bare-nosed wombats (Vombatus ursinus) are limited and are either observational or based on microhistological studies. The current study determined the diet of wombats through DNA metabarcoding across five study sites in New South Wales over a one-year period. Metabarcoding was chosen as it is non-invasive, less time consuming and more specific than traditional techniques. The list of 209 plant species identified as eaten by wombats in this study is much higher than previously reported, with grasses being the most common plant group identified in all samples. Most dietary items identified were introduced plant species. Seasonal differences in plants eaten occurred at four of the five study sites and may reflect dietary abundance and floristic composition at different times of year. Further studies are required to determine if the dietary items differ markedly across the entire range of wombats, and if nutrition influences dietary preferences.

Diet Selection of a Solitary Forest-Dwelling Ungulate, the Japanese Serow (Capricornis crispus), in Cool Temperate Forest

Diet Selection of a Solitary Forest-Dwelling Ungulate, the Japanese Serow (Capricornis crispus), in Cool Temperate Forest

Faecal bacterial communities differ amongst discrete foraging populations of dugongs along the east Australian coast.

Gut bacterial communities play a vital role in a host's digestion and fermentation of complex carbohydrates, absorption of nutrients, and energy harvest/storage. Dugongs are obligate seagrass grazers with an expanded hindgut and associated microbiome. Here, we characterised and compared the faecal bacterial communities of dugongs from genetically distinct populations along the east coast of Australia, between subtropical Moreton Bay and tropical Cleveland Bay. Amplicon sequencing of fresh dugong faecal samples (n=47) revealed Firmicutes (62%) dominating the faecal bacterial communities across all populations. Several bacterial genera (Bacteroides, Clostridium sensu stricto 1, Blautia and Polaribacter) were detected in samples from all locations, suggesting their importance in seagrass digestion. Principal coordinate analysis showed the three southern-most dugong populations having different faecal bacterial community compositions from northern populations. The relative abundances of the genera Clostridium sensu stricto 13 and dgA-11 gut group were higher, but Bacteroides was lower, in the southern dugong populations, compared to the northern populations, suggesting potential adaptive changes associated with location. This study contributes to our knowledge of the faecal bacterial communities of dugongs inhabiting Australian coastal waters. Future studies of diet selection in relation to seagrass availability throughout the dugong's range will help to advance our understanding of the roles that seagrass species may play in affecting the dugong's faecal bacterial community composition.

Selecting appropriate diets for management of chronic enteropathies

Gastrointestinal signs including inappetence, vomiting, diarrhoea and weight loss that persist for more than 3 weeks are described as chronic enteropathy. Chronic enteropathies are further classified as food-responsive enteropathy, antimicrobial-responsive enteropathy, immunosuppressant-responsive enteropathy and non-responsive enteropathy. Diagnosis of each type of enteropathy relies on the exclusion of other causes, along with the response to various therapeutic interventions including diet trials, use of therapies directed towards the microbiome and/or immunosuppressant medications. Chronic inflammatory enteropathy is a diagnosis based on the chronicity of clinical signs while inflammatory bowel disease can only be confirmed by obtaining tissue biopsy demonstrating histopathological evidence of intestinal mucosal inflammation. Diet may play a role in the pathogenesis of chronic enteropathies, but it is critical to the management of these patients. Since between 50% and 66% of cases are food responsive, diet trials are essential in the management of these patients. The selection of appropriate therapeutic diets relies on thorough patient nutritional assessment, detailed dietary history (including both historical diets and current diet) and inventory of feeding management practices and the patient's environment.

Forage plants in grasslands with different topographies affect yak foraging preferences on the eastern Tibetan plateau.

Diet selection, a core problem of foraging behavior, is a nutritional adaptation strategy formed in the long-term natural selection process by grazing herbivores and is significant for the sustainable management of grassland. Studies have mainly focused on the impacts of the individual and whole community spatial characteristics and herbivore body status on herbivore foraging behavior; thus, the response and mechanism of forage plants in different terrains to the diet selection of grazing herbivores remains unclear. Therefore, in this study, forage plants (gramineae, cyperaceae, legume, forbs, edible shrubs, and community) in different topographies (terrace, riparian zones, shady slope, half shady slope, half sunny slope, sunny slope) on the eastern Tibetan plateau were selected to study changes in nutrient and mineral content characteristics of forage plants, as well as the difference in feeding bias of yaks for forage plants in different terrains by using an indoor cafeteria trial. A structural equation model was used to illustrate the impact of the forage plants in different terrains on the feeding bias of yak. The multi-criterion decision model TOPSIS showed that the nutritional value of gramineae was highest for the shaded slope, and that of cyperaceae and leguminosae was the highest for the terraces. The nutrient value of forbs and the whole community was highest for the sunny slope. Dry matter intake by yaks of leguminosae, forbs, and the whole plant community was significantly higher for terraces than for grasslands with other topographies, and all were significantly lower in riparian zones. Yak forage preference of leguminosae, forbs, and the whole community was the highest for the terrace and the lowest for the riparian zones. Structural equation modeling showed that for functional groups, the interactions between topography and functional groups were the drivers influencing yak forage preferences. Our study highlights the propensity of yaks to forage for plants in areas with different topographies. These results have provided a scientific basis for understanding the relationship between herbivores and plants in grasslands and for formulating scientific grazing management strategies, which are of considerable importance for sustainable grassland livestock husbandry.