Low Palatability Research Articles

Time-limited access to palatable food reveals differential effects of psychological stress on homeostatic vs. hedonic feeding behavior in male rats

Psychological stress has complex effects on eating behavior, appearing to reduce homeostatically regulated feeding, while increasing hedonically motivated feeding. The present work tests this idea using two feeding paradigms that offer a highly palatable food on a time-limited basis, together with continual access to a low palatability food. This approach provides a natural separation between periods of eating that are primarily homeostatic vs. hedonically regulated. First, the impact of acute stress exposure on feeding behavior was tested using an acute “meal-dessert” paradigm. When fasted adult male rats were given a recent stressor of moderate intensity (restraint), refeeding with a chow-meal was reduced, without affecting chocolate-dessert intake, thereby increasing the proportion of calories derived from chocolate. Next, the effect of chronic moderate stress was tested using a “binge” eating paradigm. Chow-fed rats were given unexpected (3d per week) vs. expected (7d per week) brief access to a highly palatable high-fat diet (HFD), and feeding behavior was compared to control groups that were maintained with continuous access to only chow or only HFD. Chronic stress reduced total caloric intake in all groups, including binge-like HFD intake. Binge-like HFD intake caused metabolic dysfunction (increased adiposity and impaired glucose homeostasis) to an extent beyond that predicted by total caloric intake or body weight gain. Finally, binge-like HFD intake shifted stress coping behavior from an active to a passive phenotype, particularly in rats receiving concurrent chronic stress, suggesting the possibility of increased risk for stress-related disorders, like depression, in individuals who binge eat during stress.

Pediatric Orally Disintegrating Tablets (ODTs) with Enhanced Palatability Based on Propranolol HCl Coground with Hydroxypropyl-β-Cyclodextrin.

Propranolol, largely prescribed as an antihypertensive and antiarrhythmic drug in pediatrics, is characterized by a bitter taste and an astringent aftertaste. Currently, the therapy requires crushing of tablets for adults and their dispersion in water many times a day, leading to loss of dosing accuracy, low palatability, and poor compliance for both patients and caregivers. This work aimed to exploit cyclodextrin complexation by cogrinding to develop orally disintegrating tablets (ODTs) endowed with reliable dosing accuracy, good palatability and safety, ease of swallowability, and ultimately better compliance for both pediatric patients and caregivers. Different formulation variables and process parameters were evaluated in preparing ODTs. The technological and morphological characterization and disintegration tests were performed according to official and alternative tests to select the ODT formulation based on the drug Hydroxypropyl-β-cyclodextrin (HPβCD) coground complex form containing Pearlitol® Flash as the diluent and 8% Explotab® as the superdisintegrant, which demonstrated the highest % drug dissolution in simulated saliva and acceptable in vitro palatability assessed by the electronic tongue, confirming the good taste-masking power of HPβCD towards propranolol. Such a new dosage form of propranolol could represent a valid alternative to the common extemporaneous preparations, overcoming the lack of solid formulations of propranolol intended for pediatric use.

Польза элиминационной диеты из гидролизованной рыбы и рисового крахмала для диагностики неблагоприятных пищевых реакций у кошек: открытое клиническое исследование

Background: diagnosis of adverse food reaction (AFR) is based on an eight week elimination diet (ED) and is confirmed by relapse upon re-challenge with the previously fed diet. Hydrolysed EDs are commonly used for this purpose. Objective: to evaluate the commercially available hydrolysed fish protein and rice starch ED Farmina UltraHypo (FUH) for the diagnosis of feline AFR. Animals: thirty-two nonseasonally pruritic cats. Materials and methods: pruritus was assessed with a new dual Visual Analog Scale, lesions with the Scoring Feline Allergic Dermatitis scale and Quality of Life with a validated questionnaire on days 0 and 56. Short-acting corticosteroids or oclacitinib were permitted during the first six weeks. Cats showing 50% pruritus and/or lesional improvement were separately challenged with their prior diet, fish and rice. Cats not responding to the study diet were fed another hydrolysed diet for two months. Results: 25 cats completed the ED: four dropped out due to vomiting and/or diarrhoea, one owing to low palatability and two were lost to follow-up. In 17 cats, pruritus improved by >50% and these underwent dietary challenges. Of these, nine reacted to their prior diet and/or fish and/or rice and were diagnosed with AFR, while eight did not relapse (and a diagnosis of AFR was considered to be doubtful). Of the eight cats in which pruritus did not improve, four underwent a second ED with no improvement. Conclusion and clinical importance: FUH may be a useful ED for the diagnosis of feline AFR, even in cats reacting to fish or rice

Reduced palatability, fast flight, and tails: decoding the defence arsenal of Eudaminae skipper butterflies in a Neotropical locality.

Prey often rely on multiple defences against predators, such as flight speed, attack deflection from vital body parts, or unpleasant taste, but our understanding on how often and why they are co-exhibited remains limited. Eudaminae skipper butterflies use fast flight and mechanical defences (hindwing tails), but whether they use other defences like unpalatability (consumption deterrence) and how these defences interact have not been assessed. We tested the palatability of 12 abundant Eudaminae species in Peru, using training and feeding experiments with domestic chicks. Further, we approximated the difficulty of capture based on flight speed and quantified it by wing loading. We performed phylogenetic regressions to find any association between multiple defences, body size, and habitat preference. We found a broad range of palatability in Eudaminae, within and among species. Contrary to current understanding, palatability was negatively correlated with wing loading, suggesting that faster butterflies tend to have lower palatability. The relative length of hindwing tails did not explain the level of butterfly palatability, showing that attack deflection and consumption deterrence are not mutually exclusive. Habitat preference (open or forested environments) did not explain the level of palatability either, although butterflies with high wing loading tended to occupy semi-closed or closed habitats. Finally, the level of unpalatability in Eudaminae is size dependent. Larger butterflies are less palatable, perhaps because of higher detectability/preference by predators. Altogether, our findings shed light on the contexts favouring the prevalence of single versus multiple defensive strategies in prey.

A pivotal nutritional potential of understory vascular plants in Patagonian forests

Native forests can support wild and domestic herbivores, but their nutritional potential of understory vascular plants is rarely explored. We analysed the composition of understory plant species and their biochemical components to reveal the nutritional potential of forest types (deciduous, evergreen, mixed) and their associated open-lands (e.g. grasslands in forestlands) in Northern Patagonia. We proposed an approach combining our data (e.g. plant composition, occurrence frequency) with bibliographic research (e.g. Scopus database) to develop our findings. Data were evaluated using descriptive statistical analyses and multivariate analyses. This study presents the nutritional values for the 20 pivotal species under examination. The results highlight the significant impact of taxonomic families on nutritional profiles, where the species that presented the most relevant occurrence frequency: the herbs T. officinale (60.4 % of total occurrence frequency-TOF) and T. repens (47.9 % TOF), the graminoid H. lanatus (58 % TOF), and the fern B. penna marina (44.4 % TOF). Multivariate analyses showed that the first two PCA axes explained 76.1 % (p = 0.001) and 10.5 % (p = 1.000) of forest type variation, with ñire forests and open-lands having the highest palatable plant coverage. Biochemical PCA axes explained 52.1 % (p = 0.024) and 22.5 % (p = 0.874) of the variation, distinguishing species by protein content and structural components. The deciduous forests exhibited the highest coverage of palatable plants, while target plants with low palatability and high coverage were predominantly found in evergreen forest types. The confirmed presence of pivotal species across forest types and open-lands underscores its nutritional potential, characterised by highly digestible dry matter, crude protein, highly digestible non-nitrogenous nutrients, and relative feed value. Considering their widespread distribution and nutritional factors, the native and non-native plants merit attention due to their pivotal nutritional potential.

Exploring the effects of fire on bryophyte functional groups along an elevational gradient on an oceanic island

Fire modifies the composition and distribution of biodiversity, but the availability of broad elevational gradients for evaluating its effects is limited. Studies conducted along elevational gradients provide valuable insights into the impacts of large-scale disturbances. Due to their sensitivity to environmental changes and low palatability to invasive herbivores, bryophytes serve as effective bioindicators for analyzing disturbance levels in oceanic island ecosystems where herbivores have been introduced. Our research focused on examining how α and β diversity and bryophyte species composition change along an elevational gradient from 200 to 2000 m a.s.l. in areas affected by fire 20 years ago compared to control areas that have been fire-free for at least 50 years. This study was carried out using different functional bryophyte groups in the pine forest of La Palma Island (Canary Islands), where this ecosystem is well represented. The findings revealed the sensitivity of the Canarian pine forest ecosystem to fire. Pine forest areas burnt 20 years ago were significantly poorer in bryophyte species than those in areas free from fire for at least 50 years. α-diversity is proposed as the most indicative parameter for analyzing the impacts of fire on the studied functional groups along the entire gradient analyses. However, β-diversity is more dependent on environmental conditions, increasing in the wettest pine forests. The results suggest that the fire impacts vary depending on the specific functional group of bryophytes and the type of pine forest.

Effect of size and shape of artificial pellets on capture success for Octopus tetricus paralarvae

The culture of the paralarvae of merobenthic octopus species generally results in high mortalities with many attempts failing to rear the paralarvae through to juvenile stage. Progress has been made with higher survival for paralarvae cultures, but all successful paralarvae cultures rely heavily on decapod zoeae, which are labour intensive and costly to maintain in many instances. The development of an artificial pellet that is easily captured, can be rapidly consumed and fulfils the nutritional needs of octopus paralarvae would greatly advance octopus paralarvae culture. The aim of this study was to evaluate the effect of shape and size of artificial pellets on feeding behaviour for early Octopus tetricus paralarvae. This study tested the capture success of six different artificial pellets in a crossed experiment for size (i.e., small, medium and large), and shape (i.e., spherical or rectangular). Paralarvae were observed individually for up to 5 min with the number, size, shape and handling time of pellets captured by 2 days post-hatch O. tetricus paralarvae being recorded. A total of 105 out of 250 paralarvae captured one of the six artificial pellets with no difference between the two provided shapes for small and large pellets. In contrast, there was a strong preference for smaller artificial pellets with 57 out of 105 paralarvae capturing the small pellets. The handling times ranged from 1 to 485 s across all sizes and shapes of artificial pellets with shorter mean handling times for rectangular artificial pellets (mean of 13 ± 41 s) compared to spherical artificial pellets (mean of 31 ± 97 s), regardless of size. Overall, handling times were rather short (< 20 s) for the majority of (91%) of paralarvae that captured artificial pellets. The results show that pellet shape is mostly irrelevant to early O. tetricus paralarvae, but size is an important factor that must be considered. Moreover, the short handling times suggest a low palatability of the artificial pellets used in the current study, which will be addressed in future studies.

Appetite, food intake, and gut hormone responses to glycomacropeptide protein ingestion in older adults: A feasibility, acceptability, and pilot study

Glycomacropeptide (GMP) has a unique amino acid profile which may make less satiating than other dietary proteins. This study assessed the feasibility and likely acceptability of a leucine-enriched GMP drink and determined appetite response in older adults (OA). Thirteen OA (11f; 70 ± 4 years) were recruited for sensory assessments of a leucine-enriched GMP drink when mixed with water and with fruit smoothie, compared with whey protein isolate (WHEY). Participants also partook in a single focus group exploring acceptability to protein and supplementation. Separately, a counterbalanced, double-blind study with twelve OA (8f; 69 ± 3 years) was conducted to determine appetite and gut hormone responses. Fasting subjective appetite was recorded using visual analogue scales and a fasted venous blood sample was collected (to measures acyl-ghrelin, PYY, GLP-1, and CCK) before participants consumed either: GMP protein (27g + 3g leucine, 350 mL water), WHEY (30g, 350 mL water), or water. Participants rested for 240 min, with appetite measures and blood sampling throughout. An ad libitum pasta-based meal was then consumed. Sensory testing revealed low pleasantness rating for GMP in water vs. WHEY (16 ± 14 vs 31 ± 24, p = 0.016). GMP addition to smoothie reduced pleasantness (26 ± 21 vs. 61 ± 29, p = 0.009) and worsened the aroma (46 ± 15 vs. 69 ± 28, p = 0.014). The focus group revealed uncertainty of protein needs and a scepticism of supplements, with preference for food. Gut hormone response did not differ between GMP and WHEY (nAUC for all gut hormones p > 0.05). There was no difference between conditions for lunch ad libitum intake (549 ± 171 kcal, 512 ± 238 kcal, 460 ± 199 kcal for GMP, WHEY, and water, p = 0.175), or for subjective appetite response. Leucine-enriched GMP was not less satiating than WHEY, and low palatability and scepticism of supplements question the likely acceptability of GMP supplementation. Providing trusted nutritional advice and food enrichment/fortification may be preferred strategies for increasing protein intake in OA.

Evaluation of Fluid Loading Protocols for Use Before Returning from Spaceflight

Reductions in plasma volume (PV) during spaceflight contribute to post-spaceflight orthostatic intolerance (OI) during re-exposure to a gravitational environment. Both the National Aeronautics and Space Administration (NASA) and the Russian Space Agency (RSA) utilize fluid loading prior to re-entry to expand PV and mitigate the risk of post flight OI, but the timing of ingestion differs. Before landing NASA crewmembers consume 1-1.5 L of water with salt tablets to produce an isotonic solution in ~1 hour, whereas RSA cosmonauts consume the same, over ~4 hours. Anecdotal reports suggest low palatability and gastrointestinal (GI) distress with salt tablet and water fluid loading. To address this concern, the NASA Space Food Systems Laboratory developed an electrolyte solution. The purpose of this study is to test the effcacy and palatability of the two fluid loading compositions ingested in 1 hour versus 4 hours. Seven participants (2 Female, 39±9 years, 178.2±9.9 cm, 74.9±8.6 kg) completed four randomized visits separated ≥ 48 hours. The four visits were (1) no fluid loading (control), (2) 4 hour ingestion of the electrolyte solution (4hr-Electro), (3) 1 hour ingestion of the electrolyte solution (1hr-Electro), and (4) 4 hour ingestion of salt tablets and water (4hr-Salt). Participants reported to the lab at ~7:00 a.m. fasted, and PV was measured using a carbon monoxide re-breathing technique. During each visit subjects consumed 500 mL of water representing normal daily water intake through the first five hours of the session along with breakfast and lunch meals identical to those provided to astronauts. During the control visit, no other fluid consumption was allowed. During the three fluid loading visits, participants also consumed up to 1.2 L of additional fluid, either water with salt tablets or the electrolyte solution. After completion of the fluid loading protocol no additional fluid was consumed during the final 3.5 hours of the test. Participants remained seated for all portions of the study. Hemoglobin and hematocrit were measured at 0, 1, 2, 3, and 3.5 hours after cessation of food and fluid intake to assess changes in PV. In these preliminary data, PV was not significantly different from baseline at any timepoint during the control and 4hr-Electro sessions ( P&gt;0.20). PV increased from baseline at all timepoints for the 1hr-Electro session ( P&lt;0.003) and at all timepoints, other than 0 ( P=0.17 ), for the 4hr-Salt condition ( P&lt;0.01 ). GI distress was reported by participant during the 4hr-Electro (n=2), 1hr-Electro (n=1), and 4hr-Salt protocols (n=4). No GI distress was reported during the control visit. The most severe GI symptom (18/20) was nausea reported with the 4hr-Salt protocol. These data suggest that both the 4hr-Salt and 1hr-Electro fluid loading protocols successfully expands PV, however the 1hr-Electro results in fewer participants reporting GI symptoms. Supported by Mars Campaign Development - Exploration Capabilities. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Nutrition Mass of Fermented Coconut Pulp with Rumen Fluid as Poultry Feed

The use of coconut pulp as animal feed is still limited due to the high content of crude fat and crude fiber, which are difficult to digest by livestock and low palatability, so feed processing technology is needed, one of which is through the fermentation process with the addition of microorganisms from rumen fluid. This study aimed to determine the nutritional quality of coconut (Cocos nucifera l.) pulp with different fermentation lengths using Bali cow rumen fluid. The study used a completely randomized design (CRD) consisting of 3 treatments and 4 replicates. The treatments used in this study were AA = 0-day coconut pulp (control), AB = 5-day fermented coconut pulp, and A2 = 7-day fermented coconut pulp. The variables observed were dry matter (DM), crude protein (CP), crude fiber (CF), and crude fat (FF). The results showed a significant effect (P&lt;0.05) on the mean values of BK AA (94.669±0.33) AB (91.89±0.23) and AC (90.46±0.44), PK AA (5.33±0.41), AB (6.00±0.14) and AC (6.59±0. 15), SK AA (16.99±0.31), AB (10.16±0.21), and AC (9.24±0.24) and showed no significant effect (P&gt;0.05) on the mean value of LK AA (44.55±0.50), AB (44.52±0.3), and AC (43.29±0.58). Based on the results of the study, it was concluded that 7-day fermentation decreased BK, LK, and SK and increased PK of coconut pulp. The best fermentation time of coconut pulp with Bali cow rumen fluid is on day 7.

The effect of turmeric and black pepper powder incorporated in breakfast on postprandial glycemia, appetite, palatability, and gastrointestinal well-being in normal-weight adults.

Culinary herbs and spices are primarily known as flavor enhancers, research suggests that black pepper (Piper nigrum) and turmeric (Curcuma longa) have now been proven to prevent many non-communicable chronic diseases such as diabetes. Bioactive components of black pepper and turmeric ameliorate glucose metabolism and appetite regulation. The present research was designed to investigate the impact of turmeric and black pepper on blood glycemia, gastrointestinal well-being, appetite, and palatability. In a randomized crossover study, four iso-caloric experimental meals each having 50 g of available carbohydrates were subjected to healthy human participants (N = 20). Turmeric and black pepper were incorporated in the breakfast meal, 1 g black pepper (BP), 1 g turmeric (TR), and combination of the (BP + TR) was added in the breakfast. Standard questionnaires were used to evaluate palatability, subjective appetite, and gastrointestinal well-being. Blood glycemia, subjective gastrointestinal well-being, and appetite were measured at 0, 30, 60, 120, and 180 min. Experimental meals BP and BP + TR resulted in lower blood glycemia (p < .05) significantly compared to control meal. A decrease in perceived eating ability and hunger, and an increase in satiety after BP + TR and BP meal was observed. No significant changes were observed after consuming test meals on gastrointestinal well-being. Compared to control and BP + TR meals, BP and TR meals had considerably lower palatability. Results showed that compared to the control intake of starchy meals supplemented with black pepper and turmeric reduced postprandial glycemia, hunger, and perceived eating ability without affecting gastrointestinal well-being.

Oak regeneration facing deer browsing: Can competition between saplings offset the diversion effect? A simulation experiment

The constraint caused by wild ungulates on forest regeneration is increasing worldwide. Hypotheses for plant association effects predict that species susceptible to herbivory can gain protection from other neighbouring plant species. In theory, such interactions could help limit the impact of browsing on the regeneration of specific tree species. However, the presence of neighbouring species can also result in increasing competition for resources between species. The resultant effects on forest regeneration of these interactions, both positive (protection against herbivores) and negative (inter-specific competition) are still unclear.To gain insight, we coupled models of browsing by roe deer (Capreolus capreolus) and of forest dynamics to simulate trajectories of oak (Quercus petraea (Matt.) Liebl.) regeneration admixed with species of contrasted palatability and growth rate under different scenarios of browsing pressure and initial sapling density. We also investigated how releasing oak saplings from all or specific neighbours during the simulation affect regeneration.We found that admixed species composition had a relatively weak effect on the density of oak recruits, but a strong effect on the duration of the regeneration phase. Oak regenerated faster when admixed with species of intermediate growth and low palatability (Fagus sylvatica) than with species of fast growth and high palatability (Carpinus betulus L.), except at intermediate sapling density and high browsing pressure where we found the opposite. Releasing oak from all competitors was most effective in promoting oak regeneration when admixed with both species together, although the benefit of competition release was much weaker at high browsing pressure. Lastly, we found that at low initial sapling density (i.e., 10 saplings/m2), oak regeneration was driven only by browsing and the effect of admixing species became negligible.Our study showed that admixing oak with palatable neighbours impedes rather than improves oak regeneration due to increased competition for resources. As such, we suggest that the benefits of herbivore diversion can be off-set by increased inter-specific competition.

Duckweed protein as an alternative plant-based protein source for dog and cat dry diets.

Duckweed has attracted increasing attention as a high-quality and sustainable novel plant-based protein source. However, little research has been conducted in dogs and cats. We evaluated the effects of inclusion of duckweed protein (Lemna; MCSelect; Parabel; Vero Beach, FL) primarily in replacement of pea protein in dog diets at 0%, 5%, and 10% and cat diets at %, 10%, and 15% on stool quality, nutrient digestibility, and palatability. We hypothesized that duckweed protein would be a viable protein source in both dog and cat diets by showing no detriment to nutritional outcomes. All feeding tests were conducted at an independent research facility (Susquehanna, PA). A standard 2-bowl palatability test over a 2-d period was conducted with adult animals (n = 30 each) to determine intake ratio between test diets (duckweed-containing diets) and control diets (0% duckweed protein). Apparent total tract nutrient digestibility was conducted with 18 adult dogs and 21 adult cats (n = 6 to 7 per diet) with 5 d of diet acclimation followed by 5 d of total fecal collection. Stool quality was evaluated on a 1 to 5 scale where 1 = non-formed or diarrhea and 5 = hard, formed. Palatability data were analyzed using paired t-test (daily consumption) and chi-square test (first choice). All other data were analyzed by ANOVA and contrast (SAS version 9.4). For cats, 10% duckweed had greater (P < 0.05) palatability than control, while no difference was observed between 15% duckweed protein and control. For dogs, 5% and 10% duckweed protein had (P < 0.05) lower palatability, demonstrating a preference to control. Both cats and dogs fed duckweed diets had acceptable stool quality (Mean = 3.4 and 3.3, respectively). No detriments in nutrient digestibility were observed in dogs fed 5% and 10% duckweed protein; however, cats fed 10% and 15% duckweed protein had (P < 0.05) lower dry matter, protein, and energy digestibility vs. control. In conclusion, the data collected indicate that duckweed can be a viable replacement for other plant-based proteins in dog diets at inclusion levels up to 10%; more development is needed for duckweed protein inclusion into cat diets.

In Vivo Challenge Trials with Dietary Antiparasitics Reveal New Insights into the Practical Use of Fenbendazole against Sparicotyle chrysophrii (Monogenea) Infection in Sparus aurata (Teleostei)

The microcotylid Sparicotyle chrysophrii is one of the most harmful parasites for the aquaculture of the gilthead seabream Sparus aurata, for which effective treatments are needed. The efficacy of dietary praziquantel (PZQ, 30–50 mg kg body weight−1 day−1), emamectin benzoate (EMB, 0.015–0.050 mg kg BW−1 day−1), and fenbendazole (FBZ, 40–75 mg kg BW−1 day−1) against S. chrysophrii on gilthead seabream was tested in four different in vivo challenge trials. Specimens of gilthead seabream naturally infected with S. chrysophrii were maintained in three separate recirculating aquaculture systems of 142 L (1 control vs. 2 treated). Fish were fed (ration 1.2% BW day−1) 5 days a week for 4 weeks, alternating weeks with medicated and control feed. On days 0, 14, and 28, samples of 7–9 fish per group were collected and the gills were examined for S. chrysophrii. The gills of hosts treated with EMB and FBZ were evaluated by histopathology. The trials showed that in‐feed PZQ has low palatability, causing rejection which did not allow its efficacy to be adequately investigated. While dietary EMB was associated with adverse effects, such as gill de‐epithelialisation and necrosis, with no demonstrated efficacy against S. chrysophrii. On the other hand, all the fish treated with FBZ lost all parasites, showing 100% efficacy and also suggesting a preventive/repellent action against the monogenean. In conclusion, the present study provides indications for the use of dietary FBZ as a medical device for the treatment/prophylaxis of sparicotylosis in aquaculture.

Effects of leaf traits of tropical trees on the abundance and body mass of herbivorous arthropod communities.

In tropical forests, herbivorous arthropods remove between 7% up to 48% of leaf area, which has forced plants to evolve defense strategies. These strategies influence the palatability of leaves. Palatability, which reflects a syndrome of leaf traits, in turn influences both the abundance and the mean body mass not only of particular arthropod taxa but also of the total communities. In this study, we tested two hypotheses: (H1) The abundance of two important chewer guilds ('leaf chewers' and 'rostrum chewers'), dominant components of arthropod communities, is positively related to the palatability of host trees. (H2) Lower palatability leads to an increased mean body mass of chewers (Jarman-Bell principle). Arthropods were collected by fogging the canopies of 90 tropical trees representing 31 species in three plots at 1000 m and three at 2000 m a.s.l. Palatability was assessed by measuring several 'leaf traits' of each host tree and by conducting a feeding trial with the generalist herbivore Gryllus assimilis (Orthoptera, Gryllidae). Leaf traits provided partial support for H1, as abundance of leaf chewers but not of rostrum chewers was positively affected by the experimentally estimated palatability. There was no support for H2 as neither leaf traits nor experimentally estimated palatability affected the mean body mass of leaf chewers. The mean body mass of rostrum chewers was positively related to palatability. Thus, leaf traits and experimentally estimated palatability influenced the abundance and mean body mass of chewing arthropods on the community level. However, the data were not consistent with the Jarman-Bell principle. Overall, our results suggest that the palatability of leaves is not among the dominant factors influencing abundance and mean body mass of the community of chewing arthropod herbivores. If other factors, such as the microclimate, predation or further (a-)biotic interactions are more important has to be analyzed in refined studies.

De novo transcriptome sequencing of drought tolerance-associated genes in little millet (Panicum sumatrense L.).

The genome size of the little millet Panicum sumatrense is unknown, although its genome is fairly diploid (2n = 4x = 36). Despite tremendous nutritional value and adaptability to adverse climatic conditions, P. sumatrense use was limited by their low palatability, coarse grain, and lack of variety of culinary preparations. Hence, understanding how to vary their usage to offer food and nutritional security in the continuously changing modern world, the proposed study was aimed to determine potential genes and metabolites implicated in drought resistance. The drought-resistant genotype of tiny millet OLM-203/Tarini was offered in pots under both relaxed and demanding circumstances. The experimental seedlings were 32days old and had been under water stress for 23days. A total of 7606 genes were compared between 23 and 32days for roots and 7264 total genes were compared between 23 and 32days for leaves, according to a research on differential expression genes (DEGs). Twenty essential genes for drought tolerance were up-or down-regulated in the control and treated roots of the OLM-203 genotype. For instance, the genes RS193 and XB34 were up-regulated in leaves while, WLIM1 was found to be down-regulated. Gene SKI35 was up-regulated in roots, whereas MPK6 and TCMOp1 were down-regulated in root samples. The roots and leaves of the tiny millet OLM-203 genotype expressed 36 up-regulated and 21 down-regulated serine transcripts, respectively. Gene annotations for leaf samples were classified as having "molecular function" (46%), "cellular component" (19%), and "biological process" (35%), while root sample gene annotations were categorized as having "biological process" (573 contigs), "molecular function" (401 contigs), and "cellular components" (166 contigs). Noteworthy, polyamines play a crucial role in drought stress tolerance in the genotype, and it was found that top ten DEGs encoding for polyamines were common in two tissues (leaf and root). Collectively, transcriptomics profiling (RNA-seq) unveiled transcriptional stability drought stress provide a new insight in underlying modus of operandi in little millet genotype "OLM-203/Tarini" in response to heat stress.

Feeding spent hemp biomass to lactating dairy cows: Effects on performance, milk components and quality, blood parameters, and nitrogen metabolism

The legalization of industrial hemp by the 2018 Farm Bill in the United States has driven a sharp increase in its cultivation, including for cannabinoid extraction. Spent hemp biomass (SHB), produced from the extraction of cannabinoids, can potentially be used as feed for dairy cows; however, it is still illegal to do so in the United States, according to the US Food and Drug Administration Center for Veterinary Medicine, due to the presence of cannabinoids and the lack of data on the effect on animals. To assess the safety of this byproduct as feed for dairy cows, late-lactation Jersey cows (245 ± 37 d in milk; 483 ± 38 kg body weight; 10 multiparous and 8 primiparous) received a basal total mixed ration (TMR) diet plus 13% alfalfa pellet (CON) or 13% pelleted SHB for 4 wk (intervention period [IP]) followed by 4 wk of withdrawal period (WP), where all cows received only the basal TMR during WP. The dry matter intake (DMI), body weight, body condition score, milk yield, milk components, and fatty acid profile, blood parameters, N metabolism, methane emission, and activity were measured. Results indicated that feeding SHB decreased DMI mainly due to the low palatability of the SHB pellet, as the cows consumed only 7.4% of the total TMR with 13.0% SHB pellet offered in the ration. However, milk yield was not affected during the IP and was higher than CON during the WP, leading to higher milk yield/DMI. Milk components were not affected, except for a tendency in decreased fat percentage. Milk fat produced by cows fed SHB had a higher proportion of oleate and bacteria-derived fatty acids than CON. The activity of the cows was not affected, except for a shorter overall lying time in SHB versus CON cows during the IP. Blood parameters related to immune function were not affected. Compared with CON, cows fed SHB had a lower cholesterol concentration during the whole experiment and higher β-hydroxybutyric acid during the WP, while a likely low-grade inflammation during the IP was indicated by higher ceruloplasmin and reactive oxidative metabolites. Other parameters related to liver health and inflammatory response were unaffected, except for a tendency for higher activity of alkaline phosphatase during IP and a lower activity of gamma-glutamyl transferase during WP in the SHB group versus CON. The bilirubin concentration was increased in cows fed SHB, suggesting a possible decrease in the clearance ability of the liver. Digestibility of the dry matter and protein and methane emission were not affected by feeding SHB. The urea, purine derivatives, and creatinine concentration in urine was unaffected, but cows fed SHB had higher N use efficiency and lower urine volume. Altogether, our data revealed a relatively low palatability of SHB affecting DMI with minimal biological effects, except for a likely low-grade inflammation, a higher N use efficiency, and a possible decrease in liver clearance. Overall, the data support the use of SHB as a safe feed ingredient for lactating dairy cows.

Variation in nutritional quality of an invasive seagrass does not explain its low palatability to two key herbivores in a Caribbean Bay

The seagrass Halophila stipulacea continues to spread rapidly through the Caribbean. Documenting native herbivore use of this invasive plant is important for understanding its impacts on marine communities and the mechanisms favoring its expansion. This study used observational and experimental data to determine if juvenile green turtles (Chelonia mydas) and long-spine urchins (Diadema antillarum) from the US Virgin Islands consumed H. stipulacea in the presence of native seagrass. Juvenile turtles associated significantly more with beds of native seagrass than mixed (native and invasive), and monospecific H. stipulacea, beds or sand bottoms. When individuals were followed, turtles foraged significantly more within mixed beds, but selectively fed on native species within them and were never observed feeding on monospecific H. stipulacea stands. When offered the native Thalassia testudinum and Syringodium filiforme, along with H. stipulacea, sea urchins significantly preferred S. filiforme over the other two choices. Measurements of fourteen nutritional and chemical parameters in these three seagrasses showed strong interspecific differences, with fewer and less predictable seasonal variations. Expressing these nutritional data by wet mass, rather than dry mass, also decreased the number of significant seasonal contrasts. Despite these differences, no parameters explained low herbivore preference for the invasive seagrass satisfactorily because nutrient values of H. stipulacea were often similar to those of the preferred natives. Our results conflict with recent studies pointing at low nutritional quality aiding against herbivory and suggest other mechanisms, such as herbivore learning and recognition of a novel resource, could be more important than currently appreciated.

A review of Madagascar's derived grasslands: Low palatability following anthropogenic fires may threaten food security

Societal Impact StatementThe 26th United Nations Climate Change Conference emphasised the need to modify practices that negatively impact biodiversity and food security in the context of global change. Following Madagascar's drought‐induced famine, our systematic review supports the theory that grasslands of the Malagasy Central Highland that are subjected to human‐lit fires are anthropogenically derived. Furthermore, these overly frequent fires that characterise much of the Malagasy Central Highland grasslands select poorly palatable grasses. Given the reliance on pastoralism as insurance against crop failure in Madagascar, fire‐dependent practices that degrade rangeland emerge as a threat to food security and biodiversity. Education can mitigate against future humanitarian crises.SummaryFood insecurity is greatest in countries where impacts of global change are predicted to be severe. Many, like Madagascar, rely on livestock‐based pastoralism (and consequently palatable rangelands) for insurance against natural disasters and crop failure. It is recognised that derived grasslands can impact climate and biodiversity. Furthermore, the well‐established palatability‐flammability trade‐off predicts that overly‐frequent fires select increasingly unpalatable, fire‐adapted grassland. The drought‐induced Malagasy famine of 2021 highlights the need to identify factors that threaten food security. Given the ubiquitous practice of rangeland preparation through annual, landscape‐scale human‐lit fires, we evaluate whether Malagasy grasslands are derived and then test for fire‐driven selection of increasingly degraded and unpalatable rangelands across Madagascar's largest grassland system, the Malagasy Central Highland (MCH). We conducted a systematic literature review, evaluating for a palatability‐flammability trade‐off, by determining dominant Malagasy grass species, and then applying functional traits, and palatability ratings to these species. Data were extracted using a suite of relevant search terms, and of 1977 studies identified, 145 were directly relevant to the questions posed. Evidence from the review is compelling for much of the Malagasy highland grassland being derived. Furthermore, Malagasy dominant grass species are fire‐adapted with poor forage‐value, suggesting current burning practices negatively impact both biodiversity and pastoralism. Decreasing rangeland palatability caused by human‐lit fires in a society suffering food insecurity emphasises the need to re‐evaluate pastoralist burning practices. Identifying optimal fire frequencies can avert breaching fire‐induced tipping points to rangeland palatability and the humanitarian crises that may follow.

Biology and ecology of Juniperus drupacea Labill.

This literature review focuses on the biology and ecology of Juniperus drupacea. Within the context of the series ‘Our Forest Trees’ by the Institute of Dendrology PAS at Kórnik, the following key topics are discussed: taxonomy with paleo-records, morphology, anatomy, geographical distribution, ecology (including habitat, communities, response to biotic factors and the environment, and phenology), disease, and conservation. Juniperus drupacea, also known as the Syrian juniper, is a dioecious evergreen gymnosperm found primarily in two distribution centers: one in the southern Peloponnese in Europe and the other in the mountains along the Mediterranean Sea in Southwest Asia. The populations from Europe and Asia differ genetically, biochemically, and morphologically. Juniperus drupacea is a medium-sized tree occurring in mountains, predominantly at elevations of 800–1400 m, on basic to moderately alkaline soils and even on calcareous rock. It is a component of fir, pine, cedar, and sometimes also juniper forest, rarely entering maquis. As with other junipers, it is a light-demanding, moderately frost- and drought-resistant, sometimes acting as an invader of abandoned fields and pastures. It is rarely grazed by goats. Its low palatability is a result of the high content of volatile oils in the needles and cones. The volatile oils have been extensively used in folk medicine and have been investigated for new medicinal uses. The species is rare, endangered and protected in Greece, parts of Turkey and Lebanon. Its ecological niche could potentially be reduced by global climate change.