Feeding Preferences Research Articles

Formula with large, milk phospholipid-coated lipid droplets in late-moderate preterm infants: a double-blind RCT.

Limited evidence exists on the preferred feeding method when breastfeeding is not possible in late and moderate preterm (LMPT) infants. This RCT evaluates growth, safety, and tolerance of a concept infant formula (IF) with large, milk phospholipid-coated lipid droplets enriched in dairy lipids in LMPT infants with primary objective to demonstrate non-inferiority of daily weight gain from randomization to 3 months corrected age compared to a standard IF. LMPT infants were randomized before or around term equivalent age to either the concept (n = 21) or standard IF (n = 20). Forty-one breastfed (BF) infants served as reference. Due to unintended low recruitment, non-inferiority in daily weight gain could not be demonstrated for the Concept compared to the Control group, but was compared to the BF group. Other outcomes were similar between the formula groups, except for an apparent larger head circumference gain in the Concept group. No apparent differences in growth and body composition outcomes were observed between the Concept and BF reference groups. This small-scale study suggests the concept IF is a safe alternative for parents who choose IF to feed their LMPT infant. Larger trials are needed to better determine impacts on head growth or body composition. In a small group of late and moderate preterm infants, growth from randomization until 3 months corrected age of infants fed with a concept infant formula with large, milk phospholipid-coated lipid droplets was not -significantly different from infants fed a standard infant formula. Infants in the Concept group had non-significant larger gain in head circumference compared to the Control group; larger trials are needed to confirm this finding. Both formulas were well-tolerated, with no differences in adverse events. The concept formula is potentially a safe alternative for parents of moderate to late preterm infants who choose to use formula milk.

Molecular Cloning of the scd1 Gene and Its Expression in Response to Feeding Artificial Diets to Mandarin Fish (Siniperca chuatsi).

Background/Objectives: Stearoyl-coenzyme A desaturase 1 (SCD1) plays a crucial role in fatty acid metabolism. However, its roles in the feeding habit transformation of mandarin fish (Siniperca chuatsi) remain largely unknown. Methods: Juvenile mandarin fish (10.37 ± 0.54)g were trained to feed on an artificial diet and then divided into artificial diet feeders and nonfeeders according to their feed preference. Afterwards, the scd1 gene of mandarin fish (Sc-scd1) was identified and characterized, and its transcription difference was determined between S. chuatsi fed live artificial diets and those fed prey fish. Results: Our results show that Sc-scd1 coding sequence is 1002 bp long, encoding 333 amino acids. The assumed Sc-SCD1 protein lacks a signal peptide, and it contains 1 N-linked glycosylation site, 24 phosphorylation sites, 4 transmembrane structures, and 3 conserved histidine elements. We found that Sc-SCD1 exhibits a high similarity with its counterparts in other fish by multiple alignments and phylogenetic analysis. The expression level of Sc-scd1 was detected with different expression levels in all tested tissues between male and female individuals fed either live prey fish or artificial diets. Conclusions: In particular, the Sc-scd1 expression level was the highest in the liver of both male and female mandarin fish fed artificial diets, indicating that scd1 genes may be associated with feed adaption of mandarin fish. Taken together, our findings offer novel perspectives on the potential roles of scd1 in specific domestication, and they provide valuable genetic information on feeding habits for the domestication of mandarin fish.

240 Feed preference of weanling pigs fed diets containing extruded corn ground to different particle sizes

Abstract The objective was to test the null hypothesis that there were no effects of reducing particle size of extruded corn on feed preference by weanling pigs. Three corn-based diets containing extruded corn ground to 700, 500, or 300 μm were prepared. An 8-d feed preference test was conducted with all possible combinations of the three diets. Each pair of diets constituted a treatment group (i.e., 700 vs. 500 μm; 700 vs. 300 μm; 500 vs. 300 μm). A total of 48 growing pigs [initial body weight (BW) = 12.1 ± 1.34 kg] were allotted to the three preference test combinations using a randomized complete block design with initial BW group as the blocking factor, resulting in eight replicate pens per treatment group. Two pigs were housed in each pen. Pigs had ad libitum access to feed and water. For each preference test, each pen contained two feeders with two of the three diets. Feeder positions within each pen were switched daily to minimize positional preference. Feed allotments and feed disappearances were recorded daily. Feed preference (%) was calculated by dividing the amount of feed disappeared for each diet by the total amount of two diets consumed by pigs. Three statistical models for each preference test included particle size of corn as fixed effect and block as random effect. Results indicated that pigs had greater (P < 0.05) daily feed disappearance and preference for corn with 700 µm on d 1, 4, 5, 7, and 8 when pigs had a choice between 700 µm vs. 500 µm (Table 1). For the other two preference tests, which were 700 µm vs. 300 µm and 500 µm vs. 300 µm, pigs had a greater (P < 0.05) preference for the larger particle size corn (700 and 500 µm, respectively) for d 3 to 8. In conclusion, it was demonstrated that pigs have a preference for larger particle sizes of extruded corn when given the choice. This may be a result of better texture of feed, a satisfying chewing experience, and the perception of greater bulkiness provided by greater particle sizes. However, further research with longer-term feeding trials is needed because pigs may have already adapted to consuming diets with 700 µm particle size prior to the experiment, which is similar to commercial diets.

Distribution and Biology of Protaetia fieberi (Coleoptera, Scarabaeidae)-Is Protection Status Required?

Studies on saproxylic species of Coleoptera have garnered significant attention due to the rarity of some of them. To investigate the distribution and biology of Protaetia fieberi (Kraatz, 1880) (Scarabaeidae: Cetoniinae) in European Russia, we analyzed data from 16 regions collected between 2018 and 2024. This species has been reliably recorded in 26 regions. We describe the species' distribution area boundaries and discuss limiting factors that inhibit its spread to the north, south, and southeast of European Russia. The primary limiting factor is the lack of suitable biotopes. Within its distribution, Protaetia fieberi prefers deciduous and mixed forests of various types. These habitats include both old-growth forest ecosystems and secondary forests that have regenerated following logging. The species also inhabits man-made forest ecosystems, such as field protection forest belts, old parks, and gardens. In forest ecosystems, Protaetia fieberi tends to occupy the upper levels and is rarely found on the ground layer. Conversely, in open areas such as glades, the species is more commonly found at ground level. This distribution pattern is linked to the adults' feeding preferences, which include consuming sap on tree trunks in forests and feeding on flowering plants in open ecosystems. The seasonal activity of Protaetia fieberi peaks from the third decade of June to the second decade of July. It is hypothesized that the perceived rarity of Protaetia fieberi in research samples is due to the specific baiting methods used, with beer traps being the most effective. The status of the species is re-evaluated in light of new data, suggesting that Protaetia fieberi is common rather than rare in European Russia.

Captive spawning, early development, and larviculture of largescale blackfish, Girella punctata (Gray, 1835), and effects of macroalgae and alternative protein sources on its juvenile growth performance

The largescale blackfish, Girella punctata (Gray, 1835), inhabits rocky substrates in the coastal waters of Japan and northeastern Taiwan. Despite its commercial significance, there is limited knowledge regarding its reproductive biology due to the sparse occurrence of broodstocks in its natural environment. This study investigated the reproductive performance and embryonic development of G. punctata, assesses its feeding preferences through controlled feeding trials, and evaluates the impact of various feed types on its growth performance. In total, 124 wild-caught G. punctata were reared for 3–4 years, and their reproductive performance was assessed in 2015 and 2016. Their egg production increased with a sudden water temperature change from 17 ℃ in 2015–22 ℃ and 2016. The total and daily average egg production weights were 3589.22 and 40.79 g, respectively, whereas the total and daily average fertilized egg production weights were 1630.72 and 18.59 g, respectively; moreover, the hatching rate was 42.61 %. During embryonic development, the eggs hatched 45 h post fertilization at 19 ℃. Newly hatched larvae were 2.26 ± 0.04 mm in length with a yolk sac of 1.09 ± 0.02 mm in length. The yolk sac was almost completely absorbed 3 days post hatch (dph), when the larvae grew to a length of 3.42 ± 0.06 mm. We found that fish meal with 40 % protein was the optimal G. punctata fish diet. The weight gain in juveniles fed Cladophora fascicularis ranged from 47 % to 52 %, which was significantly higher than that in those fed Hypnea charoides (p < 0.05). The present study provided a practical guideline on the conditions required for successful fertilization and early development of G. punctata embryos and other larval stages. This information should help ensure greater survival and a higher proportion of healthy G. punctata larvae for mariculture applications.

Estuarine ichthyofauna of Kamchatka: formation conditions, species diversity and ecological characterisation

Species composition of the estuarine ichthyofauna is described for the first time on a regional scale for Kamchatka Territory based on the materials of author’s field studies carried out in 2010–2022, as well as on the analysis of all available information (literature, archival, survey, fishery, etc.). Specific features of the conditions of formation of estuarine ichthyofauna of the region are revealed. Fish species dominating in abundance in Kamchatka estuaries are indicated. The main ecological groups (guilds) of estuarine fishes are outlined. It was found that 1 species of cyclostomes and 60 species of fishes belonging to 44 genera and 23 families can be attributed to the estuarine ichthyofauna of Kamchatka. All these species are, to varying degrees, euryhaline and therefore may utilize individual Kamchatka estuaries as habitats at various stages of the life cycle. The basis of species diversity of the ichthyofauna of Kamchatka estuaries is formed by marine fishes (at least 34 species), the second in importance are anadromous species (1 species of cyclostomes and 14 species of fishes), the minimum contribution belongs to freshwater resident fishes (13 species), which are found only in estuaries of some rivers of the region. Fish that can be referred to the ecological group of “solely estuarine” (i. e., those whose full life cycle takes place in estuaries) are probably absent in Kamchatka. The maximum species diversity of fish communutues is observed either in big Kamchatka estuaries that are largely open to the sea or in river basins with a diverse freshwater ichthyofauna. Environmental conditions in such estuaries are more favorable for the migrations and habitat of marine fish species (mainly coastal ichthyocene). At the same time, all anadromous or some freshwater euryhaline species may also use these same estuaries as temporary habitats at certain stages of the life cycle. Fish species diversity is significantly higher in the estuaries of the eastern coast of Kamchatka, which is explained by the milder climatic conditions of this area (compared to the coast of the Sea of Okhotsk), as well as by the greater typological diversity of estuaries. A separate section summarizes the currently available information on the biology and ecology of all species of fishes and fish of Kamchatka estuaries, which is presented in the form of brief species sketches (including, external view at individual stages of the life cycle; key morphological characters; maximum size and age; distribution over the territory of the region; habitat specifics, lifestyle and migrations; peculiarities of reproduction and development; feeding preferences; abundance in the region, commercial or economic importance).

The feeding preference and bite response between Microtus fortis and Broussonetia papyrifera.

Broussonetia papyrifera is a dioecious plant that is rich in various metabolites and widely distribute in Asia. Microtus fortis is a rodent that often causes damage to crops, especially in the Dongting Lake region of China. There is a wide overlap in the distribution areas for the above species and the M. fortis feeds on the leaves of the B. papyrifera. Preliminary experiments have shown that the reproduction of M. fortis is inhibited after feeding on the leaves of the B. papyrifera. In order to explore the potential of using B. papyrifera to develop botanical pesticides, we investigated the palatability and reactive substances. The feeding frequency of M. fortis on B. papyrifera leaves to that of on daily fodder and Carex brevicuspis that is the primary food for the wild population were compared. We also attempted to identify the responsive substances in B. papyrifera leaves that were bitten by M. fortis using metabolome analysis. In general, B. papyrifera leaves exhibited a stronger attraction to M. fortis. M. fortis foraged B. papyrifera leaves more frequently, and the intake was higher than that of the other two. Differential metabolites were screened by comparing normal leaves and leaves bitten by M. fortis, meanwhile with the intervention of clipped leaves. A total of 269 substances were screened, and many of these were involved in the biosynthesis of secondary metabolites, including terpenoids and alkaloids. These substances may be related to the defense mechanism of B. papyrifera against herbivores. These findings support further research examining animal-plant interactions and simultaneously provide insights into the utilisation of B. papyrifera resources and the management of rodents. The good palatability and the defense of B. papyrifera leaves suggest that they have the potential to contribute in development of plant rodenticide.

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 &gt; 0.05). However, diets with canola oil resulted in higher SFA intake (p &lt; 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 &lt; 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.

Variation in parental investment preferences for nestlings of the Gray‐backed Shrike (Lanius tephronotus) in alpine environments

AbstractIn the northeastern edge of the Qinghai‐Tibet Plateau, the Gray‐backed Shrike, a shrubland bird species of the plateau, confronts harsh living conditions. The impact of such an environment on their reproductive strategies has long intrigued us. This study reveals significant environmental effects on the investment of the Gray‐backed Shrike during their nestling‐rearing and egg‐laying stages. (1) Based on measurements of 215 shrike eggs from 2017 to 2021, we found that under the cold alpine climate, Gray‐backed Shrikes opt for a strategy of larger clutches and bigger eggs as average rainfall decreases. Concurrently, parents display a decreasing hatching order strategy, resulting in significant weight differences among newly hatched nestlings. (2) Marginal and core offspring exhibited no significant differences in fledging conditions. Core offspring generally have a slightly larger physique than marginal ones. However, marginal offspring exhibit the highest growth rate, with similar survival rates across different offspring categories. Parental rearing adopts a nest survival strategy. (3) The food provisioning rate by parents correlates strongly with the number of nestlings, the age of the nestling, and the nest's sex ratio. Differences exist between female and male provisioning rates based on begging intensity and average temperature; higher average temperatures lead to more food, with males providing more food. (4) Factors like nest sex ratio, offspring category, nestling age, and nestling sex influence the feeding preferences of parents. When overall nestling ratios skew towards either male or female, parental feeding preferences align with the actual nest sex ratio. Male and female parental feeding preferences differ based on average temperature and nestling sex. Males consistently exhibit a stronger preference for feeding male nestlings, regardless of the nest's sex ratio. In contrast, females don't show a clear preference, leading to differences in survival rates for different nestling sex under male feeding preferences.

Evaluation of the Blood Feeding Preference of Aedes aegypti (Diptera: Culicidae) when Offered Diabetic and Non-Diabetic Blood.

Aedes aegypti (L.,1762) is a primary vector of arboviral infections like dengue, yellow fever, Zika. Female mosquitoes are influenced by various physical and chemical cues from host when blood feeding, e.g., they find some individuals with certain blood types or certain conditions more attractive than others. This study determined whether Ae. aegypti shows a preference when offered blood from a patient with diabetes mellitus (DM), an endocrine disorder associated with abnormal glucose metabolism, compared to healthy blood from non-DMs. In the dual feeding experiments, forty newly emerged female mosquitoes were provided with two blood feeding systems with blood from a non-diabetic (healthy) and diabetic patient using artificial feeders. Blood from 12 diabetic and 12 non-diabetic patients was matched by ABO blood type (e.g., diabetic type O blood was compared with non-diabetic type O blood). The number of mosquitoes that landed and fed from each membrane was counted every 2min for thirty minutes. Ae. aegypti species significantly preferred for blood from non-diabetic individuals (50-65% among the different blood type groups) compared to blood from diabetic individuals. Using multiplex allele-specific PCR it was also determined that, Ae. aegypti significantly preferred the O blood group regardless of blood sugar level compared to others. Ae. aegypti has less preference for diabetic blood to non-diabetics. Regardless people affected with this condition need to take preventive measures to reduce mosquito bites as they tend to have weaker immune systems and can experience more severe cases of dengue.

Effect of seasonal variation on feeding and food preference of olive baboons (Papio anubis) in a protected Guinean savannah of West Africa

Abstract This study investigates the effects of seasonal changes in vegetation productivity on olive baboon feeding behavior in a protected Guinea savannah (Kainji Lake National Park). Over two consecutive years (2017 and 2018), observations were conducted both during the wet and dry seasons using a scan sampling method. Results revealed that olive baboons consumed 34 plant species belonging to 20 families, with 28 species in the wet season and 12 in the dry season. A total of 922 feeding events were recorded in the wet season and 621 in the dry season, indicating significant seasonal variation. Fruits were the preferred food item, especially in the dry season, followed by animal matter, seeds, leaves, and subterranean food. Interestingly, baboons also consumed tree bark regardless of season. In addition, their consumption of fruits (in both seasons) and seeds (in the dry season) highlights their ecological role in seed dispersal and plant regeneration within the park. To sustain baboon (and all non-human primates) conservation efforts within the park, it’s important to maintain a high diversity and abundance of native fruit trees throughout the year. This study highlights the importance of understanding how seasonal changes in vegetation affect olive baboon feeding behavior for effective park management and biodiversity conservation.

The feeding preference of red flour beetle Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) on wheat flour stored at varied temperatures: The perspective of volatile components

As a common pest in wheat flour, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) is responsible for economic losses and potential risks to food safety. This study aimed to investigate the feeding preferences of T. castaneum on wheat flour stored at different temperatures, analyzed the key flavor compounds influencing its feeding preferences, and laid down the foundation for the development of new T. castaneum attractants and repellents. According to results, in the early storage period, T. castaneum showed a higher preference for feeding on wheat flour stored at higher temperatures, but this trend decreased over the storage time with a preference shift towards the flour preserved at lower temperatures. The findings from GC-MS revealed changes in the types and concentrations of volatile components in wheat flour during storage. PCA and correlation analysis suggested that compounds such as 2-methyldodecane, 3-methyl-3-ethylheptane, benzaldehyde, decanal, and n-hexanol exhibited potential attractiveness to T. castaneum. Conversely, 2-methyloctane, 2,5-dimethyldodecane, and dodecane were identified as potential repellents. At different storage temperatures, benzaldehyde and 2-methyloctane displayed consistent attractant and repellent effects, indicating their potential as effective components for attractance and repellence. Overall, our work shed the light regarding the feeding preference of T. castaneum on wheat flour stored at different temperatures from the perspective of volatile component variations, and provided a theoretical basis for the development of novel attractants and repellents.

Host-feeding preferences and temperature shape the dynamics of West Nile virus: A mathematical model to predict the impacts of vector-host interactions and vector management on [formula omitted]

West Nile virus (WNV) is prevalent across the United States, but its transmission patterns and spatio-temporal intensity vary significantly, particularly in the Eastern United States. For instance, Chicago has long been a hotspot for WNV cases due to its high cumulative incidence of infection, with the number of cases varying considerably from year to year. The abilities of host species to maintain and disseminate WNV, along with eco-epidemiological factors that influence vector-host contact rates underlie WNV transmission potential. There is growing evidence that several vectors exhibit strong feeding preferences towards different host communities. In our research study, we construct a process based weather driven ordinary differential equation (ODE) model to understand the impact of one vector species (Culex pipiens), its preferred avian and non-preferred human hosts on the basic reproduction number (R0). In developing this WNV transmission model, we account for the feeding index, which is defined as the relative preference of the vectors for taking blood meals from a competent avian host versus a non-competent mammalian host. We also include continuous introduction of infected agents into the model during the simulations as the introduction of WNV is not a single event phenomenon. We derive an analytic form of R0 to predict the conditions under which there will be an outbreak of WNV and the relationship between the feeding index and the efficacy of adulticide is highly nonlinear. In our mechanistic model, we also demonstrate that adulticide treatments produced significant reductions in the Culex pipiens population. Sensitivity analysis demonstrates that feeding index and rate of introduction of infected agents are two important factors beside the efficacy of adulticide. We validate our model by comparing simulations to surveillance data collected for the Culex pipiens complex in Cook County, Illinois, USA. Our results reveal that the interaction between the feeding index and mosquito abatement strategy is intricate, especially considering the fluctuating temperature conditions. This induces heterogeneous transmission patterns that need to be incorporated when modelling multi-host, multi-vector transmission models.

Harmfulness and biological characters of a leaf beetle Gastrolina depressa (Coleoptera: Chrysomelidae) to its host plant Pterocarya stenoptera (Fagales: Juglandaceae)

Gastrolina depressa (Coleoptera: Chrysomelidae) has been found to damage many walnut plants in China. It prefers to feed on the annual leaves of an important economic plant, Pterocarya stenoptera (Fagales: Juglandaceae), and causes extensive cosmetic destruction, even plant death. Nevertheless, its biological characteristics are mostly unknown. In this study, we investigate the harmful and biological characteristics of G. depressa with different developmental stages. The results showed that G. depressa had four developmental stages: egg, larva (1st -3rd instar), pupa, and adult, the life history lasted nine days, with obvious overlapping generations. The food intake of the larvae increased with the increase of the instar, and the maximum food intake of the 3rd instar larvae was 448.19 mm2. The abdomen of the females was enlarged before oviposition, and the average number of eggs laid was 47.63 ± 13.53. Bioassay showed that there was no difference in the search time for the young (2.03, 1.25, 1.15, and 0.91 min) and old leaves (1.68, 1.15, 0.90, and 1.93 min) of P. stenoptera between 1st -3rd instar larvae and adults; the feeding preference of 1st -3rd instar larvae and adults for young leaves was higher than that to old leaves (23.33%, 26.67%, 33.33%, and 21.67%, respectively). The successful selection rates of 1st -3rd instar larvae and adults to young leaves (81.67%, 80%, 85.00%, and 70.00%, respectively) was higher than to old leaves (8.35%, 11.67%, 3.34%, and 11.67%, respectively).

Adaptation and feeding preference of Chinese soft-shelled turtle (Pelodiscus sinensis) to different feeding levels in rice–turtle co-culture system

Rice–turtle co-culture is an ecological method involving a low exogenous input of chemicals and excessive feeding might increase the cost and reduce the mutual beneficial effect. To determine the optimal feeding level for co-cultured P. sinensis and for its adaptation, the turtles (878.0±10.3 g) were fed at feeding levels of 0.7 %, 1.4 % and 2.1 % for 90 days. The observation of feeding behavior showed that a low feeding level prompted the turtles to move into field paddies and prolonged their stay. The specific growth rate increased with increasing feeding level, but did not further increase when it exceeded 1.4 %, and the feed conversion ratio increased with increasing feeding level from 0.7 % to 2.1 %. The activities of digestive enzymes were higher in the group with a low feeding level. The plasma triglyceride and total cholesterol levels increased with increasing feeding level, while the creatinine level was significantly lower at a high feeding level of 2.1 %. The trend analysis of gene expression showed that the expression of most of differentially expressed genes (DEGs) in the brain decreased with increasing feeding levels from 0.7 % to 1.4 % and did not further decrease at a feeding level of 2.1 %, while in the gut, most of the genes were significantly downregulated or upregulated at a feeding level of 1.4 %. In the brain, the pathways associated with the DEGs were involved in the relaxin signaling pathway, melanogenesis and the age–rage signaling pathway in diabetic complications. In the gut, the DEGs were most associated with pancreatic secretion, protein digestion and absorption. The related genes expression was consistent with feeding behavior, growth and physiological metabolism. These findings suggest that co-cultured turtles can adapt to different feeding levels, that the optimal feeding level for co-cultured turtles is 1.4 %, and that additional feeding reduced the economic and ecological benefits of co-culture.

Effects of heat stress on the feeding preference of yellow-feathered broilers and its possible mechanism

Heat stress is the most critical factor affecting animal feeding in summer. This experiment was conducted to investigate the effects of heat stress on the feeding preference of yellow-feathered broilers and its possible mechanism. As a result, the preference of yellow-feathered broilers for Tenebrio molitor was significantly decreased, and the fear response and serum corticosterone of broilers were significantly increased when the ambient temperatures are 35 °C (P < 0.05). In the central nervous system, consistent with the change in feeding preference, decreased dopamine in the nucleus accumbens (NAc) and increased mRNA levels of MAO-B in the ventral tegmental area (VTA) and NAc were found in yellow-feathered broilers (P < 0.05). In addition, we found significantly increased mRNA levels of corticotropin-releasing hormone receptor 1, corticotropin-releasing hormone receptor 2 and glucocorticoid receptor in the VTA and NAc of female broilers (P < 0.05). However, no similar change was found in male broilers. On the other hand, the serum levels of insulin and glucagon-like peptide-1 were increased only in male broilers (P < 0.05). Accordingly, the mRNA levels of insulin receptor and glucagon-like peptide-1 receptor in the VTA and the phosphorylation of mTOR and PI3K were increased only in male broilers (P < 0.05). In summary, the preference of yellow-feathered broilers for Tenebrio molitor feed decreased under heat stress conditions, and hedonic feeding behavior was significantly inhibited. However, the mechanism by which heat stress affects hedonic feeding behavior may contain gender differences. The insulin signaling pathway may participate in the regulation of heat stress on the male broiler reward system, while stress hormone-related receptors in the midbrain may play an important role in the effect of heat stress on the reward system of female broilers.

Luteolin promotes neuronogenesis in hippocampus of chronic unpredictable mild stress rats and primary hippocampus of fetal rats.

To investigate the effects of luteolin on chronic unpredictable mild stress (CUMS)-induced depressive rats and corticosterone (CORT)-induced depressive primary hippocampal neurons, and to elucidate the mechanism behind the action. The antidepressant mechanism of luteolin was studied by using CUMS rat model and primary hippocampal neurons in fetal rats. In vivo, novelty suppressed feeding, open-field and sucrose preference tests as well as Morris water maze were evaluated. The content of brain derived neurotrophic factor (BDNF), 5-hydroxytryptamine (5-HT), norepinephrine (NE), and dopamine (DA) in serum were detected by enzyme-linked immunosorbent assay. The mechanisms of luteolin were explored based on neurotrophin and hippocampal neurogenesis, and proliferation. Survival of the septo-temporal axis in hippocampus was assayed using the 5-bromo-2-deoxyuridine (BrdU), the expression of BDNF, neurotrophin-3 (NT-3), and nerve growth factor (NGF) in hippocampus dentate gyrus region were measured by Western-blotting. In vitro, BDNF, NT-3, tropomyosin receptor kinase B (TrkB), and phosphorylated cyclic adenosine monophosphate responsive element binding protein (p-CREB) were detected through the high content analysis (HCA) to investigate neurotrophin and apoptosis. Induction of CUMS in rats induced depressive symptoms, while luteolin significantly enhanced sucrose consumption, decreased feeding latency, increased locomotor activity, escape latency, distance of target quadrant and regulated the content of depressive-like biomarkers. Histology analysis revealed that luteolin increased the abundance of new born neurons that had been labeled with BrdU, BrdU + neuronal nuclear antigen, and BrdU + doublecortin in septo-temporal axis of S2 (mid-septal) and T3 (mid-temporal). Moreover, expression of BDNF, NT-3, and NGF increased significantly in the septo-temporal axis of S2 and T3. HCA showed increased expression of BDNF, NT-3, TrkB and p-CREB in primary hippocampal neurons. The results provided direct evidence that luteolin has an antidepressant effect and could effectively promote the regeneration of the septotemporal axis nerve and hippocampal neuronutrition, which suggested that the antidepressant effect of luteolin may be related to hippocampal neurogenesis.

Functional morphology and ontogeny of mouthparts and mouth aperture of Panulirus ornatus and Sagmariasus verreauxi: Implications towards formulated feeds development

Development of formulated feed is now a focal point in advancing the aquaculture of spiny lobster species. This study investigated the functional morphology of two spiny lobsters, Panulirus ornatus and Sagmariasus verreauxi, by analysing mouthpart morphology and mouth aperture. The analysis is focussed on determining likely feed preference based on morphology with the aim to provide knowledge for the development of formulated feeds. There is a strong correlation between the mouth aperture being approximately 4.0 and 7.5% of the carapace length of S. verreauxi and P. ornatus juvenile and adult lobsters, respectively. This finding provides knowledge for development of a species-specific tool that could be used in experimental studies to define optimal dimensions of artificial manufactured pellets in relation to the size of the lobster. Differences in mouthpart morphology through ontogeny included increase of calcification and robustness, and this is likely to reflect a different requirement in the texture (softness/hardness) of the pellet as the animals develop. Spines and setation are a prominent feature of the mouthpart morphology and differ between species and during ontogeny. Spines on maxillipeds II and III and crista dentata on maxillipeds III are likely to play an important role in holding and manipulation of feed prior to ingestion. Pellet texture may need to accommodate these differences in species and age specific mouthpart ontogeny. Ontogenetic changes in setation were found, with much richer setation proportionally to the size of mouthpart in first instar juvenile lobsters, which decreases with size increase. Furthermore, species-specific differences indicate function shifts in mouthparts with life stages. This may indicate differences in filter feeding capacity with age and between species, as reported for other decapods. This is unlikely to be of high importance in pellet feeding but may represent an avenue of investigation for first feeds in juveniles. Collectively, the differences during ontogeny and between species suggest that formulated feeds may need to be tailored to species and life stage, particularly regarding pellet dimensions and texture.

Preferencia alimenticia y de oviposición de Gonipterus platensis(Coleoptera: Curculionidae) en tres especies comerciales de Eucalyptus en Colombia

Gonipterus platensis (Marelli, 1926), is a beetle that belongs to the family Curculionidae, a phytophagous species within the genus Eucalyptus. It is native to Australia, where it is not considered a pest due to the presence of biological controllers. In Colombia, eucalyptus trees are the second exotic species with the largest planted area, and because in 2016 was recorded the presence of G. platensis in the country, efforts have been made to study and determine the potential damage that this species can cause in plantations through studies of its feeding preferences and oviposition, among others. The present study aims to determine the preference of G. platensis for the three most planted commercial eucalyptus species in the country: Eucalyptus grandis W.Hill ex Maiden, E. urophylla S.T. Blake, and the hybrid E. grandis W.Hill ex Maiden × E. urophylla S.T. Blake (E. urograndis). An experiment was conducted using a multiple-choice design to assess feeding and oviposition preference. Two assays were carried out: one with seedlings and the other with an olfactometer. The present study reveals that G. platensis has a feeding preference for E. grandis, followed by E. urophylla, and to a lesser extent, the hybrid species E. urograndis. Furthermore, G. platensis is capable of ovipositing in all three eucalyptus species studied without making any differentiation.

Alterations in feeding preference and gastric emptying of giant freshwater prawn (Macrobrachium rosenbergii) following administration of varying quantities of fermented soybean meal

Alterations in feeding preference and gastric emptying of giant freshwater prawn (Macrobrachium rosenbergii) following administration of varying quantities of fermented soybean meal