Feeding Preference Tests Research Articles

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.

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.

SCREEN-HOUSE REARING OF THE CASHEW MIRID HELOPELTIS SCHOUTEDENI REUTER (HETEROPTERA: MIRIDAE) ON THREE VEGETABLES FOR ITS MANAGEMENT ON CASHEW

Helopeltis schoutedeni (Heteroptera: Miridae) is a significant cashew and cotton pest in East and West Africa. To date, viable laboratory rearing and maintenance protocols have been lacking to facilitate biological investigations on the bug. This drawback has largely hindered its successful management. The potential of three vegetable intercrops, cucumber fruit (Cucumis sativus L.), fresh French bean (Phaseolus vulgaris L.) pods, and pigeon pea (Cajanus cajan L.) were the suitable host plants for establishing laboratory colonies of H. schoutedeni. The developmental time, survival, oviposition, and feeding behaviors of H. schoutedeni under screen-house conditions were monitored. Newly hatched nymphs reared on these substrates successfully developed into adults with varying average developmental times of 25.72, 25.81, and 33.26 days for French beans, pigeon peas, and cucumbers, respectively. Similarly, survival varied significantly on the different plants, with the highest survival occurring on pigeon pea seedlings (97-100%) and the lowest on cucumber (48-69%; P < 0.05). Significantly more feeding lesions were recorded on pigeon peas (349.6 ± 82.56) than on cucumbers (52.6 ± 13.62) in the feeding preference test. The proportion of adult feeding during the scotophase was significantly higher than in the photophase (Pigeon pea seedling: t = -3.545; df = 18; P < 0.05, French beans: t = -2.684; df = 28; P < 0.05 and Cucumber t = 3.713; df = 18; P < 0.05). Oviposition was only recorded on pigeon pea seedlings. Present findings demonstrate the potential for using specific vegetables as suitable host plants for H. schoutedeni under confined and open field settings to aid future research studies toward effective management.. KEYWORDS :Cashew, Helopletis Schoutedeni, Legumes, Pest Management, Rearing

Lamb feeding preference for maize, bean, and broad bean stubble treated with silage effluent, urea-molasses, or phosphoric acid

molasses (MaUM), silage effluent with phosphoric acid (MaEflAcP), and control (MaTes); bean stubble treated with silage effluent (FrEfl), effluent silage with urea-molasses (FrEflUM), and control (FrTes); and broad bean stubble treated with silage effluent and urea-molasses (HaEflUM), urea-molasses and phosphoric acid (HaUMAcP), and control (HaTes). Design/Methodology/Approach: Six Dorper/Katahdin lambs of 21 kg (LW) were used to carry out the feeding preference test. In the morning, lambs were fed with a mixture of the three treatments of each stubble (70% of the dry matter (DM) requirement/40 min); meanwhile, in the evenings, they were offered each treatment in independent feeders (10% of the DM requirement/20 min). This treatment lasted 7 days. Intake was measured in grams (offer minus rejection). Once the ordinal qualitative variables of consumption frequency (1=low, 2=medium, and 3=high) were classified, the data were analyzed using the ordinal logistic regression model. The results were expressed as the estimated proportion of incidence of the frequencies (1, 2, or 3). Results: The proportion estimated for the high consumption frequency recorded higher results for MaUM, HaUMAcP, and FrEflUM, reaching 95.24, 73.44, and 43.49%, respectively. The proportion estimated for the low consumption frequency for HaTes, MaTes, and FrTes was 95.12, 88.11, and 48.77%, respectively. Study Limitations/Implications: The diets with different quality and flavors did not meet the assumptions of normality and homoscedasticity; however, the results provide valuable information for the improvement of dry matter intake and animal production. Finding/Conclusions: Urea-molasses (UM) promoted consumption preference both alone or in combination with other ingredients, in all the stubbles tested.

Forage Preference, Voluntary Intake, and In Vivo Digestibility of Six Tropical Tree Leaves by Sheep in Semi-Arid Areas in Benin Republic (West Africa)

Livestock supplementation with forage trees is becoming a sustainable alternative to traditional grazing on the open pastures during the dry season in Benin. However, little is known about the feeding preferences of sheep and the digestibility of such native tree/shrub fodder. Such knowledge could improve their use on smallholder farms. Multiple-choice feeding preference tests were conducted on six tree fodders (Annona senegalensis, Blighia sapida, Cassia sieberiana, Gmelina arborea, Khaya senegalensis, and Mangifera indica) to determine the best choice to feed the local rams and ewe Djallonke sheep. The cafeteria test involved four rams and four ewes. In addition, an in vivo trial using metabolic cages was conducted to evaluate the voluntary intake of dried woody leaves and the dry matter digestibility of diets containing these dried leaves. Preferences varied significantly (p ≤ 0.05) according to the woody species. Based on relative intake values, sheep preferred, in decreasing order, the leaves of M. indica, B. sapida, K. senegalensis, G. arborea, A. senegalensis, and C. sieberiana. The apparent digestibility of dry matter was highest (p ≤ 0.01) in the G. arborea diet (86.8%); all diets presented a value higher than 70%. This study provided helpful information about better resource utilization to improve animal productivity. Further study could evaluate the growth performance of sheep supplemented with tree fodder.

Does fungal infection increase the palatability of oilseed rape to insects?

Multiple and simultaneous attacks by pathogens and insect pests frequently occur in nature. Plants respond to biotic stresses by activating distinct defense mechanisms, but little is known about how plants cope with multiple stresses. The focus of this study was the combined interaction of fungal infection caused by Leptosphaeria maculans (synonym Plenodomus lingam) and arthropod infestation by the diamondback moth (Plutella xylostella) in oilseed rape (Brassica napus). We hypothesized that infection by the fungal pathogen L. maculans could alter oilseed rape palatability to P. xylostella-chewing caterpillars. Feeding preference tests were complemented with analyses of defense gene transcription, and levels of glucosinolates (GLSs) and volatile organic compounds (VOCs) in L. maculans-inoculated and non-inoculated (control) leaves to determine possible causes of larval choice. Caterpillars preferred true leaves to cotyledons, hence true leaves were used for further experiments. True leaves inoculated with L. maculans were more palatable to caterpillars over control leaves during the early stage of infection at 3 days post inoculation (dpi), but this preference disappeared in the later stages of infection at 7 dpi. In parallel, genes involved in the salicylic acid and ethylene pathways were up-regulated in L. maculans-inoculated leaves at 3 and 7 dpi; L. maculans increased the level of total aliphatic GLSs, specifically glucobrassicanapin, and decreased the level of glucoiberin at 3 dpi and altered the content of specific VOCs. A group of 55 VOCs with the highest variability between treatments was identified. We suggest that the P. xylostella preference for L. maculans-inoculated leaves in the early stage of disease development could be caused by the underlying mechanisms leading to changes in metabolic composition. Further research should pinpoint the compounds responsible for driving larval preference and evaluate whether the behavior of the adult moths, i.e. the stage that makes the first choice regarding host plant selection in field conditions, correlates with our results on larval host acceptance. © 2024 Society of Chemical Industry.

Housing European Ground Squirrels (Spermophilus citellus) for an Ex Situ Conservation Program.

European ground squirrel (Spermophilus citellus) populations have declined precipitously over the last 70 years. Its protection cannot be ensured solely by protecting its habitat; it is also necessary to protect the animals ex situ. In our study, within a European ground squirrel species protection program, we examined two elements of indoor housing technology. Knowledge of the animals' needs is essential for captive housing and breeding success, so in our tests, the animals could freely choose both nest-building materials and feed. In the nest material preference test, the animals could choose from three materials with different structures: paper, Lignocel and hay. In the feed preference test, the animals could also choose from three types of feed: commercial rabbit feed, complete rabbit feed and a natural feed mixture. The first two feeds were in granulated format, and the third was a grain feed mix. Among the nesting materials, they preferred hay, which allowed them to build better-quality nests. Among the feeds, they preferred the grain feed mix, the composition closest to their natural feed, and it was the only one that contained animal protein. Our results contribute to the successful maintenance and breeding the European ground squirrel in captivity.

A Study on the Feeding Biology of Soil Oribatid Mite Papillacarus (Papillacarus) elongatus (Acari, Lohmanniidae)

The feeding biology of lohmanniid mite Papillacarus (Papillacarus) elongatus Xavier, 2007 was investigated under laboratory conditions (relative humidity 80 ± 2 % and temperature 27 ± 2˚C) using appropriate feeding preference tests. Different microfungi and semi-degraded leaves were provided as food items. To validate feeding biology, the gut enzymes and structural morphology of mouth parts of P. (P.) elongatus were also examined. The results demonstrated that the P. (P.) elongatus are panphytophages, and could feed on both higher and lower plant elements. These alternative feeding guilds might enable these mites to coexist with other soil organisms; moreover, they can be directly involved in the biodegradation of leaf litter and indirectly influence the microbial activity in the soil ecosystem.

Induction of Resistance by Organic and Micro Nutrients against Bhendi Shoot and Fruit Borer Earias vittella Fab.

Bhendi Abelmoschus esculentus L. (Moench), is an economically and largely cultivated vegetable crop in India. Bhendi is susceptible to the attack of various insects from seedling to fruiting stage. Bhendi shoot and fruit borer, E. vittella is most serious pests which cause direct damage to tender shoots and fruits. The present study was undertaken to analyses the role of organic and micro nutrients in enhancing insect resistance in the selected bhendi accessions. With regard to the influence of organic nutrients on the feeding preference of E. vittella, plants supplied with vermicompost was less preferred. With regard to the influence of micronutrients on resistance in bhendi accessions, manganese applied plants recorded the minimum damage caused by E. vittella larvae in fruit feeding preference tests. The data these obtained by various experiments conducted were statistically using factorial randomized block design (FRBD).

Feeding Preferences of Domestic and Wild Ungulates for Forage Trees in the Dry Tropics

Silvopastoralism based on livestock feeding on forage trees is becoming a sustainable alternative to traditional grazing on the open pastures of dry tropical Central America. Four autochthonous trees, Acacia pennatula, Enterolobium cyclocarpum, Gliricidia sepium and Guazuma ulmifolia, and one exotic (Moringa oleifera) tree are the preferred species for these silvopastoral systems. Little is known, however, about the feeding preferences of cattle, sheep and goats for such fodder trees and whether wild ungulates (white-tailed deer, Odocoileus virginianus) feed on these plants. In this work, we conducted several multiple-choice feeding preference tests (cafeteria test) to compare the best choice to feed cattle, sheep, goats and white-tailed deer in these farming systems. Although all ruminant species included the four autochthonous trees and the exotic M. oleifera in their diets, G. ulmifolia was the preferred forage tree by far. The preference for the rest of the trees varied among our ruminant species. When M. oleifera was added to the cafeteria test, it was well accepted by white-tailed deer but little appreciated by their domestic counterparts. The use of these forage trees for livestock feeding is thus interesting not only for sustainable animal production but also to support wild herbivores in the dry tropics of Central America.

Doru luteipes (Dermaptera: Forficulidae) and Orius insidiosus (Hemiptera: Anthocoridae) as Nocturnal and Diurnal Predators of Thrips.

Thrips (Thysanoptera, Thripidae) are pests of several crops and their chemical control is mainly hindered by their thigmotactic habits, which in turn allows the use of biological control agents with similar habits. Orius (Hemiptera: Anthocoridae) are effective control agents for thrips and are commercialized in many countries. Habitat overlap exists between Doru luteipes (Scudder) (Dermaptera: Forficulidae) and thrips, making D. luteipes a potential predator in the control of these insects. Our goals were to confirm the predatory ability of D. luteipes when exposed to thrips, Caliothrips phaseoli (Hood), and to evaluate the interaction between D. luteipes and Orius insidiosus Say for the control of thrips using behavioral and feeding preference tests. The ability of D. luteipes and O. insidiosus to prey on thrips at all stages was tested by predation bioassays; adults of D. luteipes consumed 210.9 ± 23.2 thrips per day, while adults of O. insidiosus consumed 32.4 ± 3.6 thrips per day. Intraguild predation was absent, and the predatory behavior feeding of the two predatory species was not altered in the presence of the other predator. In addition, these predators forage at different times-O. insidiosus during the day and D. luteipes at night, indicating that both predators do not interact negatively, allowing the use of both in a biological pest control program for thrips.

The impact of intermittent exercise on mouse ethanol drinking and abstinence-associated affective behavior and physiology.

Negative emotional states are associated with the initiation and maintenance of alcohol use and drive relapse to drinking during withdrawal and protracted abstinence. Physical exercise is correlated with decreased negative affective symptoms, although a direct relationship between drinking patterns and exercise level has not been fully elucidated. We incorporated intermittent running wheel access into a chronic continuous access, two-bottle choice alcohol drinking model in female C57BL/6J mice. Wheel access was granted intermittently once mice established a preference for alcohol over water. After 6weeks, alcohol was removed (forced abstinence) and mice were given continuous access to unlocked or locked wheels. Negative affect-like behavior, home cage behavior, and metabolic activity were measured during protracted abstinence. Wheel access shifted drinking patterns in the mice, increasing drinking when the wheel was locked, and decreasing drinking when unlocked. Moreover, alcohol preference and consumption were strongly negatively correlated with the amount of running. An assessment of negative affect-like behavior in abstinence via the novelty suppressed feeding and saccharin preference tests (SPT) showed that unlimited wheel access mitigated abstinence-induced latency increases. Mice in abstinence also spent more time sleeping during the active dark cycle than control mice, providing additional evidence for abstinence-induced anhedonia- and depression-like behavior. Furthermore, running wheel access in abstinence decreased dark cycle sleep to comparable alcohol- and wheel-naïve mice. Given the positive impact of exercise and the negative impact of alcohol on metabolic health, we compared metabolic phenotypes of alcohol-abstinent mice with and without wheel access. Wheel access increased energy expenditure, carbon dioxide production, and oxygen consumption, providing a potential metabolic mechanism through which wheel access improves affective state. This study suggests that including exercise in AUD treatment regimens has the potential to reduce drinking, improve affective state during abstinence and could serve as a non-pharmacological approach to prevent the development of an AUD in high-risk individuals.

Activity of grindelanes against important maize pest Spodoptera frugiperda and their selectivity of action on non‐target environmental bacteria

AbstractIn the search for new plant‐derived products with antifeedant and insecticidal potential against economically important insects, 11 grindelanes (two as natural acids and nine as methylated derivatives) purified from the foliar tissue of Grindelia chiloensis (Cornel.) Cabrera (Asteraceae) were evaluated against the fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae). Larvae of this moth are considered to be the main pest of maize that causes severe losses on local agricultural production. Remarkable alterations in feeding behavior, larval weight, larval and pupal stage lengths, and adult fertility, as well as malformations and mortality in specimens during their life cycle were noticed in the feeding preference tests and no‐choice diet assays. Antifeedant indexes (AI%) calculated in food preference bioassays reached up to 79% for the lipophilic grindelane 3b, the most potent antifeedant agent. Grindelane 7b showed a better insecticidal activity (median lethal dose, LD50 = 26.49 µg g−1) and 8b was potentially neurotoxic due to acetylcholinesterase inhibition. Ultrastructure of the middle portion of the digestive tract of larvae fed with small amounts of natural grindelane 9a supplemented to the diet revealed cell damage, and thickening of the peritrophic membrane and a striking number of mitochondria, as evident signs of defense against toxic substances ingested by the larvae. Besides, this study demonstrated that these effective insecticides did not have inhibitory effects on beneficial plant and soil bacteria which would allow ecological pest management.

Biology and Feeding Preferences of <em>Spodoptera Frugiperda</em> (Lepidoptera: Noctuidae) On Maize and Selected Vegetable Crops

Purpose : Fall Armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae) was recently reported for the first time in Sri Lanka in Oct 2018 as a new invasive pest of maize. Therefore, the objectives of present study were to study biology and to evaluate feeding preferences of S. frugiperda on maize and selected vegetable crops. Research Method : During the experiment, newly hatched larvae were fed with maize, cabbage, okra, beans, radish and brinjal leaves under laboratory conditions. Maize was used as the positive control. Duration of development from larva to adult, pupal weight, pupal length, sex ratio, survival percentage, and oviposition (Choice and No-Choice test) on different vegetable crops were evaluated. Findings : Results of the feeding preference test envisaged that there was no host dependent variability among neonate larvae for maize, cabbage, raddish and brinjal. The highest damage (50-75%) was reported in larvae fed on okra, and (25-50%) damage was showed in beans after 24 hours of inoculation. The highest survival percentage of larvae (80%) and shortest larval development period (23.8±0.3days) were reported in larvae fed with maize where as it was the longest in brinjal. The highest oviposition (4.1±1.2 in Choice test and 3.6±0.7 in No-choice test) was observed in maize compared to other crops. With the absence of the most preferred host (maize) for oviposition, other hosts were used by the pest. During the off season Fall armyworm could survive in alternate crops. Research Limitations : Field observations were not carried out to confirm (validate) the laboratory observations with the time limitation. Originality/ Value : The research provides interest and idea about the survival mechanism of S. frugiperda during off season of maize and potential alternative host plants of the pest. It identifies the possibility of moving of S. frugiperda into five vegetable crops and thereby make awareness of the farmers about the pest to follow the suitable management practice of the S. frugiperda.

Host preference of Tribolium castaneum (Herbst) on six kinds of flour

The red flour beetle, Tribolium castaneum (Herbts) is a major pest of flour from various grains. The infested flour is discoloured and will emit a disagreeable odour due to the secretion of benzoquinone from the insect’s abdominal glands. Considering the economic losses effected by T. castaneum, new alternative control measures are needed for this pest. This study sought to determine the host preferences of T. castaneum from amongst six kinds of flour to assess their vulnerability to infestation. The research was conducted in the Plant Pest Laboratory, Department of Plant Pests and Diseases, Faculty of Agriculture, University of Brawijaya. The host preferences of T. castaneum were examined using a six-arm olfactometer. Feeding preference tests were performed for a duration of 12 hours at 200 ml/minute airflow in each chamber-arm, followed by oviposition preference observations one week later. Feeding preference was calculated for the total pool of adults observed, segregated by sex, whereas oviposition preference was calculated as the number of eggs laid. Flour nutrition (proximate composition, phenolic content, and riboflavin content) were analyzed. Our results showed a feeding preference by T. castaneum for bran, soy and tapioca flour was greater over wheat, corn, and white gelatinous rice flour, while for oviposition, bran flour was the most preferred.

Processed false yam seed meals in broiler chicken diets: effects on feed preference and apparent nutrient digestibility

This study evaluated feed preference and apparent nutrient digestibility of a maize-based diet and modified diets containing treated false yam seed meals (TFYSM). False yam seeds were sun-dried (Un_T), or first soaked in water and treated with one of the following: urea (Urea_T), sodium chloride (NaCl_T), sodium hydroxide (NaOH_T), or potassium hydroxide (KOH_T) and blanched. The TFYSM replaced maize (wt/wt) in experimental diets at 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50%, respectively in a feed preference test (experiment 1). In that study, feed preference test was conducted with 6 × 4 broiler chicks aged 21days in a randomized complete design; each level of each TFYSM was fed for 24h and feed intake recorded. In experiment 2 of the study, apparent nutrient digestibility of TFYSM-based diets was evaluated for 15days with 4-week-old chicks allocated to 5 groups of 20 birds which were further subdivided into 5 treatment groups of 4 birds (replicates) using the inclusion levels of 10, 20, 30, 40, and 50% respectively. The preference test data indicated that feed intake was not compromised when maize was substituted by NaCl_T, NaOH_T, Urea_T, and KOH_T FYSM at all levels, and Un_T FYSM up to 5% inclusion. Dry matter digestibility was generally high (> 75%) in all diets except for Un_T. Control diet and NaOH_T diets had similar CP digestibility, but higher than KOH_T diets, while Un_T diets had reduced CP digestibility. Digestibility of NFE ranged from (77.4%) (Un_T) to (93.8%) (KOH_T). Improving apparent nutrient digestibility of FYSM by sequential use of water-based and chemical treatment methods especially NaOH_T or KOH_T offers the potential to use this alternative feedstuff in broiler diets.

Translocator protein-mediated fast-onset antidepressant-like and memory-enhancing effects in chronically stressed mice.

Fast-acting and cognitive-enhancing antidepressants are desperately needed. Activation of translocator protein (18 kDa, TSPO) is a novel strategy for developing potential antidepressants, but there are no data available on the onset time of TSPO ligands. This study aimed to investigate the fast-onset antidepressant actions of AC-5216, a selective TSPO ligand, in TSPO knock-out (KO) mice. TSPO wild-type (WT) and KO mice were subjected to a six-week chronic unpredicted stress (CUS) paradigm. Then, the mice were treated with AC-5216 and tested with depressive and cognitive behaviours. A single dose of AC-5216 (0.3 mg/kg) exerted anxiolytic- and antidepressant-like actions in TSPO WT mice. Moreover, in chronically stressed WT mice, two to four days of AC-5216 treatment (0.3 mg/kg, once per day) produced fast-onset antidepressant-like effects in the novelty-suppressed feeding and sucrose preference tests, as well as memory-enhancing effects in the novel object recognition test. In addition, a rapid (with five days of treatment) restoration of serum corticosterone levels and prefrontal cortex (PFC) allopregnanolone levels was found. Further studies showed that in these stress-exposed WT mice, AC-5216 significantly increased the levels of mTOR signalling-related proteins (mBDNF, p-mTOR, PSD-95, synapsin-1, GluR1), as well as the total dendritic length and branching points of pyramidal neurons in the PFC. These results suggest that TSPO mediates the fast-onset antidepressant-like and memory-enhancing effects of AC-5216, possibly through the rapid activation of mTOR signalling and restoration of dendritic complexity in the PFC.

Nutritional evaluation of animal feed infested with Aleuroglyphus ovatus and Tyrophaghus putrescentiae

Compound feed for animals are produced in the feed industry based on grains, seed oil, by-products of animal origin, which are sources of carbohydrates, fats, proteins, and are attractive foods to species which infest them, causing changes in energy, feed nutrition composition, and in their hygienic-sanitary quality. The objective of this study was to evaluate the nutritional profile of feeds infested with Aleuroglyphus ovatus and Tyrophaghus putrescentiae, and identify the preference of these mites for raw materials used to prepare the feeds. Mitefauna were evaluated in poultry, cattle, and pork feeds. In the feeding preference test, species were offered the possibility to choose between rice (R), soybean (S) and wheat bran (W), meat meal (M), milled maize (C), and animal feed colonizer fungi (F). To evaluate the nutritional profile of feeds with A. ovatus and T. putrescentiae, the contents of either extract (fat), crude fiber, ash, crude protein, riboflavin, thiamine, and moisture, as well as the presence of fungi and yeasts, were evaluated. The predominant and most abundant species was T. putrescentiae (60%), followed by Cheyletus malaccensis (20%) and A. ovatus (8%). Aleuroglyphus ovatus preferred M, C and R, whereas T. putrescentiae preferred M, F, and R. Aleuroglyphus ovatus reduced fat content by 72%, and protein by 3.93%. Ash increased by 28.35% and 40.56%, while T. putrescentiae decreased fat by 35.11%, protein by 6.06%, and moisture by 13.53%. Tyrophaghus putrescentiae increased the concentration of crude fiber by 13.40% and caused changes in vitamins at 60 days, increasing thiamine concentration by 38.57% and reducing riboflavin by 50%.

Entomopathogenic nematodes for the control of Gryllus sp. (Orthoptera: Gryllidae) under laboratory and field conditions

ABSTRACT: Entomopathogenic nematodes are effective in controlling soil insects and they are used in agricultural systems. The virulence of entomopathogenic nematodes on crickets (Gryllus L.) (Orthoptera: Gryllidae) was evaluated under different conditions in order to select populations for application in the field. Virulence tests with Heterorhabditis amazonensis RSC05, H. amazonensis MC01, Steinernema carpocapsae All (Weiser) and H. amazonensis GL were performed. Evaluations were then made of the concentrations of infective juveniles (100, 200, 400 and 600 infective juveniles per insect); feeding preference with or without choice; and field tests using traps to evaluate insect sampling. All isolates were found to cause mortality in Gryllus sp., and H. amazonensis MC01 and S. carpocapsae All were selected; an increase in concentration resulted in increased insect mortality. Regarding the feeding preference tests, after 16 h there was no feeding in any of the treatments. In treatments with a chance of choice, it was verified that the crickets fed, independently of the presence of the nematodes. In the field tests, 19 live crickets were found in the traps, and, after application of entomopathogenic nematodes in aqueous suspension, 2 live crickets were found. Results suggested that H. amazonensis MC01 was promising in the control of Gryllus sp. under the tested conditions.

Argan Oil Supplementation Reverses Anxiety and Depressive-Like Behaviors, Neurodegeneration and Oxidative Stress in Amygdala Induced by Chronic Mild Stress in Rats

Background: Argan Oil (AO) has been used as a natural remedy in traditional medicine, mainly in Morocco, for several centuries. In this study, we evaluated the beneficial effects of AO dietary on vulnerability of rats to the chronic unpredictable mild stress (UCMS) using behavioral tests, biochemical and histological markers of depression or anxiety. Method: Rats were handled daily (home cage control) or subjected to the UCMS procedure during 6 weeks (i.e., from 43th to 85 Post-natal Day (PND)) (Stress group, n=12). Animals were previously administered orally by NaCl 0.9% (Control group, n=11) or AO (10 ml/kg/day) (AO+Stress group, n=12) for 10 weeks (i.e., from weaning 21th to 93 PND). The efficacy of UCMS or AO dietary on behavioral performances of the animals in the open field, the forced swimming, the light/dark, the novelty suppression of feeding and sucrose preference tests, was measured. Following behavioral assays, oxidative stress in amygdala, histologic semiquantitative analysis of neurodegeneration in the hippocampus, frontal cortex and basolateral amygdala (BLA) subregions, and corticosterone level in plasma was also performed. Results: Our data supports pharmacological and biochemical evidences for the antidepressant and anxiolytic-like effects of AO. Prolonged supplementation with AO reverses all the behavioral changes that occurred due to UCMS and restored corticosterone level in the plasma, oxidative status of amygdala and the neurons level in the CA3 subregion of rats’ hippocampus. Conclusion: This study suggests that antidepressant and anxiolytic like effects of AO in adult rats can be the result of modulation of brain antioxidant enzyme activities, the activation of hippocampal neurogenesis and the modulation of HPA axis activity. However, more experiment and detailed analysis is required for definitive conclusion.