Average Meal Size Research Articles

Effect of increasing concentration of ergot alkaloids in the diet of feedlot cattle: performance, welfare, and health parameters.

This study was designed to evaluate the effects of feeding increasing dietary concentrations of ergot alkaloids from cereal grains (EA; 0, 0.75, 1.5, 3.0 mg/kg of dietary DM) to feedlot cattle over backgrounding (BG) and finishing (FS) phases on health, welfare, and growth performance. Two hundred and forty commercial steers (280 ± 32 kg BW) were stratified by weight and randomly allocated to 16 pens (15 steers/pen), 4 of which were equipped with the GrowSafe system (1 pen/treatment) to measure individual feed intake. Each pen was randomly assigned to a treatment (n = 4/treatment). Treatments included 1) control (CTRL), no added EA; 2) CTRL + 0.75 mg/kg EA (EA075); 3) CTRL + 1.5 mg/kg EA (EA150); and 4) CTRL + 3.0 mg/kg EA (EA300). Steers were fed barley-based BG diets containing 40% concentrate: 60% silage (DM basis) for 84 d. Steers were then transitioned over 28 d to an FS diet (90% concentrate: 10% silage DM basis) and fed for 119 d before slaughter. The diet fed to EA300 steers was replaced with the CTRL diet after 190 d on feed (DOF), due to EA-induced hyperthermia starting at 165 DOF. In the BG phase, average meal length (P = 0.01) and size (P = 0.02), daily feeding duration (P = 0.03), final body weight (BW; P = 0.03), and total BW gain (P = 0.02) linearly decreased with increasing EA levels, while gain to feed (G:F) responded quadratically (P = 0.04), with EA150 having the poorest value. Increasing concentrations of EA in the diet linearly increased rectal temperature (P < 0.01) throughout the trial. Over the full FS phase, a quadratic response was observed for ADG (P = 0.05), final BW (P = 0.05), total BW gain (P = 0.02), and carcass weight (P = 0.05) with steers fed EA150 having the lowest performance, as EA300 steers were transferred to CTRL diet after 190 DOF. Dressing percentage (P = 0.02) also responded quadratically, with the lowest values observed for EA300. Thus, EA reduced ADG during BG and FS phases, although more prominently in FS, likely due to increased ambient temperatures and high-energy diet in FS triggering hyperthermia. When EA300 steers were transferred to the CTRL diet, compensatory gain promoted higher hot carcass weight (HCW) when compared with steers fed EA150. In conclusion, feeding feedlot steers diets with > 0.75 mg/kg EA caused reductions in performance and welfare concerns, although this breakpoint may be affected by duration of feeding, environmental temperatures, and EA profiles in the feed.

Methane emissions in growing heifers while eating from a feed bin compared with 24-hour emissions and relationship with feeding behavior

The objective of the current study was to determine the relationship of daily CH4 emissions estimated during mealtime compared with measured daily CH4 emissions, and determine the relationship with feeding behavior, in growing heifers fed alfalfa silage in respiration chambers. Data from 8 growing cattle (Hereford × Holstein-Friesian) individually housed in 4 respiration chambers and fed ad libitum alfalfa silage delivered in Insentec feed-bins to record feeding behavior and intake were used. The 4 chambers are linked to 1 analyzer, which measures CH4 in each chamber approximately every 3 min. Each 3-min measurement was expressed as grams per day and averaged per 24 h or per time during a meal. A strong correlation (r = 0.88; determined using Deming regression) was observed between CH4 emissions (g/d) during mealtime (276 ± 22.7 g/d) and measured over 24 h (262 ± 24.0 g/d), without apparent systematic bias. Feeding behavior parameters that were correlated with CH4 yield (g/kg dry matter intake) in the current study were a negative correlation with the number of visits to the feed bin (r = −0.45), average meal size (r = −0.57), and average daily eating rate (r = −0.48). In summary, CH4 measured during meals was similar to 24-h measured CH4 output in growing heifers fed ad libitum alfalfa silage in respiration chambers, and some feeding behavior parameters, based on feed bin visits, explained some of the variation in CH4 yield between animals.

PSIV-B-27 Effect of feed flavour on the feeding behaviour and kinetics of daily feed intake of lactating high-prolific sows during summer

Abstract Increasing voluntary feed intake of the sow is a major challenge for nutritionists in tropical climate conditions. The present study aimed to evaluate the impact of the dietary supplementation of a feed flavour for sows during lactation on their feeding behavior and kinetics of daily feed intake under tropical conditions. A total of 60 high-prolific mixed parity sows divided into 10 batches of 6 sows each were used, distributed in a completely randomized experimental design among 2 dietary treatments (0 or 500 g/ton of Krave®, Adisseo). The average meal size was 107 g/meal lower in sows fed the control diet when compared with flavour fed sows. Daily feed intake was greater in the flavored diet than in the control (6,417 vs. 5,362 g/d; P &amp;lt; 0.05). The flavor improved ingestion time (58.4 vs. 46.6 min/ d, respectively flavour and control; P &amp;lt; 0.05). Sows receiving flavor showed a higher nocturnal (704 vs. 583 g/meal) and diurnal (678 vs. 582 g/meal) feed intake. Sows also showed a higher voluntary intake between 00:00 and 10:00 am, which was equivalent to 83% of the total daily feed intake. From a comparison of hourly feed intakes or variations from hour to hour (during 24 h), the nycthemeral pattern of feed intake peaked twice daily for both dietary treatments. However, the size of the peak was greater (P &amp;lt; 0.05) for flavour fed sows when compared with the control at 0400 and 1900 h (Figure 1a). Diets also influenced on kinetics of daily feed intake during the lactation period.Feed intake was higher for the flavour fed sows from d 3 to 8 and from d 10 to 24 (Figure 1b; P &amp;lt; 0.05).In conclusion, the strategic use of a feed flavour to manipulate the sensorial properties of feed is a viable strategy to increase the sows’ voluntary feed intake.

Feed flavour supplementation improves kinetics of intake and feeding behaviour pattern of lactating sows in a tropical climate

A total of 60 mixed parity sows were used in our study to evaluate the impact of the supplementation of a feed flavour during lactation on their feeding behaviour under tropical climatic conditions. Sows were distributed in a 2 x 2 factorial experimental design: two seasons: hot and cool; and two diets: control diet and a diet with the inclusion of a feed flavour during 24 d lactation. The average relative humidity and ambient temperature for the cool season were 23.1°C and 56.5%, respectively. The corresponding values for the hot season were 26.2ºC and 70.1%. No interaction between season and diet composition was found for all traits. Daily feed intake was affected by season (P < 0.001), whereby the feed intake was lower during the hot season than in the cool season (5.66 vs. 7.23 kg/ d). The daily ingestion time was less in the hot than in the cool season (36.8 vs. 72.3 min/ d; P < 0.01) and the ingestion time per meal was also lower in the hot compared to the cool season (5.7 vs. 7.5 min/ meal; P < 0.05). The hot season also reduced (P < 0.01) rate of daily intake when compared to the cool season (36.8 vs. 72.3 g/ min). In both seasons, the proportion of total daily feed intake was higher from 00:00 to 10:00 am. The number of meals per day was not affected (P > 0.10) by dietary flavour inclusion. The average meal size was lower (P < 0.05) in sows fed the control diet when compared with flavour fed sows. Daily feed intake was greater (P < 0.01) in the flavour diet than in the control (6.42 vs. 5.36 kg/ d). The ingestion time was affected (P < 0.05) by the flavour, whereas sows from the control had a lower ingestion (58.4 vs. 46.6 min/ d). Sows receiving flavour showed a higher (P < 0.01) nocturnal (704 vs. 583 g/ meal) and diurnal (678 vs. 582 g/ meal) feed intake when compared to control fed sows. This study confirms that the feeding behaviour of the lactating sow is affected by seasonal variations of the tropical climate. Irrespective of season, the strategic use of feed flavour improved feed consumption and performance under tropical conditions.

Fractionation and Characterization of Glycol Lignins by Stepwise-pH Precipitation of Japanese Cedar/Poly(ethylene glycol) Solvolysis Liquor

Recently, we have demonstrated the initial process design of acid-catalyzed poly(ethylene glycol) (PEG) solvolysis of softwood Japanese cedar (JC) in a large-scale batch reactor (50 kg wood meal per batch) to produce PEG-modified glycol lignins (GLs) as a potential feedstock for high-value-added applications. Typically, GLs were produced by acidification (pH 2) of the alkaline JC/PEG solvolysis liquor (pH 11) obtained after the solvolysis reaction using three kinds of JC wood meal sizes (average meal size, JC-L (1.6 mm) > JC-M (0.8 mm) > JC-S (0.4 mm)) and PEG solvent molecular masses (PEG200 < PEG400 < PEG600). In this study, stepwise-pH precipitation (pH 11–8–6.5–4.5–2) was conducted using a JC/PEG solvolysis liquor to further understand the characteristics of bulk GLs. Notably, the molecular weight-dependent fractionation of four GL fractions was obtained with different fractional yields. Consequently, the contents of intermonomeric linkages and functional groups slightly varied according to the fractionation pH while exhibiting a similar chemical structure and thermal behavior to the corresponding bulk GLs. The overall thermal analysis data suggested that bulk GLs prepared from PEG400 solvolysis processes are suitable for the fabrication of melt-processed materials, such as fiber-reinforced plastics (FRPs), automobile parts, and speaker cones.

Vagal afferent nerve ghrelin signaling influences energy balance and episodic memory

Vagal afferent nerve (VAN) signaling sends sensory information from the gut to the brain and participates in the regulation of meal size and blood glucose control. Recent findings reveal that VAN signaling also plays a critical role in cognitive processes, including hippocampus(HPC)‐ dependent memory function. The nodose ganglia (VAN neurons) express receptors for various gut‐derived endocrine signals, however, the function of these receptors with regards to feeding behavior, glucose regulation, and HPC‐dependent memory is poorly understood. We hypothesized that these VAN‐mediated behavioral and physiological processes are influenced by ghrelin, a stomach‐derived orexigenic hormone, via communication to its receptor (growth hormone secretagogue receptor [GHSR]) expressed on gut‐innervating VAN terminals. To examine this hypothesis, adult male rats received bilateral nodose ganglion injections of an adeno‐associated virus (AAV) expressing short hairpin RNAs targeting GHSR (or a scrambled control AAV) for RNA interference‐mediated VAN GHSR knockdown. Meal‐pattern analyses revealed a significant increase in meal frequency in the VAN GHSR knockdown group compared with controls, coupled with a nonsignificant trend in reduced average meal size such that cumulative 24h food intake did not differ between groups. Results from an intraperitoneal glucose tolerance test revealed impaired glucose tolerance in VAN GHSR knockdown animals vs. controls. Despite no differences in cumulative 24h food intake, the VAN GHSR knockdown group also had significantly increased body weight gain compared with controls. Lastly, to examine the role of VAN GHSR signaling in HPC‐dependent memory function, the rats were tested in novel object in context task that measures contextual episodic memory. Results reveal that VAN GHSR knockdown impairs memory performance in this task, yet has no effect on measures of anxiety‐like behavior or levels of general activity. Collectively, these results reveal that VAN GHSR signaling is important for the control of both energy balance as well as HPCdependent memory function.

Effect of Heat Treatment on the Chemical Structure and Thermal Properties of Softwood-Derived Glycol Lignin.

A large-scale glycol lignin (GL) production process (50 kg wood meal per batch) based on acid-catalyzed polyethylene glycol (PEG) solvolysis of Japanese cedar (JC) was developed at the Forestry and Forest Products Research Institute (FFPRI), Tsukuba, Japan. JC wood meal with various particle size distributions (JC-S < JC-M < JC-L) (average meal size, JC-S (0.4 mm) < JC-M (0.8 mm) < JC-L (1.6 mm)) and liquid PEG with various molecular masses are used as starting materials to produce PEG-modified lignin derivatives, namely, GLs, with various physicochemical and thermal properties. Because GLs are considered a potential feedstock for industrial applications, the effect of heat treatment on GL properties is an important issue for GL-based material production. In this study, GLs obtained from PEG400 solvolysis of JC-S, JC-M, and JC-L were subjected to heating in a constant-temperature drying oven at temperatures ranging from 100 to 220 °C for 1 h. All heat-treated GL series were thermally stable, as determined from the Klason lignin content, TMA, and TGA analyses. SEC analysis suggests the possibility of condensation among lignin fragments during heat treatment. ATR-FTIR spectroscopy, thioacidolysis, and 2D HSQC NMR demonstrated that a structural rearrangement occurs in the heat-treated GL400 samples, in which the content of α–PEG-β–O-4 linkages decreases along with the proportional enrichments of β–5 and β–β linkages, particularly at treatment temperatures above 160 °C.

Relation between feeding behaviour and energy metabolism in pigs fed diets enriched in dietary fibre and wheat aleurone

Feed intake and its daily pattern are regulated both at a short and a long term by several control pathways, including energy balance regulation. This trial aimed to determine the effect of dietary fibre (DB) (mix of wheat, soy and sugar beet pulp fibres) and aleurone supplementation and their interaction on energy and nitrogen balances in growing pigs with ad libitum access to feed. Forty pigs (BW: 35 kg) were fed diets differing by fibre concentration (NDF concentration: 10% or 14% DM) and aleurone supplementation (0, 2 or 4 g/kg) during 3 weeks. Pigs were housed individually in a respiration chamber during the last week to record feeding behaviour and measure energy and nitrogen balances (n = 36). Glucose oxidation was studied on the 6th day with an injection of [U-13C] glucose and measurement of 13CO2 production. There was no significant interaction between DB inclusion and aleurone supplementation on any variables characterizing feeding behaviour. Pigs had less but longer meals with high level of DB, with an increased interval between two meals without effect on daily feed intake. The meal frequency significantly decreased when aleurone supplementation increased. Total tract apparent digestibility coefficient of DM, organic matter, ash, nitrogen and gross energy decreased when pigs received high DB level. Dietary fibre level increased significantly faecal excreted nitrogen. Aleurone supplementation decreased nitrogen retention. Free access to the feed induced a great individual variability not only in feed intake level (from 784 to 2290 g/day) but also in feeding behaviour (from 5.5 to 21.5 meals per day). This variability can be linked with the importance of underlying feed intake regulation pathways and difference in energy balance and metabolism efficiency. Several profiles of metabolism efficiency can be discriminate, thanks to a clustering based on feeding behaviour and pre-prandial concentrations of metabolites and hormones. In conclusion, DB inclusion decreased meal frequency, increased average meal size, decreased total tract apparent faecal digestibility coefficient of nitrogen and gross energy. Supplementation of aleurone decreased average daily feed intake with a reduction of the meal number per day, without modification of average meal size. Aleurone supplementation decreased nitrogen retention and nutrient deposition. Independently of experimental diets, the high individual variability permitted discriminating different profiles with different metabolic strategies. Efficient pigs with a high energy retention as protein and lipid seem to be able to adapt their metabolism according to energy sources.

Foraging mode, relative prey size and diet breadth: A phylogenetically explicit analysis of snake feeding ecology.

Foraging modes (ambush vs. active foraging) are often correlated with a suite of morphological, physiological, behavioural and ecological traits known as the "adaptive syndrome" or "syndrome hypothesis." In snakes, an ecological correlate often reported in the literature is that ambush-hunting snakes have a higher relative meal size compared to actively foraging snakes which feed on smaller prey items. This "large meal versus small meal" feeding hypothesis between ambush and active foragers has become a widely accepted paradigm of snake feeding ecology, despite the fact that no rigorous meta-analysis has been conducted to support this generalization. We conducted a phylogenetically explicit meta-analysis, which included ca. 100 species, to test this paradigm of snake feeding ecology. We gathered data on prey size by inducing regurgitation by palpation in free-ranging snakes and by examining the stomach contents of preserved museum specimens. When we found prey, we recorded both snake and prey mass to estimate relative prey mass (prey mass/snake mass). We also reviewed published studies of snake feeding ecology to gather similar information for other species. Ambush and active foragers did not differ in minimum or average meal size but the maximum meal sizes consumed by ambush-foraging snakes were larger than the maximum meal sizes eaten by active foragers. This results in ambush-foraging snakes consuming a significantly wider range of meal sizes, rather than being large meal specialists compared to active foragers. We argue that ambush foragers evolved to be more opportunistic predators because they encounter prey less frequently compared to active foragers. This hypothesis is further supported by the fact that ambush foragers also exhibited marginally wider diet breadths, consuming a broader range of prey types in comparison with active foragers. Our study challenges aspects of the foraging syndrome as it is currently conceived, and our results have important implications for our understanding of how foraging mode has shaped the behaviour and physiology of ambush-foraging snakes.

Endogenous GLP-1 in lateral septum contributes to stress-induced hypophagia.

Glucagon-like peptide 1 (GLP-1) neurons of the caudal brainstem project to many brain areas, including the lateral septum (LS), which has a known role in stress responses. Previously, we showed that endogenous GLP-1 in the LS plays a physiologic role in the control of feeding under non-stressed conditions, however, central GLP-1 is also involved in behavioral and endocrine responses to stress. Here, we asked whether LS GLP-1 receptors (GLP-1R) contribute to stress-induced hypophagia. Male rats were implanted with bilateral cannulas targeting the dorsal subregion of the LS (dLS). In a within-subjects design, shortly before the onset of the dark phase, rats received dLS injections of saline or the GLP-1R antagonist Exendin (9-39) (Ex9) prior to 30 min restraint stress. Food intake was measured continuously for the next 20 h. The stress-induced hypophagia observed within the first 30 min of dark was not influenced by Ex9 pretreatment, but Ex9 tended to blunt the effect of stress as early as 1 and 2 h into the dark phase. By 4-6 h, there were significant stress X drug interactions, and Ex9 pretreatment blocked the stress-induced suppression of feeding. These effects were mediated entirely through changes in average meal size; stress suppressed meal size while dLS Ex9 attenuated this effect. Using a similar design, we examined the role of dLS GLP-1R in the neuroendocrine response to acute restraint stress. As expected, stress potently increased serum corticosterone, but blockade of dLS GLP-1Rs did not affect this response. Together, these data show that endogenous GLP-1 action in the dLS plays a role in some but not all of the physiologic responses to acute stress.

Self-reported protein intake and properties of bone in community-dwelling older individuals

SummaryThis study revealed that a quick and simple estimation of protein intake was related to measures of bone density and area in 70-year-old individuals. Furthermore, these associations were mediated by muscle mass when investigating peripheral measurement sites such as arms and legs.PurposeRecent evidence suggests that dietary protein is beneficial for bone health in older individuals, but less is known about the influence of muscle mass on this relationship. This cross-sectional study aimed to investigate associations among protein intake, bone health, and muscle mass in 2332 men and women aged 70 years.MethodsVolumetric bone mineral density of the radius and tibia was measured using peripheral quantitative computed tomography. Using dual-energy X-ray absorptiometry, we measured areal bone mineral density (aBMD) at the L1–L4 vertebrae, radius, and femoral neck, together with appendicular lean mass. Participants reported their average meal size and proportion of meat/fish intake. Associations were investigated using multiple linear regression models, adjusted for multiple covariates.ResultsSelf-reported protein intake was associated with aBMD of the femoral neck (β = 0.082) and L1–L4 vertebrae (β = 0.063) in men (both p < 0.05) after adjusting for multiple covariates, including appendicular muscle mass. No significant association was detected among women. In addition, protein intake was associated with tibial cortical area (β = 0.08), periosteal circumference (β = 0.072), radial aBMD (β = 0.064), and trabecular area (β = 0.078) in men (all p < 0.05), although these associations were attenuated after adjustment for appendicular muscle mass (all p > 0.05).ConclusionSelf-reported protein intake was associated with bone properties in 70-year-old men. The strength of these associations in peripheral bone sites may be partially mediated by muscle mass from protein intake.

Glucagon-Like Peptide-1 Receptor Signaling in the Lateral Dorsal Tegmental Nucleus Regulates Energy Balance.

The neurobiological substrates that mediate the anorectic effects of both endogenous glucagon-like peptide-1 (GLP-1) and exogenous GLP-1 receptor (GLP-1R) agonists are an active area of investigation. As the lateral dorsal tegmental nucleus (LDTg) expresses the GLP-1R and represents a potential neuroanatomical hub connecting the nucleus tractus solitarius (NTS), the major central source of GLP-1, with the other nuclei in the midbrain and forebrain, we tested the hypothesis that GLP-1R signaling in the LDTg controls food intake. Direct activation of LDTg GLP-1R suppresses food intake through a reduction in average meal size and independent of nausea/malaise. Immunohistochemical data show that GLP-1-producing neurons in the NTS project to the LDTg, providing anatomical evidence of endogenous central GLP-1 in the LDTg. Pharmacological blockade of LDTg GLP-1Rs with exendin-(9-39) dose-dependently increases food intake and attenuates the hypophagic effects of gastric distension. As GLP-1 mimetics are administered systemically in humans, we evaluated whether peripherally administered GLP-1R agonists access the LDTg to affect feeding. Immunohistochemical data show that a systemically administered fluorescent GLP-1R agonist accesses the LDTg and is juxtaposed with neurons. Additionally, blockade of LDTg GLP-1Rs attenuates the hypophagic effects of a systemic GLP-1R agonist. Together, these data indicate that LDTg GLP-1R signaling controls energy balance and underscores the role of the LDTg in integrating energy balance-relevant signals to modulate feeding.

Peripheral endocannabinoid signaling controls hyperphagia in western diet-induced obesity

The endocannabinoid system in the brain and periphery plays a major role in controlling food intake and energy balance. We reported that tasting dietary fats was met with increased levels of the endocannabinoids, 2-arachidonoyl-sn-glycerol (2-AG) and anandamide, in the rat upper small intestine, and pharmacological inhibition of this local signaling event dose-dependently blocked sham feeding of fats. We now investigated the contribution of peripheral endocannabinoid signaling in hyperphagia associated with chronic consumption of a western-style diet in mice ([WD] i.e., high fat and sucrose). Feeding patterns were assessed in male C57BL/6Tac mice maintained for 60days on WD or a standard rodent chow (SD), and the role for peripheral endocannabinoid signaling at CB1Rs in controlling food intake was investigated via pharmacological interventions. In addition, levels of the endocannabinoids, 2-AG and anandamide, in the upper small intestine and circulation of mice were analyzed via liquid chromatography coupled to tandem mass spectrometry to evaluate diet-related changes in endocannabinoid signaling and the potential impact on food intake. Mice fed WD for 60days exhibited large increases in body weight, daily caloric intake, average meal size, and rate of feeding when compared to control mice fed SD. Inhibiting peripheral CB1Rs with the peripherally-restricted neutral cannabinoid CB1 receptor antagonist, AM6545 (10mg/kg), significantly reduced intake of WD during a 6h test, but failed to modify intake of SD in mice. AM6545 normalized intake of WD, average meal size, and rate of feeding to levels found in SD control mice. These results suggest that endogenous activity at peripheral CB1Rs in WD mice is critical for driving hyperphagia. In support of this hypothesis, levels of 2-AG and anandamide in both, jejunum mucosa and plasma, of ad-libitum fed WD mice increased when compared to SC mice. Furthermore, expression of genes for primary components of the endocannabinoid system (i.e., cannabinoid receptors, and endocannabinoid biosynthetic and degradative enzymes) was dysregulated in WD mice when compared to SC mice. Our results suggest that hyperphagia associated with WD-induced obesity is driven by enhanced endocannabinoid signaling at peripheral CB1Rs.

Determination of Minimum Meal Interval and Analysis of Feeding Behavior in Shaded and Open-Lot Feedlot Heifers

Abstract. Feeding behavior contains valuable information that can be useful for managing livestock, identifying sick animals, and determining genetic differences within a herd. The objectives of this work were to determine the minimum meal interval and to assess changes in feeding behavior of feedlot heifers when exposed to various temperatures with and without access to shade. Feeding behavior data from feedlot cattle with and without access to shade were evaluated. Prior to evaluating feeding behavior data, the time between two eating events that should be considered a single meal (minimum meal interval) was determined. The length of this minimum meal interval impacts the interpretation of meal data. The minimum meal interval was first determined by analyzing feeding behavior data to determine the number of meals, average meal length, and total time spent eating at minimum meal intervals ranging from 1 to 60 min. These data were evaluated using rate of change based on interval differencing. A subsequent analysis identified the inflection point of the rate of change graph. A minimum meal interval of 10 min for finishing feedlot cattle was determined using this method. Feeding behavior data from 256 feedlot heifers (of four different breed types) were evaluated over two summer periods (128 heifers each year). Cattle were penned in one of 16 pens (eight shaded and eight unshaded). Individual feeding behavior data were collected every 30 s throughout the six-week summer period. Cattle decreased the time spent eating, average meal size, and number of meals as the THI increased. In addition, cattle provided with shade spent more time eating, with longer meal lengths over all THI categories.

Optimising translocation efforts of Mottled Petrels (Pterodroma inexpectata): growth, provisioning, meal size and the efficacy of an artificial diet for chicks

In an effort to promote population recovery, translocations of the endemic Mottled Petrel (Pterodroma inexpectata) from remote offshore islands to the mainland are planned within New Zealand. To optimise these efforts we studied chick growth, adult provisioning and meal size for this species and report the results of a simulated translocation undertaken to assess how translocated chicks, fed an artificial diet, performed in comparison with handled and non-handled controls that were provisioned by their parents. Our results found that wing-chord length and chick mass did not differ between translocated and control chicks, with all chicks fledging at approximately the same mass and wing size ranges. There was no difference in the timing of emergence from burrows before fledging between control and translocated chicks. The probability of a chick receiving a meal each night declined as chicks approached fledging and average meal size did not change as chicks approached fledging. From these data we now have the basis with which to make recommendations to increase the success of future translocation efforts for Mottled Petrels. It is important to share any knowledge of the biology and ecology of gadfly petrels, and any successes or failures in translocation practices in order to promote the best possible chance of future conservation of these species.

Leptin receptor signaling in the lateral parabrachial nucleus contributes to the control of food intake.

Pontine parabrachial nucleus (PBN) neurons integrate visceral, oral, and other sensory information, playing an integral role in the neural control of feeding. Current experiments probed whether lateral PBN (lPBN) leptin receptor (LepRb) signaling contributes to this function. Intra-lPBN leptin microinjection significantly reduced cumulative chow intake, average meal size, and body weight in rats, independent of effects on locomotor activity or gastric emptying. In contrast to the effects observed following LepRb activation in other nuclei, lPBN LepRb stimulation did not affect progressive ratio responding for sucrose reward or conditioned place preference for a palatable food. Collectively, results suggest that lPBN LepRb activation reduces food intake by modulating the neural processing of meal size/satiation signaling, and highlight the lPBN as a novel site of action for leptin-mediated food intake control.

Fish consumption behavior and rates in native and non-native people in Saudi Arabia

Fish are a healthy source of protein and nutrients, but contaminants in fish may provide health risks. Determining the risk from contaminants in fish requires site-specific information on consumption patterns. We examine consumption rates for resident and expatriates in the Jeddah region of Saudi Arabia, by species of fish and fishing location. For Saudis, 3.7% of males and 4.3% of females do not eat fish; for expatriates, the percent not eating fish is 6.6% and 6.1% respectively. Most people eat fish at home (over 90%), and many eat fish at restaurants (65% and 48%, respectively for Saudis and expatriates). Fish eaten at home comes from local fish markets, followed by supermarkets. Saudis included fish in their diets at an average of 1.4±1.2 meals/week at home and 0.8±0.7 meals/week at restaurants, while expats ate 2.0±1.7 meals/week at home and 1.1±1.1 meals/week in restaurants. Overall, Saudis ate 2.2 fish meals/week, while expats ate 3.1 meals/week. Grouper (Epinephelus and Cephalopholis) were eaten by 72% and 60% respectively. Plectropomus pessuliferus was the second favorite for both groups and Hipposcarus harid and Lethrinus lentjan were in 3rd and 4th place in terms of consumption. Average meal size was 68g for Saudis and 128g for expatriates. These data can be used by health professionals, risk assessors, and environmental regulators to examine potential risk from contaminants in fish, and to compare consumption rates with other sites.

Analyses of meal patterns across dietary shifts

The direct controls of meal size can be categorized into positive signals such as those from the oral cavity and negative signals such as postoral inhibitory cues. It follows that the relative contribution of these signals, and in turn meal pattern parameters, change across periods of high-energy diet exposure. Here, we compared daily intake and meal pattern analysis in male Sprague–Dawley rats presented a high-energy diet for 6weeks then standard chow for ∼1week (HE), with those of standard chow fed controls (CHOW). These measures allow for evaluation of (1) whether there are distinct dynamic and static phases of DIO and if so, how they are characterized, (2) how meal patterns change across short and long term HE experience, and (3) ingestive behavioral changes when HE-fed animals are returned to standard chow. The HE animals showed significantly higher intake primarily driven by an increase in meal size compared to CHOW controls. This was most pronounced during the first several days of high-energy diet exposure thus characterizing the dynamic phase. Intake and meal size decreased with longer exposure to the diet but remained significantly higher than those of CHOW. Increased meal size could be driven by enhanced orosensory stimulation and/or reduced sensitivity to postoral inhibitory feedback. Distribution curves derived from histogram plots of meal size revealed both larger average meal size (right shift) and spread (standard deviation) thus it is tempting to speculate that more than one type of mechanism influences increased meal size. Meal number decreased suggesting post meal inhibitory signaling is relatively intact. However, this increase was insufficient to compensate for the increased meal size. When HE animals were switched to standard chow, daily intake and meal size decreased and eventually returned to values comparable to those of the CHOW rats. Meal number remained lower suggesting altered physiological mechanism(s) that underlie the control of ingestive behavior as a function of previous high-energy diet exposure.

5-HT1A receptor antagonists reduce food intake and body weight by reducing total meals with no conditioned taste aversion

Serotonin acts through receptors controlling several physiological functions, including energy homeostasis regulation and food intake. Recent experiments demonstrated that 5-HT1A receptor antagonists reduce food intake. We sought to examine the microstructure of feeding with 5-HT1A receptor antagonists using a food intake monitoring system. We also examined the relationship between food intake, inhibition of binding and pharmacokinetic (PK) profiles of the antagonists. Ex vivo binding revealed that, at doses used in this study to reduce food intake, inhibition of binding of a 5-HT1A agonist by ~40% was reached in diet-induced obese (DIO) mice with a trend for higher binding in DIO vs. lean animals. Additionally, PK analysis detected levels from 2 to 24h post-compound administration. Male DIO mice were administered 5-HT1A receptor antagonists LY439934 (10 or 30mg/kg, p.o.), WAY100635 (3 or 10mg/kg, s.c.), SRA-333 (10 or 30mg/kg, p.o.), or NAD-299 (3 or 10mg/kg, s.c.) for 3days and meal patterns were measured. Analyses revealed that for each antagonist, 24-h food intake was reduced through a specific decrease in the total number of meals. Compared to controls, meal number was decreased 14–35% in the high dose. Average meal size was not changed by any of the compounds. The reduction in food intake reduced body weight 1–4% compared to Vehicle controls. Subsequently, a conditioned taste aversion (CTA) assay was used to determine whether the feeding decrease might be an indicator of aversion, nausea, or visceral illness caused by the antagonists. Using a two bottle preference test, it was found that none of the compounds produced a CTA. The decrease in food intake does not appear to be a response to nausea or malaise. These results indicate that 5-HT1A receptor antagonist suppresses feeding, specifically by decreasing the number of meals, and induce weight loss without an aversive side effect.

Role of self-caught fish in total fish consumption rates for recreational fishermen: average consumption for some species exceeds allowable intake

Studies of fish consumption focus on recreational or subsistence fishing, on awareness and adherence to advisories, consumption patterns, and contaminants in fish. Yet the general public obtains their fish from commercial sources. In this paper I examine fish consumption patterns of recreational fishermen in New Jersey to determine: (1) consumption rates for self-caught fish and for other fish, (2) meals consumed per year, (3) average meal size, and average daily intake of mercury, and (4) variations in these parameters for commonly-consumed fish, and different methods of computing intake. Over 300 people were interviewed at fishing sites and fishing clubs along the New Jersey shore. Consumption patterns of anglers varied by species of fish. From 2 to 90% of the anglers ate the different fish species, and between 9 and 75% gave fish away to family or friends. Self-caught fish made up 7–92% of fish diets depending upon species. On average, self-caught fish were eaten for only 2–6 months of the year, whereas other fish (commercial or restaurant) were eaten up to 10 months a year. Anglers consumed from 5 to 36 meals of different fish a year, which resulted in intake of mercury ranging from 0.01 to 0.22 μg/kg/day. Average intake of Mako shark, swordfish, and tuna (sushi, canned tuna, self-caught tuna) exceeded the US Environmental Protection Agency’s oral, chronic reference dose for mercury of 0.1 μg/kg/day. However, computing intake using consumption for the highest month results in average mercury intake exceeding the reference dose for striped bass and bluefish as well. These data, and the variability in consumption patterns, have implications for risk assessors, risk managers, and health professionals.