Meal Size Research Articles

The effect of feeding and visiting behavior on methane and hydrogen emissions of dairy cattle measured with the GreenFeed system under different dietary conditions

The objectives were to investigate the effect of feeding and visiting behavior of dairy cattle on CH4 and H2 production measured with voluntary visits to the GreenFeed system (GF) and to determine whether these effects depended on basal diet (BD) and 3-nitrooxypropanol (3-NOP) supplementation. The experiment involved 64 lactating dairy cattle (146 ± 45 d in milk at the start of trial; mean ± SD) in 2 overlapping crossover trials, each consisting of 2 measurement periods. Cows within block were randomly allocated to 1 of 3 types of BD: a grass silage-based diet consisting of 30% concentrates and 70% grass silage (DM basis), a grass silage- and corn silage-mixed diet consisting of 30% concentrates, 42% grass silage, and 28% corn silage (DM basis), or a corn silage-based diet consisting of 30% concentrates, 14% grass silage, and 56% corn silage (DM basis). Each type of BD was subsequently supplemented with 0 and 60 mg 3-NOP/kg DM in one crossover, or 0 and 80 mg 3-NOP/kg DM in the other crossover. Diets were provided in feed bins which automatically recorded feed intake and feeding behavior, with additional concentrate fed in the GF. All visits to the GF that resulted in a spot measurement of both CH4 and H2 emission were analyzed in relation to feeding behavior (e.g., meal size and time interval to preceding meal) as well as GF visiting behavior (e.g., duration of visit). Feeding and GF visiting behavior was related to CH4 and H2 production measured with the GF, in particular the meal size before a GF measurement and the time interval between a GF measurement and the preceding meal. Relationships between gas production and both feeding and GF visiting behavior were affected both by type of BD and 3-NOP supplementation. With an increase of the time interval between a GF measurement and the preceding meal, CH4 production decreased with 0 mg 3-NOP/kg DM but increased with 60 and 80 mg 3-NOP/kg DM, whereas type of BD did not affect these relationships. In contrast, CH4 production increased with 0 mg 3-NOP/kg DM but decreased with 60 and 80 mg 3-NOP/kg DM upon an increase in the size of the meal preceding a GF measurement. With an increase of the time interval between a GF measurement and the preceding meal, or with a decrease of the size of the meal preceding a GF measurement, H2 production decreased for all treatments, although the effect was generally somewhat stronger for 60 and 80 mg 3-NOP/kg DM than for 0 mg 3-NOP/kg DM. Hence, the timing of GF measurements next to feeding and GF visiting behavior are essential when assessing the effect of dietary treatment on the production of CH4 and H2 in a setting where a spot sampling device such as a GF is used and where the measurements depend on voluntary visits from the cows.

Modeling the effect of ambient temperature on reticulorumen temperature, and drinking and eating behaviors of late-lactation dairy cows during colder seasons

Dairy cows may suffer thermal stress during the colder seasons especially due to their open-air housing systems. Free water temperature (FWT) and feed temperature (FT) are dependent on ambient temperature (AT) and can be critical for maintaining body and reticulorumen temperature (RT) in cold conditions. The objective of this study was to determine the effects of FWT and FT on RT fluctuations, and of AT on RT and drinking and eating behaviors in late-lactation cows during cold exposure. Data were collected from 16 multiparous lactating cows for four 6-d periods during the autumn and winter seasons. The cows (224 ± 36 days in milk; mean ± SD) had an average milk yield (MY) of 24.8 ± 4.97 kg/d and RT of 38.84 ± 0.163 °C. Daily average AT ranged from 4.38 to 17.25 °C. The effects of the temperature and amount of the ingested water or feed on RT change and recovery time, and the effect of the daily AT on RT, feed and water intake, and drinking, eating, and rumination behaviors were analyzed using the generalized additive mixed model framework. Reticulorumen temperature change and recovery time were affected by FWT (+0.0596 °C/°C and −1.27 min/°C, respectively), but not by FT. The amount of the ingested free water and feed affected RT change (−0.108 °C/kg drink size and −0.150 °C/kg meal size, respectively), and RT recovery time (+2.13 min/kg drink size and + 3.71 min/kg meal size, respectively). Colder AT decreased RT by 0.0151 °C/°C between 9.91 and 17.25 °C AT. Cows increased DM intake (DMI) by 0.365 kg/d per 1 °C drop in AT below 10.63 °C, but with no increase in MY. In fact, MY:DMI decreased by 0.0106/°C as AT dropped from 17.25 to 4.38 °C. Free water intake (FWI) was reduced by 0.0856 FWI:DMI/°C as AT decreased from 17.25 to 8.27 °C. Cold exposure influenced animal behavior with fewer drink and meal bouts (−0.432 and −0.290 bouts/d, respectively), larger drink sizes (+0.100 kg/bout), and shorter rumination time (−5.31 min/d) per 1 °C decrease in AT from 17.25 °C to 8.77, 12.53, 4.38, and 10.32 °C, respectively. In conclusion, exposure to low AT increased feed intake, reduced water intake, and changes in eating, drinking and rumination behaviors of dairy cows in late lactation. Additionally, the consequences of cold exposure on cows may be aggravated by ingestion of feed and free water at temperatures lower than the body, potentially impacting feed efficiency due to the extra energetic cost of thermoregulation.

Unraveling the Variability of Human Satiation: Implications for Precision Obesity Management.

Satiation is the physiologic process that regulates meal size and termination, and it is quantified by the calories consumed to reach satiation. Given its role in energy intake, changes in satiation contribute to obesity's pathogenesis. Our study employed a protocolized approach to study the components of food intake regulation including a standardized breakfast, a gastric emptying study, appetite sensation testing, and a satiation measurement by an ad libitummeal test. These studies revealed that satiation is highly variable among individuals, and while baseline characteristics, anthropometrics, body composition and hormones, contribute to this variability, these factors do not fully account for it. To address this gap, we explored the role of a germline polygenic risk score, which demonstrated a robust association with satiation. Furthermore, we developed a machine-learning-assisted gene risk score to predict satiation and leveraged this prediction to anticipate responses to anti-obesity medications. Our findings underscore the significance of satiation, its inherent variability, and the potential of a genetic risk score to forecast it, ultimately allowing us to predict responses to different anti-obesity interventions.

Effects of Dietary Factors on Gastroesophageal Reflux Disease (GERD) Among the Student and Faculty of Public and Private Medical Universities of Karachi, Pakistan

Aim: Gastroesophageal reflux disease (GERD) results from gastric contents moving into the esophagus, causing distressing symptoms and complications. Its prevalence has surged in the past two decades, notably in Asian countries. While nutritional management is common in clinical practice, definitive recommendations remain unclear. Few studies have explored the link between food and GERD. Methods: We conducted a descriptive cross-sectional study involving 359 eligible subjects out of 405 participants. We employed purposive sampling, targeting medical students, teachers, and staff aged 18 to 60 from four universities. Data were analyzed using SPSS version 26.0 with a confidence interval of 95% and a significance threshold of p < 0.05. Results: Among participants, 56.5% were female, with an average age of 24.55. Notably, 70.4% tested positive for GERD. Trigger foods included oily (24.2%) and spicy (45.4%) items, while 24.2% reported no specific triggers. Conclusion: This study underscores the significance of dietary modifications in managing GERD symptoms. Tailoring diets to individual symptoms and adjusting meal size, timing, and composition offer more benefits than elimination diets, particularly focusing on smaller meals and avoiding late-night eating habits. Keywords: Gastroesophageal reflux disease (GERD), reflux, esophageal disease, diet, nutrition, food intake, heartburn, fast-food.

Meal effects on gastric bioelectrical activity utilizing body surface gastric mapping in healthy subjects.

Gastric sensorimotor disorders are prevalent. While gastric emptying measurements are commonly used, they may not fully capture the underlying pathophysiology. Body surface gastric mapping (BSGM) recently emerged to assess gastric sensorimotor dysfunction. This study assessed varying meal size on BSGM responses to inform test use in a wider variety of contexts. Data from multiple healthy cohorts receiving BSGM were pooled, using four different test meals. A standard BSGM protocol was employed: 30-min fasting, 4-h post-prandial, using Gastric Alimetry® (Alimetry, New Zealand). Meals comprised: (i) nutrient drink + oatmeal bar (482 kcal; 'standard meal'); (ii) oatmeal bar alone; egg and toast meal, and pancake (all ~250 kcal). Gastric Alimetry metrics included BMI-adjusted Amplitude, Principal Gastric Frequency, Gastric Alimetry Rhythm Index (GA-RI) and Fed:Fasted Amplitude Ratio (ff-AR). 238 participants (59.2% female) were included. All meals significantly increased amplitude and frequency during the first postprandial hour (p < 0.05). There were no differences in postprandial frequency across meals (p > 0.05). The amplitude and GA-RI of the standard meal (n = 110) were significantly higher than the energy bar alone (n = 45) and egg meal (n = 65) (all p < 0.05). All BSGM metrics were comparable across the three smaller meals (p > 0.05). A higher symptom burden was found in the oatmeal bar group versus the standard meal and pancake meal (p = 0.01, 0.003, respectively). The consumption of lower calorie meals elicited different postprandial responses, when compared to the standard Gastric Alimetry meal. These data will guide interpretations of BSGM when applied with lower calorie meals.

Not feeling the heat? Effects of dietary protein on satiation and satiety in mice are not due to its impact on body temperature

Dietary protein modulates food intake (FI) via unclear mechanism(s). One possibility is that higher protein leads to greater post-ingestive heat production (Specific dynamic action: SDA) leading to earlier meal termination (increased satiation), and inhibition of further intake (increased satiety). The influence of dietary protein on feeding behaviour in C57BL/6J mice was tested using an automated FI monitoring system (BioDAQ), simultaneous to body temperature (Tb). Total FI, inter meal intervals (IMI, satiety) and meal size (MS, satiation) were related to changes in Tb after consuming low (5%, LP), moderate (15%, MP) and high (30%, HP) protein diets. Diets were tested over three conditions: 1) room temperature (RT, 21 ± 1 °C), 2) room temperature and running wheels (RTRW) and 3) low temperature (10 °C) and running wheels (LTRW). The differences between diets and conditions were also compared using mixed models. Mice housed at RT fed HP diet, reduced total FI compared with LP and MP due to earlier meal termination (satiation effect). FI was lowered in RTRW conditions with no differences between diets. FI significantly increased under LTRW conditions for all diets, with protein content leading to earlier meal termination (satiation) but not the intervals between feeding bouts (satiety). Tb fell immediately after feeding in all conditions. Despite a reduction in total FI in mice fed HP, mediated via increased satiation, this effect was not linked to increased Tb during meals. We conclude effects of dietary protein on intake are not mediated via SDA and Tb.

PSIV-A-8 Effects of meal frequency on heart rate in horses

Abstract In humans, meal size has been shown to affect heart function with meal ingestion being associated with an increase in heart rate (HR) and cardiac output lasting significantly longer when larger meals are consumed. In horses, HR spikes at the sight of feed due to anticipation, but no studies have specifically evaluated the effect of meal frequency or size on HR. Heart rate has also been used as a measure both positive and negative stress. Domesticated horses are often meal fed, with small frequent meals requiring more labor than large infrequent meals. Fewer larger meals may have negative welfare implications for a grazing species. As part of a larger project investigating the effects of meal frequency on the behavior and metabolism of horses, the objective of this study was to evaluate equine HR in response to feeding frequencies commonly practiced in the field [once (1x), twice (2x), or thrice (3x) per day]. Feeding times were at 0800 (1x, 2x, and 3x), 1300 (3x), and 1800 (2x and 3x) h. The 12 adult clinically healthy horses [average ± SD; 14 ± 6 yr and 572 ± 32 kg body weight (BW)] were separated into two equal groups before completing a 14-d acclimation period to the diet during which they were fed 2x. The diet was provided at 2% BW on a dry matter (DM) basis (1.55% BW grass hay in a slow feed hay net plus 0.45% BW complementary fortified feed). During the study the same diet was fed but the meal frequency, and therefore meal size, differed between the treatments. The order of treatments, lasting 1 wk each, was decided at random for each group. On d 6 of each treatment HR was measured using individual H10 Polar HR monitors, which recorded every second from 0700 to 1900 h yielding 1,514,799 data points. During this time the aisleways housing the stalled horses were blocked off to minimize exposure to human presence other than at feeding time(s). After removing outliers, the mode was calculated for HR of each horse, which was considered to be the resting HR for that horse and ranged from 31 to 46 beats/min. The percentage of data above, below, or at the mode was calculated for each horse over the 12 h period and evaluated using Chi Square tests for statistical significance. The proportion of HR values above, below, or at the mode differed between treatments (P = 0.02). When fed 1x, 69 ± 14% of the HR readings were above the mode on average, as compared with 42 ± 18% and 44 ± 18% for 2x and 3x, respectively. These results suggest that the increase in HR was more than anticipatory and that there may be sustained stress when horses are fed at fewer frequency, such as once daily.

The role of pituitary adenylate cyclase-activating polypeptide neurons in the hypothalamic ventromedial nucleus and the cognate PAC1 receptor in the regulation of hedonic feeding

We explored the role of pituitary adenylate cyclase-activating polypeptide (PACAP) neurons in the hypothalamic ventromedial nucleus (VMN) in regulating hedonic feeding. We hypothesized that VMN PACAP neurons would inhibit reward-encoding mesolimbic (A10) dopamine neurons and thereby suppress impulsive consumption brought on by intermittent exposure to highly palatable food. Visualized whole-cell patch clamp recordings coupled with in vivo behavioral experiments were utilized in wildtype, PACAP- cre, TH- cre and TH- cre/PAC1 receptor-floxed mice. We found that optogenetic stimulation of VMN PACAP neurons inhibited postsynaptic targets in the ventral tegmental area (VTA), an effect replicated by bath application of exogenous PACAP during recordings from preidentified A10 dopamine neurons. These inhibitory actions were abrogated by the PAC1/VPAC2 receptor antagonist PACAP6-38, the KATP channel blocker tolbutamide, and by selective knockdown of the PAC1 receptor in A10 dopamine neurons. PACAP delivered directly into the VTA decreases binge feeding accompanied by reduced meal size and duration. These effects are negated by PACAP6-38, PAC1 receptor knockdown in A10 dopamine neurons, and apoptotic ablation of VMN PACAP neurons. These findings demonstrate that VMN PACAP neurons blunt impulsive, binge feeding behavior by activating PAC1 receptors and KATP channels to inhibit A10 dopamine neurons. As such, they impart impactful insight into potential treatment strategies for conditions such as obesity and food addiction. Work funded by PHS grant DA024314. Work funded by PHS grant DA024314. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Gastrointestinal release site for delayed release and gelatin capsules in healthy dogs.

Gelatin capsules deliver their contents to the stomach, while delayed-release (DR) capsules are designed to allow delivery to the small intestine. This study evaluated the gastrointestinal release site of DR capsules in six healthy adult dogs compared to gelatin capsules. Both gelatin and DR capsules were filled with barium-impregnated polyethylene spheres (BIPS™), and following enteral administration, release site was assessed using abdominal radiographs at baseline, immediately after ingestion, 15 min post-ingestion, 30 min post-ingestion, and then every 30 min thereafter. The evaluated phases included fasted conditions (phase 1, n = 6), increased meal size (phase 2, n = 2), double encapsulation (phase 3, n = 2), and altered capsule size (phase 4, n = 1). The released site was the stomach in all phases for both capsule types. In phase 1, DR capsules had a significantly prolonged time (median 60 min, range 60-90) to release BIPS™ compared to gelatin capsules (15 min, range 15-30; p = .03). In phase 2 (full meal size), 3 (double encapsulation), and 4 (smaller capsule size) pilot studies, release time was prolonged but still occurred in the stomach. This is similar to the release site for gelatin capsules but differs from the release site for DR capsules in people. This has implications for pharmacologic outcomes for products that are affected by gastric physiology (e.g. fecal microbiota transplantation). Based on this pilot data, clinicians and researchers should not assume DR capsules will allow for intestinal delivery of contents in dogs. Future studies should be conducted on larger and varied populations of dogs.

Important role of NPY-Y4R signalling in the dual control of feeding and physical activity

The control of feeding and physical activity is tightly linked and coordinated. However the underlying mechanisms are unclear. One of the major regulatory systems of feeding behaviour involves neuropeptide Y (NPY) signalling, with the signalling mediated through NPY Y4 receptor also known to influence activity. Here we show that mice globally lacking the Npy4r (Npy4r−/−) in the absence of access to a running wheel behaved WT-like with regards to food intake, energy expenditure, respiratory exchange ratio and locomotion regardless of being fed on a chow or high fat diet. Interestingly however, when given the access to a running wheel, Npy4r−/− mice while having a comparable locomotor activity, showed significantly higher wheel-running activity than WT, again regardless of dietary conditions. This higher wheel-running activity in Npy4r−/−mice arose from an increased dark-phase running time rather than changes in number of running bouts or the running speed. Consistently, energy expenditure was higher in Npy4r−/− than WT mice. Importantly, food intake was reduced in Npy4r−/−mice under wheel access condition which was due to decreased feeding bouts rather than changes in meal size. Together, these findings demonstrate an important role of Npy4r signalling in the dual control of feeding and physical activity, particularly in the form of wheel-running activity.

Associations between Social Contact, Sleep and Dietary Patterns among Children: A Cross-Sectional Study.

Social isolation in adults can be associated with altered sleep and eating behavior. This study aimed to investigate the interactions between the extent of social contact, eating behavior and sleep in infants and preschool children. In an observational study, 439 caregivers of 562 children aged 0-6 years provided information on sleep (i.e., duration, latency, bedtimes and nighttime awakenings), eating behaviors (i.e., meal size, consumption of sweet snacks, salty snacks, fruits and vegetables) and social contact (i.e., quarantine status, household size, social activities) during the COVID-19 pandemic (April 2020). In infants (0-3 years), the change in meal size and consumption of snacks, fruits, and vegetables did not significantly relate to the extent of social contact. For preschool children (3-6 years), a trend was observed, suggesting that quarantine status was associated with increased meal size. Changes in sleep duration, sleep latency, bedtimes and nighttime awakenings from before to during the pandemic were not significantly linked to the three variables quantifying social contact in both age groups. This study highlights that, contrary to expectations, the extent of social contact has negligible associations with infants' and preschool children's sleep and eating behaviors. These findings indicate that other factors beyond social isolation play a role in shaping children's eating habits and sleep patterns.

Chronic pramlintide decreases feeding via a reduction in meal size in male rats

Amylin, a pancreatic hormone, is well-established to suppress feeding by enhancing satiation. Pramlintide, an amylin analog that is FDA-approved for the treatment of diabetes, has also been shown to produce hypophagia. However, the behavioral mechanisms underlying the ability of pramlintide to suppress feeding are unresolved. We hypothesized that systemic pramlintide administration in rats would reduce energy intake, specifically by reducing meal size. Male rats were given b.i.d. administration of intraperitoneal pramlintide or vehicle for 1 week, and chow intake, meal patterns, and body weight were monitored throughout the test period. Consistent with our hypothesis, pramlintide decreased chow intake mainly via suppression of meal size, with corresponding reductions in meal duration on several days. Fewer effects on meal number or feeding rate were detected. Pramlintide also reduced weight gain over the 1-week study. These results highlight that the behavioral mechanisms by which pramlintide produces hypophagia are similar to those driven by amylin itself, and provide important insight into the ability of this pharmacotherapy to promote negative energy balance over a period of chronic administration.

Association of Evening Eating with Sleep Quality and Insomnia among Adults in a Brazilian National Survey

Abstract Objective To examine the association of evening eating clock time, its elapsed time to the midpoint of sleep (TEM), consumption of caffeine and sugary foods, and dinner meal size with sleep quality indicators and insomnia. Methods The present study's participants (n = 2,050; 18–65 y) were part of a population-based research, with virtual data collection. Logistic regression models were fitted to assess differences in the odd ratios (ORs) (95% confidence interval [CI]) of sleep duration &lt; 7 hours, sleep latency &gt; 30 min, poor sleep quality, and insomnia (outcomes) with the evening diet-related variables. Linear regression analyses evaluated differences in sleep duration and latency associated with the same variables. Restricted cubic splines were used to investigate the shape of the association of mealtime and TEM with sleep duration and latency. Results For each hour delay in evening eating and increase in the duration of TEM, the odds of sleep duration &lt; 7 h [OR(95%CI):1.30(1.20,1.40); OR(95%CI):0.51(0.47,0.56)], sleep latency &gt; 30 [OR(95%CI):1.14(1.07,1.22); 0.88(0.83,0.94)], poor sleep quality [OR(95%CI):1.21(1.13,1.30); 0.80(0.76,0.85)] and insomnia [OR(95%CI):1.12(1.04,1.20); 0.89(0.84,0.95)], respectively, increased and decreased. We found a dose-response association of evening eating (clock time and TEM) with sleep duration. The shortest latency was seen when evening eating was at ∼ 8 PM and ∼ 7 to 8 hours before the midpoint of sleep. Participants who reported dinner as their largest meal and consumed caffeine and/or sugary foods/beverages after 6 PM presented higher odds of sleep duration &lt; 7 hours, poor sleep quality, and insomnia. Conclusions Our findings indicate that an early-eating schedule has beneficial sleep effects and that it will be necessary to consider evening eating patterns and timing, along with sleep and circadian hygiene, to improve sleep quality and circadian health.

Parental duties and foraging strategies of a tropical pelagic seabird (Phaethon aethereus, Aves: Phaethontidae) during the breeding season

Breeding seabirds must balance the energetic demands of feeding themselves and their offspring while coping with the constraints imposed by central-place foraging. As such, foraging strategies and parental care patterns are usually linked. Here, the foraging behavior of the Red-billed Tropicbird (Phaethon aethereus; n = 161) of Peña Blanca Islet, Mexico (19° 06ʹ 11ʺ N, 104° 29ʹ 12ʺ W) during the incubation and chick-rearing (≤ 4 weeks of age) stages was characterized with the aid of GPS loggers. Blood samples from adults and chicks were collected to determine δ15N and δ13C, and parental presence at the nest, meal size, and parent-chick feeding events were recorded. During incubation, parents made long trips offshore to areas far from the colony; however, immediately after their chicks hatched, the parents switched to a bimodal foraging strategy by undertaking both short and long foraging trips. The δ15N values indicated that trophic differences were present between parents and their offspring, with chicks being fed prey enriched in 15N. Parental presence at the nest was greater during early chick-rearing, which was associated with a higher provisioning rate. Parents adopted a strategy in which the parent on nest duty only made short foraging trips to provide for its offspring without leaving it unattended for long periods, while its mate undertook long trips to feed itself. After the early chick-rearing period, the parents gradually reduced the time spent at the nest and increased the time spent foraging, compensating with larger meal sizes for their offspring.Graphical abstract

Factors Associated With Food Insecurity Among a Community-Based Sample of Older Adults in a North Florida County.

Food insecurity impacts the lives of 7.6 million U.S. adults aged 60 and older and is linked to numerous life challenges. This study examined the nature of food insecurity among community-based participants ≥65 years in a north Florida county and conceptualized food insecurity as encompassing the lack of food and individual adaptability. Thus, food insecurity was measured using three dependent variables: (1) worrying that food would run out, (2) cutting meal size or skipping meals, and (3) food not lasting. Logistic regression revealed that older participants, those with better-perceived health status, and those who were confident that they could find solutions to their problems had lower odds of reporting food insecurity. However, respondents who lived in low-income, low-access zip codes and those who received food assistance were more likely to report food insecurity. To improve outcomes and reduce healthcare disparities, solutions to food insecurity must vary in focus and approach.

CALORIC RESTRICTION AND AGING: FROM CALORIES TO FASTING Times

Abstract The caloric content and manipulations of nutrient composition have defined our research focus over decades, leading to the formulation of ideal diets and supplements for every phase of life. In the last few years, the control of meal size, frequency, and timing have become a powerful strategy to ameliorate and postpone disease onset and delay aging. Emerging evidence highlights the importance of prolonged fasting periods for the health and survival benefits of calorie restriction (CR) and time-restricted feeding (TRF) across multiple species. Furthermore, there is new evidence of the potential combinatorial use of these dietary interventions with established therapeutical approaches to enhance outcomes, particularly in anticancer treatments.

Climate risk screening for food security in karenga and kapchesombe districts, evidence for policy, Uganda

Geographically, the Karenga and Kapchesombe Districts communities close to the Mount Elgon and Kidepo Valley National Parks, respectively are the focus of the climate change risk analysis. The influence of climate change on the availability of food is examined in this study, along with the methods employed by small-scale farmers in the two districts to adjust to changing family food requirements. A decrease in crop and fodder output is one of the implications of climate change and seasonal variations on food security. It has been noted that rainfall variability is the main factor affecting households' food security. 74.4 percent of the 379 respondents were able to adapt to addressing challenges related to food shortages through buying less expensive food, having meals for 4 days a week, reducing the size of meals in 7 days, and restricting consumption to certain times; but more respondents reported reducing the number of meals. In Karenga, meals were not regular and the majority missed critical meals such as breakfast and lunch which was replaced by local brew. The main barriers to food security were: inadequate financial resources, not being knowledgeable, looking at climate change as a natural calamity, lack of skills of adaptation, and inadequate labor to produce more food.

Effect of micronization and meal size of corn grain on glycemic response and in vitro hindgut acidosis potential in horses

This study aimed to 1) evaluate the interaction of corn grain micronization and starch levels per meal on equine plasma glucose, and 2) determine if micronization affects the risk of hindgut acidosis. Six mature (aged 6 to 10 years), healthy, non-pregnant mares (initial body weight [BW]: 301 to 463 kg) were used in a 2×3 factorial cross-over design. The treatments included two forms of corn grain (ground and micronized flaked) at three levels of starch (1, 1.5, and 2 g/kg BW per meal). The blood was sampled before and 30, 60, 90, 120, 180, 240, and 300 min after morning feeding and the glucose concentration in the plasma was determined. Small intestine and hindgut dry matter (DM) disappearances of ground and micronized corn were also compared using in vitro techniques. Micronized flaked corn grain showed three times more in vitro enzymatic DM disappearance (p < 0.001) compared with ground corn. Residues of in vitro enzymatic digestion of micronized flaked corn fermented 38.59 % faster than ground corn during in vitro hindgut incubation. The horses that consumed micronized flaked corn had higher post-prandial plasma glucose concentrations (p < 0.001). Increasing starch levels per meal from 1–2 g/kg BW resulted in higher plasma glucose concentrations (P = 0.005). However, no interaction of processing and starch meal size was found. Overall, processing the corn grain by micronization or increasing starch level per meal increased the plasma glucose concentrations, but the magnitude of the increases did not match that expected from in vitro studies.

Dynamic, sex- and diet-specific pleiotropism in the PAC1 receptor-mediated regulation of arcuate proopiomelanocortin and Neuropeptide Y/Agouti related peptide neuronal excitability by anorexigenic ventromedial nucleus PACAP neurons.

This study furthers the investigation of how pituitary adenylate cyclase activating polypeptide (PACAP) and the PAC1 receptor (PAC1R) regulate the homeostatic energy balance circuitry. We hypothesized that apoptotic ablation of PACAP neurones in the hypothalamic ventromedial nucleus (VMN) would affect both energy intake and energy expenditure. We also hypothesized that selective PAC1R knockdown would impair the PACAP-induced excitation in anorexigenic proopiomelanocortin (POMC) neurones and inhibition of orexigenic neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurones in the hypothalamic arcuate nucleus (ARC). The results show CASPASE-3-induced ablation of VMN PACAP neurones leads to increased energy intake and meal frequency as well as decreased energy expenditure in lean animals. The effects were more robust in obese males, whereas we saw the opposite effects in obese females. We then utilized visualized whole-cell patch clamp recordings in hypothalamic slices. PAC1R knockdown in POMC neurones diminishes the PACAP-induced depolarization, increase in firing, decreases in energy intake and meal size, as well as increases in CO2 production and O2 consumption. Similarly, the lack of expression of the PAC1R in NPY/AgRP neurones greatly attenuates the PACAP-induced hyperpolarization, suppression of firing, decreases in energy intake and meal frequency, as well as increases in energy expenditure. The PACAP response in NPY/AgRP neurones switched from predominantly inhibitory to excitatory in fasted animals. Finally, the anorexigenic effect of PACAP was potentiated when oestradiol was injected into the ARC in ovariectomized females. This study demonstrates the critical role of anorexigenic VMN PACAP neurones and the PAC1R in exciting POMC and inhibiting NPY/AgRP neurons to control homeostatic feeding.

Impact of enzyme inclusion on the digestibility of protein, amino acids, calcium and phosphorus in growing pigs depending on meal size, frequency and sampling period

When digestibility trials are conducted, pigs are typically fed twice a day with a restricted amount of feed. These conditions are not representative of the feeding conditions in commercial farm. The present study aimed to determine the effects of meal size and frequency, xylanase and phytase inclusion as well as digesta sampling period, on the digestibility of protein, amino acids (AA), calcium (Ca) and phosphorus (P). Pigs (n = 6) were fitted with a T cannula, and each received all treatments following a 2 × 3 factorial arrangement in a 6 × 6 Latin square experimental design. The diets were supplemented or not with a combination of xylanase and phytase and divided into 3 feeding programs: one received 2 meals per day that met 3 times the maintenance energy requirement (2M), one received the same quantity of feed in 8 meals (8M), and another received an amount that supplied 5 times the maintenance energy requirements in 8 meals (8M+). Digesta was sampled from 0800 to 1200, 1200–1600, 1600–2000 and 0800–2000. The results indicated an improvement in the coefficient of apparent ileal digestibility of dry matter, crude protein, P, Ca, Val and Thr with enzyme inclusion in all meal distribution (enzyme effect, P < 0.05). Apparent ileal digestibility of Ca in the 0800–1200 period was reduced in 8M+ treatment compared to 2M and 8M whereas no difference was observed for meal size or frequency in 1200–1600 and 1600–2000 periods (Interaction meal × period, P = 0.017). A meal effect was observed for coefficient of apparent total tract digestibility of Ca (meal effect, P = 0.003) which was higher by 8% in pigs fed 8M compared to 8M+ (contrast 8M vs 8M+, P = 0.040). Saturation of the absorption processes may explain lower digestibility with 8M+ . Enzyme efficacy was not affected by meal size or frequency indicating minor modifications of digestive conditions. An 8-h sampling period would allow collection of a representative sample and avoid underestimating or overestimating digestibility of certain nutrients.