Chewing Behavior Research Articles

The effect of oral tactile sensitivity on texture perception and mastication behavior.

Mastication is a notable source of interindividual variation in texture perception and could be linked to oral tactile sensitivity. To better understand the influence of oral tactile sensitivity on mastication behavior, this study measured masticatory behavior and texture discrimination in participants of high (n = 20) and low (n = 21) oral tactile sensitivity. Overall, there was no significant difference between high and low sensitivity participants in their ability to distinguish texture changes (p = .486). However, there were significant differences found between the groups based on their masticatory behaviors including chewing pattern and overall number of chewing cycles. Additionally, those in the high sensitivity group used more stochastic chewing movements, while those in the low sensitivity group were found to use crescent-shaped chewing cycles. It was also noted that in the high sensitivity group, the jaw moved further distances in all phases and moved at a higher velocity when opening but not when closing, when compared to the low sensitivity group. These results show what particular aspects of mastication are most influenced by oral tactile feedback. Chewing patterns have been shown to influence texture and flavor perception, as well as energy intake. However, much of the person-to-person variability in chewing patters comes from unknown sources. This study shows which chewing behaviors are different between a group of individuals with high oral tactile sensitivity and another with low oral tactile sensitivity. These findings highlight the manner in which tactile feedback from the mouth influences chewing.

The rumen washes off abrasives before heavy-duty chewing in ruminants

Based on comparative mandibular anatomy, observations of chewing behaviour, chewing forces and dental microwear, it has been suggested that an additional effect of the ruminant digestive strategy could be a reduction of both the required chewing load and tooth wear ruminants are exposed to. This effect is hypothesized to be the result of digestion, mixing, and digesta sorting prior to regurgitation for rumination, which might both soften the material and wash off external abrasives such as sand, grit and dust. Putatively, these external abrasives would thus be trapped in the (fore)stomach and excreted via the faeces. We investigated the location of sand in the stomach of goats fed diets containing phytoliths and sand for several months. The contents of the stomach section from where rumination material is recruited were comparatively depleted of sand. Sand mainly accumulated in another stomach section, the abomasum, without causing clinical problems. A certain phytolith content should hence affect ruminants and non-ruminant herbivores somewhat alike; however, a certain external abrasives content should affect ruminants less than non-ruminants. Results from feeding experiments as well as tooth wear studies support this hypothesis, and caution against the default use of dental anatomy and wear as taxon-free environmental proxies in paleobiology.

Comparison of the effects of different kibble shape on voluntary food intake and palatability of weight loss diets in pet dogs

Altering characteristics of a dry proprietary diet can increase chewing, slow ingestion speed and reduce voluntary food intake. Panels of healthy research dogs consumed kibbled weight loss diets with either a l round (pastille) or a cross shape. Two panels (‘small-size’ panel, dogs<10 kg ‘all-size’ panel, dogs with a range of sizes) were used to determine palatability (study 1), whilst a third panel (‘consumption kinetics panel’) was used to determine voluntary food intake [VFI] and meal duration (study 2). Study 3 was a field trial where the cross kibble was fed to client-owned overweight dogs undergoing controlled weight loss, and attitudes of owners were sort. In study 1, dogs in the all-size panel consumed more of the cross-kibble diet than of the round-kibble diet (P < .001), but there was no significant difference in dogs of the small-size panel (P = 1.000). In study 2, VFI was broadly similar for both diets, with no difference in total consumption across all four meals (P = .370). However, meal duration was significantly longer for the cross kibble (meal 1: 292 s; meal 2: 650 s) compared with the round kibble (meal 1: 186 s; meal 2: 282, P < .001 for both). In study 3, owners observed more chewing behaviour (P = .031), slower ingestion speed (P = .031), and a significant decrease in food-seeking behaviour (P = .020) when eating the cross-kibble compared with the round-kibble. Altering the kibble shape of a canine therapeutic weight loss diet can decrease ingestion speed without affecting palatability, but studies are now required to determine the effect on outcomes of weight management.

Application of electromyography (EMG) in food texture evaluation of different Indian sweets

The present study was undertaken to correlate surface electromyography variables acquired during chewing of different Indian sweets with the instrumental texture parameters and their sensory attributes. Firstly, a comparison of acquired absolute EMG variables with the relative EMG variables was conducted. The results revealed that the relative EMG mastication parameters can effectively distinguish different textured food products by eliminating the subject variance. Then, the two different recordings of masticatory parameters in an EMG session for human subjects were correlated to investigate the reproducibility of chewing patterns. The correlation coefficients were found to be statistically significant (p less than 0.05) indicating highly reproducible chewing behaviour within a session for human subjects. Finally, acquired surface EMG variables were clustered into six representative variables using dendrograms. The principal component analysis conducted for these representative variables could explain 76% of cumulative proportion of variance. The scores of first principal component correlated significantly with instrumental and sensory hardness and sensory stickiness, while scores of second component correlated with sensory stickiness.

Feeding Diets Moderate in Physically Effective Fibre Alters Eating and Feed Sorting Patterns without Improving Ruminal pH, but Impaired Liver Health in Dairy Cows.

Simple SummaryThis study tested the hypothesis that the content of physically effective fibre in the diet modifies eating and feed sorting patterns of cows, which is reflected in rumen and systemic health variables. We observed that switching cows from a diet high to a diet moderate in physically effective fibre (17.8%; 28% starch on dry matter basis) in an attempt to stabilize rumen pH variations altered eating, sorting, and chewing behaviour. However, this attempt did not prevent ruminal pH drop and the impairment of liver health variables. Therefore, our study emphasizes the importance of increasing the level of physically effective fibre for particles >8 mm beyond 17%–18% of the diet when (barley grain-based) starch content is at a 28% level.The main challenge in dairy cattle feeding is to find a balance between the energy and physically effective fibre (peNDF), required to maintain rumen health. In an attempt to regulate the balance between energy intake and rumen buffering, we hypothesized that the content of peNDF in the diet modifies eating and feed sorting patterns of the cows. Sixteen lactating Simmental cows were switched from a diet high in peNDF, with which they were fed for one week, to a diet moderate in peNDF for four weeks. Data showed that during the moderate peNDF feeding the cows increased sorting for medium-sized particles and avoided both long and very fine particles. In addition, cows decreased their eating time per meal, but increased the number of meals per day, obviously attempting to decrease the amount of fermentable substrate per time unit while maintaining high levels of nutrient/energy intake. Although these changes during the moderate peNDF feeding went along with a lower diurnal variation of ruminal pH, feeding of the latter diet did not prevent ruminal pH drop and increased the level of all liver enzymes, indicating liver tissue damage. In conclusion, the altered eating, chewing, and sorting behaviour of the cows during the moderate peNDF feeding could not alleviate the deficiency in peNDF, which resulted in ruminal pH depression and impairment of liver health variables.

Mouth work: bodily action in sensory science

ABSTRACTSensory science is a scientific discipline that measures human responses to the sensory qualities of food products. In order for study subjects to reflect on their tasting experience, the products under study have to be put into the mouth: chewed, sucked, savored, and (possibly) swallowed. The mouth and its actions are key areas of interest for sensory science: the movements of the mouth can potentially affect how subjects perceive sensory qualities and thus determine the reliability of data. To control the actions of the mouth, sensory tests may include strict instructions on chewing behavior. This paper explores the concept of the mouth in sensory science: how is the mouth controlled, imagined, and organized in an experimental modality? It draws on the analogy of work to elucidate the mouth as a regulated and productive instrument in sensory tests. As a correlate to the productive mouth, it also shows how the consumer’s mouth is conceptualized either in contrast to, or as emanating from, standardized behaviors. Based on ethnographic research with US sensory scientists and on sensory science literature, it examines how a focus on work and its excesses can illuminate the mouth as the intimate site that scales up to mass markets.

Reconstituted versus dry alfalfa hay in starter feed diets of Holstein dairy calves: Effects on feed intake, feeding and chewing behavior, feed preference, and health criteria

We investigated the effect of reconstitution of alfalfa hay on feeding and chewing behavior, sorting activity, and health status using 20 neonate Holstein male calves (3 d of age; 40.3 ± 1.30 kg of body weight) that were assigned randomly to 2 treatments, a starter feed containing either 10% dry (AH) or reconstituted alfalfa hay (RAH), each consisting of 10 calves. Alfalfa hay was reconstituted with water 24 h before feeding to achieve a theoretical dry mater (DM) content of 20%. Both starter diets had the same ingredients and nutrient compositions but differed in their DM content (90.9 vs. 66.6% DM for AH vs. RAH, respectively). Calves were weaned on d 50 and remained in the study until d 70. Reconstitution of alfalfa hay increased the percentage of particles retained on 8- and 1.18-mm sieves, but reduced feed materials retained on the bottom pan. Feeding RAH tended to increase meal frequency (preweaning) and increased meal duration (pre- and postweaning), and thereby increased time devoted to eating without affecting nutrient intake. Calves fed RAH tended to have lower eating rate during the pre- and postweaning periods. Tendencies to concurrent increase in rumination frequency and rumination duration in calves fed RAH increased time devoted to ruminating during the preweaning period; however, a tendency to longer rumination duration did not affect ruminating time during the postweaning period. Calves fed RAH spent less time resting and standing and more time drinking during the postweaning period. Non-nutritive oral behaviors were not affected by treatment during the pre- and postweaning period. Feeding RAH decreased sorting of particles retained on 8-mm sieve compared with AH; however, calves in both treatment groups sorted for particles retained on 8- and 1.18-mm sieves and against the feed materials retained on the bottom pan. Crude protein and neutral detergent fiber intakes of particles retained on the both 8- and 1.18-mm sieves increased in calves fed RAH versus AH, with no changes in intake of nutrients retained on the bottom pan. Calves fed AH were more susceptible to develop diarrhea (odds ratio = 2.02) and pneumonia (odds ratio = 4.74) and thereby had lower chances of being treated. We found no difference between treatment groups for frequency and medication days of diarrhea; however, calves fed RAH experienced fewer days with diarrhea. Furthermore, frequency and number of days with pneumonia and administration of medication were greater for calves fed AH compared with calves fed RAH. Blood concentrations of total protein and globulin tended to be higher in calves fed RAH compared with calves fed AH. Overall, feeding RAH increased time devoted to eating by increasing meal frequency and meal duration but did not affect feed intake due to lower eating rate. Calves in both treatment groups exhibited feed sorting at the extent to which they balanced intake of nutrients and met their nutritional needs. Calves, in general, were healthy, but it seems that feeding a diet containing reconstituted alfalfa hay has a potential health-promoting effect, possibly through reducing diet dustiness and improving immune status.

Dynamics of motor cortical activity during naturalistic feeding behavior

Objective. The orofacial primary motor cortex (MIo) plays a critical role in controlling tongue and jaw movements during oral motor functions, such as chewing, swallowing and speech. However, the neural mechanisms of MIo during naturalistic feeding are still poorly understood. There is a strong need for a systematic study of motor cortical dynamics during feeding behavior. Approach. To investigate the neural dynamics and variability of MIo neuronal activity during naturalistic feeding, we used chronically implanted micro-electrode arrays to simultaneously recorded ensembles of neuronal activity in the MIo of two monkeys (Macaca mulatta) while eating various types of food. We developed a Bayesian nonparametric latent variable model to reveal latent structures of neuronal population activity of the MIo and identify the complex mapping between MIo ensemble spike activity and high-dimensional kinematics. Main results. Rhythmic neuronal firing patterns and oscillatory dynamics are evident in single-unit activity. At the population level, we uncovered the neural dynamics of rhythmic chewing, and quantified the neural variability at multiple timescales (complete feeding sequences, chewing sequence stages, chewing gape cycle phases) across food types. Our approach accommodates time-warping of chewing sequences and automatic model selection, and maps the latent states to chewing behaviors at fine timescales. Significance. Our work shows that neural representations of MIo ensembles display spatiotemporal patterns in chewing gape cycles at different chew sequence stages, and these patterns vary in a stage-dependent manner. Unsupervised learning and decoding analysis may reveal the link between complex MIo spatiotemporal patterns and chewing kinematics.

Dust affects chewing efficiency and tooth wear in forest dwelling Western chimpanzees (Pan troglodytes verus).

In humans it has been shown that abrasive particles in the diet result in increased tooth wear and less intense chewing behavior, both of which decrease chewing efficiency. This behavioral response may also exist in non-human primates as a means to reduce the wear effect of dust-laden food. Here we tested whether the periodical occurrence of abrasive dust particles in the diet of Western chimpanzees affects tooth wear and reduces chewing efficiency. We measured fecal particle size of undigested food matter as an indicator of chewing efficiency in 13 Western chimpanzees of the Taï National Park (Ivory Coast) before (wet), after (wet) and during a dust-rich (dry) period. Moreover, feeding data were compiled for a further 12 chimpanzees and matched to three-dimensional surface texture data measured on two molar facets of 26 skulls of the same population. Fecal particles were larger during the dry period, indicating a reduced chewing efficiency compared to wet periods; age and sex did not have an effect. Concomitantly, dust led to an increase of abrasive wear evidenced by smaller texture features and higher density of fine furrows on wear facets. Our findings show that a periodical increase in dust loads on foods places a dietary-physiological stress on the digestive system in chimpanzees. We suggest that the impact of extrinsic abrasive particles from globally acting periodical dust-laden winds may affect evolutionary fitness. Further studies are required to elucidate this relationship in other non-human primates and fossil hominins.

Dietary protein level and corn processing method: Intake, digestibility, and feeding behavior of lactating dairy cows✰

The effects of corn processing and dietary protein level and their interaction on intake, digestibility, and feeding behavior in dairy cow was examined using eight multiparous Holstein dairy cows in mid-lactation (105 ± 9 days in milk and 47.2 ± 3 kg/day milk production at the start of the experiment) that were placed in a replicated 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments. Experimental diets contained either finely ground corn (FGC) or steam-flaked corn (SFC) based on either low protein (LP, 14.8%) or high protein (HP, 16.2%) content. Diets contained 40% forage (corn silage and alfalfa hay) and 40% corn grain. Dry matter intake did not differ between HP and LP diets. In contrast, cows fed LP had greater total tract digestibility compared with that for HP-fed cows. Cows fed LP had greater chewing time and lower chewing rate (g of DM/min) compared to those for cows fed HP. Cows receiving SFC had a lower intake of nutrients and tended to have greater ADF and starch digestibility than cows fed FGC. There was an interaction between corn processing and level of protein with respect to the apparent total tract digestibility with cows fed FGC with HP resulted in the lowest digestibility. Steam-flaked corn had lower density and greater moisture and mean particle size than the FGC. In comparison with FGC, SFC did not pass through the 8-mm sieve and caused significant increase in physical effectiveness factor (pef) and physically effective fiber (peNDF) in SFC diets compared to that for FGC diets. Cows fed SFC sorted against longer particles (P = 0.04) to a greater extent than cows fed FGC. Dietary protein level had no detectable effect on sorting index. Chewing time did not differ for cows fed SFC or FGC; however, cows fed SFC had lower chewing and rumination rate (g of DM/min). Chewing time per kg of DM and CP were greater and per kg of peNDF were lower in cows fed SFC rather than cows fed FGC. Results indicated that corn processing and dietary protein level may interact to affect nutrient digestibility, but did not affect the feeding and chewing behavior of lactating cows under our experimental conditions. Results also showed that dietary peNDF content and chewing activity can be effectively manipulated by steam flaking of corn, and cows fed SFC had greater peNDF and energy intake despite lower DMI.

Feeding processed soybean to mid-lactation Holstein cows: ingestive behaviour and rumen fermentation characteristics

The objective of this study was to evaluate the effects of roasted soybean (RSB), extruded soybean (ESB) and their equal blend (RSB + ESB) compared with soybean meal (SBM) on nutrient intake, feed preference, meal and rumination patterns, feeding and chewing behaviour and rumen fermentation characteristics of mid-lactation dairy cows. Eight Holstein dairy cows were used in a replicated 4 × 4 Latin square design with four 28-d periods. Cows received one of the four following experimental diets: (1) 13.88% of diet dry matter (DM) as SBM; (2) 15.22% of diet DM as RSB, (3) 15.55% of diet DM as ESB and (4) 7.69% RSB plus 7.69% ESB (RSB + ESB). Each experimental period consisted of a 21-d diet adaptation period and a 7-d data collection period. Meal patterns, including meal size and inter-meal interval, were not affected by the experimental diets and thereby DM intake was not different among diets. Sorting index was not different across dietary treatments but intake of particles retained on 1.18-mm sieve and on pan increased and decreased in both SBM and ESB as compared with RSB and RSB + ESM, respectively. Total time spent eating and ruminating and rumen volatile fatty acid concentrations were unaffected by dietary treatments. Feeding processed soybean instead of SBM had minimal effects on sorting behaviour and meal patterns and thereby no changes in feed intake occurred. Finally, RSB and ESB and their equal blend had a similar effect on feed intake and chewing behaviour of mid-lactation Holstein cows.HighlightsFeeding processed soybean products had the minor effect on feed intake and can be considered as alternative feedstuffs when the price is competitive.

Tobacco and Betel Nut Chewing Behaviour and its Association with Potentially Malignant Disorders in Chennai

Background: Betel nut and tobacco chewing habit is considered to be common amongst the individuals of Asian origin. It is associated with oral and oropharyngeal cancer and other potentially malignant disorders (PMD). Attributes like the frequency, duration of chewing, placement of betel nut and tobacco seems to plays a significant role in the initiation of potentially malignant disorders and oral squamous cell carcinoma. Aim: To assess the Tobacco & Betel nut chewing behaviour& its association with PMDs in chennai population. Materials and Method: The study group consisted of 20 tobacco & betel nut chewing individuals from sub-urban and rural areas near Chennai with the habit > 1 year. A questionnaire consisting of 16 questions relevant to tobacco and betel nut chewing habits were given and the data was acquired, Clinical examination was done to document the oral findings of the study population associated with PMDs. Results: There was presence of oral leukoplakia (50%), OSMF (34%) and oral lichen planus (18%) among the study population. Conclusion: Betel nut and tobacco chewing behaviour and its patterns plays a major role in causing potentially Malignant disorders and it is considered to be one of the major risk factor for the development of Oral squamous cell carcinoma.

Supplementation of a clay mineral-based product modulates plasma metabolomic profile and liver enzymes in cattle fed grain-rich diets

Grain-rich diets often lead to subacute ruminal acidosis (SARA) impairing rumen and systemic cattle health. Recent data suggest beneficial effects of a clay mineral (CM)- based product on the rumen microbiome of cattle during SARA. This study sought to investigate whether the CM supplementation can counteract SARA-induced perturbations of the bovine systemic health. The study used an intermittent diet-induced SARA-model with eight dry Holstein cows receiving either no additive as control or CM via concentrates (n=8 per treatment). Cows received first a forage diet (Baseline) for 1 week, followed by a 1-week SARA-challenge (SARA 1), a 1-week recovery phase (Recovery) and finally a second SARA-challenge for 2 weeks (SARA 2). Cows were monitored for feed intake, reticular pH and chewing behavior. Blood samples were taken and analyzed for metabolites related to glucose and lipid metabolism as well as liver health biomarkers. In addition, a targeted electrospray ionization-liquid chromatography-MS-based metabolomics approach was carried out on the plasma samples obtained at the end of the Baseline and SARA 1 phase. Data showed that supplementing the cows’ diet with CM improved ruminating chews per regurgitated bolus by 16% in SARA 1 (P=0.01) and enhanced the dry matter intake during the Recovery phase (P=0.05). Moreover, the SARA-induced decreases in several amino acids and phosphatidylcholines were less pronounced in cows receiving CM (P≤0.10). The CM-supplemented cows also had lower concentrations of lactate (P=0.03) and biogenic amines such as histamine and spermine (P<0.01) in the blood. In contrast, the concentration of acylcarnitines with key metabolic functions was increased in the blood of treated cows (P≤0.05). In SARA 2, the CM-cows had lower concentrations of the liver enzymes aspartate aminotransferase and γ-glutamyltransferase (P<0.05). In conclusion, the data suggest that supplementation of CM holds the potential to alleviate the negative effects of high-grain feeding in cattle by counteracting multiple SARA-induced perturbations in the systemic metabolism and liver health.

Betel Nut Chewing Behavior among Adolescents in Papua Province, Indonesia

Chewing betel nuts is a Papuan tradition that has been passed down from generation to generation, and is widely accepted in Papuan community. However, betel nut contains a psychotropic substance called arecoline, which is a stimulant with a similar effect to that of nicotine. In this study, it was found that the group age of 17 to 29 is significant (0.0) in consuming betel nut compared to other group ages. This study used the descriptive cross-sectional method. The objective of this study is to find what dominant factors exist regarding the betel nut chewing behavior among adolescents in Papua province. Data were taken from 293 respondents from eight different high schools in Papua and were used as a sample for this study. One dominant factor influencing high school students in chewing betel nuts was the cultural factor (mean 2.81). This study also considered the habits of eating betel nuts based on level of education, religion, and tribe. In addition, there is a significant difference (0.0) between participants from SDA and non-SDA schools in terms of chewing betel nuts. This study will help young people in Papua province to be informed about the negative effects of chewing betel nuts on health and social life.

The Effect of a Financial Incentive Designed of Transtheoretical Model–Based Interventions on Betel Quid Cessation

Background: Betel quid (BQ) and cigarette smoking (CS) are oral cancer risk factors. It has been estimated that hundreds of million people mainly in the Asia-Pacific region were consume certain variety of BQ. BQ is the fourth most commonly used psychoactive substance in the world and require assist the chewers to withdraw it. In Taiwan, Health Promotion Administration (HPA) has initiated a hospital-based in-reach screening services for oral cancer to chewers and smokers since 2010 and proposed a financial incentive BQ cessation program designed based on Transtheoretical Model (TTM) to BQ chewers within entrusted “Cancer Control Advanced Program” hospitals in 2017. Aim: This study aims to examine whether this strategy can assist BQ chewers to diminish or quit chewing BQ. Methods: This study was a longitudinal study design used an administration database. BQ chewers were interviewed with 3 times within 1 year follow by a uniform TTM-based BQ cessation intervention by HPA-trained health educators. A face-to-face questionnaire interview were conducted to obtain baseline information, 3 interventions' behavior change stages as well as final BQ chewing status. Generalized linear mixed model was used to determine the association between TTM changing process and effectiveness of BQ chewing behavior changes. Results: A total of 5476 BQ chewers completed 3 times interventions and classified into high-reduction group (N = 2698), middle-reduction group (N = 1978), and low-reduction group (N = 800) after 1-year follow-up. We found BQ chewers were primarily men and aged 40 to 60 years. Over half participants chewed BQ ≤10 BQ per day. Most of them were higher percentage on cigarette smoking and alcohol drinking. Almost 45% BQ chewers did not have regular oral mucosa screening. The stages of change were shift from precontemplation and contemplation stage to action and maintenance stage during 3 interventions. After adjusting for covariates, participants in preparation stage compared with those in precontemplation stage were associated with an increasing odds ratio in middle-reduction BQ (odds ratio = 2.79, 95% confidence interval = 2.27-3.44) and in high-reduction BQ (odds ratio = 3.75, 95% confidence interval = 3.02-4.66). Moreover, BQ chews who chewed BQ ≤10 BQ per day and did not a cigarette smoking had higher chance to had high-reduction of BQ. Conclusion: This modified TTM BQ cessation provides according to behavior change 5 stages could benefit from hospital-based health education to lower BQ, however, future relapse rate should be concerned.

Transcranial focused ultrasound stimulation of motor cortical areas in freely-moving awake rats

BackgroundLow-intensity transcranial focused ultrasound (tFUS) has emerged as a new non-invasive modality of brain stimulation with the potential for high spatial selectivity and penetration depth. Anesthesia is typically applied in animal-based tFUS brain stimulation models; however, the type and depth of anesthesia are known to introduce variability in responsiveness to the stimulation. Therefore, the ability to conduct sonication experiments on awake small animals, such as rats, is warranted to avoid confounding effects of anesthesia.ResultsWe developed a miniature tFUS headgear, operating at 600 kHz, which can be attached to the skull of Sprague–Dawley rats through an implanted pedestal, allowing the ultrasound to be transcranially delivered to motor cortical areas of unanesthetized freely-moving rats. Video recordings were obtained to monitor physical responses from the rat during acoustic brain stimulation. The stimulation elicited body movements from various areas, such as the tail, limbs, and whiskers. Movement of the head, including chewing behavior, was also observed. When compared to the light ketamine/xylazine and isoflurane anesthetic conditions, the response rate increased while the latency to stimulation decreased in the awake condition. The individual variability in response rates was smaller during the awake condition compared to the anesthetic conditions. Our analysis of latency distribution of responses also suggested possible presence of acoustic startle responses mixed with stimulation-related physical movement. Post-tFUS monitoring of animal behaviors and histological analysis performed on the brain did not reveal any abnormalities after the repeated tFUS sessions.ConclusionsThe wearable miniature tFUS configuration allowed for the stimulation of motor cortical areas in rats and elicited sonication-related movements under both awake and anesthetized conditions. The awake condition yielded diverse physical responses compared to those reported in existing literatures. The ability to conduct an experiment in freely-moving awake animals can be gainfully used to investigate the effects of acoustic neuromodulation free from the confounding effects of anesthesia, thus, may serve as a translational platform to large animals and humans.

Longitudinal study on acceptance of food textures between 6 and 18 months

The timely complementary food introduction is important for the development of healthy eating. However, little evidence is available about when to introduce which texture during this period. This study aims to fill this gap by measuring the evolution of food texture acceptance and feeding behaviours between 6 and 18 months. Two groups of healthy children participated in the study: at 6, 8, and 10 months (n = 24) and at 12, 15 and 18 months (n = 25), respectively. They were offered foods with different textures (purees, double textures, cooked pieces, sticky and hard foods) at an age when few infants were already familiar with these textures. For each food texture, children’s acceptance (ability to process and swallow a food) and feeding behaviours (sucking and chewing) were assessed by the investigator; liking was assessed by parents. At 6 months, pureed and double textures were highly accepted (Acceptance Probability AP > 0.8); when offered at 8 months, cooked pieces were highly accepted (AP > 0.8). Up to 10 months, the acceptance of more complex textures (e.g. cheese, bread crust) increased strongly with age as did chewing behaviour. At 12 months, most food textures were accepted (AP > 0.5), except raw vegetable pieces and pasta (AP < 0.35), and chewing behaviour was predominant over sucking. Up to 18 months, raw vegetable pieces and pasta acceptance increased with age and was >0.5 at 18 months. In conclusion, children accepted most textures at an earlier age than their parents’ feeding practices; their feeding behaviours depended on age and food texture and acceptance of hard textures was related to the development of chewing.

Effect of fish oil supplementation and forage source on performance, rumen fermentation, nutrient digestion and chewing behaviour of Holstein bulls

Background: Fat supplementation in ruminants ration often adversely affect dry matter intake (DMI), rumen fermentation and nutrients digestion. Basal diet ingredients is an undeniable determinant of ruminants responses including performance, chewing behaviour and nutrient digestibility to fat supplementation. Objective: Current study was conducted to evaluate the effect of Fish oil (FO) supplementation under different proportion of alfalfa hay (AH) and corn silage (CS) in ration on performance, rumen fermentation, nutrient digestibility and chewing behaviour of Holstein young bulls. Methods: Thirty six Holstein young bulls were used in a 2 × 3 factorial arrangement, with 2 levels of AH proportion (10 and 20 % of AH versus 20 and 10 % of dietary CS) combined with 3 levels of FO supplement (0, 1 and 2.1% of dietary dry matter). Calves were fed TMR consisting of 30 % of forage and 70 % of barley grain-based concentrate mix (dry matter basis). The experiment lasted for 90 days. Results: Dry matter intake was not affected by interaction of AH proportion and FO supplementation. Higher dietary CS proportion caused more DMI regardless of FO supplementation (8.71 versus 8.00 kg/d respectively for treatments with high and low CS proportion; P 1.18 were increased in response to FO supplementation regardless of AH proportion (P 1.18 intake and eating times per kg of DM and peNDF > 1.18 intake (P < 0.01) regardless of FO supplementation. Conclusion: The results demonstrate that AH can be replaced by CS to prevent depression in DMI and stimulate chewing activity in the case of fat supplementation.

Invited review: Current perspectives on eating and rumination activity in dairy cows

Many early studies laid the foundation for our understanding of the mechanics of chewing, the physiological role of chewing for the cow, and how chewing behavior is affected by dietary characteristics. However, the dairy cow has changed significantly over the past decades, as have the types of diets fed and the production systems used. The plethora of literature published in recent years provides new insights on eating and ruminating activity of dairy cows. Lactating dairy cows spend about 4.5 h/d eating (range: 2.4-8.5 h/d) and 7 h/d ruminating (range: 2.5-10.5 h/d), with a maximum total chewing time of 16 h/d. Chewing time is affected by many factors, most importantly whether access to feed is restricted, intake of neutral detergent fiber from forages, and mean particle size of the diet. Feed restriction and long particles (≥19 mm) have a greater effect on eating time, whereas intake of forage neutral detergent fiber and medium particles (4-19 mm) affects rumination time. It is well entrenched in the literature that promoting chewing increases salivary secretion of dairy cows, which helps reduce the risk of acidosis. However, the net effect of a change in chewing time on rumen buffing is likely rather small; therefore, acidosis prevention strategies need to be broad. Damage to plant tissues during mastication creates sites that provide access to fungi, adhesion of bacteria, and formation of biofilms that progressively degrade carbohydrates. Rumination and eating are the main ways in which feed is reduced in particle size. Contractions of the rumen increase during eating and ruminating activity and help move small particles to the escapable pool and into the omasum. Use of recently developed low-cost sensors that monitor chewing activity of dairy cows in commercial facilities can provide information that is helpful in management decisions, especially when combined with other criteria. Although accuracy and precision can be somewhat variable depending on sensor and conditions of use, relative changes in cow behavior, such as a marked decrease in rumination time of a cow or sustained low rumination time compared with a contemporary group of cows, can be used to help detect estrus, parturition, and some illnesses. This review provides a comprehensive understanding of the dietary, animal, and management factors that affect eating and ruminating behavior in dairy cows and presents an overview of the physiological importance of chewing with emphasis on recent developments and practical implications for feeding and managing the modern housed dairy cow.

Dough and bread making from high- and low-protein flours by vacuum mixing: Part 3. Oral processing of bread

This study aimed to understand the impact of vacuum mixing induced changes in the structural and physical characteristics of bread, which had extensively been investigated in the first two parts of the series of study, on human oral processing of baked bread and steamed bread. The chewing behaviour, dynamic texture perception and swallowing thresholds of twelve healthy panellists were characterised using surface electromyography (EMG), temporal dominance of sensation (TDS) and bolus characterization, respectively. There was no difference in the swallowing thresholds between the vacuum mixed bread and control bread, for either baked bread or steamed bread. Nevertheless, baked bread made from vacuum mixed dough required slightly longer chewing duration and greater muscle activities than the control baked bread, which was attributed to its denser structure and harder texture. On the other hand, steamed bread made from vacuum mixed dough required smaller muscle activities compared to the control steamed bread. Significance difference in texture perception was only observed between baked and steamed bread but not among the same type of bread made between vacuum and atmospheric mixing. Results indicated that vacuum mixing might be used as a technique to change bread structure that affects consumer's eating behaviour but not texture perception.