Chewing Behavior Research Articles

Betel nut chewing behaviour and its association with oral mucosal lesions and conditions in Ghaziabad, India.

To assess the practices and behaviour among Betel nut users in Ghaziabad and to detect the clinically associated oral mucosal lesions and conditions. A community-based survey was conducted in Ghaziabad among 332 betel nut users. Data on betel nut use was obtained through a self-administered questionnaire. Oral mucosal lesions and conditions were recorded using WHO criteria. Out of 332 betel nut users, 32.8% consumed Gutkha. 62.3% users used betel nut with tobacco. Most of the study population started chewing betel nut because of peer pressure and the habit started at the workplace or school. A majority found that there was no physical discomfort due to the habit. The significant oral diseases detected were oral leukoplakia in 11.7% and oral submucous fibrosis in 6.1% of individuals. The findings of the present study revealed that 74.7% of the participants were current chewers. 30.4% of all participants had oral mucosal lesions and conditions.

聴覚障がい幼児の咀嚼習慣と口腔機能発達を支援する食教育の実践

聴覚障がい幼児の咀嚼習慣と口腔機能発達を支援する食教育の実践

Endplate Potential Oscillation of Jaw Closing Muscles in Natural Chewing

Surface electromyograms (EMGs) in natural gum chewing were recorded in a monopolar manner from paired anterior temporalis and masseter muscles of four subjects. Electrodes were placed on the temple of the former muscle, and on the inferior portion of the latter muscle. The endplate potential (EPP) component was extracted from raw EMGs of the muscles using a digital filter: the frequency of the high-cut digital filter for eliminating action potentials was set to 12.5 Hz or 45 Hz. The EPP component of the EMG burst of each stroke in the natural chewing showed two phases, early negative slow wave and following oscillation, which was same as observed in the clenching task. From FFT analysis, the frequencies of the ipsilateral EPP oscillations were around 30 Hz for both the temporalis and masseter muscles, which was also the same for the clenching task. It is concluded that the contraction of the jaw closing muscles is regulated in an oscillating manner of the EPP even in natural chewing behaviors. This oscillation phenomenon of the EPP gives a useful hint about the mechanism of muscular movements including chewing.

Effects of Khat Chewing Behaviours on Health Outcomes among Male Khat Chewers in Bahir Dar, North West Ethiopia

Khat is found in the evergreen tree or large shrub, consists of whole fresh leaves and buds of a plant known as Catha edulis. It is an indigenous tree to Ethiopia, Kenya, and Yemen and more than 20 different compounds are fund in khat. Cathinone, which is the main active ingredient in Khat leave, is responsible for the pharmacological properties of Khat. Bahir Dar is a city that three percent of Ethiopia’s total production of khat is originated from. There is no community based study that has been done in Bahir Dar city to determine effects of khat chewing behaviours on self rated oral health status and risk on elevated blood pressure. Therefore, this study aimed to determine the effects of Khat chewing behaviors on oral health status and blood pressure on chewers. A community based cross-sectional study was conducted from January to September 2013 among chewers of Bahir Dar city. A total of 422 male khat chewers were included in study, 422 respond to the questioners, giving a response rate of 100%. The study found that the mean age of participants with standard deviation was 30.31 ± 1.39 years old. Sixty two percent of participants reported oral health problems and started khat chewing at early age. Started khat chewing at early age was found to be statistically significantly associated with self rated oral health problem (AOR: 2.85, CI 95%:1.26-6.45). Frequent chewers were 7.58 times more likely to be affected by self rated oral health problem compared to those who chewed less frequently (AOR: 7.58,95%CI:3.53-16.27). Chewers who chewed more than or equal to 100gms of khat per session were 4.33 times more likely to be affected by oral health problem compared to those who chewed less amount (AOR: 4.33, 95%CI: 2.49-7.53). As for the time period spent for Khat session, those who spent more than 6 hours in a khat session were 7.25 times more likely to have elevated systolic blood pressure compared to those who spent less than 6 hours, (AOR :7.25; 95%CI: 4.03-13.05). It was also found that those who spent more than 6 hours in a khat session were almost 9 times more likely to have elevated diastolic blood pressure compared to who spent less than 6 hours (AOR:8.99,95%CI:4.85-16.66).The risk of elevated systolic blood pressure was more than 5.26 times more likely among male chewers who reported increase amount of khat chewing compared to who reported decrease the amount in last 12 months, (AOR:5.26:95% CI: 2.76-10.15) and the risk of elevated diastolic blood pressure was more than 7 times more likely among chewers who reported increase amount of khat chewing in the last 12 months (AOR:7.25,95%CI:3.66-14.38).

Dynamics and Compliance Control of a Linkage Robot for Food Chewing

A chewing robot based on a six-bar linkage is developed to reproduce a variety of human chewing trajectories in 2-D space. In order to mimic human chewing behaviors for the purpose of objective measurements of food texture changes during chewing and preparation of food bolus, a compliance control is considered for the robot. In this paper, the dynamics of the robot is derived and validated through both simulations and experiments. Food models of peanuts and marshmallow are developed to simulate the food force-compression profiles. The compliance control of the robot is realized by a combination of an adaptive fuzzy velocity controller and a fuzzy adaptation mechanism for type of foods. By means of experimental comparisons between the chewing velocity and force results with food models, it is found that the compliance control proposed is able to control the chewing velocity in adapting to the food texture. The chewing robot developed is a valuable potential tool for evaluating food properties and bolus preparation in the field of food sciences.

Khat chewing and risky sexual behavior in Sub-Saharan Africa: a systematic review protocol

The objective of this review is to investigate the association between khat chewing and risky sexual behavior in Sub-Saharan Africa. Inclusion criteria Types of participants This review will consider studies that include young people aged between 10-24 years who practice khat chewing irrespective of their HIV status. Types of exposure(s) This review will consider studies that evaluate the association between khat chewing, which is the exposure of interest and risky sexual behavior. Types of outcomes The primary outcome of interest is risky sexual behavior. This review will consider studies that measure risky sexual behavior, which may be defined as early sexual debut, inconsistent use of condoms, unprotected sexual intercourse, having sex with commercial sex workers, or sex with multiple sexual partners. The secondary outcome of interest is HIV infection, other STIs or unwanted pregnancy.

Khat Chewing and Restrictive Dietary Behaviors Are Associated with Anemia among Pregnant Women in High Prevalence Rural Communities in Eastern Ethiopia

BackgroundAnemia affects a high proportion of pregnant women in the developing countries. Factors associated with it vary in context. This study aimed to determine the prevalence and predictors of anemia among pregnant women in the rural eastern Ethiopia.MethodsA community-based cross-sectional study was done on 1678 pregnant women who were selected by a cluster random sampling technique. A pregnant woman was identified as anemic if her hemoglobin concentration was <11 g/dl. Data were collected in a community-based setting. Multilevel mixed effect logistic regression was used to determine the adjusted odds ratios (AOR) with 95% confidence intervals (CI) for the predictors of anemia.ResultsAnemia was observed among 737(43.9%) of the 1678 pregnant women studied (95% CI 41.5%–46.3%). After controlling for the confounders, the risk of anemia was 29% higher in the women who chewed khat daily than those who sometimes or never did so (AOR, 1.29; 95% CI, 1.02–1.62). The study subjects with restrictive dietary behavior (reduced either meal size or frequency) had a 39% higher risk of anemia compared to those without restrictive dietary behavior (AOR, 1.39; 95% CI, 1.02–1.88). The risk of anemia was increased by 68% (AOR, 1.68; 95% CI, 1.15–2.47), and 60% (AOR, 1.60; 95% CI, 1.08–2.37) in parity levels of 2 births and 3 births, respectively. Compared to the first trimester, the risk of anemia was higher by two-fold (AOR, 2.09; 95% CI, 1.46–3.00) in the second trimester and by four-fold (AOR, 4.23; 95% CI, 2.97–6.02) in the third trimester.ConclusionIn this study, two out of five women were anemic. Chewing khat and restrictive dietary habits that are associated with anemia in the setting should be addressed through public education programs. Interventions should also focus on the women at higher parity levels and those who are in advanced stages of pregnancy.

The influence of religious affiliation on heavy drinking, heavy smoking and heavy betel nut chewing

The results of a national survey of determinants of drinking, smoking and betel-nut chewing behaviors are analyzed. The purpose of this paper is to empirically investigate whether drinking, smoking and betel-nut chewing are influenced by a variety of religions based on Taiwan data. Our results suggest that Buddhism, Taoism and practitioners of Chinese folk region are positively associated with heavy betel nut chewing while the religion effects on heavy smoking and drinking are statistically insignificant. Our findings on religion effects in Taiwan can be a valuable reference for comparison in Christian and western countries.

Salt and fat contents influence the microstructure of model cheeses, chewing/swallowing and in vivo aroma release

ABSTRACTThe effects of the lipid/protein ratio (20/28, 24/24, 28/20) and salt content of model cheeses were investigated simultaneously with respect to chewing behaviour, swallowing events and in vivo aroma release. Chewing parameters were measured by electromyography. Swallowing events were recorded manually. In vivo aroma release was investigated using nose‐space on‐line atmospheric pressure chemical ionisation–mass spectrometry. The values for chewing activity and time before swallowing were higher with lower lipid/protein ratios and lower salt contents, due to the greater mechanical resistance of the model cheeses. The corresponding microstructure was made up of smaller and more circular fat droplets in a stronger protein network. Furthermore, the maximum intensity and in‐mouth release rate of aroma decreased as the lipid/protein ratio fell. This could be explained by a retention effect of the proteins, which was stronger than the chewing effect. A rise in salt content triggered more rapid aroma release from the protein phase of the model cheese to the oral cavity, and thence to the nasal cavity. The larger fat droplet size in salt‐supplemented model cheeses slowed down the transfer of aroma release and the levels of aroma release after swallowing were higher. A more rapid swallowing was observed for model cheeses containing added salt and with a higher L/P ratio. It is suggested that this was due to greater salivation and lubrication. Moreover, the number of swallows was positively correlated to the total amount of aroma release. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Effects of alfalfa hay particle size in high-concentrate diets supplemented with unsaturated fat: Chewing behavior, total-tract digestibility, and milk production of dairy cows

This study evaluated the effects of increasing the physically effective neutral detergent fiber (peNDF) intake of lactating dairy cows fed high-concentrate diets supplemented with unsaturated fat on intake, eating behavior, diet sorting, chewing activity, total-tract digestibility, and milk production and composition. Diets contained 24% alfalfa hay (AH), 16% corn silage, 58% concentrate, and 2% yellow grease [dry matter (DM) basis], and dietary peNDF content was increased by varying the particle size (PS) of the AH. Nine multiparous cows averaging 87.8±14.8d in milk and weighing 653±53kg were randomly assigned to a triplicate 3×3 Latin square. During each 21-d period, cows were offered 1 of 3 total mixed rations that varied in PS of AH: fine, medium, and long, with a geometric mean particle length of 3.00, 3.57 and 3.87mm, respectively. Increasing PS quadratically affected DM intake (DMI; 24.7, 25.4, and 23.7kg/d, for fine, medium, and long, respectively), but cumulative DMI at 2, 4, and 6h after feeding was similar across treatments, averaging 23.4, 35.6 and 46.4% of total DMI for the 3 time points, respectively. Increased peNDF intake did not affect feed sorting, but increased daily eating time, and eating and total chewing time per kilogram of DMI. Daily rumination time exhibited a quadratic response, with highest rumination time for the medium diet. Dietary PS had no effects on digestibility in the total tract, but we observed, for fine, medium, and long diets, quadratic responses in milk production (41.5, 43.3, and 40.4kg/d), 4% fat-corrected milk production, and milk protein yield. Milk fat content decreased linearly with increasing PS, but milk fat content and fat:protein ratio were low for all treatments, likely due to adding unsaturated fat to a diet containing a high level of nonfiber carbohydrates (42.2% of DM). The composition, degree of saturation, and total conjugated linoleic acid content of fatty acids in milk fat were not affected by the change in peNDF content of the diet. The study indicates that a moderate increase in the PS of AH in diets containing unsaturated fat elevates peNDF intake and increases chewing activity, DMI, milk yield and milk fat production. However, the effects of dietary PS were quadratic, with maximum DMI and milk production observed with diets supplying 24% dietary peNDF (measured as the proportion of the ration retained on sieves >1.18mm multiplied by dietary neutral detergent fiber content; DM basis).

Physiological changes during feeding and rumination in cows

In this study, we investigated the physiological changes in cattle during feeding and rumination. We collected blood samples every 5 min by using an automated blood sampling system and simultaneously recorded feeding, ruminating, and other behaviors using a video camera. Plasma non-esterified fatty acid (NEFA) concentrations continuously decreased during feeding and decreased temporarily during rumination. Plasma glucose concentration continuously decreased during feeding and remained stable during rumination. During feeding and rumination, there were no characteristic increases and subsequent decreases in plasma insulin and growth hormone (GH) concentrations, although insulin concentrations were positively correlated with glucose concentration. NEFA concentrations were not correlated with GH and insulin concentrations. In terms of chewing behavior, feeding and rumination are similar; therefore, the changes in metabolites such as NEFA might have been the same. Combination of behavioral observations and application of an automated blood sampling system could contribute to new findings on behavioral and physiological changes regarding the temporary decrease in plasma NEFA concentration during rumination in ruminants.

Canine toys and training devices as sources of exposure to phthalates and bisphenol A: Quantitation of chemicals in leachate and in vitro screening for endocrine activity

Chewing and mouthing behaviors exhibited by pet dogs are likely to lead to oral exposures to a variety of environmental chemicals. Products intended for chewing and mouthing uses include toys and training devices that are often made of plastics. The goal of the current study was to determine if a subset of phthalates and bisphenol A (BPA), endocrine disrupting chemicals commonly found in plastics, leach out of dog toys and training devices (bumpers) into synthetic canine saliva. In vitro assays were used to screen leachates for endocrine activity. Bumper leachates were dominated by di-2-ethylhexyl phthalate (DEHP) and BPA, with concentrations reaching low μgmL−1 following short immersions in synthetic saliva. Simulated chewing of bumpers during immersion in synthetic saliva increased concentrations of phthalates and BPA as compared to new bumpers, while outdoor storage had variable effects on concentrations (increased DEHP; decreased BPA). Toys leached substantially lower concentrations of phthalates and BPA, with the exception of one toy which leached considerable amounts of diethyl phthalate. In vitro assays indicated anti-androgenic activity of bumper leachates, and estrogenic activity of both bumper and toy leachates. These results confirm that toys and training devices are potential sources of exposure to endocrine disrupting chemicals in pet dogs.

Dietary grain source and oil supplement: Feeding behavior and lactational performance of Holstein cows

Effects of grain source and dietary oil supplement on dry matter intake (DMI), feeding, chewing behavior, and production performance of lactating dairy cows were evaluated using eight multiparous Holstein cows (77±22.1 days in milk; mean±SD) in a duplicated 4×4 Latin square design with a 2×2 factorial arrangement of treatments. Experimental diets contained either ground barley or ground corn supplemented with either fish oil or soybean oil at 2% of dietary dry matter (DM). Geometric mean particle size of dietary treatments was 4.1mm. Dry matter intake tended (P=0.09) to be greater for barley- vs. corn-based diets (23.2 vs. 22.3kg/d), but was reduced for the fish oil compared to soybean oil supplemented diets (21.1 vs. 24.3kg/d; P<0.001). This reduction in DMI was attributed to smaller meal size (1.24 vs. 1.55kg of DM; P=0.004) and slower eating rate (0.082 vs. 0.098kg of DM/min; P<0.001) for fish oil compared to soybean oil supplemented diets. Main treatment effects interacted (P=0.005) for DMI of particles retained on 19mm sieve but not for sorting index. Eating rate (0.090kg of DM/min) was similar between barley- and corn-based diets, however, rumination time was greater for barley- compared to corn-based diets as result of longer rumination bout duration (32.5 vs. 28.5min/bout; P=0.01). Barley- compared to corn-based diets increased total chewing time by 71min (709 vs. 638min) for cows fed fish oil, but not for cows fed soybean oil. Grain source did not affect milk yield or milk composition. Compared to soybean oil, fish oil negatively affected milk yield (40.4 vs. 43.4kg/d; P=0.01), and thereby, both milk fat (0.91 vs. 1.26kg/d; P<0.001) and protein (1.23 vs. 1.33kg/d; P=0.007) production. However, feed efficiency (milk yield/DMI) was greater in fish oil compared to soybean oil supplemented diets (1.94 vs. 1.80; P=0.003). Results indicated that grain source and oil supplement can interact to affect feeding and chewing behavior, but not lactational performance of lactating cows.

Health risk perception and betel chewing behavior — The evidence from Taiwan

In this study, we provided an empirical examination of the interaction between people's health risk perception and betel chewing. We hypothesized that a better knowledge of possible health risks would reduce both the number of individuals who currently chew betel and the likelihood of those who do not yet chew betel to begin the habit. We constructed a simultaneous equation model with Bayesian two-stage approach to control the endogeneity between betel chewing and risk perception. Using a national survey of 26,684 observations in Taiwan, our study results indicated that better health knowledge reduced the possibility that people would become betel chewers. We also found that, in general, betel chewers have a poorer health risk perception than other population. Overall, the empirical evidence suggested that health authorities could reduce the odds of people becoming betel chewers by improving their knowledge of betel-chewing's harmful effects.

A data-analysis of lime addition on the nutritive value of sugarcane in Brazil

A statistical analysis of data from published studies was conducted to evaluate the effect of the addition of lime to fresh sugarcane in terms of its chemical composition, digestibility, and animal performance. A data set that included 55 treatment means from 20 refereed journal articles was collected and analyzed using a mixed model regression analysis with a random study effect. Lime addition directly increased dry matter (DM), ash, and Ca contents, as well as Ca:P ratio, and lowered organic matter (OM) concentration. The alkaline nature of lime linearly raised the sugarcane pH. Conversely, the concentration of nonfiber carbohydrates (NFC) was quadratically reduced by lime addition, whereas there was a quadratic increase in the neutral detergent fiber (NDFall), indigestible neutral detergent fiber (iNDF), and lignin (sa) and a linear increase in potentially digestible neutral detergent fiber (g/kg OM). The proportion of hemicellulose in the NDFall was unchanged by lime addition; thus, net fiber hydrolysis was not observed. The only beneficial effect of lime on the chemical composition of sugarcane was a linear decrease in the iNDF:NDFall ratio. The addition of lime to sugarcane did not affect DM intake or chewing behavior, although it increased the intake of NDFall. However, the mean NDFall intake was 0.87kg/100kg body weight, which is markedly lower than the reported value for traditional forages (1.00–1.20kg/100kg body weight). Indeed, NDFall digestibility was quadratically improved, but it was not enough to offset the loss of NFC across air exposure which, in turn, led to a linear decrease in the diet DM digestibility. Thus, lime treatment linearly decreased the average daily gain. It was concluded that lime increased fiber digestibility, but this effect did not offset the loss of water soluble carbohydrates, leading to a lower nutritive value of fresh sugarcane and a decrease in animal performance.

Chewing activities and particle size of rumen digesta and feces of precision-fed dairy heifers fed different forage levels with increasing levels of distillers grains

The objective of this study was to determine the effects of 2 differing forage to concentrate ratios (F:C) and various levels of corn dry distillers grain with solubles (DDGS) replacing canola meal in precision-fed dairy heifer rations on chewing behavior, rumen pH and fill, and particle size of rumen contents and feces. A split plot design with F:C as whole plot and DDGS inclusion level as subplot was administered in a 4-period 4 × 4 Latin square. Eight rumen-cannulated Holstein heifers (12.5±0.5 mo of age and 344±15kg of body weight, respectively) housed in individual stalls were allocated to F:C 50:50 (low forage) or 75:25 [high forage (HF); dry matter basis] and to a sequence of DDGS level (0, 7, 14, and 21%; dry matter basis). Forage was a mix of 50% corn silage and 50% grass hay (dry matter basis). Diets were fed once daily and formulated to provide equal amounts of nutrients and body weight gain. No differences were found for rumen pH between dietary treatments. Time spent eating tended to be longer for HF and was not affected by DDGS inclusion rate. Ruminating time did not differ by F:C, but linearly increased as DDGS increased (422 to 450±21 min/d). Total chewing time tended to be longer for HF and to increase linearly as DDGS increased (553 to 579±33 min/d). Wet rumen digesta weight and volume were greater for HF. Geometric mean particle length of rumen contents was greater for HF 2h prefeeding when analyzed with solubles (particles <0.15mm). Proportion of rumen solubles decreased as DDGS increased 5h postfeeding. Fecal geometric mean particle length and proportion of particles >1.18mm increased with increasing levels of DDGS and did not change with F:C. Total chewing time increased by the addition of DDGS and higher F:C. Heifers can compensate for lower physically effective neutral detergent fiber by modifying their chewing behavior. Rumen pH was never at a level that could induce acidosis, and lower eating time at lower F:C was somewhat compensated by time spent ruminating per unit of physically effective neutral detergent fiber intake. Dry distillers grains with solubles, when used in dairy heifer rations as a replacement for canola meal, yielded similar rumen digestion traits.

Association between textural profiles and surface electromyographic (sEMG) behaviors of microwavable cassava cuttlefish crackers with various expansion ratios

In this study, we monitored dynamic texture changes of microwaved cuttlefish crackers. Differing expansion ratios of crackers were observed in chips dried under various conditions. Correlations of expansibility, textural profile, and surface electromyography (sEMG) of crackers were evaluated. Semi-finished chips with moisture content of 7.13–9.63% gave maximal expansion. Higher expansion of samples resulted in decreased hardness but higher breaking energy. The integrity status and expansibility of crackers significantly affected sEMG behaviors during mastication. Chewing force during the early phase was significantly correlated with expansibilities and textural profiles, with coefficients of 0.811–0.858. Crackers with fewer fractures and more integrity during early chews gave significant correlations between chewing force and hardness. Likewise, variations in chewing work during mastication correlated with changes of breaking energy, with coefficients of 0.800–0.974. Potentially, differences in crunchiness textures can be easily perceived during later chewing actions. Results of this study revealed details of dynamic quality changes, and of relationships between chewing behaviors and textural properties of crackers during mastication.

Automatic recognition and classification of cattle chewing activity by an acoustic monitoring method with a single-axis acceleration sensor

Monitoring the eating habits and rumination of cattle is effective for evaluating forage values and making animal management decisions for stalls and grazing pastures. Acoustic monitoring is a feasible method to monitor these activities, but it requires automatic distinction and quantification of activities to gain broader application. This automatic distinction and quantification may be possible using a pattern matching method, which distinguishes jaw movements by extracting characteristic patterns from eating and ruminating, and then matches similar characteristic patterns in unanalyzed activities. The objectives of this study were to define an acoustic monitoring system with a single-axis acceleration sensor, to determine an effective sensor attachment site (i.e., the horn, forehead, or nasal bridge), and to assess the automatic classification of ingestive and ruminative chewing behaviors using a pattern matching method. Four beef cows fed Italian ryegrass silage were each recorded eating and ruminating for more than 60 and 20min, respectively. The oscillatory waveforms generated while eating and ruminating were clearly recorded by the single-axis acceleration sensor, regardless of sensor attachment site. The pattern matching method correctly distinguished ingestive chewing with an accuracy of over 0.9, regardless of the sensor site (estimated number of chews by automatic detection/true number of chews by manual detection). Placement of the sensor on the horn of the animal resulted in the most matched measurement (0.99). In contrast, the method overestimated ruminating chewing time (approximately 1.50) because noises that occurred during idling were misclassified as ruminating chewing. The provision of an additional chewing criterion for automatic detection, i.e., chewing is performed consecutively (context-based cues), improved the classification accuracy of ruminating to a range of 1.02–1.08. In conclusion, automatic detection using a pattern matching method successfully classified ingestive chewing and ruminating chewing in cattle, and a single-axis acceleration sensor was useful for acoustic monitoring at all sensor attachment sites.

Conspecific body weight, food intake, and rumination time affect food processing and forage behavior

Much research has been directed at the chemical characteristics of plants that influence forage digestibility but there is less investigation into relationships between chewing and foraging in herbivores. The role of body size on forage processing, via chewing, and ingestive behavior is poorly understood in spite of associations between conspecific body size of ruminants and botanical and nutritional composition of their diets. I examined the implications from a relationship between body weight and absolute forage intake (kg/day) and no relationship between body weight and rumination time (h/day) on chewing behavior and feeding time (h/day). Cattle were selected as the model species because the diets presented offered benefits to digestion from increased chewing and because of the number of studies that measured body weight, daily food intake, dietary nutritional characteristics, feeding time, and rumination characteristics on the same individuals. Data were extracted from 24 studies of cattle (n ≤ 74). Absolute food intake scaled allometrically (0.75) with body weight but rumination time was unrelated to body weight, meaning smaller animals had more rumination time for a unit weight of ingesta. Correspondingly, small cattle chewed the weight-specific ingesta more and fed longer than large animals, probably because of a reduction in time of rumen turnover. These findings might be revealing as to how differences in digestion and foraging are associated with body size among conspecific animals of wild ruminant species.

Ritualistic Chewing Behavior induced by mCPP in the rat is an animal model of Obsessive Compulsive Disorder

Obsessive Compulsive Disorder (OCD) is characterized by recurrent, anxiety-producing thoughts accompanied by unwanted, overwhelming urges to perform ritualistic behaviors. Pharmacological treatments for this disorder (serotonin uptake inhibitors) are problematic because there is a 6–8week delayed onset and half of the patients do not adequately respond. The present study evaluated whether Ritualistic Chewing Behaviors (RCBs) induced by the serotonin agonist mCPP in the rat is a behavioral model for OCD. The effects upon the RCBs induced by mCPP (1mg/kg) were evaluated following treatments with either the serotonin antagonist mianserin (3mg/kg), the dopamine antagonist haloperidol (1mg/kg), the GABA modulator diazepam (10mg/kg), or the serotonin uptake inhibitors clomipramine and fluvoxamine (15mg/kg). The response to mCPP was blocked by acute treatment with mianserin, but not with acute haloperidol or diazepam. Further experiments revealed that the effects of mCPP were blocked by chronic, but not acute, treatment with clomipramine and fluvoxamine. A time-course demonstrated that 14days of chronic treatment were required for blockade of the mCPP-evoked response.The current study demonstrates that mCPP-evoked RCBs may be a rodent model for OCD that can be used to predict the clinical efficacy and time course of novel OCD treatment. Future investigations may be able to use the current model as a tool for bench-marking corresponding changes in other measures of neurological activity that may provide insight into the mechanisms underlying OCD.