Coarse Diet Research Articles

Effect of Particle Size of Wheat and Barley Grain on the Digestibility and Fermentation of Carbohydrates in the Small and Large Intestines of Growing Pigs

The objective of this investigation was to study the effects of different cereal types, barley and wheat, with different particle sizes (PS) on the recovery of ileal digesta and fecal excretion, digestion of nutrients and fiber components, mean transit time (MTT), and short-chain fatty acid content and composition in growing pigs studied in two experiments. Five barrows with ileal cannulas (initial BW 35.9 ± 1.5 kg) in Experiment 1 and thirty-two castrated pigs (30.8 ± 1.3 kg) in Experiment 2 were fed four different diets: barley fine, barley coarse, wheat fine and wheat coarse diets. The cereal type and PS did not influence the relative weight of the small and large intestines and pH of digesta, whereas MTT in the large intestine of pigs fed the coarse barley diet was lower compared to pigs fed other diets (p < 0.05). Pigs fed the coarse barley diet had lower apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients and fiber (p < 0.05), whereas pigs fed the fine barley diet had similar AID and ATTD to pigs fed wheat fine and coarse diets (p < 0.05). In conclusion, the barley diet was more influenced by PS in comparison to wheat, thereby inducing lower AID and ATTD of nutrient.

New material of Stephanorhinus (Rhinocerotidae, Mammalia) from Jinyuan Cave, Luotuo Hill in Dalian, Northeast China

ABSTRACT Middle Pleistocene rhinocerotid material from the upper strata of Jinyuan Cave, Luotuo Hill, Dalian, is described in the present study. The specimens mainly consist of maxillary and mandible with dentition of juvenile and aged individuals, respectively. Based on comparison between the new discovery and known records of Pleistocene rhinocerotid, the Jinyuan Cave specimens are most similar to Stephanorhinus kirchbergensis and then have been identified as Stephanorhinus cf. kirchbergensis. Tooth loss has been present on the Jinyuan Cave rhinocerotid specimen, represented by a mandible without both p2s. This problem could be a result of heredity issues. This condition may be due to mechanical damage from a coarse diet, which can lead to tooth loss and alveolar remodelling, according to the findings from an environmental investigation.

Morpho-Histological Studies of the Gastrointestinal Tract of the Orange-Rumped Agouti (Dasyprocta leporina Linnaeus, 1758), with Special Reference to Morphometry and Histometry.

The morphology of the gastrointestinal tract (GI) is a strong indicator of a species' dietary habits. The objective of this study was to describe and quantitatively analyze the gross and microanatomy of the digestive tract of the orange/red-rumped agouti (Dasyprocta leporina) and relate it to the feeding habits of this animal. The digestive tracts of six adult males were used for this study. The results showed that the esophagus was thick (mean thickness of 1023.78 ± 28.97 μm) and lined by keratinized epithelium with scant esophageal glands. Mucosa-associated lymphocytic infiltration was robust throughout the GI tract. These findings suggest that the esophagus was well adapted to a coarse diet. The simple stomach with well-developed gastric glands in the fundus region (mean thickness of 605.39 ± 28.68 μm) was indicative of an adaptation to a carnivorous diet. The small intestine constituted approximately 80% of the length of the GI tract. The remarkable development of the jejunum with a greater villus length (mean thickness of 182.50 ± 27.38 μm) indicated a greater absorptive capacity in frugivorous and carnivorous diets. The long cecum and well-developed colon clearly indicated that the GI tract was well adapted to frugivorous and herbivorous diets. Overall, D. leporina showed that it is well adapted to an omnivorous diet. These results suggest that D. leporina can be fed a balanced omnivorous dry diet with a high protein content of plant or animal origin that is well suited to the architecture of the GI tract in captivity.

Nutrition al manipulation of feeding behaviour of birds

A research to manipulate the feeding behaviour of laying hens from nutritional perspective was conducted with 504 ISA Brown. Seventeen (17) week old ISA brown with weights ranging between 1590 and 1812 g were allocated to six dietary treatments. There were seven replicates per treatment with 12 birds each making a total of 42 pens in all. Experimental diets differed in the levels of energy, levels insoluble Non Starch Polysaccharide (NSP) and the particle sizes of the NSP. Birds had free access to water and feed during which feeding observations with video cameras were made to observe and record the feeding behaviour of birds at 17, 21, 25, 29, 33 and 35 weeks of age. A computer software programme called Observer 5.0 was used to analyze the observations by one person for 30 minutes per cage. In order to gain more insight in the feeding behaviour of laying hens, 60 laying hens were used for a passage rate experiment using titanium dioxide as an inert marker: Five birds were used for each dietary treatment, and replicated twice. At t=0, three titanium capsules were offered to each bird. After five different time points (30, 90, 180, 270 and 360 minutes), these birds were sacrificed and dissected. The gut (titanium) contents from different segments of the GIT (crop, gizzard, ileum, colon and caeca) of each bird were analysed using spectrophotometer at an absorbance of 408 nm. Results from the study indicate that the feeding behaviour of laying hen can be manipulated nutritionally. Bulky diets (10.6 MJ/kg) significantly (P<0.05) increased the eating time of laying hens by 15% compared with normal energy content (11.8 MJ/kg) and this led to consumption of more feed (average 2355g) than those of normal energy diets (2175g). Similarly, the separate effect of NSP, NSP coarseness and interaction between low energy; NSP and NSP coarseness influenced the eating behaviour. Feeding layers with low density diet containing a combination of low energy high NSP coarse NSP increased the amount of time birds spent feeding by 32% and consequently increased the feed intake by 11% (average feed intake of 135g ) above normal energy low NSP mixture diet (average feed intake of 120g). The passage rate experiment showed that Low energy High non starch polysaccharide coarse (LeHnspcoarse) diet reduces the gut transit time, thus birds quickly feel hungrier after a period of satiety, possibly resulting in a short inter-meal interval. Conclusively, the interaction between low energy, high NSP and NSP coarseness influence birds' feeding behaviour necessitating increase in eating time and faster passage rate via the GIT

Influence of Particle Size and Xylanase in Corn-Soybean Pelleted Diets on Performance, Nutrient Utilization, Microbiota and Short-Chain Fatty Acid Production in Young Broilers.

Simple SummaryThe use of enzymes, such as xylanase, in poultry production has the objective of improving the productive value of diets by releasing nutrient content and boosting animal performance, with the consequent reduction in feed costs and environmental impact. Additionally, xylanase could have benefits in the intestinal microbiota through the prebiotic effect of oligosaccharides produced from the arabinoxylans present in the diet. In broilers, little is known of how feed processing of the diet, such as pelletizing, particle size, and grinding method, could affect enzyme efficacy in corn-based diets. The present study aimed to understand the effects of corn particle size and xylanase supplementation in pelleted diets on the performance, nutrient utilization, short-chain fatty acid concentration, gut microbiota, and intestinal development of young broilers. Our results have shown evidence of the importance of coarse particles on the gut development and digestibility of nutrients, and along with the xylanase, has shown benefits on microbiota modulation and in reducing the variation in body weight.The objective of this study was to investigate the effects of particle size and xylanase supplementation in corn-based pellet diets on the performance and digestive traits in young broilers. A total of 512 male Ross 308 broilers were used in a 21-day study. The treatments were designed in a 4 × 2 factorial arrangement with four levels of geometric mean diameter (Dgw) of corn (540, 660, 1390, and 1700 µm), and two levels of xylanase (0 or 16,000 BXU/kg diet). Feeding coarse corn diets (1390 and 1700 µm Dgw) and xylanase supplementation showed an inferior coefficient of variation of body weight. Higher gizzard weight, microbiome alpha-diversity, and clustered separately beta-diversity (p < 0.05) were observed in birds fed coarse diets. The addition of xylanase promoted changes in relative bacteria abundance, increasing Lachnospiraceae, Defluviitaleaceae, Bacteroidaceae, Bacillaceae, Eggerthellaceae, and Streptococcaceae families in the 1700 µm group, and Christensenellaceae and Lachnospiraceae families in the 540 µm Dgw group. In conclusion, xylanase supplementation and particle size of corn interact in the intestinal environment, showing changes in microbial composition. Coarse diets and xylanase supplementation showed improved body weight homogeneity, which might be related to a better gut development and microbiota modulation.

The Effects of Feed Particle Size and Floor Type on the Growth Performance, GIT Development, and Pododermatitis in Broiler Chickens.

Simple SummaryThe use of dietary structural components like whole grains together with using different floor designs is of great interest in terms of alterations of the digestive tract, level of feed intake, growth performance and foot pad health in broilers. The current study tested the impact of feed particle size and various floor systems (litter only; litter with floor heating; 50% or 100% slatted floors) on the abovementioned parameters in broiler chickens. A finely ground diet reduced gizzard and pancreas weights compared to a coarsely ground diet. A coarse diet led to a marked higher body weight. No effect of feed particle size on foot pad health was observed. Housing broilers on different flooring designs showed no effect on gizzard and pancreas weights. Using a fully slatted floor led to a higher body weight while having no effect on reducing the incidence of foot pad dermatitis.The aim of the present study was to evaluate the effects of feed particle size and flooring designs on organ traits, performance and pododermatitis in broilers. A total of 480 broilers (Ross 308) of both sexes were randomly assigned to two feeding groups (finely or coarsely ground pelleted diets; with addition of 5% to 10% intact wheat in coarsely diets) and four different housing systems (litter; litter with floor heating; partially or fully slatted floor) with three subgroups each. A coarse diet increased the final gizzard and pancreas weights (p < 0.001) while decreasing the risk of Isthmus gastrici dilatation compared to a fine diet (p < 0.001). Broilers fed a coarse diet displayed an increased final body weight (p = 0.023) and led to a favourable feed conversion ratio. Final body weight was the highest (p < 0.001) for birds housed on partially or fully slatted floor. Housing birds on litter with floor heating showed the lowest pododermatitis scoring (p < 0.001). It seems to be favourable to use coarse diets for organ development, whereas slatted floors seem to foster enlargement of the Isthmus gastrici. Increasing growth performance was possible both when using coarse diets or slatted floors.

Effects of dietary particle size and fiber source on nutrient digestibility and short chain fatty acid production in cannulated growing pigs

The objective of this study was to evaluate the effects of different feed particle sizes and fiber sources on nutrient digestibility and short chain fatty acids (SCFA) concentration in different intestinal segments of pigs. Eighteen barrows with T-cannula in the distal ileum were randomly allotted to a 3 × 2 factorial arrangement with 3 different high-fiber diets including corn bran (CB), sugar beet pulp (SBP) and soybean hulls (SH), and 2 different feed particle sizes. The experiment contained 2 periods, and each period lasted for 15 days, including 10 days for diets adaptation, 3 days for fecal collection, and 2 days for ileal digesta collection. The results indicated that coarse diets decreased (P < 0.05) the apparent ileal digestibility (AID) of gross energy (GE), dry matter (DM), organic matter (OM), total dietary fiber (TDF) and insoluble dietary fiber (IDF), but tended to increase (P < 0.10) the hindgut disappearance of GE. Feed particle sizes did not affect the apparent total tract digestibility (ATTD) of dietary nutrients except for ether extract (EE), the AID of amino acid (AA) and SCFA concentrations in ileal digesta, but fiber sources had significant effects on (P < 0.05) the AID, ATTD and hindgut disappearance of most nutrients in diets and the fecal SCFA concentrations. Moreover, there were interactive effects (P < 0.05) between particle sizes and fiber sources on the hindgut disappearance of fiber fractions. Coarse CB diets increased (P < 0.05) the hindgut disappearance of TDF, soluble dietary fiber (SDF), IDF, neutral detergent fiber (aNDF), acid detergent fiber (ADF) and cellulose, but the different particle size of SBP and SH did not affect the hindgut disappearance of TDF, ADF and cellulose. In conclusion, particle size mainly affected the ileal digestibility of nutrients and fiber fractions in pigs, but had few effects on their whole gastrointestinal digestibility, and these influences varied among different dietary fiber sources.

The effects of coarse and wet feeding on performance parameters, gastrointestinal tract and tibia traits, and digesta phytase activity in egg-type pullets, either fed a low or moderate phosphorus diet

In a 2 × 2 × 2 factorial design, the effects of dietary non-phytate phosphorus (NPP) levels, 0.17% (low) and 0.33% (moderate), diet moisture (dry and wet), and diet particle size (coarse and fine), were studied on egg production, characteristics of gastrointestinal tract (GIT) and tibia, digesta pH, and phytase activity in layer pullets (16 to 28 wk of age). The low NPP diet increased average daily water intake (ADWI) to ADFI ratio (4.2%) from 16 to 17 wk, but decreased this ratio (2.8%) from 23 to 27 wk. It decreased ADFI (1.5%) and egg mass production (3.8%) from 19 to 22 wk. It decreased egg weight (0.29g) and ADWI (2.1%) from 23 to 27 wk. At 22 wk, the GIT relative empty organ weights were (g/kg BW) higher for proventriculus + gizzard (0.96), duodeneum (0.94), and jejunum + ileum (1.95) with the low vs. moderate NPP diet. The low NPP diet decreased digesta phytase activity in crop and proventriculus+gizzard at 28 wk. The wet diet increased ADFI, ADWI, and ADWI/ADFI ratio from 16 to 27 wk, egg mass production (3.0%) from 19 to 22 wk, and egg weight (0.45g) from 23 to 27 wk. The wet diet also increased digesta phytase activity in proventriculus+gizzard. The coarse diet decreased ADFI from 19 to 22 wk (1.7%) and 23 to 27 wk (1.2%). The coarse diet caused reduced egg mass production (2.6%) from 23 to 27 wk. Egg shell breaking strength was increased on the coarse diet (0.9 Newton). The coarse diet increased ADWI/ADFI ratio from 16 to 27 wk, and increased relative gizzard weight by 1.95 and 0.81g/kg BW at 22 and 28 wk, respectively. The coarse diet increased jejunal/ileal pH with 0.16 units at 28 wk. None of the tested parameters affected tibia characteristics. It was concluded that a low NPP diet did not clearly affect the studied parameters. The wet diet increased ADFI, ADWI, and egg production. The coarse diet increased ADWI, egg shell breaking strength, relative gizzard weight, and reduced ADFI and egg production.

Effect of ingredient particle sizes and dietary viscosity on digestion and faecal waste of striped catfish (Pangasianodon hypophthalmus )

The ingredients' particle size and dietary viscosity may alter digestion, performance and faecal waste management of fish. This study aimed to assess the effect of grinding screen sizes of feed ingredients and dietary viscosity on digestibility, faecal waste and performance of striped catfish (Pangasianodon hypophthalmus, Sauvage, 1878). The experiment had a 2 × 3 factorial-design: two feed mesh particle sizes, by grinding ingredient mixtures at two screen sizes (0.8 versus 1.0 mm); and three dietary viscosity levels, created by exchanging carboxymethylcellulose by guar gum (GG) (0, 3 and 6 g of GG/kg of diet). Six diets were assigned to 18 tanks, each connected to three faecal settling tanks. All aquaria were stocked with 20 fish (82 g per fish). After 52 experimental days, dietary viscosity negatively affected both feed digestibility and performance of striped catfish; as a result, the amount of organic matter in the culture system through faeces had increased significantly. The coarse diets significantly increased the digestibility of dry matter and carbohydrate but worsened feed conversion ratio. Increasing dietary viscosity tended to increase the viscosity and moisture content of the faeces, but significantly accelerated the faecal disintegration through the reduction of both faecal recovery and the amount of recovered faeces.

Erosive and Mechanical Tooth Wear in Viking Age Icelanders.

(1) Background: The importance of the Icelandic Sagas as a source of information about diet habits in medieval Iceland, and possibly other Nordic countries, is obvious. Extensive tooth wear in archaeological material worldwide has revealed that the main cause of this wear is believed to have been a coarse diet. Near the volcano Hekla, 66 skeletons dated from before 1104 were excavated, and 49 skulls could be evaluated for tooth wear. The purpose of this study was to determine the main causes of tooth wear in light of diet and beverage consumption described in the Sagas; (2) Materials and methods: Two methods were used to evaluate tooth wear and seven for age estimation; (3) Results: Extensive tooth wear was seen in all of the groups, increasing with age. The first molars had the highest score, with no difference between sexes. These had all the similarities seen in wear from a coarse diet, but also presented with characteristics that are seen in erosion in modern Icelanders, through consuming excessive amounts of soft drinks. According to the Sagas, acidic whey was a daily drink and was used for the preservation of food in Iceland, until fairly recently; (4) Conclusions: It is postulated that the consumption of acidic drinks and food, in addition to a coarse and rough diet, played a significant role in the dental wear seen in ancient Icelanders.

Possible Causes of Tooth Wear in Medieval Icelanders

Objectives: The importance of the Icelandic Sagas as a source of information on the way of life and diet habits in Iceland and possibly other Nordic countries 1000 years ago is obvious. Extensive tooth wear in archaeological human skull material worldwide has been blamed on coarse diet. Near volcano Hekla, 66 skeletons dated from before 1104 were excavated from a graveyard. The purpose of this study was to determine the main causes of tooth wear in Icelanders 1000 years ago. Materials and methods: Available were 49 skulls for research. Two methods were used to evaluate tooth wear and seven for age estimation. An attempt was made to determine main causes of tooth wear in the light of likely diet and beverage consumption according to a computer search on food and drink customs described in the Icelandic Sagas. Results: Extensive tooth wear was seen in all groups, increasing with age. The first molars had the highest score with no difference between sexes. It had all the similarities seen in wear from coarse diet. In some instances it had similar characteristics as seen in erosion in modern Icelanders consuming excessive amounts of soft drinks. According to the Sagas, acidic whey was a daily drink and used for preservation of food in Iceland until recently. Conclusions: It is postulated that consumption of acidic drinks and food in addition to a coarse and rough diet, played a significant role in the dental erosion seen in ancient Icelanders.

Diet and Implant Complications.

A hard or coarse diet may impart a substantial off-axial load to dental implant-supported prostheses and may induce a component, implant midbody fracture or late loss of integration. This may be especially true when there is a large crown to implant ratio. A patient who is able to generate an excessive bite force along with chronic cyclic loading with hard or coarse foods may have implant body or component fractures. There are no established parameters for crown to implant ratio or for detrimental bite loads. Implant longevity may be dependent on many factors, including the supporting bone quality and volume, crown to implant ratio, implant width and length, the prosthetic occlusal scheme and bite force/arch location, and the patient's dietary load.

Enamel erosion and mechanical tooth wear in medieval Icelanders

Objectives: The Icelandic Sagas are an important source of information on the way of life and diet habits in Iceland and possibly other Nordic countries 1000 years ago. Archaeological human skull material worldwide has revealed extensive tooth wear, with the main cause believed to be coarse diet. From a graveyard near volcano Hekla, 66 skeletons dated from before 1104 were excavated. The purpose of this study was to determine the main causes of tooth wear in Icelanders 1000 years ago.Materials and methods: Forty-nine skulls were available for research. Two methods were used to evaluate tooth wear and seven for age estimation. An attempt was made to determine the main causes of tooth wear in the light of likely diet and beverage consumption according to a computer search on food and drink customs described in the Icelandic Sagas. Results: Tooth wear was extensive in all groups, increasing with age. The highest score was on first molars, with no difference between sexes. It had all the similarities seen in wear from coarse diet. In some instances it had similar characteristics to those seen in erosion in modern Icelanders consuming excessive amounts of soft drinks. According to the Sagas, acidic whey was a daily drink and used for preservation of food in Iceland until recently. Conclusions: Since acidic whey has considerably high dental erosive potential, it is postulated that consumption of acidic drinks and food, in addition to a coarse and rough diet, played a significant role in the dental wear of ancient Icelanders.

Diet structure, butyric acid, and fermentable carbohydrates influence growth performance, gut morphology, and cecal fermentation characteristics in broilers

An experiment with 288 male (Ross 308) 1-d-old broilers was conducted to test the hypothesis that a coarse diet supplemented with butyric acid (BA) and fermentable carbohydrates (FC) improves performance of broilers with a poorly digestible protein source. The interaction effects of diet structure (fine or coarse), FC supplementation (with or without), and BA supplementation (with or without) in a poorly digestible diet based on rapeseed meal (RSM) were tested in a factorial arrangement of 8 (2 × 2 × 2) dietary treatments. The coarseness of the diet affected feed intake (FI) (P < 0.001), BW gain (P = 0.001), and the feed conversion ratio (FCR) (P = 0.001) positively. Broilers fed the coarse diets had, on average, 14% heavier gizzards and 11, 7, 5, and 6% lower relative empty weights of the crop, duodenum, jejunum, and ileum, respectively, compared with those fed the fine diets. Dietary coarseness resulted in, on average, 6% greater ileal protein digestibility, 20% lower gizzard pH, 19% greater villus height, 18% lower crypt depth, and 23% reduced cecal branched chain fatty acids (BCFA) compared with chickens fed the fine diets. Broilers fed BA-supplemented diets had an improved FCR (P = 0.004) and decreased crypt depth (P < 0.001) compared with those fed diets without BA. Fermentable carbohydrate supplementation did not influence growth performance, gut development, or contents of total BCFA and total biogenic amines in the cecal digesta (P > 0.05). Supplementation with FC, however, decreased the cecal concentration of spermine by approximately 31% compared with broilers fed diets without FC (P = 0.002). In conclusion, feeding a coarse diet supplemented with BA improved performance of broilers fed a diet containing a poorly digestible protein source. The negative effects of a poorly digestible protein source can thus be partly counterbalanced by coarse grinding and BA supplementation in the diet.

Functional Characterization Reveals Novel Putative Coding Sequences in Prevotella ruminicola Genome Extracted from Rumen Metagenomic Studies

Aim: To reassemble Prevotella ruminicola genome from rumen metagenomic data of cattle and buffalo and compare with the published reference genome. Method: Rumen microbial communities from Mehsani buffaloes (n = 8) and Kankrej cattle (n = 8), each adapted to different proportions of a dry or green roughage diet, were subjected to metagenomic sequencing by Ion Torrent PGM, and subsequent reads were analyzed by MG-RAST. Using reference-guided assembly of the sequences against the published P. ruminicola strain 23, draft genomes of 2.56 and 2.46 Mb were reconstructed from Mehsani buffalo and Kankrej cows, respectively. The genomes were annotated using the RAST Server and carbohydrate active enzyme (CAZyme) analysis. Results: Taxonomic analysis by MG-RAST revealed P. ruminicola to be the most abundant species present among the rumen microflora. Functional annotation of reconstructed genomes using the RAST Server depicted the maximum assignment of coding sequences involved in the subsystems amino acid and derivatives and carbohydrate metabolism. CAZyme profiling revealed the glycoside hydrolases (GH) family to be the most abundant. GH family subclassification revealed that the extracted genomes had more sequence hits for GH2, GH3, GH92 and GH97 as compared to the reference. Conclusion: The results reflect the metabolic significance of rumen-adapted P. ruminicola in utilizing a coarse diet for animals based on acquisition of novel genetic elements.

Protein source and dietary structure influence growth performance, gut morphology, and hindgut fermentation characteristics in broilers

An experiment with 210 male (Ross 308) 1-d-old broilers was conducted to test the hypothesis that a coarse diet improves performance of broilers fed a poorly digestible protein source. A highly digestible diet based on soybean meal was gradually replaced by a low digestible diet based on rapeseed meal (RSM) in 5 steps (RSM-0%, RSM-25%, RSM-50%, RSM-75%, and RSM-100%). Two diet structures (fine and coarse) were used as an additional factor. These 2 factors and their interactions were tested at different ages in a factorial arrangement with 10 dietary treatments. An increase in indigestible dietary protein negatively affected feed intake (P = 0.003), BW gain (P = 0.008), and feed conversion ratio (P = 0.034). This increase in dietary indigestible protein contents resulted in a decrease (P = 0.001) in total cecal volatile fatty acid concentration from 209.1 to 125.9 mmol/kg of DM digesta in broilers with increasing RSM in diets. Increase in the indigestible protein level, from RSM-0% to RSM-100%, resulted in a decrease (P = 0.042) in villus heights (1,782 vs. 1,574 µm), whereas crypt depths increased (P = 0.021; 237 vs. 274 µm). A coarse diet improved feed intake (P = 0.006), BW gain (P = 0.014), and feed conversion ratio (P = 0.009). Broilers fed coarse diets had approximately 11, 24, and 10% lower relative empty weights of the crop, proventriculus, and jejunum, respectively, whereas a 15% heavier gizzard was found compared with those fed the fine diets. Dietary coarseness resulted in approximately 16% lower gizzard pH, 21% greater villus heights, 27% lower crypt depths, 24% reduced branched-chain fatty acids, and 12% lower biogenic amines in the cecal digesta compared with broilers fed fine diets. In conclusion, feeding coarse particles improved broiler performance irrespective of digestibility of the diet. Hindgut protein fermentation can be reduced by coarse grinding of the diet.

Loss of molar occlusion and mandibular morphology in adults in an ancient human population consuming a coarse diet

The purpose of the study is to investigate the link between number of molar teeth retained in occlusion and mandibular morphology in adults in an ancient, high dental wear human population. The study material comprises skeletons from Mediaeval Wharram Percy, England (N = 50 female, 69 male adults). It was hypothesized that adults retaining fewer occluding molars would show reduction in mandibular dimensions, particularly in the ascending ramus and gonial regions where the main muscles of mastication have their insertions. Molar occlusal status is assessed using the concept of functional units. Mandibular morphology is assessed using a suite of ten linear measurements plus the mandibular angle. Results show no evidence for any association between number of molars retained in occlusion and mandibular angle. There was an association between mandibular size and number of molars retained in occlusion, with smaller mandibular dimensions in those retaining fewer occluding molars. Some measurements were affected more than others so that there was also some shape alteration. Alteration of mandibular dimensions was more clearly demonstrable in females than in males. Only in females could significant reduction in the ascending ramus and gonial regions be demonstrated. Reasons for the apparent difference in response to loss of molar occlusion between male and female mandibles are unclear, but sex differences in bony metabolism mediated by hormonal factors may be implicated. Results suggest that care should be exercised when including mandibles from individuals showing loss of molar occlusion in morphological studies.

Gastro-Intestinal Response and Passage Time of Pelleted Diets in Digestive Tract of Broilers

An experiment was conducted to examine the effect of pellet size and fibrous diet on intestinal passage time of feed in the digestive tract of broilers. A total of 64 day old chicks were used in a completely randomized factorial design with two different diets (copra meal and corn-soy based diets) and two pellet size (fine and coarse). On day 1-5 of week seven, the birds were fed the experimental diets. On day 6, after a 12 h feed restriction, all birds were orally administered with 85 mg chromium oxide in a gelatine capsule. Four birds per treatment were killed by cervical dislocation. Gizzard and small intestine were weighed and opened. The colour of the digesta observed to visually determine the location of the chromium oxide. The faeces were observed for first appearance of entire coloured faeces and then on an hourly basis up to the disappearance of coloured faeces. The experimental design was a two way factorial with two basal diets and pellet sizes. Data indicated that a copra meal diet moved in the digestive tract was slower than a corn-soy diet. The first appearance of the marker in the faeces of birds fed the copra meal diet was 52 min later than for those fed the corn-soy diet. The movement in the digestive tract of the fine ground diets was slower than that of the coarse diets. The effect of pellet size on feed passage time was only evident in the copra meal based diet.

Effects of Particle Size of Barley on Intestinal Morphology, Growth Performance and Nutrient Digestibility in Pigs

A growth trial and a digestibility trial were conducted to examine the effect of feed particle size on the performance, nutrient digestibility, gastric ulceration and intestinal morphology in pigs fed barley-based diets. Barley was processed through a hammer mill to achieve four diets varying in particle size (average particle size+standard deviation): coarse (1,100±2.19 μm), medium (785±2.23 μm), fine (434+1.70 μm) and mixed (1/3 of coarse, medium and fine) (789+2.45 μm). Sixty-four entire male pigs were used in the growth trial and the diets were fed ad libitum between 31 kg and 87 kg live weight. Following slaughter, stomach and ileal tissues were scored for integrity (ulceration or damage) and histological measurements taken. Twenty-four entire male pigs were used in the digestibility trial, which involved total faecal collection. Over the entire growth phase, there were no differences (p>0.05) in average daily gain and feed conversion ratio between pigs fed diets of different particle size. Pigs fed the coarse and medium diets had lower (p 0.05) being observed for villous height or crypt depth. Faecal digestibility coefficients of neutral and acid detergent fibre were the highest (p<0.05) for the mixed diet, intermediate for the fine and coarse diets and the lowest for the medium diet. A similar numerical trend (p = 0.103) was observed for the apparent faecal energy digestibility coefficient. It is concluded that, with barley based diets, a variation in average particle size between 400 μm and 1,100 μm had no effect on pig performance but the fine dietary particle size affected the integrity of the stomach, as well as the structure of the small intestine, thus compromising overall gut health. Our data also demonstrate that changes in particle size distribution during the digestion process, rather than average particle size or particle size variation, are related to apparent faecal digestibility.

Apparent nutrient digestibility and excreta quality in African grey parrots fed two pelleted diets based on coarsely or finely ground ingredients

A feeding trial was performed to study the influence of particle size in extruded parrot pellets on apparent digestibility and excreta consistency and pH. Two test diets were alternately provided to eight African grey parrots according to a 2 x 2 cross-over design. Both diets were similar in nutrient content and ingredient composition but differed in particle size of the composing particles of individual pellets. Apparent digestibility of macronutrients was studied using the total collection method. Next, the appearance of the excreta was studied by calculation of weight-surface ratio of individual excrements as an objective measurement of consistency. Last, excreta pH was measured directly on fresh excrements and on homogenized 10% excreta solutions. Neither apparent digestibility coefficients nor excreta pH values were significantly different in parrots fed the two diets. However, excreta consistency was significantly (p < 0.05) more solid when fed the coarse diet than when fed with the finely ground diet. The results of this study suggest that excreta consistency can be improved through larger particle size, without adverse effects on nutritive value of the diet.