Coarse Diet Research Articles

A refined fish consumption model for lactating Cape fur seals (Arctocephalus pusillus pusillus), based on scat analyses

AbstractA refined fish consumption model for lactating Cape fur seals in Namibia during the eight-month lactation period, which allows for spatio-temporal variation in the diet as determined by scat analyses, has been developed. Previous estimates of prey consumption by Cape fur seals have been based mostly on coarse diet composition models. Sensitivity analyses showed that the energetic requirement and mass of lactating females (bioenergetic variables), as well as the energetic density of prey (diet variable), contributed most to the uncertainty in consumption estimates. Uncertainty in the remaining input variables had minimal effects on the estimates of food consumption. The consumption of commercial prey (horse mackerel, hake and pelagic fish) was greatest by the colony at Cape Cross. The model estimated that a female of average mass 55 kg ingested, on average, 11% of her body mass per day. This model is easily applied to other age/sex classes of the seal population. It permits improvement of the estimates of prey consumption by seals, which are useful for assessing levels of competitive interactions between seals and fisheries or other predators, or the impacts of seals on prey species.

Effect of feed particle size and feed processing on morphological characteristics in the small and large intestine of pigs and on adhesion of Salmonella enterica serovar Typhimurium DT12 in the ileum in vitro1

A 2 x 2 factorial experiment with pigs was undertaken to investigate the effect of particle size (fine and coarse) and feed processing (pelleted and nonpelleted) on morphological characteristics in the small intestine, cecum, and colon of pigs and on the adhesion of Salmonella enterica serovar Typhimurium DT12 to the ileum in vitro. Ninety-six pigs (average BW = 33 +/- 7 kg) were fed the experimental diets. After 4 wk, 24 pigs were selected (six pigs per diet) and euthanized, and tissue samples were taken from the mid and distal small intestine, cecum, and distal colon. The effects of particle size and feed processing on villus height and crypt depth in the small intestine were minor. Feeding coarse diets increased (P = 0.05) the crypt depth in the colon. The crypt depth was 420 +/- 12 and 449 +/- 12 microm in pigs fed finely and coarsely ground feed, respectively. Pigs fed pelleted diets had a larger (P = 0.01) staining area for neutral mucins, as well as for acidic and sulfomucins on the villi of the distal small intestine than pigs fed nonpelleted diets. The area was 41, 46, and 33% larger for neutral, acidic, and sulfomucins, respectively. The mucin-staining areas of the crypts in the cecum and the colon were not affected by the experimental diets. Examination of lectin binding characteristics of the distal small intestine and the cecum did not reveal any differences between the experimental diets. Using a pig intestine organ culture model, Salmonella adhered less (P < 0.05) to the ileal tissue of pigs fed the nonpelleted diets than to those fed pelleted diets; the adherence was 60% less in these pigs. Results of this study suggest that pigs fed pelleted diets secrete mucins that are capable of binding Salmonella enterica serovar Typhimurium DT12 and thereby allowing for colonization. Therefore, pigs fed a nonpelleted diet are better protected against Salmonella infections than pigs fed a pelleted diet.

Effects of physical properties of feed on microbial ecology and survival of Salmonella enterica serovar Typhimurium in the pig gastrointestinal tract.

A two-by-two factorial experiment with pigs was conducted to study the effect of feed grinding (fine and coarse) and feed processing (pelleted and nonpelleted) on physicochemical properties, microbial populations, and survival of Salmonella enterica serovar Typhimurium DT12 in the gastrointestinal tracts of pigs. Results demonstrated a strong effect of diet on parameters measured in the stomachs of the pigs, whereas the effect was less in the other parts of the gastrointestinal tract. Pigs fed the coarse nonpelleted (C-NP) diet showed more solid gastric content with higher dry matter content than pigs fed the fine nonpelleted (F-NP), coarse pelleted (C-P), or fine pelleted (F-P) diet. Pigs fed the C-NP diet also showed significantly increased number of anaerobic bacteria (P < 0.05), increased concentrations of organic acids, and reduced pH in the stomach. In addition, pigs fed the C-NP diet showed increased in vitro death rate of S. enterica serovar Typhimurium DT12 in content from the stomach (P < 0.001). Pigs fed the C-NP diet had a significantly higher concentration of undissociated lactic acid in gastric content than pigs fed the other diets (P < 0.001). A strong correlation between the concentration of undissociated lactic acid and the death rate of S. enterica serovar Typhimurium DT12 was found. In the distal small intestine, cecum, and midcolon, significantly lower numbers of coliform bacteria were observed in pigs fed the coarse diets than in pigs fed the fine diets (P < 0.01). Pigs fed the C-NP diet showed the lowest number of coliform bacteria in these segments of the gastrointestinal tract. Pigs fed the coarse diets showed increased concentration of butyric acid in the cecum (P < 0.05) and colon (P < 0.10) compared with pigs fed the fine diets. It was concluded that feeding a coarsely ground meal feed to pigs changes the physicochemical and microbial properties of content in the stomach, which decreases the survival of Salmonella during passage through the stomach. In this way the stomach acts as a barrier preventing harmful bacteria from entering and proliferating in the lower part of the gastrointestinal tract.

Site and extent of starch digestion of whole-plant maize silages differing in maturity stage and chop length, in dairy cows

The aims of this study were to determine the extent of starch digestion in the different digestive compartments in cows fed high whole-plant maize silage (WPMS) diets, and to evaluate the effect of maturity and chop length of WPMS on starch digestion, ruminal fermentation and milk production. The study was conducted on four dairy cows fitted with ruminal, duodenal, and ileal cannulas, in a 4×4 Latin square design. Dietary treatments differed in maturity stage (early vs. late) and chop length (fine vs. coarse) of WPMS. The WPMS were not processed. Diets, containing 80% WPMS, were fed at 90% of ad libitum intake level. Organic matter digestion in the different segments of the gastrointestinal tract and mean retention time of particles in the rumen and total tract, were similar between treatments. In late harvested WPMS, starch particle size distribution differed between coarse and fine chop length, and differences disappeared in rumen content. Total tract digestibility of starch was lower with late (95% of intake) than with early (99% of intake) stage. Starch ruminal digestion was high in comparison with diets containing similar proportion of starch provided by maize grain. Ruminal starch digestion was the highest with the early fine diet (95.4% of intake) and the lowest with the late coarse diet (71.3% of intake), and 70% of starch escaping ruminal digestion was digested in the small intestine. Starch digestion in hindgut was unaffected by treatments. The ruminal and total tract digestion of NDF and the ruminal pH, VFA, and ammonia concentrations were not or poorly affected by treatments. There was no difference in milk production and composition between treatments. Although differences in site of starch digestion between treatments were not statistically significant, this study suggested that the site and extent of starch digestion could be modulated by controlling maturity stage and chop length of WPMS, without affecting the energy value of the diet.

Effect of feed particle size and dietary melatonin supplementation on gastric ulcers in swine

Gastric ulcers may be an underrecognized problem in the swine industry. An experiment was conducted to evaluate the effects of dietary melatonin supplementation and particle size on prevalence and severity of ulcers in growing pigs. Sixty-four Yorkshire barrows and gilts (29.5 ± 1.0 kg) received either a finely ground (763 ± 2.18 µm) or a coarsely ground (953 ± 2.29 µm) corn–wheat diet, either with or without added melatonin (5 mg kg−1). One half of the pigs underwent endoscopic examination to assess the severity of ulcers on days 4 and 25. Growth performance and feed consumption were monitored throughout the experiment. All pigs were slaughtered on day 28, and ulcers were assessed postmortem. Endoscopy at the beginning of the experiment found that 53% of the pigs already had some degree of ulceration. Pigs fed the fine diet had greater average daily gain and average daily feed intake than pigs fed the coarse diet (P &lt; 0.05), but particle size did not significantly affect prevalence of stomach ulcers. Melatonin supplementation increased the apparent digestibility of crude protein (P &lt; 0.04) and dry matter (P &lt; 0.08) of the diets and decreased the prevalence of ulcers (P &lt; 0.05) but did not significantly affect growth performance. Pigs that received melatonin had higher levels of melatonin (P &lt; 0.01) in most gastrointestinal tissues, with highest concentrations found in the stomach (P &lt; 0.001). Pigs that did not have ulcers had a higher concentration of melatonin in the plasma and stomach than pigs with ulcers (P &lt; 0.05). Melatonin may be useful in decreasing ulcers. Initial ulcer condition may be a significant source of variation in growth experiments. Key words: Pigs, gastric ulcers, particle size, melatonin, gastrointestinal tract

Effect of particle size and addition of sunflower hulls to diets on the occurrence of oesophagogastric lesions and performance in growing-finishing pigs

Four treatments different in particle size distribution were applied to 288 growing-finishing pigs to investigate its influence on the occurrence of oesophagogastric lesions and performance. Through differences in grinding, the four treatments were: (1) fine diet; (2) medium diet consisting of 50% of diet 1 and 50% of coarse diet 3; (3) coarse diet, (4) fine diet +5% whole sunflower hulls. All diets were pelleted. A digestibility trial was carried out in parallel with pigs of approximately 55 kg and fed the fine and coarse diets. In order to obtain a measured particle size distribution from pelleted diets, the particle size was measured by a dry and wet sieve method. Coarse milling caused a significant increase of growth performance from 25 to 45 kg live weight compared to the fine diet due to a higher feed intake. Feed conversion was not changed in this part of the growing period. The use of hulls in a fine diet showed a trend towards a decreased feed conversion. Average daily weight gain was not affected by treatment during the complete experimental period from 25 to 110 kg live weight. Feed conversion was increased by coarse milling of the diet in this period. Addition of sunflower hulls decreased feed conversion in the same experimental period. There were no differences in mean dressing and meat percentage in pigs between treatments. Coarse particles in the diet had a negative influence on pellet quality. Pigs fed the coarsely milled diet or the fine diet to which hulls were added had a lower proportion of stomachs with severe lesions in the pars oesophagea. Growth performance was not influenced by severe oesophagogastric lesions in this experiment.

Relationship between melatonin levels in plasma and gastrointestinal tissues and the incidence and severity of gastric ulcers in pigs

Four weeks of administration of melatonin mixed in the diet (5 mg/kg of food) significantly reduced the incidence of gastric ulcers in young pigs. In control and melatonin supplemented animals, significantly higher levels of melatonin were found in the stomach tissues as compared to jejunum, ileum, or colon. Pigs with the most severe ulcers exhibited significantly lower concentrations of melatonin in their stomach tissue and the blood plasma. Pigs fed coarsely ground diet exhibited higher tissue levels of melatonin in the stomach than animals fed a finely ground diet. Coarse diet was also associated with a lower score of gastric ulcers. No relationship between tissue levels of melatonin and the severity of gastric ulcers was found in other segments of the gastrointestinal tract. In the second experiment we determined that there was no significant difference between the gastro-protective effects of 2.5, 5.0, and 10.0 mg of melatonin mixed per 1 kg of food. A coarsely ground diet is hypothesized to have a gastro-protective effect by stimulating the production of melatonin in the stomach tissues. Dietary supplementation of food with melatonin, at threshold levels perhaps lower than 2.5 mg/kg/feed, may significantly reduce the incidence of gastric ulcers in pigs.

Effects of cereal type and feed particle size on morphological characteristics, epithelial cell proliferation, and lectin binding patterns in the large intestine of pigs.

The present study was undertaken to investigate the effects of cereal type and feed particle size on the morphological characteristics and epithelial cell proliferation of the large intestinal tissue in pigs. Forty pigs, weighing approximately 30 kg, were fed diets containing either coarsely or finely milled barley or wheat for a period of 4 wk. Tissue samples were taken from the cecum and from the proximal, medial, and distal colon at slaughter. The pigs fed the coarse diets had significantly larger crypts, in terms of height as well as volume, than did pigs fed the fine diets. The cereal type had no effect on the mucosal architecture. The epithelial cell proliferation, in terms of counted native mitoses in the crypts, was significantly higher in pigs fed the coarse barley diet than in pigs fed the coarse wheat diet or the fine diets. The volume of the mucin granules in the crypts constituted from 32 to 52% of the crypt volume and was greatest in the pigs fed the coarse diets. This effect of feed particle size was observed for neutral as well as for acidic mucins and sulfomucins. Lectin binding patterns indicated that more of the terminal sugars on glycoconjugates of the apical membrane on the mucosal surface were the sialic acid alpha-2,3 neuraminic acid, but less were mannose in the pigs fed the coarse barley diet. Distinct regional differences were observed among the intestinal sites. These included a decline in the epithelial cell proliferation and an increase in the volume of mucin in the crypts along the intestinal tract. Furthermore, the sialic acid alpha-2,3 neuraminic acid was more abundant in the medial colon than in the cecum; the contrary was seen for mannose and galactose. This study shows that the feed particle size of barley and wheat diets, more than the cereal type itself, affects the mucosal architecture, epithelial cell proliferation, and production and composition of the mucins in the large intestine of pigs. The study suggests that pigs fed a coarse diet are better protected against intestinal infections than pigs fed a fine diet.

A New Method of Measuring Diet Abrasion and Its Effect on the Development of the Forestomach

Twelve newborn Holstein bull calves were used to evaluate the effects of dietary abrasiveness, determined by a new method, on ruminal development. Calves were blocked by age and body weight and were assigned to one of three different diets. Each diet had the same ingredients but different particle sizes, which resulted in different abrasive values. No differences were detected in molar percentages of volatile fatty acids in ruminal fluid or in plasma concentrations of urea, glucose, or β-hydroxybutyrate. The pH of ruminal fluid was lower for calves fed the fine and intermediate diets than for those fed the coarse diet. Digesta-free weights of the stomach and stomach compartments were similar among calves fed the three diets, except that omasum weights were heavier for calves fed the fine diet. Length of the ruminal papillae increased as the abrasive value of the diet decreased. Measurements of ruminal tissue layers from the ventral floor of the cranial sac were not different among diets, but the keratin portion represented more of the epithelial layer for calves fed the diet with the lowest abrasive value, thus decreasing the percentage of metabolically active tissue for those calves.

Comparison of diets based on grass silage, hay or oat straw supplemented with four levels of concentrates in the feeding of growing Ayrshire bulls

This experiment was conducted during three consecutive years with 144 Ayrshire bulls of an initial age of 185 days and live weight of 186kg. The experimental period lasted for 224 days. The ad libitum fed roughages were grass silage, hay and oat straw, each supplemented with four levels of concentrates, the number of treatments thus being 12. Daily supplements of concentrates were 0,1, 2 or 3 kg on grass silage feeding, 1,2, 3 or 4 kg on hay feeding and 2,3, 4 or 5 kg on straw feeding. Barley was used as a concentrate on grass silage feeding, but part of it was replaced by rapeseed meal and urea in the hay and straw feeding groups to balance the nitrogen intake. An increase in concentrate intake was found to decrease the roughage intake with each type of roughage, but the total intake of dry matter (DM) was increased. Increasing the level of concentrates enhanced both the rate of daily live weight gain (LWG) and carcass gain. However, 2 kg more concentrates was needed on hay feeding than on grass silage feeding to obtain similar carcass gain. On straw feeding, 4 kg of concentrates was not sufficient to obtain a comparable carcass gain as with grass silage alone. The response to concentrate supplementation on grass silage feeding indicated, however, that the growth potential of the bulls receiving silage alone or silage with small amounts (1 or 2 kg/day) of concentrates was not completely utilized. The study showed that LWG is an inadequate measure of animal performance when diets with different fill characteristics are compared. With coarse diets, a relatively large proportion of LWG is rumen contents. Comparisons of animal performance and feed conversion should, instead, be done in terms of carcass gain.

Effect of Particle Size of Sorghum Grains on Feed Intake and Performance of Young Broilers

Sorghum grains were ground with a hammer mill (HM) or a roller mill (RM) into three different particle sizes: fine, medium, or coarse. The ground sorghum samples were similar in their mean particle diameter and in specific surface within the three types of grinding. Six broiler starter diets (a complete factorial of two methods of preparation and three particle sizes) were fed to chicks in three experiments.In all studies, feed intake was inversely related to the calculated surface area of the ground sorghum, independent of the method of grinding. In one experiment feed intake was recorded daily during 10 days starting at 4 days of age, in a choice situation. The chicks consumed feed in accordance to its coarseness.In a short-term experiment, chicks 7 days of age were kept in individual cages (two per cage) and fed the diets following an overnight fast. Feed consumption was determined 2 and 4 h after feeding. When compared with intake of the fine diet, feed intake of the medium ground diet was 19 and 13% greater, and intake from the coarse diet was 26 and 17% greater at 2 and 4 h respectively, after feeding the two diets.Feed intake, body weight gain, and feed:gain ratio were determined in chicks kept in individual cages (two per cage) from 7 to 21 days of age. Feed intake and body weight gain were positively related to the coarseness of the feed. Feed:gain ratio did not differ among treatment groups.

Adaptive remodeling of the rabbit temporomandibular joint following discectomy and dietary variations

This study evaluates the healing of the rabbit temporomandibular joint (TMJ) following discectomy in four groups of animals fed a ground diet for 3 consecutive months (group 1), a ground diet for 1 month followed by 2 months of a coarse diet (group 2), a ground diet for 6 consecutive months (group 3), or a ground diet for 3 months followed by a coarse diet for 3 months (group 4), in order to evaluate the effects of changing the diet texture following discectomy. After 3 and 6 months, histologic evaluation demonstrated that 1) an early hyperplastic response in the fibrocartilage regressed in the later period regardless of diet, and 2) switching the ground diet to a hard diet caused degenerative scores to increase after both 1 and 3 months.

The effect of diet texture on healing following temporomandibular joint discectomy in rabbits.

This study evaluates the healing of the rabbit temporomandibular joint (TMJ) following discectomy in animals fed coarse or ground diets. Twenty New Zealand rabbits were divided into four groups with two unoperated groups serving as controls. A unilateral discectomy was performed and the animals were placed on either a regular (coarse) or a ground diet immediately following surgery. After 3 months, histologic evaluation demonstrated that fibrocartilage thickness was greatest in the discectomy-coarse diet operated joint, less in the discectomy-ground diet operated joint, still less in the discectomy-coarse diet unoperated joint, and unaffected in the control animals. The results of this study demonstrate that diet texture can affect TMJ healing following discectomy. The adverse responses of the coarse diet affected not only the operated joint but also the unoperated contralateral joint.

INFLUENCE OF FEED PARTICLE SIZE ONpH, CARBOHYDRATE CONTENT, AND VISCOSITY OF RUMEN FLUID

Four fistulated cows were used to compare the rumen fluid properties produced from feeding all-concentrate feeds of fine (344 μ), or coarse (519 μ) geometric mean particle size, or alfalfa hay. A severe frothy condition developed in the rumens of cows fed the fine particle size feed but not in the rumens of cows fed the coarse or hay diets. The average viscosity of rumen fluid from cows fed hay was 7.4 centipoises (cP), about 14.7 cP when fed the coarse feed, and about 30.7 cP when fed the fine feed. After the cows became accustomed to their feed, rumen fluid pH declined from 6.5 to 5.6 when fed the fine particle feed and from 6.9 to 6.0 when fed the coarse. The rumen fluid from the cows fed the fine feed exhibited two viscosity maxima, between pH 5.5 and 5.8, and between pH 7.5 and 8.5, whereas the viscosity of the rumen fluid from the cows fed the coarse feed was not influenced by pH. Soluble carbohydrate levels were 650 μg/ml in the rumen fluid of cows fed the coarse-particle diet and over 1,000 μg/ml in that from cows fed the fine-particle feed. Cows fed hay had less than 300 μg/ml of soluble carbohydrate in the rumen fluid.

INFLUENCE OF PARTICLE SIZE OF CONCENTRATE ON RUMEN CONDITIONS ASSOCIATED WITH FEEDLOT BLOAT

Some rumen characteristics associated with bloat were measured in identical twin cows fed diets of coarse and fine particle size (geometric mean particle size of 715 and 388 μ). A foamy condition developed in the rumen of all cows fed the fine diet and in one of those fed the coarse diet on the 2nd day of the experiment. In vitro gas production 1 h after feeding was 3.46 ml/h per g dry matter (DM) on fine feed and 2.35 ml/h per g DM on the coarse (P &lt; 0.05). During the 1st week of feeding the pH value of rumen of cows fed the coarse diet was 4.86 and that of cows fed the fine diet was 4.75. During the 2nd week the pH of both were lower at 4.53 and 4.12 (P &gt; 0.05). There was no difference in the numbers of Streptococcus bovis present in the rumen attributable to the particle size of the diet. The number of S. bovis increased with an increasing proportion of concentrate fed until the cows were changed to the all-concentrate diet, when numbers declined sharply to a low level. S. bovis does not appear to be a primary cause of feedlot bloat.

The Treatment of Gastric Subacidity with a Coarse Diet and Lemon Juice

The Treatment of Gastric Subacidity with a Coarse Diet and Lemon Juice