Stomach Morphology Research Articles

Effects of particle size and pelleting on growth performance, nutrient digestibility, and stomach morphology in finishing pigs.

The effects of particle size and pelleting on growth performance, carcass characteristics, nutrient digestibility, and stomach morphology were determined using 160 finishing pigs. The pigs were fed a corn-soybean meal-based diet with the corn milled to particle sizes of 1,000, 800, 600, or 400 microns. The diets were fed in meal or pellet form. Pelleting the diets resulted in 5% greater ADG (P < .01) and 7% greater grain/feed (P < .001). Also, pelleting increased digestibilities of DM, N, and GE by 5 to 8% (P < .001). Reducing particle size increased electrical energy required for milling and decreased milling production rates, especially as particle size was decreased from 600 to 400 microns. Reducing particle size of the corn from 1,000 to 400 microns increased gain/feed by 8% (linear effect, P < .001) and digestibility of GE by 7% (quadratic effect, P < .03). Improved nutrient digestibility and lower ADFI resulted in 26% less daily excretion of DM and 27% less daily excretion of N in the feces as particle size was reduced from 1,000 to 400 microns (linear effects, P < .001). Stomach lesions and keratinization increased with reduced particle size (P < .003) and keratinization increased with pelleting (P < .02), although they were unrelated to growth performance (i.e., gain/feed actually improved as lesion scores increased). Considering milling energy, growth performance, stomach morphology, nutrient digestibility, and nutrient excretion, a particle size of 600 microns, or slightly less, is an acceptable compromise for corn in both meal and pelleted diets for finishing pigs.

Effects of dietary buffers on growth performance, nutrient digestibility, and stomach morphology in finishing pigs2

The effects of supplemental alkaline salts on growth performance, blood chemistry, and stomach morphology were determined in two experiments using 248 finishing pigs fed finely ground diets. In Exp. 1, 128 pigs (56 kg average initial BW) were fed a corn-soybean meal-based diet (488-microns mean particle size) for 66 d. Treatments were control and 1, 2, or 3% added NaHCO3 in a randomized complete block design. Average daily gain (linear effect, P < .005), dressing percentage (linear effect, P < .04), and plasma urea N concentration (linear effect, P < .004) decreased as the concentration of NaHCO3 in the diet was increased, but primarily at the 2 and 3% additions. Feed intake, gain/feed, backfat thickness, stomach ulceration score, blood gases (pCO2 and HCO3), and plasma Na and K were not affected by treatment (P > .11). In Exp. 2, 120 pigs (55 kg average initial BW) were fed a pelleted wheat-soybean meal-based diet (355-microns mean particle size) during a 64-d growth assay. Treatments were 1) control, 2) 1% NaHCO3, and 3) 1% KHCO3. Average daily gain, ADFI, gain/feed, backfat thickness, stomach keratinization score, blood pCO2, plasma urea N, and digestibilities of DM and N were not affected by treatment (P < .15). However, addition of NaHCO3 and KHCO3 tended to decrease (P < .10) the incidence of ulcers and increased (P < .05) the concentration of blood HCO3- and digestibility of GE. These data indicate that 1% addition of either NaHCO3 or KHCO3 may help to reduce the severity of gastric ulcers in finishing pigs without adversely affecting growth performance or nutrient digestibility.

Effects of mill type and particle size uniformity on growth performance, nutrient digestibility, and stomach morphology in finishing pigs.

The effects of particle size uniformity and mill type used to grind corn were determined in three experiments. In Exp. 1, 120 pigs (47.8 kg initial BW) were used. Treatments were 1) a 40:60 blend of coarsely rolled (in a roller mill) and finely ground (in a hammermill) corn with a large standard deviation (sgw) of particle size (sgw of 2.7), 2) hammermilled corn with an sgw of 2.3, and 3) roller-milled corn with an sgw of 2.0. Mean particle size of the corn was approximately 850 microns for all treatments. Growth performance was not affected (P > .11); but, stomach keratinization tended to be less severe (P < .08) and apparent nutrient digestibilities were greater (P < .008) when the sgw was smaller. In Exp. 2, 128 pigs (55.3 kg initial BW) were used. Treatments were corn ground in a hammermill and a roller mill to 800 and 400 microns. Pigs fed corn ground to 400 microns were more efficient (P < .004) and had greater apparent digestibilities of DM, N, and GE (P < .001) than pigs fed corn ground to 800 microns. Mill type did not affect growth performance (P > .40), but pigs fed corn ground in the roller mill had greater apparent nutrient digestibilities (P < .008). In Exp. 3, 128 pigs (67.3 kg initial BW) were used. Treatments were corn ground to 400 microns in a hammermill and a roller mill fed in meal and pelleted forms. Pigs fed pelleted diets had greater ADG (P < .003) and gain/feed (P < .03) but also had greater incidence of ulcers (P < .04). Pigs fed roller-milled corn were more efficient (P < .05) and had a lower incidence of ulcers (P < .04), but diets with hammermilled corn had lower sgw and greater apparent digestibilities of nutrients (P < .02). Our results suggest that mill type had inconsistent effects on growth performance, but more uniform particle sizes consistently gave greater nutrient digestibilities.

Effects of dry-extruded whole soybeans on growth performance of nursery pigs and growth performance, carcass characteristics, and stomach morphology of finishing pigs (1995)

In a 3 I-d nursery experiment, replacing soybean meal (SBM) with dry-extruded whole soybeans (DEWS) tended to improve F/G (6% overall difference), but ADG was not affected. Adjusting the diet with DEWS to the nutrient:calorie ratio of the diet with SBM did not greatly improve growth performance compared to the diet that was simply formulated to the same concentration of lysine as the diet with SBM. In a second experiment (with finishing pigs), 50 and 100% of the SBM in a corn-based diet was replaced with DEWS. Replacement resulted in 2% greater ADG and 8% better F/G, without significantly increasing carcass fatness or the incidence of stomach ulcers. Our data suggest that DEWS are an acceptable (if not superior) alternative to SBM in diets for nursery and finishing pigs.; Swine Day, Manhattan, KS, November 16, 1995

Sorghum genotype and particle size affect growth performance, nutrient digestibility, and stomach morphology in finishing pigs (1993)

Sorghum genotype and particle size affect growth performance, nutrient digestibility, and stomach morphology in finishing pigs (1993)

Effects of hammermills and roller mills on growth performance, nutrient digestibility, and stomach morphology in finishing pigs (1993)

The effects of particle size and mill type used to grind corn were determined with 128 pigs (122 lb average initial body wt). Treatments were corn ground in a hammermill and a roller mill to 800 and 400 μm. The roller mill was more efficient than the hammermill when grinding the corn, with less energy consumption and greater production rate per horsepower hour. For the 800 μm treatments, greater uniformity of particle size was achieved with the roller mill than the hammermill; however, at the 400 μm treatments, corn ground with the hammermill was slightly more uniform. Pigs fed corn ground to 400 μm had 7% greater efficiency of gain, and had greater digestibilities of dry matter, nitrogen, and energy than pigs fed corn ground to 800 μm. Mill type did not affect growth performance, but pigs fed corn ground in the roller mill had greater digestibilities of dry matter, nitrogen, and energy and excreted 18% less dry matter and 13% less nitrogen as feces than pigs fed corn ground in a hammermill. There were interactions among mill type and particle size, with digestibilities much greater for the diet with corn ground to 800 μm in the roller mill compared to the hammermill, but only small advantages in nutrient digestibility for diets with corn ground to 400 μm in the roller mill. Mill type did not affect rate or efficiency of gain, but pigs fed diets with roller-milled corn had greater digestibilities of nutrients and, thus, lower excretions of nutrients in feces.; Swine Day, Manhattan, KS, November 18,1993

Effects of mill type (hammer vs roller) and particle size uniformity on growth performance, nutrient digestibility, and stomach morphology in finishing pigs (1992)

Two experiments were conducted to determine the effects of mill type and particle size uniformity on finishing pigs. In Exp. 1, 120 pigs, with an average initial weight of 105 lb, were fed corn-soybean meal-based diets for 57 d. The corn was milled so that all diets had an average mean particle size of 800 11m (± 20), yet differed in particle size uniformity (Sgw). To obtain the most uniform treatment (1.9 Sgw), corn was milled through a roller mill. The intermediate treatment (2.3 Sgw) was obtained by milling corn through a hammermill. The least uniform treatment (2.7 Sgw) was obtained by blending coarsely and finely ground corn. Growth performance of pigs was not affected by Sgw of the diet. However, digestibilities of DM, N, and GE increased as Sgw was reduced. In Exp. 2, 128 pigs, widl an average initial weight of 150 lb, were fed diets with corn milled to 450 JLm (± 7) in a hammermill or a roller mill. The hammermilled corn had an Sgw of 1.8 and the rollermilled corn had an Sgw of 2.0. The diets were fed in meal or pelleted form. There were no interactions among mill type and diet form. Digestibilities of DM and N were greater for the hammermilled treatments, but no growth performance differences were due to mill type. Pelleting increased ADG 9% and improved efficiency of gain by 5 %. Pelleting also increased the severity of stomach lesions. In conclusion, at 800 and 450 p.m, mill type did not affect growth performance. However, nutrient digestibilities were improved by decreasing variability in particle size, a response that merits further investigation.; Swine Day, Manhattan, KS, November 19, 1992

Nutrition of domesticated South American llamas and alpacas

A review of the existing literature on the nutrition of llamas ( Lama glama) and alpacas ( L. pacos) revealed that these South American camelids are better adapted to the harsh environment of the Andean region than are advanced ruminants. Llamas and alpacas differ from advanced ruminants in stomach morphology, digestion, diet selectivity, and intake. Available data indicate that stocking ratios should be 1.0:1.0 for alpacas:sheep and 1.5:1.0 for llamas:sheep. Further research is recommended in digestive physiology, foraging behavior, and nutritional requirements of South American camelids.

A new hydrozoan, Geomackiea zephyrolata gen. nov., sp. nov. (Anthomedusae: Pandeidae), from inland marine waters of British Columbia and Washington State

The hydromedusa Geomackiea zephyrolata gen. nov., sp. nov. is described and illustrated. It has been placed in the subfamily Protiarinae of the family Pandeidae on the basis of its stomach and gonad morphology and the four large perradial tentacles with conical basal bulbs. A new genus has been erected because the medusa is supplied with four broad interradial bulbs, each rimmed by up to eight closely packed solid tentaculae. A total of 29 specimens with bell heights of 0.9–3.5 mm have been collected in the plankton of Saanich Inlet, British Columbia, and Friday Harbor, Washington, between 1978 and 1981. Juvenile as well as adult specimens are described and the cnidome, gametes, seasonal and vertical distributions, and taxonomic affinities within the family Pandeidae are discussed.

Glutathione and GSH-dependent enzymes in the human gastric mucosa.

The gamma-glutamyl-transferase activity, the total glutathione content, the GSH-peroxidase activity, and the GSH S-transferase activity using an aryl substrate were estimated in the S9 fraction of gastric biopsy specimens taken from patients with normal stomach morphology (n = 24), acute gastritis (n = 15), chronic-atrophic gastritis (n = 10), gastric ulcer (n = 9), and carcinoma of the stomach (n = 12). The total glutathione content of normal gastric mucosal specimens was significantly higher than that of human liver biopsy specimens, whereas the GSH-peroxidase and the GSH S-aryltransferase activities were much lower than those found in the liver. Specimens of gastric ulcer had significantly lower enzyme activities of GSH-peroxidase and GSH-aryltransferase, whereas gastric cancer tissue had significantly lower concentrations of total glutathione. The intraindividual comparison of tumorous and non-tumorous tissue showed a consistent decrease of total glutathione as well as of GSH-aryltransferase activity in carcinomatous tissue.

Development of acute feeding disorders, hyperactivity, and stomach pathology after medial and lateral hypothalamic lesions in rats

The acute effects of medial (VMH) and lateral (LH) hypothalamic lesions on stomach morphology, motor activity, and feeding behavior were compared in two experiments. Rats received VMH or LH lesions and were sacrificed 4, 8, or 24 h later. Both lesions produced high activity counts at 4 h and a comparable number of ulcers, starting at the earliest interval tested. Neither VMH nor LH lesions produced acute changes in other organs, such as the adrenals, thymus, or spleen. In a second experiment, quantitative measures of stomach pathology did not indicate significant differences between ulceration produced by VMH and LH lesions in 24 h. A separate group receiving VMH lesions showed pronounced hyperphagia and hyperdipsia immediately after the lesion, while LH rats were aphagic and adipsic. Motor activity levels after the lesions correlated positively with ulcer incidence and severity. Possible relations between these acute behavioral and visceral effects of hypothalamic lesions are discussed.

Feeding processes of members of the genus Macoma (Mollusca:Bivalvia)

The eight species of Macoma examined fall into three feeding categories: two are deposit feeders, five are suspension feeders, and one feeds on the surface films of bacteria on sand grains. The type of particle which is found in the stomach depends on the behavior of the siphons, the quality or quantity of mucus secreted by the gills and labial palps, and, to some extent, on the sorting function of the labial palps. The labial palps act as supplementary filtering mechanisms. The stomach of M. secta, which ingests sand grains, is adapted to this diet by the enlargement of the gastric shield, but in the other species there is no obvious relationship between diet and stomach morphology.