Influence of feed preparation and number of pigs per pen on performance and occurrence of esophagogastric ulcers in swine

Processing of ingredients and diets and effects on nutritional value for pigs

A conventional diet based on corn and soybean meal fed to pigs is usually provided in a mash form and in most cases, processing other than grinding and mixing is not used. However, due to the high cost of energy in pig diets, use of high fiber ingredients such as soybean hulls, distillers dried grains with solubles, and wheat middlings has increased. High fiber concentrations in the diet usually results in reduced energy and nutrient digestibility due to the low capacity of pigs to digest fiber, which negatively impacts growth performance and carcass composition of the pigs. Feed processing technologies such as changes in grinding procedures, expansion, extrusion, pelleting, use of enzymes or chemical treatments may, however, be used to solubilize some of the cellulose and hemicellulose fractions that form the cell wall of plants in the ingredients, and therefore, increase nutrient availability. This may have a positive effect on energy digestibility, and therefore, also on pig growth performance and carcass composition, but effects of different feed technologies on the nutritional value of feed ingredients and diets fed to pigs are not fully understood. It has however, been demonstrated that reduced particle size of cereal grains usually results in increased digestibility of energy, primarily due to increased digestibility of starch. Extrusion or expansion of ingredients or diets may also increase energy digestibility and it appears that the increase is greater in high fiber diets than in diets with lower concentrations of fiber. Chemical treatments have not consistently improved energy or nutrient digestibility, but a number of different enzymes may be used to increase the digestibility of phosphorus, calcium, or energy. Thus, there are several opportunities for using feed technology to improve the nutritional value of diets fed to pigs.

Effect of diet grinding and pelleting fed either dry or liquid feed on dry matter and pH in the stomach of pigs and the development of gastric ulcers

The physical form of diets has a marked impact on the development of gastric ulcers in pigs. Earlier studies showed effects of fine grinding and pelleting on the integrity of gastric mucosa as well as on local intragastric milieu. This study was conducted to evaluate the effects of dry or liquid feeding on intragastric milieu (DM and pH) in pigs. The 23 piglets were housed individually and fed with test diets and water ad lib for 6 wk. Both experimental diets [coarsely ground diet fed as mash (CM) vs. finely ground pelleted diet (FP)] were identical in ingredients (39.5% wheat, 34% barley, 20% soybean meal) and chemical composition and were either offered dry or in liquid (25% DM) form. At the end of the trial the animals were slaughtered; the stomach was removed and samples were taken from different localizations. Feeding diets dry or liquid had no effect on the pH (P > 0.05). The diet noticeably affected the gastric content. The FP diets resulted in a more liquid chyme (P < 0.05), and the intragastric pH did not differ between regions. Feeding CM caused marked effects of localization regarding pH (highest values: pars nonglandularis; lowest values: fundus). None of the pigs fed CM showed signs of gastric ulcers, but the score was markedly higher (P < 0.05) when pigs were fed FP. Therefore the predominant factor for development of gastric ulcers seems to be the structure (particle size) of the diet.

A note on the performance of young pigs given maize-based diets in different physical forms

The experiment compared the performance of pigs from 11 to 56 days of age when given diets based on maize which had been rolled, or ground through coarse, medium or fine screens, or which were made with maize which had been ground through a medium screen and which were then pelleted or pelleted and crumbled. All diets were given ad libitum.

From 11 days to weaning at 28 days, little feed was eaten and there were no significant effects of the treatments. From 29 to 35 days, daily gain and feed conversion were best on the fine, medium and pelleted diets. From 36 to 56 days, pellets and crumble gave the best performance. There were no significant differences between treatments in the incidence of scouring.

Comparison of the severity of esophagogastric, lung and limb lesions at slaughter in pigs reared under standard and enriched conditions

Two hundred and ten pigs were reared in three groups (according to genotype) under enriched conditions of large open-front sawdust-bedded barns. Eight hundred and twenty pigs were reared under standard conditions of small 15-animal pens in a conventional barn with partially slatted floors and natural ventilation. Production parameters including percentage mortality, feed conversion rate and average daily weight gain were calculated at the end of the fattening period. Stomachs, limbs and lungs were examined at slaughter in order to compare the number and severity of lesions between the enriched environment groups and the standard environment group. There was a significantly greater number of esophagogastric lesions in the standard environment group than in the enriched environment groups. No esophagogastric ulcers were observed in any pigs from the enriched groups, while 17.5% of stomachs from pigs in the standard environment group displayed this condition. There were no significant differences in the number of lung lesions associated with enzootic pneumonia between pigs from the standard and enriched environment groups. The limbs of animals reared in the standard environment had more lesions, especially in floor-contact areas, than those reared in the enriched environment (23.84% versus 1.08%). The production parameters measured were improved in the pigs from the enriched environment. These results suggest that the welfare of fattening pigs may be improved by the provision of enrichment in their housing environment. Evaluation of esophagogastric ulceration could be a useful indicator of welfare in pigs.

Porcine gastric ulcer

Ulceration of the pars esophagea in swine develops from a complex interaction of dietary particle size, gastric fluidity, dietary carbohydrate content, and presence of certain species of commensal gastric organisms capable of fermenting dietary carbohydrates. Unlike in humans, the significance of the role of Helicobacter sp. in development of porcine gastric ulcers is yet undefined. Management practices that limit the incidence and severity of gastric ulceration without interfering with growth performance appear to be the best option for control.