The effects of various dietary ingredients on gastric pH, salivary pH, gastric ulcerations, oral stereotypies, and heart rate in gestating sows

This thesis looks at the relationship between the addition of various dietary treatments for gastric ulcers and their effects on gastric ulcerations in the esophageal area of the stomach of gestating sows. Other potential effects of the gastric ulceration treatments; gastric pH, salivary pH, heart rate, and oral stereotypies, were also measured. In the first study, testing was done to determine the difference in the ability of two oral antacids to increase gastric pH in gilts. Both ranitidine, an H2-receptor blocker, and omeprazole, a proton-pump inhibitor, were fed to gilts on a rotational schedule while gastric pH was recorded throughout the day. While there was no significant difference in gastric pH when gilts were fed diets with the control diet or omeprazole, the ranitidine diet produced significantly lower gastric pH than the control diet and omeprazole diet. Therefore, the omeprazole may be diet more effective than ranitidine in raising gastric pH and maintaining a higher gastric pH over time in gilts. In the second study, gastric ulcer treatments were started at day 30 of gestation and included control, omeprazole, high dietary fiber in the form of 25% soybean hulls, and 2% sodium bicarbonate. These treatments were added to the gestation and lactation diets of pregnant sows and gilts. At day 30, 60, and 90 of gestation, endoscopies were performed on the sows and gilts to determine the levels of gastric ulceration, saliva samples were collected to determine salivary pH, video was recorded to collect data on oral stereotypies, and heart rate was monitored before and after feeding. Endoscopies were also performed on the stomachs of recently slaughtered sows to compare with direct morphological scoring. There were no significant differences in dietary treatment effects on ulceration rate, however, numerically, sows fed the sodium bicarbonate diet did not increase stomach ulcer scores from gestation days 30 to 60, while sows fed the high fiber diet had the least increase in stomach ulcer scores from gestation days 60 to 90. Dietary treatments had no effect on sow behavior with the exception that sows fed sodium bicarbonate had increased water drinking activity. The endoscopy validation performed on the sow stomachs showed moderate agreement between ulcer scores when viewed through an endoscope and examined morphologically. However, the endoscopy consistently uncerscored the ulceration, which could suggest that differences in ulceration in the sows and gilts fed treatment diets may have been larger but due to limitations of the endoscopic examination, these differences were not apparent