Effects of feed physical form and buffering solutes on water disappearance and proximal stomach pH in swine.

Abstract

The effects of the physical form of feed on water disappearance and the effects of buffered water on proximal stomach pH in swine were determined in two experiments. In Exp. 1, 32 barrows were used to evaluate the water disappearance in pigs fed a finely ground and pelleted diet vs those fed a coarsely ground and mashed diet for ad libitum consumption over a 2-wk interval. There were four replicates with eight pigs per replicate. Average daily water and feed disappearance did not differ (P = 0.06 and P = 0.10, respectively). However, average daily water to feed ratio was higher for pigs on the pelleted diet (4.21+/-0.31 L/kg vs 3.04+/-0.33 L/kg; P = 0.02). The higher ratio for the pelleted diet indicated that this may be the cause of a more fluid digesta allowing reflux of irritants from the distal stomach to damage the pars esophageal region of the proximal stomach. In Exp. 2, four barrows (25+/-2 kg) had gastric cannulas surgically implanted into the proximal region of the stomach. Pigs were given ad libitum access to a finely ground and pelleted diet. The experimental design was a Latin square. Water treatments included water (control), 200 mOsm NaHCO3, 250 mOsm NaHCO3, and 250 mOsm mono-dibasic sodium phosphate. Pigs were given a 4-d adjustment period, and pH measurements began on the morning of the 5th d and continued for 24 h under normal feeding conditions. Feed was removed and measurements were continued for 16 h. Buffered water raised the pH of the proximal region of the stomach compared to the control (P < 0.001). Average pH while consuming the water treatments was 3.65+/-0.11 (n = 4) for water control, 4.86+/-0.11 (n = 4) for the 200 mOsm NaHCO3, 4.63+/-0.11 (n = 4) for the 250 mOsm NaHCO3, and 4.59+/-0.14 (n = 3) for the 250 mOsm mono-dibasic sodium phosphate. Buffers also raised the pH of the proximal region of the stomach for the fed (P < 0.001) and the feed restriction (P < 0.01) phases of the trial. Water disappearance rates in pigs given NaHCO3 were higher than in the control (P < 0.01). Average daily water disappearance for the treatments was 9.13+/-0.74 L for the control, 13.56+/-0.74 L for 200 mOsm NaHCO3, 13.77+/-0.74 L for the 250 mOsm NaHCO3, and 10.33+/-0.95 L for the phosphate buffer. The proximal pH of the stomach was increased by adding buffers to the water supply. Addition of NaHCO3 buffers also caused increased water disappearance.

The water disappearance and manure production at commercial growing-finishing pig farms

“…Thus, it was added oil in the pig diets of the cold phase to reduce the total feed intake as explained by some authors (Miyada, 1999). The water-to-feed ratio obtained at experiment, with the exception of NI farms, were similar to the highest value of the range reported in the literature for thermoneutral conditions À 2.2-4.4 L kg À 1 (Mount et al, 1971;Crumby, 1986;Miyawaki et al, 1994;Turner et al, 1999;Ange et al, 2000). The NRC (1998) recommended a minimum water-to-feed ratio of 2.0 for pigs between 20 and 90 kg of BW.…”

Integrity of gastric mucosa in reared piglets – effects of physical form of diets (meal/pellets), pre‐processing grinding (coarse/fine) and addition of lignocellulose (0/2.5 %)

“…In the present study, the piglets fed pelleted diets showed a tendency towards higher dry matter contents in the gastric chyme than piglets fed a coarse meal (see Table 9). In previous studies (Maxwell et al, 1970;Kamphues, 1988;Regina et al, 1999;Ange et al, 2000), a higher fluidity of the stomach content resulted in a more intensive mixing of the proximal and distal gastric chyme. This deviant composition of stomach contents in pigs fed finely ground and pelleted diets was related to ulcerations of the non-glandular area (Regina et al, 1999;Ange et al, 2000).…”

“…In previous studies (Maxwell et al, 1970;Kamphues, 1988;Regina et al, 1999;Ange et al, 2000), a higher fluidity of the stomach content resulted in a more intensive mixing of the proximal and distal gastric chyme. This deviant composition of stomach contents in pigs fed finely ground and pelleted diets was related to ulcerations of the non-glandular area (Regina et al, 1999;Ange et al, 2000). The contribution of saliva to an increased fluidity of the stomach content remains unclear as it seems presumable to detect a higher salivation in pigs fed meal instead of pelleted diets which provides protection for the non-glandular area -depending on the amount and composition of buffering constituents in the saliva.…”

In Situ Prebiotics for Weaning Piglets: In Vitro Production and Fermentation of Potato Galacto-Rhamnogalacturonan

“…The pHs of the stomach and the small intestine were measured to be 4.1 to 4.6 and 6.0 to 7.0, respectively, which are in agreement with those reported in the literature (43). A pH of 3.0 was chosen as the value for the stomach, as this level of acidity is realistic in piglets that have eaten little or after an overnight fast (44,45). Proteolytic activity, which can potentially degrade the pectinolytic enzymes, was added to mimic the measured values, as the values in the literature are not directly applicable due to differences in the methods and the definition of units of activity.…”