The effect of dietary phosphorus and calcium level, phytase supplementation, and ileal infusion of pectin on the chemical composition and carbohydrase activity of fecal bacteria and the level of microbial metabolites in the gastrointestinal tract of pigs1,2

Abstract

Two experiments with growing pigs were conducted to determine the effects of dietary P and Ca level, phytase supplementation, and ileal pectin infusion on ileal and fecal P and Ca balance, chemical composition of fecal mixed bacterial mass (MBM), and bacterial metabolic activity. Pigs (initial BW = 30 kg) were fitted with simple T-cannulas at the distal ileum. They were fed a low-P corn-soybean meal control diet (3 g of P/kg) or the control diet supplemented with monocalcium phosphate (MCP; 7 g of P/kg; Exp. 1) or 1,000 FTU phytase/kg (Exp. 2). The daily infusion treatments consisted of 60 g of pectin dissolved in 1.8 L of demineralized water or 1.8 L of demineralized water as the control infusion, infused via the ileal cannula. In each experiment, 8 barrows were assigned to 4 dietary treatments according to a double, incomplete 4 x 2 Latin square. The dietary treatments in Exp. 1 were the control (Con-) diet with water infusion; the control (Con+) diet with pectin infusion; the MCP diet with water infusion; and the MCP diet with pectin infusion. In Exp. 2, the pigs received the same Con- and Con+ treatments as in Exp. 1 and, in addition, the phytase-supplemented diet in combination with water or pectin infusion. After a 15-d adaptation period, feces were collected for 5 d followed by ileal digesta collection for 24 h. In Exp. 1, supplemental MCP increased (P </= 0.003) ileal and fecal P and Ca recovery as well as P and Ca content of the MBM. Pectin infusion increased the N content of the MBM (P = 0.054) and polygalacturonase activity (P = 0.032) in feces. In addition, pectin decreased (P = 0.049) ileal and tended (P < 0. 079) to increase fecal VFA concentrations. In Exp. 2, phytase decreased ileal and fecal P recovery (P < 0.001) and the P content of the MBM (P = 0.045), whereas the N content of the MBM (P = 0.094) and fecal cellulase activity (P = 0.089) tended to decrease. Similarly, pectin infusion decreased (P = 0.036) fecal cellulase activity but increased (P < 0.001) polygalacturonase activity. In conclusion, these data indicate that bacterial P and Ca assimilation and metabolic activity depend on P and Ca availability in the large intestine and on the availability of fermentable substrate, such as pectin. Thus, increasing dietary P and Ca levels increases bacterial P and Ca assimilation due to greater intestinal P and Ca availability, whereas decreasing intestinal P availability for bacteria through phytase addition to low-P diets reduces bacterial P incorporation and seems to decrease bacterial activity.

Influence of limestone and phytase on broiler performance, gastrointestinal pH, and apparent ileal nutrient digestibility

“…Supplementation of a microbial phytase at 250, 500, or 1,000 FTU/kg did not influence stomach pH in 32kg pigs (Radcliffe et al, 1998), gastrointestinal pH in 42-d-old broilers (Nourmohammadi et al, 2011), or ileal pH in 21-d-old broilers (Akyurek et al, 2011). However, feeding 1,000 FTU/kg of phytase significantly increased fecal pH in 53-kg pigs (Metzler et al, 2008). The increase in gastric pH associated with high levels of supplemental phytase may be directly related to the breakdown of the phytate molecule by phytase.…”

Effects of Adding Super Dose Phytase to the Phosphorus-deficient Diets of Young Pigs on Growth Performance, Bone Quality, Minerals and Amino Acids Digestibilities

“…Our results verified the speculation on the basis of AID of GE, in which diets containing 1,000 and 20,000 FTU/kg phytase contributed 548 kJ/kg and 1,922 kJ/kg as digested energy in the ileum, respectively. However, the lack of change in total tract energy digestibility may indicate that phytase supplementation depresses microbial fermentation in the lower intestine due to a possible deficiency of P and Ca (Metzler et al, 2008). Metzler et al (2010) reported that dietary phytase supplementation tended to reduce the concentration of total volatile fatty acids and the total number of bacteria in the feces.…”

Enzymatically Modified Starch Favorably Modulated Intestinal Transit Time and Hindgut Fermentation in Growing Pigs

“…Health was monitored daily and illness was determined by appetite, lethargy, behavior, and/or cannula function. Post-surgery, the skin around the cannula was cleaned with lukewarm water several times daily, treated with a skin-protecting paste (Stomahesive Paste, Convatec, Princeton, UK), and foam material was placed between the retaining ring and the skin to absorb leaking digesta to prevent erythema [21]. Pigs received new empty plastic water bottles as chewing material every day.…”