Effect of Minerals and Fiber on Avian Intestinal pH

Abstract

F OR a number of years this station has been conducting a series of experiments with chickens consuming abnormal amounts of minerals either in the mixed feed or in the drinking water. A previous report (Heller, 1933) described the deleterious results produced by the use of excessive amounts of minerals but gave no definite cause of the abnormalities. It has been suggested that the presence of high concentrations of salt might interfere with the normal hydrogenion concentration of the intestinal tract due to hydrolysis of the salts as well as to the neutralizing and buffering action that might result; that normal digestion and absorption might be interfered with, or that even the normal acid-base balance of the body might be disturbed.In order to determine whether such changes might result the hydrogen-ion con-centration of the intestinal tract of several hundred chickens has been determined. METHODThe chickens used for these determinations were of the general purpose breeds selected from the college flocks. In all cases they were killed by rapid bleeding. The abdominal cavity was opened, and the digestive organs were quickly removed. Samples were then taken with a small glass scoop from the crop, proventriculus, gizzard, duodenum, upper ileum, lower ileum, caecum, colon, and the gall bladder and were placed in dry test tubes. The samples were macerated at once with 5 ml. of redistilled water after which 10 drops of an acetone solution of quinhydrone containing .036 grams per ml. were added. A portion of the well mixed sample was then transferred TABLE 1.-pH of intestinal tract of 10-month-old chickens consuming basic ration and supplements as Ration Supplement None 10% Ca(OH) 2 10% CaCOs 5% Na 2 HPO, 20% Lard 5% CaCl 2

The Hydrogen Ion Concentration in Avian Digestive Tracts

“…Mussehl, Blish, and Ackerson (1935), also using a quinhydrone electrode, showed in an extensive investigation that various diets produced little change in the hydrogen ion concentration of the proventriculus and gizzard and practically no change in the intestine and caecum. These observations were confirmed by Heller and Penquite (1936). Their data showed that while basic salts may raise the pH in the gizzard and crop, the intestine and caeca are unaffected.…”

“…The fact that the birds of other investigators were fed on a diet different from the grain diet used in these experiments could not account for this difference in hydrogen ion concentration in the lower intestine since Penquite and Heller-(1936) as well as Mussehl, Blish, and Ackerson (1935) have shown that the diet exerts little effect on the pH in the lower intestine.…”

The Effect of Certain Dietary Factors on Gastric Hydrogen Ion Concentration and Acidity in the Domestic Fowl

“…There is in general a correlation between the changes in pH and "free HC1." The data on hydrogen ion concentration agree fairly well with those of Heller and Penquite (1936). The consistently lower pH values obtained in this study are probably due to the fact that the gizzard fluid was removed from live birds.…”

“…In these studies the experimental birds were killed and fluid removed from the gizzards for determinations. This same procedure was used by Heller and Penquite (1936) and Mussehl, Blish, and Ackerson (1933) in studying the effect of dietary factors on gastric pH. In the latter investigation the additions of cod liver oil, NaHC0 3 , NH 4 C1, starch, dextrin, sucrose, or lactose were found to affect the gastric pH.…”

“…In the latter investigation the additions of cod liver oil, NaHC0 3 , NH 4 C1, starch, dextrin, sucrose, or lactose were found to affect the gastric pH. Heller and Penquite (1936) revealed that the gastric hydrogen ion concentration could be reduced by the addition to the basic diet of 10 percent Ca(OH) 2 , 10 percent CaC0 3 , 5 percent Na 2 HP0 4 , 20 percent lard, 10 percent Cad 2 , SO percent cotton seed, SO percent milk, or 25 percent tankage. In a more recent series of experiments the author (1943) demonstrated that fluid itmoved from the gizzards of freshly killed birds has a lower hydrogen ion concentration than that removed from the gizzards of live birds which have been fed the same diet.…”