- Email: [email protected]
The Effect of Diet on pH in the Intestinal Tract of Chicks1
The Effect of Diet on pH in the Intestinal Tract of Chicks1 B. MARCH, R. TUCKEY AND J. BIELY Poultry Nutrition Laboratory* The University of British Columbia, Vancouver, B. C. (Received for publication September 20, 1957)
D
Because of the possible effects of intestinal pH upon utilization of various nutrients it was decided to investigate further the effects of different diets upon intestinal pH. EXPERIMENTAL AND RESULTS
In each of the following experiments pH in the intestine of chicks was determined 1 Aided by a grant sponsored by the Bacteriology Division, Science Service, Department of Agriculture, Ottawa, Canada. * Contribution No. 99.
by the following procedure: the chicks were encouraged to eat over a period of If to 2 hours. Since all birds would then have food in the digestive tract, secretion of the digestive juices could be assumed to be maximum. Any differences noted in pH would not be due to differences in the amounts of the digestive juices present in the intestine. Birds selected at random from each lot were killed by anaesthetization with diethyl ether. Struggling was thus minimized and, as a result, reversed peristalsis and defecation reduced. Each bird was weighed, the intestine was removed, and the desired sections cut out. The intestinal sections were slit and clamped flat. The determinations were made by placing the electrodes of the pH meter (Beckman Model M) directly into the intestinal contents without making any dilution. The regions in which pH was measured were the duodenal loop, the upper mesenteric intestine six inches posterior to the duodenum, the lower small intestine six inches anterior to the cecal junction, and the left cecum. In experiment 6, the determinations in the lower small intestine were made one inch anterior to the cecal junction. The formulae of the basal diets fed in the experiments are shown in Table 1. New Hampshire chicks were used throughout the experiments. The age of the birds at the time the measurements were made varied in the different experiments. The age of the birds and their average weights in each experiment are shown in Table 2 together with the average values for hydrogen ion concentration
405
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
ATA on the hydrogen ion concentration in the intestine of the chick have been reported by Farner (1942), McLaughlin (1931), Mayhew (1935). It is difficult to compare results obtained by different investigators because of differences in the methods used. There is also the possibility that differences in the diets fed may have been responsible for some of the differences observed. Mussehl, Blish and Ackerson (1935) and Olson and Mann (1935) found that variations in the diet did not appreciably change intestinal pH. Heller and Penquite (1936) showed that although basic salts may raise pH in the crop, gizzard and proventriculus, the intestinal pH was not appreciably affected. Beach (1925) showed that cecal pH was rapidly reduced by feeding lactose or milk. Ashcraft (1933) found that pH in the duodenum and ileum was increased while pH of the cecal contents was decreased when milk products were fed. Wiseman, Bushnell and Rosenberg (1956) reported that intestinal pH was similar in chicks fed diets containing either yellow corn or B-grade molasses as the chief source of carbohydrate.
406
B. MARCH, R. TUCKEY AND J. BIELY TABLE 1.—Composition of basal diets per 100 lbs. Experiment Ingredient 2
3
5
6
lb
lb.
20% protein
30% protein
lb.
lb.
15.0 37.84 9.0
55.585 75.88 7.5
52.52 7.5
75.88 7.5
38.75 20.0 8.0
18.3
39.640
63.3 7.5 7.5 15.0
9.12
26.48 6.0
10.72
25.0
0.5 1.0 2.0
2.0 2.0 0.2 0.5 1.25 0.5
0.5 2.0 2.0 0.5 1.0 1.5
0.5 2.0 2.0 0.5 1.0 1.5
0.5 2.0 0.4 0.5 1.0 1.5
2.0 2.5 0.25 0.5 1.0 1.75
0.025
0.015
0.015
0.015
0.015
0.0125
0.25
0.25
4
3.0 2.5 1.0 2.5 0.5 1.18 0.35 0.1 0.25 9.32
Niacin Calcium pantothenate Riboflavin Dry vitamin A Dry vitamin D 3
in the intestine. The pH values shown were calculated from the means of the antilogarithms of the pH readings. Analyses of variance were also based on the antilogarithms. In order to facilitate comparison of the values, they have been expressed both as pH and as actual hydrogen ion concentrations. In many instances conclusions which might be drawn upon cursory examination of pH values will be seen to be fallacious when the actual hydrogen ion concentrations are studied. Variability in hydrogen ion concentration in the intestine increased posteriorly with the greatest range in pH occurring in the ceca. The range in the average values in the duodenum was from 6.13 to 6.51; in the upper mesenteric intestine, 5.85 to 6.41; in the lower intestine 6.15 to
gm. 0.75
0.25 gm. 0.8 0.5 0.1
gm. 0.8 0.5 0.1
gm. 0.8 0.5 0.1
Units 200,000 15,000
Units 200,000 15,000
Units 200,000 15,000
7.60 and in the cecum, 5.12 to 6.82. Experiment 1. In this test the chicks were fed: (1) the basal diet shown in Table 1, (2) the basal diet in which 8 percent animal fat2 was substituted for an equal amount of the cellulose in the basal diet, (3) the basal diet supplemented with 2 mg. procaine penicillin G/lb. and (4) the high fat diet supplemented with penicillin. In the chicks fed the diets containing added fat, pH was significantly lowered in the cecum both with the basal diet and the basal diet supplemented with penicillin. Penicillin did not significantly affect pH in the intestine. Experiment 2. The basal diet was a relatively simple corn-soybean ration. 2 Sta-y-fat. Courtesy Gordon Young B.C. Ltd., Vancouver, B. C.
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
Ground yellow corn Ground wheat Fish meal (70% protein) Meat meal (50% protein) Soybean oil meal (44% protein) Isolated soya protein Dried brewers' yeast Dried skim milk Dried butyl fermentation solubles Dehydrated cereal grass Choline chloride (25%) Iodized salt Limestone Bone meal Tricalcium phosphate Trace mineral mix Manganese sulphate Feeding oil (2,250 units A300 units D8) Ground cellulose
1 lb.
407
D I E T AND INTESTINAL P H TABLE 2.—pH in the intestine of chicks fed different diets Experiment No.
Characteristic of diet
1
1. 2. 3. 4.
control animal fat penicillin animal fat, penicillin
2
1, 2. 3. 4.
control animal fat chlortetracycline animal fat, chlortetracycline
Age of birds (weeks)
Av. No. body of weight (gm.) detns.
7
567 596 598 710
10 10 10 9
4*
277 213 316 314
8 7 8 8
Duodenal loop nH PH
1. 2. 3. 4. 5. 6. 7. 8.
wheat wheat, animal fat wheat, chlortetracycline wheat, animal fat, chlortetracycline corn corn, animal fat corn, chlortetracycline corn, animal fat, chlortetracycline
4i
,0,
pH
H+ X10'
6'up pH
pH
6.11 5.93 6.13 5.98
7.7 11.7 7.4 10.5
6.92 7.04 7.43 7.30
1.2 0.91 0.37 0.50
5.89 5.59 6.27 5.38
13.0 26.0 5.4 41.6 13.13 17.60
6.51 6.36 6.45 6.38
3.1 4.4 3.5 4.2
6.23 6.12 6.24 6.20
5.8 7.6 5.7 6.3
6.92 7.38 7.35 7.52
1.2 0.42 0.45 0.30
5.96 5.87 6.09 5.98
11.0 13.6 8.2 10.5
.66 .89
1.3
0.50
376 364 353 342
8 8 8 8
6.44 6.33 6.42 6.35
3.6 4.7 3.8 4.5
6.20 6.20 6.31 6.19
6.3 6.3 4.9 6.5
7.23 6.60 6.96 7.04
0.59 2.5 1.1 0.92
6.60 6.82 6.54 6.32
2.5 1.5 2.9 4.8
363 358 378 384
8 8 8 8
6.41 6.32 6.38 6.42
3.9 4.8 4.2 3.8
6.24 6.22 6.22 6.19
5.8 6.1 6.1 6.4
7.43 7.51 7.28 7.60
0.37 0.31 0.53 0.25
6.52 6.50 6.54 6.55
3.0 3.2 2.9 2.8
429 463 411 420 506 516
8 8 8 8 8 8
1. control 2. animal fat
8
577 588
10 10
6.28 6.29
5.3 5.1
6.04 6.11
1. control 2. animal fat
10
806 824
10 10
6.24 6.15
5.8 7.1
4
344* 358 283 330
6 6 6 6
6.33 6.35 6.17 6.29
345 340
6 6
342 347
5
6
1.27 1.67
a
1. 2. 3. 4. 5. 6.
1. 2. 3. 4.
2 0 % protein 2 0 % protein, animal fat 2 0 % protein, corn oil 3 0 % protein 3 0 % protein, animal fat 3 0 % protein, corn oil
control chlortetracycline whey whey, chlortetracycline
5. cottonseed oil 6. cottonseed oil, chlortetracycline 7. cottonseed oil, whey 8. cottonseed oil, whey, chlortetra cycline 9. animal fat 10. animal fat, chlortetracycline 11. animal fat, whey 12. animal fat, whey, chlortetracycline
H+ X10'
4.2 5.0 4.8 4.3
MSD5% MSD1% 4
Cecum
H+ X10'
7.17 7.28 7.09 7.21 7.13 7.30
0.67 0.52 0.82 0.62 0.75 0.5
6.43 6.01 5.60 6.02 5.92 5.82
3.7 9.8 24.9 9.5 12.0 15.0 12.43
9.2 7.0
7.U 6.79
0.78 1.6
6.07 6.14
8.5 7.2
6.18 6.02
6.6 9.5
7.15 7.16
0.70 0.69
6.05 6.10
8.8 7.9
4.7 4.5 6.7 5.1
6.37 6.41 6.19 6.24
4.3 3.9 6.5 5.7
7.39 7.39 7.15 6.96
0.41 0.41 0.70 1.1
6.37 6.27 5.20 5.12
4.3 5.4 62.7 75.0
6.29 6.21
5.1 6.1
6.01 6.14
9.9 7.2
6.57 7.15
2.7 0.71
6.0 6.38
10.0 4.2
6 6
6.36 6.13
4.4 7.4
6.15 6.14
7.0 7.2
6.64 7.12
2.3 0.76
5.15 5.26
70.0 55.5
310 371
6 6
6.20 6.15
6.3 7.1
5.89 5.85
12.9 14.2
6.15 6.29
7.0 5.2
6.31 6.22
4.9 6.0
317 354
6 6
6.33 6.27
4.7 5.4
6.16 6.15
6.9 7.0
6.89 7.11
1.3 0.77
5.38 5.38
41.8 42.0
M S B 5%
MSD5% MSD1%
3.20 4.26
3.20 4.26
23.46 31.20
* Average weight of all birds in group.
Diet 2 contained 15 percent animal fat with appropriate adjustments in the levels of corn and soybean oil meal to maintain the protein level. Both these diets were fed with and without supplementary chlortetracycline HC1 at a level of 25 mg. per lb. The results varied from those of the previous experiment in that pH in the
cecum was not altered by the dietary treatment whereas pH measurements in the remainder of the intestine showed statistically significant differences. Fat reduced pH in the duodenum when fed in either the basal diet or the basal diet supplemented with chlortetracycline. In the upper mesenteric intestine fat reduced pH with the basal diet but had no effect
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
3
x
6* down
6.38 6.30 6.32 6.37 MSD5% MSD1%
MSD5% MSD1% .
H +
408
B. MARCH, R. TUCKEY AND J. BIELY
ment was made in the levels of wheat and soybean oil meal in the diet when fat was included. At the time the measurements were made, the chicks in this experiment were older (8 and 10 weeks) than in any of the other experiments. Fat was not found to exert any significant effect on intestinal pH either at 8 or 10 weeks. Experiment 6. Animal fat and cottonseed oil at levels of 10 percent in the diet were tested for their effect on intestinal pH. Inclusion of the fats was made with adjustment in the levels of corn and soybean oil meal used in the basal diet. The effect of chlortetracyclme HC1 at a level of 50 mg./lb. was studied. Likewise the effect of supplementing the diet with 20 percent of dried whey was determined, the whey being substituted for wheat in the diet. The various dietary modifications are outlined in Table 2. Animal fat and cottonseed oil both reduced pH in the upper mesenteric intestine when added to the basal diet or to the basal diet supplemented with chlortetracyclme. When the fats were added to the diets supplemented with whey there was no measurable effect on pH in this region. In the lower intestine animal fat lowered pH with the basal diet and with the diets supplemented with antibiotic. Cottonseed oil likewise lowered pH in this region but the effect was not statistically significant. When the diets contained whey there was no significant effect from the addition of fat on pH in the lower intestine. When animal fat was added to the basal diet supplemented with whey, or the diet supplemented with whey and chlortetracyclme, pH in the cecum was raised. The antibiotic did not affect intestinal pH when added to any of the diets fed in this experiment. The effect of whey on pH in the intestine depended on the nature of the diet
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
with the diet supplemented with chlortetracycline. The antibiotic raised pH in the upper mesenteric intestine when added to the high fat diet but had no effect with the basal diet. In the lower intestine, chlortetracyclme raised pH when added to the basal diet. Experiment 3. Two types of basal diet were fed in this experiment utilizing corn and wheat respectively as the cereal component. In Diet 5 (corn basal diet) corn was substituted for wheat in the diet shown in Table 1. When fat was included in the diets it was added at a level of 10 percent with adjustments in the levels of the cereal and of fish meal, meat meal and soybean oil meal. Each of the diets was fed with and without 25 mg./lb. of chlortetracyclme HC1. The only measurable effects of diet on pH in this experiment occurred in the lower part of the intestine. In the chicks fed the corn diets, pH in this region was higher than in the chicks fed the wheat diets. With the corn diets none of the dietary treatments had any significant effect. With the wheat basal diet, inclusion of fat reduced pH. Experiment 4. Basal diets containing 20 and 30 percent protein respectively were fed. At each protein level the effect of including 12 percent of animal fat or corn oil was tested. Adjustment was made in the levels of wheat and soybean oil meal. Measurements were made only in the lower intestine and the cecum. There was no effect of diet on pH in the lower intestine. The inclusion of corn oil in the 20 percent protein diet lowered pH in the cecum. None of the other differences in pH of the ceca in birds fed the various diets were significant. Experiment 5. The basal diet shown in Table 1 was fed with and without the inclusion of 12 percent animal fat. Adjust-
409
D I E T AND INTESTINAL P H
DISCUSSION
The results show the duodenum, upper part of the mesenteric intestine and the cecum of chicks to be acid with all of the diets fed in these experiments. The lower intestine was more alkaline with pH values in both the acid and alkaline ranges depending on the diet fed to the chicks. The effect of diet on the intestinal pH thus explains, in part, the apparent discrepancies in the values reported in the literature. The addition of fat to the basal diets lowered pH in the upper mesenteric intestine in those experiments where there was a significant effect from fat in this region. A higher level of dietary fat may stimulate secretion of bile in chickens as it does in other animals. Since the bile of birds is acid, an increased secretion of bile could be expected to result in a lower pH in the upper part of the intestine. The effect of fat on pH in the lower part of the intestine varied. The addition of an antibiotic had little or no effect on pH in any part of the intestine. The only significant effects noted occurred in Experiments 1 and 2. In Experiment 1, penicillin, when added to the diet with animal fat, lowered pH in the lower intestine of chicks fed the basal diet and in the upper mesenteric intestine of
chicks fed the diet containing 15 percent animal fat. When whey was added to the basal diet fed in Experiment 6, pH was decreased in the cecum of birds fed the diet. Although the effect on hydrogen-ion concentration in other parts of the intestine was not significant, pH was reduced throughout. On the other hand it was found that when whey was added to diets containing 10 percent animal fat, pH was increased in the upper and lower mesenteric intestine but lowered in the cecum. The results obtained when whey was added to the diet containing animal fat are in agreement with the results reported by Aschraft (1933) on pH in the intestinal tract of birds fed milk products. Supplementation of the diets with chlortetracycline did not modify the effects of dietary whey on intestinal pH. It would appear that the pH in the intestinal tract of the growing chick may be modified by the diet. The effect of any particular dietary ingredient on pH seems to be related to the over-all composition of the diet. It is difficult, therefore, to draw general conclusions regarding the effect on intestinal pH of any individual dietary constituent. SUMMARY
Hydrogen-ion concentrations were determined in the duodenum, the upper and lower parts of the mesenteric intestine, and the cecum of growing chicks fed different diets. Variability in the pH of the intestinal tract increased posteriorly with the greatest variability occurring in the cecum. The addition of fats to the diets tended to reduce pH in most regions of the intestine. Penicillin or chlortetracycline supplementation of the diets had little or no effect on intestinal pH. The addition of whey to the diet lowered pH in the cecum. The effect of whey in other
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
in which the whey was fed. In the case of the diets without a fat supplement, or those supplemented with cottonseed oil, there was no significant effect. When the diet contained animal fat, the inclusion of whey in the diets raised pH in the lower intestine. In the cecum, the addition of whey to the diet reduced pH markedly in every instance. It was noted in this experiment that the cecal contents in birds fed whey were often light coloured and frothy. Ashcraft (1933) made a similar observation on birds fed milk products.
410
B. MARCH, R. TUCKEY AND J. BIELY
parts of the intestinal tract depended on the fat content of the diet. REFERENCES
Investigation of Urinary Water Reabsorption in the Cloaca and Rectum of the Hen 1 J. M. DIXON Department of Veterinary Science, Louisiana State University, Baton Rouge, Louisiana (Received for publication September 23, 1957)
E
ARLY work involving short periods of urine collection and extrapolation to a 24 hour basis led many workers studying water metabolism in the hen to conclude: (1) that the amount of ureteral urine entering the cloaca and rectum may be as much as 700 to 1,000 cc. in 24 hours and (2) that 240 to 720 cc. of water was reabsorbed from this urine in the cloaca and rectum in 24 hours (Sharpe, 1923; Davis, 1927; Korr, 1939; Hester, Essex and Mann, 1940; and others). The estimated volume of urine voided daily was extremely large and greatly exceeded the daily water consumption; water balance was thus believed to be maintained by reabsorption of water from the urine in the cloaca and rectum. Hart and Essex (1942) reported ureteral urine volumes of 1 Published with the approval of the director of the Louisiana Agricultural Experiment Station.
50 to 180 cc. per day based on 24 hour quantitative collections. Their work suggested that the cloaca was unimportant and the rectum was important in reabsorption of water from the ureteral urine, but that further investigation would be required to determine the magnitude of reabsorption. The purpose of this research was to determine if water is reabsorbed from the urine in the cloaca and rectum by the comparison of water balance in normal hens and hens with exteriorized ureters or with the rectum exteriorized. MATERIAL AND METHODS
The experimental plan was to collect feces and urine quantitatively from each hen before surgical modification, then to use two surgical modifications whereby quantitative collections of feces and urine could be made separately.
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
Ashcraft, D. W., 1933. Effect of milk products on pH of the intestinal contents of domestic fowl. Poultry Sci. 12: 292-298. Beach, J. R., 1925. The effect of feeding B. acidophilus, lactose, dry skim milk or whole milk on the hydrogen ion concentration of the contents of the ceca of chickens. Hilgardia, 1:145-166. Farner, D. S., 1942. The hydrogen ion concentration in avian digestive tracts. Poultry Sci. 21: 445450. Heller, V. G., and R. Penquite, 1936. Effect of minerals and fiber on avian intestinal pH. Poultry Sci. 15: 397-399.
Mayhew, R. L., 1935. The hydrogen ion concentration of the digestive tract of the fowl. J. Amer. Vet. Med. Assoc. 86: 148-152. McLaughlin, A. R., 1931. Hydrogen ion concentration of the alimentary tracts of fowl, cat and rabbit. Science, 78: 191-192. Mussehl, F. E., M. J. Blish and C. W. Ackerson, 1935. Effect of dietary and environmental factors on the pH of the intestinal tract. Poultry Sci. 12: 120-123. Olson, C , and F. C. Mann, 1935. The physiology of the cecum of the domestic fowl. J. Amer. Vet. Med. Assoc. 87: 151-159. Wiseman, R. W., O. A. Bushnell and M. M. Rosenberg, 1956. Effect of rations on the pH and microflora in selected regions of the intestinal tract of chickens. Poultry Sci. 35: 126-132.
D
Because of the possible effects of intestinal pH upon utilization of various nutrients it was decided to investigate further the effects of different diets upon intestinal pH. EXPERIMENTAL AND RESULTS
In each of the following experiments pH in the intestine of chicks was determined 1 Aided by a grant sponsored by the Bacteriology Division, Science Service, Department of Agriculture, Ottawa, Canada. * Contribution No. 99.
by the following procedure: the chicks were encouraged to eat over a period of If to 2 hours. Since all birds would then have food in the digestive tract, secretion of the digestive juices could be assumed to be maximum. Any differences noted in pH would not be due to differences in the amounts of the digestive juices present in the intestine. Birds selected at random from each lot were killed by anaesthetization with diethyl ether. Struggling was thus minimized and, as a result, reversed peristalsis and defecation reduced. Each bird was weighed, the intestine was removed, and the desired sections cut out. The intestinal sections were slit and clamped flat. The determinations were made by placing the electrodes of the pH meter (Beckman Model M) directly into the intestinal contents without making any dilution. The regions in which pH was measured were the duodenal loop, the upper mesenteric intestine six inches posterior to the duodenum, the lower small intestine six inches anterior to the cecal junction, and the left cecum. In experiment 6, the determinations in the lower small intestine were made one inch anterior to the cecal junction. The formulae of the basal diets fed in the experiments are shown in Table 1. New Hampshire chicks were used throughout the experiments. The age of the birds at the time the measurements were made varied in the different experiments. The age of the birds and their average weights in each experiment are shown in Table 2 together with the average values for hydrogen ion concentration
405
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
ATA on the hydrogen ion concentration in the intestine of the chick have been reported by Farner (1942), McLaughlin (1931), Mayhew (1935). It is difficult to compare results obtained by different investigators because of differences in the methods used. There is also the possibility that differences in the diets fed may have been responsible for some of the differences observed. Mussehl, Blish and Ackerson (1935) and Olson and Mann (1935) found that variations in the diet did not appreciably change intestinal pH. Heller and Penquite (1936) showed that although basic salts may raise pH in the crop, gizzard and proventriculus, the intestinal pH was not appreciably affected. Beach (1925) showed that cecal pH was rapidly reduced by feeding lactose or milk. Ashcraft (1933) found that pH in the duodenum and ileum was increased while pH of the cecal contents was decreased when milk products were fed. Wiseman, Bushnell and Rosenberg (1956) reported that intestinal pH was similar in chicks fed diets containing either yellow corn or B-grade molasses as the chief source of carbohydrate.
406
B. MARCH, R. TUCKEY AND J. BIELY TABLE 1.—Composition of basal diets per 100 lbs. Experiment Ingredient 2
3
5
6
lb
lb.
20% protein
30% protein
lb.
lb.
15.0 37.84 9.0
55.585 75.88 7.5
52.52 7.5
75.88 7.5
38.75 20.0 8.0
18.3
39.640
63.3 7.5 7.5 15.0
9.12
26.48 6.0
10.72
25.0
0.5 1.0 2.0
2.0 2.0 0.2 0.5 1.25 0.5
0.5 2.0 2.0 0.5 1.0 1.5
0.5 2.0 2.0 0.5 1.0 1.5
0.5 2.0 0.4 0.5 1.0 1.5
2.0 2.5 0.25 0.5 1.0 1.75
0.025
0.015
0.015
0.015
0.015
0.0125
0.25
0.25
4
3.0 2.5 1.0 2.5 0.5 1.18 0.35 0.1 0.25 9.32
Niacin Calcium pantothenate Riboflavin Dry vitamin A Dry vitamin D 3
in the intestine. The pH values shown were calculated from the means of the antilogarithms of the pH readings. Analyses of variance were also based on the antilogarithms. In order to facilitate comparison of the values, they have been expressed both as pH and as actual hydrogen ion concentrations. In many instances conclusions which might be drawn upon cursory examination of pH values will be seen to be fallacious when the actual hydrogen ion concentrations are studied. Variability in hydrogen ion concentration in the intestine increased posteriorly with the greatest range in pH occurring in the ceca. The range in the average values in the duodenum was from 6.13 to 6.51; in the upper mesenteric intestine, 5.85 to 6.41; in the lower intestine 6.15 to
gm. 0.75
0.25 gm. 0.8 0.5 0.1
gm. 0.8 0.5 0.1
gm. 0.8 0.5 0.1
Units 200,000 15,000
Units 200,000 15,000
Units 200,000 15,000
7.60 and in the cecum, 5.12 to 6.82. Experiment 1. In this test the chicks were fed: (1) the basal diet shown in Table 1, (2) the basal diet in which 8 percent animal fat2 was substituted for an equal amount of the cellulose in the basal diet, (3) the basal diet supplemented with 2 mg. procaine penicillin G/lb. and (4) the high fat diet supplemented with penicillin. In the chicks fed the diets containing added fat, pH was significantly lowered in the cecum both with the basal diet and the basal diet supplemented with penicillin. Penicillin did not significantly affect pH in the intestine. Experiment 2. The basal diet was a relatively simple corn-soybean ration. 2 Sta-y-fat. Courtesy Gordon Young B.C. Ltd., Vancouver, B. C.
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
Ground yellow corn Ground wheat Fish meal (70% protein) Meat meal (50% protein) Soybean oil meal (44% protein) Isolated soya protein Dried brewers' yeast Dried skim milk Dried butyl fermentation solubles Dehydrated cereal grass Choline chloride (25%) Iodized salt Limestone Bone meal Tricalcium phosphate Trace mineral mix Manganese sulphate Feeding oil (2,250 units A300 units D8) Ground cellulose
1 lb.
407
D I E T AND INTESTINAL P H TABLE 2.—pH in the intestine of chicks fed different diets Experiment No.
Characteristic of diet
1
1. 2. 3. 4.
control animal fat penicillin animal fat, penicillin
2
1, 2. 3. 4.
control animal fat chlortetracycline animal fat, chlortetracycline
Age of birds (weeks)
Av. No. body of weight (gm.) detns.
7
567 596 598 710
10 10 10 9
4*
277 213 316 314
8 7 8 8
Duodenal loop nH PH
1. 2. 3. 4. 5. 6. 7. 8.
wheat wheat, animal fat wheat, chlortetracycline wheat, animal fat, chlortetracycline corn corn, animal fat corn, chlortetracycline corn, animal fat, chlortetracycline
4i
,0,
pH
H+ X10'
6'up pH
pH
6.11 5.93 6.13 5.98
7.7 11.7 7.4 10.5
6.92 7.04 7.43 7.30
1.2 0.91 0.37 0.50
5.89 5.59 6.27 5.38
13.0 26.0 5.4 41.6 13.13 17.60
6.51 6.36 6.45 6.38
3.1 4.4 3.5 4.2
6.23 6.12 6.24 6.20
5.8 7.6 5.7 6.3
6.92 7.38 7.35 7.52
1.2 0.42 0.45 0.30
5.96 5.87 6.09 5.98
11.0 13.6 8.2 10.5
.66 .89
1.3
0.50
376 364 353 342
8 8 8 8
6.44 6.33 6.42 6.35
3.6 4.7 3.8 4.5
6.20 6.20 6.31 6.19
6.3 6.3 4.9 6.5
7.23 6.60 6.96 7.04
0.59 2.5 1.1 0.92
6.60 6.82 6.54 6.32
2.5 1.5 2.9 4.8
363 358 378 384
8 8 8 8
6.41 6.32 6.38 6.42
3.9 4.8 4.2 3.8
6.24 6.22 6.22 6.19
5.8 6.1 6.1 6.4
7.43 7.51 7.28 7.60
0.37 0.31 0.53 0.25
6.52 6.50 6.54 6.55
3.0 3.2 2.9 2.8
429 463 411 420 506 516
8 8 8 8 8 8
1. control 2. animal fat
8
577 588
10 10
6.28 6.29
5.3 5.1
6.04 6.11
1. control 2. animal fat
10
806 824
10 10
6.24 6.15
5.8 7.1
4
344* 358 283 330
6 6 6 6
6.33 6.35 6.17 6.29
345 340
6 6
342 347
5
6
1.27 1.67
a
1. 2. 3. 4. 5. 6.
1. 2. 3. 4.
2 0 % protein 2 0 % protein, animal fat 2 0 % protein, corn oil 3 0 % protein 3 0 % protein, animal fat 3 0 % protein, corn oil
control chlortetracycline whey whey, chlortetracycline
5. cottonseed oil 6. cottonseed oil, chlortetracycline 7. cottonseed oil, whey 8. cottonseed oil, whey, chlortetra cycline 9. animal fat 10. animal fat, chlortetracycline 11. animal fat, whey 12. animal fat, whey, chlortetracycline
H+ X10'
4.2 5.0 4.8 4.3
MSD5% MSD1% 4
Cecum
H+ X10'
7.17 7.28 7.09 7.21 7.13 7.30
0.67 0.52 0.82 0.62 0.75 0.5
6.43 6.01 5.60 6.02 5.92 5.82
3.7 9.8 24.9 9.5 12.0 15.0 12.43
9.2 7.0
7.U 6.79
0.78 1.6
6.07 6.14
8.5 7.2
6.18 6.02
6.6 9.5
7.15 7.16
0.70 0.69
6.05 6.10
8.8 7.9
4.7 4.5 6.7 5.1
6.37 6.41 6.19 6.24
4.3 3.9 6.5 5.7
7.39 7.39 7.15 6.96
0.41 0.41 0.70 1.1
6.37 6.27 5.20 5.12
4.3 5.4 62.7 75.0
6.29 6.21
5.1 6.1
6.01 6.14
9.9 7.2
6.57 7.15
2.7 0.71
6.0 6.38
10.0 4.2
6 6
6.36 6.13
4.4 7.4
6.15 6.14
7.0 7.2
6.64 7.12
2.3 0.76
5.15 5.26
70.0 55.5
310 371
6 6
6.20 6.15
6.3 7.1
5.89 5.85
12.9 14.2
6.15 6.29
7.0 5.2
6.31 6.22
4.9 6.0
317 354
6 6
6.33 6.27
4.7 5.4
6.16 6.15
6.9 7.0
6.89 7.11
1.3 0.77
5.38 5.38
41.8 42.0
M S B 5%
MSD5% MSD1%
3.20 4.26
3.20 4.26
23.46 31.20
* Average weight of all birds in group.
Diet 2 contained 15 percent animal fat with appropriate adjustments in the levels of corn and soybean oil meal to maintain the protein level. Both these diets were fed with and without supplementary chlortetracycline HC1 at a level of 25 mg. per lb. The results varied from those of the previous experiment in that pH in the
cecum was not altered by the dietary treatment whereas pH measurements in the remainder of the intestine showed statistically significant differences. Fat reduced pH in the duodenum when fed in either the basal diet or the basal diet supplemented with chlortetracycline. In the upper mesenteric intestine fat reduced pH with the basal diet but had no effect
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
3
x
6* down
6.38 6.30 6.32 6.37 MSD5% MSD1%
MSD5% MSD1% .
H +
408
B. MARCH, R. TUCKEY AND J. BIELY
ment was made in the levels of wheat and soybean oil meal in the diet when fat was included. At the time the measurements were made, the chicks in this experiment were older (8 and 10 weeks) than in any of the other experiments. Fat was not found to exert any significant effect on intestinal pH either at 8 or 10 weeks. Experiment 6. Animal fat and cottonseed oil at levels of 10 percent in the diet were tested for their effect on intestinal pH. Inclusion of the fats was made with adjustment in the levels of corn and soybean oil meal used in the basal diet. The effect of chlortetracyclme HC1 at a level of 50 mg./lb. was studied. Likewise the effect of supplementing the diet with 20 percent of dried whey was determined, the whey being substituted for wheat in the diet. The various dietary modifications are outlined in Table 2. Animal fat and cottonseed oil both reduced pH in the upper mesenteric intestine when added to the basal diet or to the basal diet supplemented with chlortetracyclme. When the fats were added to the diets supplemented with whey there was no measurable effect on pH in this region. In the lower intestine animal fat lowered pH with the basal diet and with the diets supplemented with antibiotic. Cottonseed oil likewise lowered pH in this region but the effect was not statistically significant. When the diets contained whey there was no significant effect from the addition of fat on pH in the lower intestine. When animal fat was added to the basal diet supplemented with whey, or the diet supplemented with whey and chlortetracyclme, pH in the cecum was raised. The antibiotic did not affect intestinal pH when added to any of the diets fed in this experiment. The effect of whey on pH in the intestine depended on the nature of the diet
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
with the diet supplemented with chlortetracycline. The antibiotic raised pH in the upper mesenteric intestine when added to the high fat diet but had no effect with the basal diet. In the lower intestine, chlortetracyclme raised pH when added to the basal diet. Experiment 3. Two types of basal diet were fed in this experiment utilizing corn and wheat respectively as the cereal component. In Diet 5 (corn basal diet) corn was substituted for wheat in the diet shown in Table 1. When fat was included in the diets it was added at a level of 10 percent with adjustments in the levels of the cereal and of fish meal, meat meal and soybean oil meal. Each of the diets was fed with and without 25 mg./lb. of chlortetracyclme HC1. The only measurable effects of diet on pH in this experiment occurred in the lower part of the intestine. In the chicks fed the corn diets, pH in this region was higher than in the chicks fed the wheat diets. With the corn diets none of the dietary treatments had any significant effect. With the wheat basal diet, inclusion of fat reduced pH. Experiment 4. Basal diets containing 20 and 30 percent protein respectively were fed. At each protein level the effect of including 12 percent of animal fat or corn oil was tested. Adjustment was made in the levels of wheat and soybean oil meal. Measurements were made only in the lower intestine and the cecum. There was no effect of diet on pH in the lower intestine. The inclusion of corn oil in the 20 percent protein diet lowered pH in the cecum. None of the other differences in pH of the ceca in birds fed the various diets were significant. Experiment 5. The basal diet shown in Table 1 was fed with and without the inclusion of 12 percent animal fat. Adjust-
409
D I E T AND INTESTINAL P H
DISCUSSION
The results show the duodenum, upper part of the mesenteric intestine and the cecum of chicks to be acid with all of the diets fed in these experiments. The lower intestine was more alkaline with pH values in both the acid and alkaline ranges depending on the diet fed to the chicks. The effect of diet on the intestinal pH thus explains, in part, the apparent discrepancies in the values reported in the literature. The addition of fat to the basal diets lowered pH in the upper mesenteric intestine in those experiments where there was a significant effect from fat in this region. A higher level of dietary fat may stimulate secretion of bile in chickens as it does in other animals. Since the bile of birds is acid, an increased secretion of bile could be expected to result in a lower pH in the upper part of the intestine. The effect of fat on pH in the lower part of the intestine varied. The addition of an antibiotic had little or no effect on pH in any part of the intestine. The only significant effects noted occurred in Experiments 1 and 2. In Experiment 1, penicillin, when added to the diet with animal fat, lowered pH in the lower intestine of chicks fed the basal diet and in the upper mesenteric intestine of
chicks fed the diet containing 15 percent animal fat. When whey was added to the basal diet fed in Experiment 6, pH was decreased in the cecum of birds fed the diet. Although the effect on hydrogen-ion concentration in other parts of the intestine was not significant, pH was reduced throughout. On the other hand it was found that when whey was added to diets containing 10 percent animal fat, pH was increased in the upper and lower mesenteric intestine but lowered in the cecum. The results obtained when whey was added to the diet containing animal fat are in agreement with the results reported by Aschraft (1933) on pH in the intestinal tract of birds fed milk products. Supplementation of the diets with chlortetracycline did not modify the effects of dietary whey on intestinal pH. It would appear that the pH in the intestinal tract of the growing chick may be modified by the diet. The effect of any particular dietary ingredient on pH seems to be related to the over-all composition of the diet. It is difficult, therefore, to draw general conclusions regarding the effect on intestinal pH of any individual dietary constituent. SUMMARY
Hydrogen-ion concentrations were determined in the duodenum, the upper and lower parts of the mesenteric intestine, and the cecum of growing chicks fed different diets. Variability in the pH of the intestinal tract increased posteriorly with the greatest variability occurring in the cecum. The addition of fats to the diets tended to reduce pH in most regions of the intestine. Penicillin or chlortetracycline supplementation of the diets had little or no effect on intestinal pH. The addition of whey to the diet lowered pH in the cecum. The effect of whey in other
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
in which the whey was fed. In the case of the diets without a fat supplement, or those supplemented with cottonseed oil, there was no significant effect. When the diet contained animal fat, the inclusion of whey in the diets raised pH in the lower intestine. In the cecum, the addition of whey to the diet reduced pH markedly in every instance. It was noted in this experiment that the cecal contents in birds fed whey were often light coloured and frothy. Ashcraft (1933) made a similar observation on birds fed milk products.
410
B. MARCH, R. TUCKEY AND J. BIELY
parts of the intestinal tract depended on the fat content of the diet. REFERENCES
Investigation of Urinary Water Reabsorption in the Cloaca and Rectum of the Hen 1 J. M. DIXON Department of Veterinary Science, Louisiana State University, Baton Rouge, Louisiana (Received for publication September 23, 1957)
E
ARLY work involving short periods of urine collection and extrapolation to a 24 hour basis led many workers studying water metabolism in the hen to conclude: (1) that the amount of ureteral urine entering the cloaca and rectum may be as much as 700 to 1,000 cc. in 24 hours and (2) that 240 to 720 cc. of water was reabsorbed from this urine in the cloaca and rectum in 24 hours (Sharpe, 1923; Davis, 1927; Korr, 1939; Hester, Essex and Mann, 1940; and others). The estimated volume of urine voided daily was extremely large and greatly exceeded the daily water consumption; water balance was thus believed to be maintained by reabsorption of water from the urine in the cloaca and rectum. Hart and Essex (1942) reported ureteral urine volumes of 1 Published with the approval of the director of the Louisiana Agricultural Experiment Station.
50 to 180 cc. per day based on 24 hour quantitative collections. Their work suggested that the cloaca was unimportant and the rectum was important in reabsorption of water from the ureteral urine, but that further investigation would be required to determine the magnitude of reabsorption. The purpose of this research was to determine if water is reabsorbed from the urine in the cloaca and rectum by the comparison of water balance in normal hens and hens with exteriorized ureters or with the rectum exteriorized. MATERIAL AND METHODS
The experimental plan was to collect feces and urine quantitatively from each hen before surgical modification, then to use two surgical modifications whereby quantitative collections of feces and urine could be made separately.
Downloaded from http://ps.oxfordjournals.org/ at University of Pennsylvania Library on June 20, 2015
Ashcraft, D. W., 1933. Effect of milk products on pH of the intestinal contents of domestic fowl. Poultry Sci. 12: 292-298. Beach, J. R., 1925. The effect of feeding B. acidophilus, lactose, dry skim milk or whole milk on the hydrogen ion concentration of the contents of the ceca of chickens. Hilgardia, 1:145-166. Farner, D. S., 1942. The hydrogen ion concentration in avian digestive tracts. Poultry Sci. 21: 445450. Heller, V. G., and R. Penquite, 1936. Effect of minerals and fiber on avian intestinal pH. Poultry Sci. 15: 397-399.
Mayhew, R. L., 1935. The hydrogen ion concentration of the digestive tract of the fowl. J. Amer. Vet. Med. Assoc. 86: 148-152. McLaughlin, A. R., 1931. Hydrogen ion concentration of the alimentary tracts of fowl, cat and rabbit. Science, 78: 191-192. Mussehl, F. E., M. J. Blish and C. W. Ackerson, 1935. Effect of dietary and environmental factors on the pH of the intestinal tract. Poultry Sci. 12: 120-123. Olson, C , and F. C. Mann, 1935. The physiology of the cecum of the domestic fowl. J. Amer. Vet. Med. Assoc. 87: 151-159. Wiseman, R. W., O. A. Bushnell and M. M. Rosenberg, 1956. Effect of rations on the pH and microflora in selected regions of the intestinal tract of chickens. Poultry Sci. 35: 126-132.