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The Effects of Age and Reproductive State on Plasma Uric Acid Levels in Chickens*
The Effects of Age and Reproductive State on Plasma Uric Acid Levels in Chickens* PAUL D.
STUEKIE
Physiology Laboratories, Department of Poultry Science, Rutgers New Brunswick, New Jersey
University,
(Received for publication February 20, 1961)
F
METHODS
Laying White Leghorn females (aged 7-8 months) were placed in individual laying batteries, where they were maintained until 26 months of age. Some degree of tem* Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University, the State University of New Jersey, Department of Poultry Science, New Brunswick.
perature control was maintained where birds were housed, so that temperatures never exceeded 80-85 degrees F. nor fell below 40°F. All birds were fed the same allmash laying diet throughout the period. Records of egg production, feed consumption, and state of health were kept. Blood samples were collected at varying intervals from 8-26 months of age, and determinations of uric acid were made, employing a minor modification of the uricase method of Bubhs etal. (1956). RESULTS The results are shown in Table 1. It is observed that the mean values for laying birds from 8-26 months of age range from 2.1 to 3.00 mgs./lOO ml. These values, as judged from the large standard deviations, are quite variable, a fact that was reported by Bell et al. (1959). There appears to be a slight increase in plasma uric acid with age, but none of the differences is significant statistically. It would appear also, that as long as birds are laying, the rate of laying does not influence uric acid levels, because rate of lay in these birds decreased with age. Non-laying birds, however, have significantly higher uric acid levels, regardless of age. The mean plasma uric acid for all non-laying birds was 3.90, a figure significantly higher than for laying birds, although individual variation was considerable, ranging from 1.87 to 8.00. This raises the question of whether or not duration of the non-laying state influences level of uric acid. Unfortunately these data shed little
1650
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on June 11, 2015
EW studies have been made on the effects of aging on blood uric acid in mammals, and none on chickens. Among the limited studies on humans, some of the reports have indicated a rise with age (Morgan et al., 19SS), and some have shown no change (Praetorius, 1951; Gertler and Oppenheimer, 1953). Bell, Mclndoe and Gross (1959) have shown that plasma uric acid of chickens varies considerably under standard conditions and is influenced by sex and reproductive state. Non-laying hens had considerably higher uric acid levels than laying birds, and starvation decreased the level. Before the publication of the work of Bell et al., we had made determinations of a number of chemical constituents of blood (including uric acid) in laying hens from 8-26 months of age. It became apparent that to assess the effects of age on blood uric acid level, consideration must be given to state of reproduction, health, and nutrition. This report deals with plasma uric acid levels of birds from 8-26 months of age; most of the birds were laying, but some were not laying and some were not eating.
16S1
PLASMA URIC ACID 1.—.Plasma
TABLE
uric acid of healthy female chickens from 8 to 26 months of age Mean Uric Acid mgs./lOO ml.
Group & Month
Age Months
Not Laying
Rate of Lay of Those Laying
Laying
No.
Mean
No.
Mean
S.D.
S.E.
Percent
8
—
—
24
2.1
0.80
0.16
76
B-Jan.
10
2
4.18
22
2.6
1.5
0.31
77
C-Mar.
12
3
3.83
21
2.2
0.96
0.21
76
D-Sept.
18
1
1.87
22
2.6
1.36
0.29
52
E-Dec.
21
2
4.10
20
3.00
1.41
0.31
51
F-June
26
2
5.64
17
2.70
0.86
0.21
44
Mean
3.90
2.54
S.D.
2.10
1.17
1.17
S.E.
0.63
0.27
0.27
light on this point. They do, however, include determinations on two birds that had not layed for three or more months. On one of these, when plasma uric acid was determined at intervals of approximately 1, 2, and 3 months after cessation of laying, values observed were 6.00, 3.4, and 2.7 mgs./ 100 ml., respectively; these figures, while higher than for laying birds, are highly variable. In the four determinations made on another hen that had not layed over a 4-month period, three of the four values were low, as characteristic of laying birds. The level of plasma uric acid in these birds thus bears no discernible relationship to duration of non-laying. State of health and food consumption. Bell et al. (1959) have reported that complete starvation for 36 hours depressed plasma uric acid significantly in cocks and hens, but the greatest effect was on nonlaying hens, where uric acids averaged 1.50 in comparison to 5.40 for non-starved hens. Whether or not degree of starvation, or variations of food intake short of complete starvation, influenced uric acid levels was not determined by these investigators.
Food consumption was measured on laying and non-laying birds in this study. Among the healthy birds, non-layers ate less than laying birds, as expected, but the variations in food intake of either laying or non-laying birds appeared not to influence uric-acid level. We did not study the effects of complete starvation of healthy birds, but we did, in the course of these experiments, make observations on several birds that became ill and on some that suddenly stopped eating. These birds ceased laying and plasma uric acids were determined on some of them. The results, shown in Table 2, include determinations made on birds that were laying, and not laying for 10-30 days. Values for all birds were observed to be higher when not laying, regardless of food intake. Bird A exhibited a high uric acid level, even though it had eaten no feed for 10 days. Autopsy revealed abnormal kidneys and accumulation of urates in various organs, and the resulting uricemia is attributed to depressed tubular excretion of uric acid. Bird B, which had eaten no food for 13 days, but which showed no kidney abnor-
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on June 11, 2015
A-Nov.
1652
P. D. STURKIE TABLE 2.—Plasma uric acid of hens while eating and laying normally, and when sick, or not eating and not laying
Not Laying
A
Uric Acid mgs./lOO ml. 2.23
Uric Acid mgs./lOO ml. 6.35
B
2.50
3.3
C
2.14
4.0
D
2.87
7.5 4.6
Notes
No feed eaten for 10 days (UAD)*Bird died6hours later; abnormal kidney-ruicemia No feed eaten for 13 days (UAD) died soon after— no diagnosis No feed for 6 days; then on successive days 10 gms.; 15 gms. and 20 gms. (UAD) Feed consumption normal 3 days later Eating normally
* UAD—Uric Acid determination.
mality at death, exhibited a plasma uricacid level not greatly above that when she was laying and consuming food. Thus, it appears that lack of food intake did depress uric acid in this bird, because the level in non-laying birds, consuming food, is usually much higher. The apparent effect of level of food intake on uric acid is observed in the record of bird C that ate no feed for 6 days and then consumed minute quantities for 3 days. Plasma uric acid was 4 mgs./lOO ml. This bird then began to consume normal amounts of feed; after three days, uric acid level was 7.5 mgs.
uric acid considerably in non-laying birds (Bell et al., 1959), but our meager data suggest that the intake of even small quantities of food tends to prevent extreme depression. Further studies are indicated. Our results, like those of Bell et al., suggest that variations in level of production of estrogen may influence the difference in plasma uric-acid level of laying and nonlaying hens. Studies on the effects of administration of estrogen and androgen to nonlaying females, and estrogen to males, would be particularly instructive.
SUMMARY AND DISCUSSION
Bell, D. J., W. M. Mclndoe and D. Gross, 1959. Tissue components of the domestic fowl. 3. The non protein nitrogen of plasma and erythrocytes. Biochem. J. 71: 35S-364. Dubbs, C. A., F. W. Davis and W. S. Adams, 1956. Simple micro-determinations of uric acid. J. Biol. Chem. 167: 429-504. Gertler, M. M., and B. S. Oppenheimer, 1953. Serum uric acid levels in men and women past the age of 65 years. J. Gerontol. 8: 465^171. Morgan, A. G., M. Murai and H. L. Gillum, 1955. Nutritional status of the aging. VI. Serum protein, blood non-protein nitrogen, uric acid and creatinine. J. Nutr. 55: 671-685. Praetorius E., 1951. Plasma uric acid in aged and young persons. J. Gerontol. 6: 135-137.
REFERENCES
The results of this experiment indicate that plasma uric acid of chickens is highly variable and is influenced by reproductive state, health, food intake, and, possibly, other factors. When due allowance is made for such factors, age (from 8-26 months) does not appear to affect the level significantly. Whether or not a bird is laying influences level most, but exceptions were noted. Among those birds laying, rate of lay, within the limits studied here, did not affect the level appreciably. Complete starvation depresses plasma
JUNE 17-20. 22ND ANNUAL MEETING OF THE INSTITUTE OF FOOD TECHNOLOGISTS, AMERICANA HOTEL, BAL HARBOR, MIAMI BEACH, FLORIDA
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on June 11, 2015
Laying and Eating Normally
Bird No.
STUEKIE
Physiology Laboratories, Department of Poultry Science, Rutgers New Brunswick, New Jersey
University,
(Received for publication February 20, 1961)
F
METHODS
Laying White Leghorn females (aged 7-8 months) were placed in individual laying batteries, where they were maintained until 26 months of age. Some degree of tem* Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University, the State University of New Jersey, Department of Poultry Science, New Brunswick.
perature control was maintained where birds were housed, so that temperatures never exceeded 80-85 degrees F. nor fell below 40°F. All birds were fed the same allmash laying diet throughout the period. Records of egg production, feed consumption, and state of health were kept. Blood samples were collected at varying intervals from 8-26 months of age, and determinations of uric acid were made, employing a minor modification of the uricase method of Bubhs etal. (1956). RESULTS The results are shown in Table 1. It is observed that the mean values for laying birds from 8-26 months of age range from 2.1 to 3.00 mgs./lOO ml. These values, as judged from the large standard deviations, are quite variable, a fact that was reported by Bell et al. (1959). There appears to be a slight increase in plasma uric acid with age, but none of the differences is significant statistically. It would appear also, that as long as birds are laying, the rate of laying does not influence uric acid levels, because rate of lay in these birds decreased with age. Non-laying birds, however, have significantly higher uric acid levels, regardless of age. The mean plasma uric acid for all non-laying birds was 3.90, a figure significantly higher than for laying birds, although individual variation was considerable, ranging from 1.87 to 8.00. This raises the question of whether or not duration of the non-laying state influences level of uric acid. Unfortunately these data shed little
1650
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on June 11, 2015
EW studies have been made on the effects of aging on blood uric acid in mammals, and none on chickens. Among the limited studies on humans, some of the reports have indicated a rise with age (Morgan et al., 19SS), and some have shown no change (Praetorius, 1951; Gertler and Oppenheimer, 1953). Bell, Mclndoe and Gross (1959) have shown that plasma uric acid of chickens varies considerably under standard conditions and is influenced by sex and reproductive state. Non-laying hens had considerably higher uric acid levels than laying birds, and starvation decreased the level. Before the publication of the work of Bell et al., we had made determinations of a number of chemical constituents of blood (including uric acid) in laying hens from 8-26 months of age. It became apparent that to assess the effects of age on blood uric acid level, consideration must be given to state of reproduction, health, and nutrition. This report deals with plasma uric acid levels of birds from 8-26 months of age; most of the birds were laying, but some were not laying and some were not eating.
16S1
PLASMA URIC ACID 1.—.Plasma
TABLE
uric acid of healthy female chickens from 8 to 26 months of age Mean Uric Acid mgs./lOO ml.
Group & Month
Age Months
Not Laying
Rate of Lay of Those Laying
Laying
No.
Mean
No.
Mean
S.D.
S.E.
Percent
8
—
—
24
2.1
0.80
0.16
76
B-Jan.
10
2
4.18
22
2.6
1.5
0.31
77
C-Mar.
12
3
3.83
21
2.2
0.96
0.21
76
D-Sept.
18
1
1.87
22
2.6
1.36
0.29
52
E-Dec.
21
2
4.10
20
3.00
1.41
0.31
51
F-June
26
2
5.64
17
2.70
0.86
0.21
44
Mean
3.90
2.54
S.D.
2.10
1.17
1.17
S.E.
0.63
0.27
0.27
light on this point. They do, however, include determinations on two birds that had not layed for three or more months. On one of these, when plasma uric acid was determined at intervals of approximately 1, 2, and 3 months after cessation of laying, values observed were 6.00, 3.4, and 2.7 mgs./ 100 ml., respectively; these figures, while higher than for laying birds, are highly variable. In the four determinations made on another hen that had not layed over a 4-month period, three of the four values were low, as characteristic of laying birds. The level of plasma uric acid in these birds thus bears no discernible relationship to duration of non-laying. State of health and food consumption. Bell et al. (1959) have reported that complete starvation for 36 hours depressed plasma uric acid significantly in cocks and hens, but the greatest effect was on nonlaying hens, where uric acids averaged 1.50 in comparison to 5.40 for non-starved hens. Whether or not degree of starvation, or variations of food intake short of complete starvation, influenced uric acid levels was not determined by these investigators.
Food consumption was measured on laying and non-laying birds in this study. Among the healthy birds, non-layers ate less than laying birds, as expected, but the variations in food intake of either laying or non-laying birds appeared not to influence uric-acid level. We did not study the effects of complete starvation of healthy birds, but we did, in the course of these experiments, make observations on several birds that became ill and on some that suddenly stopped eating. These birds ceased laying and plasma uric acids were determined on some of them. The results, shown in Table 2, include determinations made on birds that were laying, and not laying for 10-30 days. Values for all birds were observed to be higher when not laying, regardless of food intake. Bird A exhibited a high uric acid level, even though it had eaten no feed for 10 days. Autopsy revealed abnormal kidneys and accumulation of urates in various organs, and the resulting uricemia is attributed to depressed tubular excretion of uric acid. Bird B, which had eaten no food for 13 days, but which showed no kidney abnor-
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on June 11, 2015
A-Nov.
1652
P. D. STURKIE TABLE 2.—Plasma uric acid of hens while eating and laying normally, and when sick, or not eating and not laying
Not Laying
A
Uric Acid mgs./lOO ml. 2.23
Uric Acid mgs./lOO ml. 6.35
B
2.50
3.3
C
2.14
4.0
D
2.87
7.5 4.6
Notes
No feed eaten for 10 days (UAD)*Bird died6hours later; abnormal kidney-ruicemia No feed eaten for 13 days (UAD) died soon after— no diagnosis No feed for 6 days; then on successive days 10 gms.; 15 gms. and 20 gms. (UAD) Feed consumption normal 3 days later Eating normally
* UAD—Uric Acid determination.
mality at death, exhibited a plasma uricacid level not greatly above that when she was laying and consuming food. Thus, it appears that lack of food intake did depress uric acid in this bird, because the level in non-laying birds, consuming food, is usually much higher. The apparent effect of level of food intake on uric acid is observed in the record of bird C that ate no feed for 6 days and then consumed minute quantities for 3 days. Plasma uric acid was 4 mgs./lOO ml. This bird then began to consume normal amounts of feed; after three days, uric acid level was 7.5 mgs.
uric acid considerably in non-laying birds (Bell et al., 1959), but our meager data suggest that the intake of even small quantities of food tends to prevent extreme depression. Further studies are indicated. Our results, like those of Bell et al., suggest that variations in level of production of estrogen may influence the difference in plasma uric-acid level of laying and nonlaying hens. Studies on the effects of administration of estrogen and androgen to nonlaying females, and estrogen to males, would be particularly instructive.
SUMMARY AND DISCUSSION
Bell, D. J., W. M. Mclndoe and D. Gross, 1959. Tissue components of the domestic fowl. 3. The non protein nitrogen of plasma and erythrocytes. Biochem. J. 71: 35S-364. Dubbs, C. A., F. W. Davis and W. S. Adams, 1956. Simple micro-determinations of uric acid. J. Biol. Chem. 167: 429-504. Gertler, M. M., and B. S. Oppenheimer, 1953. Serum uric acid levels in men and women past the age of 65 years. J. Gerontol. 8: 465^171. Morgan, A. G., M. Murai and H. L. Gillum, 1955. Nutritional status of the aging. VI. Serum protein, blood non-protein nitrogen, uric acid and creatinine. J. Nutr. 55: 671-685. Praetorius E., 1951. Plasma uric acid in aged and young persons. J. Gerontol. 6: 135-137.
REFERENCES
The results of this experiment indicate that plasma uric acid of chickens is highly variable and is influenced by reproductive state, health, food intake, and, possibly, other factors. When due allowance is made for such factors, age (from 8-26 months) does not appear to affect the level significantly. Whether or not a bird is laying influences level most, but exceptions were noted. Among those birds laying, rate of lay, within the limits studied here, did not affect the level appreciably. Complete starvation depresses plasma
JUNE 17-20. 22ND ANNUAL MEETING OF THE INSTITUTE OF FOOD TECHNOLOGISTS, AMERICANA HOTEL, BAL HARBOR, MIAMI BEACH, FLORIDA
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on June 11, 2015
Laying and Eating Normally
Bird No.