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Lability of Metabolic Processes in Laying Hens
Lability of Metabolic Processes in Laying Hens C. F.
WINCHESTER
From the College of Agriculture, University of Missouri, Columbia, Missouri (Received for publication October 23, 1939)
relatively large variations in individual birds from one semi-monthly, or monthly, period to the next. In order to study the magnitude of these variations during a relatively short period, normal heat production, heart rate, respiratory quotient, body temperature, and body weight of four 2-year-old laying New Hampshire hens were measured frequently during a period of a month. It is of interest to note that Benedict and Ritzman (1935), and Ritzman and Benedict (1938) have called attention to lability in basal metabolism observed in cows, and that Dukes (1937) reported relatively large variability in heat production of hens. The respiratory exchange of the fowls used in this investigation was measured with a multiple-chamber, closed-circuit, respiration apparatus. This apparatus consists of a constant-temperature cabinet housing four independent respiration chambers each connected to an oxygen burette and a rocking battery containing an alkaline solution for the absorption of C0 2 . Oxygen consumption is calculated periodically from burette readings, and C0 2 production is determined by titration of Paper No. 192 in the Herman Frasch Foundation Series. Missouri Agricultural Experiment Station Journal Series No. 631. Grateful acknowledgments are made to Professors S. Brody, A. G. Hogan, and H. L. Kempster who cooperated in this research.
the absorbing fluid. As oxygen leaves the burettes to replace that used by the animals, it is replaced by water which automatically enters the burettes from a Mariotte bottle. By .means of alcohol tests the error in respiratory quotient determination was found to be less than 2 percent. The temperature within the cabinet was 30°C. during the trials. Mean environmental temperature of the batteries in which the birds were kept was 27°C. Heart rate of the hens was determined by means of a Western Electric 3A stethoscope (Carter, 1938) while the fowls were still in the closed chambers after the respiration trials. The results of this investigation expressed as percentages are given in Figure 1. Day to day variations in normal heat production and heart rate were very large. In one case (Hen S830) the extreme variation in heat production was over 40 percent of the maximum figure, and variations in heart rate were of the same order in the case of Hen 5848. In general, the curves of heat production and heart rate tend to rise and fall together. Body temperature exhibited variations within a limited range and tended to decline and rise with heat production. It is logical to assume that these changes in rate of metabolic activity are directly related to changes in rate of production of egg material; however, our data do not show clearly that this is true. Ritzman and Benedict (1937, p. 142) have suggested
[233]
Downloaded from http://ps.oxfordjournals.org/ at Serials Acq (Law) on May 24, 2015
INVESTIGATION of seasonal AN~ metabolic rhythms in hens showed
234
C. F. WINCHESTER
measurements of fairly large groups of laying hens. Alcohol tests made during this research indicated that the metabolism appartus was functioning normally. SUMMARY AND
10
IS
20 JUNE
23
30
5 JULY
Fio. 1. Heat production, heart rate, and body temperature at full feed expressed as percentages of highest values. Respiratory quotients are expressed in terms of values at right of figure.
that in comparison with beef type animals ". . . the more alert behavior or higher tension of the dairy type is the expression of a higher metabolic stimulus which consequently greater lability in metabolism." Lability in metabolism of laying hens may similarly be related to a high metabolic stimulus. In order to minimize the influence of individual lability on group averages it is necessary to make either frequent measurements of small groups, or less frequent
1. During a period of one month frequent measurements were made of normal heat production, heart rate, respiratory quotient, body temperature, and body weight of four laying New Hampshire hens. 2. Variations in heat production were as large as 40 percent of the maximum rate measured, and variations in heart rate were equally great. 3. In general the curves of heat production and heart rate tend to rise and fall together. 4. Body temperature exhibited variations within a limited range and tended to decline and rise with heat production. 5. The results indicate that in making seasonal studies of metabolic processes in laying hens either very frequent measurements of a small number of hens, or less frequent measurements of a fairly large group of fowls are necessary to minimize the influence of individual lability on group averages. LITERATURE CITED
Benedict, Francis G., and Ernest G. Ritzman, 1935. Lability of the basal metabolism of the dairy cow. Proc. Nat. Acad. Sci. 21:304-308. Carter, Howard A., 1938. Western Electric 3A electrical stethoscope acceptable. Jour. A.M.A., 110:1111. Dukes, H. H., 1937. Studies on the energy metabolism of the hen. J. Nutr. 14:341-354. Ritzman, Ernest G., and Francis G. Benedict, 1938. Nutritional physiology of the adult ruminant. Evidence of lability in basal metabolism. Carnegie Institution of Washington Publication No. 494, pp. 113-139.
Downloaded from http://ps.oxfordjournals.org/ at Serials Acq (Law) on May 24, 2015
S
CONCLUSIONS
WINCHESTER
From the College of Agriculture, University of Missouri, Columbia, Missouri (Received for publication October 23, 1939)
relatively large variations in individual birds from one semi-monthly, or monthly, period to the next. In order to study the magnitude of these variations during a relatively short period, normal heat production, heart rate, respiratory quotient, body temperature, and body weight of four 2-year-old laying New Hampshire hens were measured frequently during a period of a month. It is of interest to note that Benedict and Ritzman (1935), and Ritzman and Benedict (1938) have called attention to lability in basal metabolism observed in cows, and that Dukes (1937) reported relatively large variability in heat production of hens. The respiratory exchange of the fowls used in this investigation was measured with a multiple-chamber, closed-circuit, respiration apparatus. This apparatus consists of a constant-temperature cabinet housing four independent respiration chambers each connected to an oxygen burette and a rocking battery containing an alkaline solution for the absorption of C0 2 . Oxygen consumption is calculated periodically from burette readings, and C0 2 production is determined by titration of Paper No. 192 in the Herman Frasch Foundation Series. Missouri Agricultural Experiment Station Journal Series No. 631. Grateful acknowledgments are made to Professors S. Brody, A. G. Hogan, and H. L. Kempster who cooperated in this research.
the absorbing fluid. As oxygen leaves the burettes to replace that used by the animals, it is replaced by water which automatically enters the burettes from a Mariotte bottle. By .means of alcohol tests the error in respiratory quotient determination was found to be less than 2 percent. The temperature within the cabinet was 30°C. during the trials. Mean environmental temperature of the batteries in which the birds were kept was 27°C. Heart rate of the hens was determined by means of a Western Electric 3A stethoscope (Carter, 1938) while the fowls were still in the closed chambers after the respiration trials. The results of this investigation expressed as percentages are given in Figure 1. Day to day variations in normal heat production and heart rate were very large. In one case (Hen S830) the extreme variation in heat production was over 40 percent of the maximum figure, and variations in heart rate were of the same order in the case of Hen 5848. In general, the curves of heat production and heart rate tend to rise and fall together. Body temperature exhibited variations within a limited range and tended to decline and rise with heat production. It is logical to assume that these changes in rate of metabolic activity are directly related to changes in rate of production of egg material; however, our data do not show clearly that this is true. Ritzman and Benedict (1937, p. 142) have suggested
[233]
Downloaded from http://ps.oxfordjournals.org/ at Serials Acq (Law) on May 24, 2015
INVESTIGATION of seasonal AN~ metabolic rhythms in hens showed
234
C. F. WINCHESTER
measurements of fairly large groups of laying hens. Alcohol tests made during this research indicated that the metabolism appartus was functioning normally. SUMMARY AND
10
IS
20 JUNE
23
30
5 JULY
Fio. 1. Heat production, heart rate, and body temperature at full feed expressed as percentages of highest values. Respiratory quotients are expressed in terms of values at right of figure.
that in comparison with beef type animals ". . . the more alert behavior or higher tension of the dairy type is the expression of a higher metabolic stimulus which consequently greater lability in metabolism." Lability in metabolism of laying hens may similarly be related to a high metabolic stimulus. In order to minimize the influence of individual lability on group averages it is necessary to make either frequent measurements of small groups, or less frequent
1. During a period of one month frequent measurements were made of normal heat production, heart rate, respiratory quotient, body temperature, and body weight of four laying New Hampshire hens. 2. Variations in heat production were as large as 40 percent of the maximum rate measured, and variations in heart rate were equally great. 3. In general the curves of heat production and heart rate tend to rise and fall together. 4. Body temperature exhibited variations within a limited range and tended to decline and rise with heat production. 5. The results indicate that in making seasonal studies of metabolic processes in laying hens either very frequent measurements of a small number of hens, or less frequent measurements of a fairly large group of fowls are necessary to minimize the influence of individual lability on group averages. LITERATURE CITED
Benedict, Francis G., and Ernest G. Ritzman, 1935. Lability of the basal metabolism of the dairy cow. Proc. Nat. Acad. Sci. 21:304-308. Carter, Howard A., 1938. Western Electric 3A electrical stethoscope acceptable. Jour. A.M.A., 110:1111. Dukes, H. H., 1937. Studies on the energy metabolism of the hen. J. Nutr. 14:341-354. Ritzman, Ernest G., and Francis G. Benedict, 1938. Nutritional physiology of the adult ruminant. Evidence of lability in basal metabolism. Carnegie Institution of Washington Publication No. 494, pp. 113-139.
Downloaded from http://ps.oxfordjournals.org/ at Serials Acq (Law) on May 24, 2015
S
CONCLUSIONS