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Diurnal Temperature Patterns in Unrestrained Cows1
DIURNAL
TEMPERATURE
PATTERNS
IN
UNRESTRAINED
COWS ~
K. I~OGERS SIMMONS, ARTHUR E. DRACY,~ AND W. O. ESSLER 8 Department of Animal and Dairy Science, University of Vermont, Burlington ABSTRACT
Radio telemetry was used to measure the temperature in three different locations within the bodies of unmolested cows. The diurnal temperature pattern was measured over a four-day period in the reticulum, the crop area, and in a pararectal area. The reticular temperature of four mature cows varied from 32.2 C after drinking water, to a high of 40.5 C prior to feeding. Usually 60-90 rain were required for the temperature to reach the predrinking level. I-Iowever, other than at drinking time, reticular temperatures were between 39 and 40 C. The subcutaneous temperatures varied from 31.9 to 38.4 C and dropped rapidly when the animals were turned out for" exercise dm'ing outdoor temperatures of approximately 10 C. The pararectal temperatures were most constant, but ranged between 34.4 and 39.2 C, reaching a peak during feeding. When the a.nimals were lying down, pararectal temperatures dropped but the subcutaneous temperatures rose until they approached or exceeded the pararectal temperatures.
Most studies of the body temperature of animals have employed either thermometers or thermocouples (2, 5, 7, 8). These devices irapose a certain degree of irritation on an animal. I n addition, tile presence of an investigator may induce a state of nervousness in the animal which may adversely affect the body temperature. These disadvantages can be effeetively eliminated by the use of radio telemetry. With this method the animal is not connected directly to any recording device; the animal does not need to be restrained; and it can be kept in as normal a state as husbandry practices permit. Furthermore, the investigator does not have to be in the immediate area. A block diagram o~' the physical arrangements for using radio techniques has been described by Draey and Jahn (4). A number of experiments have been reported showing diurnal temperature variations in isolated portions of the animal body (5, 7, 8). Most temperature patterns thus far recorded have been based on temperatures taken from 2- to 4-hr periods. W r e n n et al. (S), however, measured the vaginal temperatures continuously in calves and nonpregnant and pregnant cows. The purpose of the present investigation was to determine the cow's diurnal temperature pattern using radio telemetry, and to compare this with previous work where conventional methods were
used. Further, the temperature was determined simultaneously at several points in an animal's body and compared with the pararectal ternperature. E X P E R I M E N T A L PROCEDURE
Three transmitters were implanted in each of four (two Ayrshires, (me Guernsey, one Holstein) mature, lactating cows. By surgery a temperature-sensitive transmitter was placed in a pararectal position. Another was located in the region of the crops, behind the left shoulder. A third was placed in the rumen via the esophagus. It was actually recovered from the reticulure when the animal was sacrificed at the end of this investigation. The transmitter located in the retieulum was 2.5 cm in diameter and 7.5 cm in length. I t was heavy enough to remain in the reti(,ulum. The transmitter located subcutaneously in the region of the crops was 1.2 cm in diameter and 4 cm in length. The parareetal transmitter was the same diameter but was 9 cm in length. When in position the temperature-sensitive end was located at a depth of approximately 10 cm from the skin and lateral to the rectal wall. All surgical implantations were completed under aseptic conditions. Actual trials were begun between 1 and 2 wk after the transmitters were implanted. This allowed for any localized tissue reaction to subside. Received for publication May 24, ~965. The trials were conducted in the late winter ~Universi~y of Vermont Agricultural Experi- and early spring. During this time the cows n~ent Station Journal Article no. 161. were tied in individual stalls. They were fed Present address: Centro De Ensenanza E In- morning and evening after milking. They had water ad lib. and were turned oat one-half vestigacion, Turrialba, Costa Rica. College of Technology, University of Vermont. hour for exercise in the morning before feeding. 1490
TEMPERATURE
The transmitting devices were designed and built in the Electrical Engineering Department at the University of Vermont. The eomponent parts, mounted on a piece of plastic, were inserted in a glass tube which was plugged and then coated with tygon to make the device water-proof. All of the transmitters had a temperature-sensitive condenser which varied the frequency of transmission. Transmission was over a range of 180-350 KC. The design of all transmitters of this type is a compromise of three factors--size, range of transmission, and battery life. An increase in any one of these factors is at the expense of the other two. The two smaller-sized devices had a transmitting life of about three or four months, whereas the intraretieular device would broadeast for a year. The signal from these devices was picked up by a commercial radio receiver (Hallicrafter WR-3000) at a distance of approximately 20 ft. The transmitters were calibrated in a water bath before being placed in the animals. They were recalibrated after recovery. The drift over this period of time was negligible. Each device within a given animal was designed to broadcast over a different range of frequencies so that the signal from one transmitter would not be confused with that of another. Furthermore, the signal from a given transmitter was identified by bringing the receiver close to the transmitter. This procedure increased the intensity of the signal and positively identified the transmitter. The frequencies transmitted were received, converted to temperature, and recorded every half hour for a period of four days for each cow. Each animal was also continuously observed through two drinking and eating periods. During this time the tempersture of the retieulure was recorded every 2 rain. The inside air temperature of the barn was recorded every half hour. The outside air temperature was recorded during the exercise periods. The water temperature was recorded immediately after the cow finished drinking. R E S U L T S AND D I S C U S S I O N
Results of these observations are best considered in several categories. These are most easily presented under the following subtopics: Pararectal temperatures. Results of this investigation show a diphasic pattern for the pararectaI temperatures. This is in agreement with the work of W r e n n et al. (8). By way of illustration (Figure 1) the data for Cow 990 (Ayrshire) show the most typical diphasic pattern for parareetal temperature.
1491
PATTERNS
39 58
37 36
PARARECTAL
~
MAX
~
MIN
1-38 37
7
IB 9
I0 II 12
IAM
3
FI6. ]. Four-day diurnal temperature record of Cow 990. The graph represents the data collected over a four-day period. The heavy line is the fourday average. The upper line represents the maximmn recorded temperature at any given time and the lower line represents the mininmm recorded temperature. Likewise, for the subcutaneous and reticular temperatures, the heavy line is the four-day average, the top line the maximum, and the bottom line the minimum. Note that the over-all pattern of parareetal temperature is diphasie. Two peaks occur, one between 5 and 7 eM, and the other between 6 and 9 AM; there are two low periods between the peaks. The two elevated portions in the diurnal temperature record occurred when the animals were eating and most probably represent the heat increment of eating. The average pararectal temperature of Cow 990 was 38.0 +-.5 C. This particular cow's parareetal temperature was most erratic in the evening and very early morning when she was continually changing between standing and lying down. The parareetal temperature rose when she stood, and decreased when she lay down. This same type of change was true for all four cows. The parareetal temperatures of the four cows dropped below the subcutaneous temperatures 11 times. I n all eases the cows were lying very still or appeared to be asleep when this occurred. The pararectal temperatures were generally lower after the cows drank quantities of water. This may be the result of a total cooling effect, since the water consumed ranged between 4 and 8 C. Subcutaneous temperatures. Generally, the subcutaneous temperature patterns were diphasic, except for that of Cow 990 (Figure 1), which was monophasic. Observations showed that when the cows were lying down the subcutaneous temperatures rose and the pararectal temperatures decreased. Occasionally, the sub-
]492
K. ~. SIMMONS ~T AL
cutaneous temperature exceeded the pararectal temperature while a cow was lying down and apparently asleep. When the cows were standing, the subcutaneous temperature never equaled the pararectal temperatures. When the cows stood, the subcutaneous temperature gradually dropped and reached a minimum when the animals were outdoors for exercise. This was especially noticeable in Cow 115 (Figure 2) when her subcutaneous temperature dropped to 32 C. Reticulum temperature. As mentioned previously, at least two of the drinking periods for each animal were monitored at 2-rain intervals. As soon as a cow started drinking, the temperature of the reticulum dropped precipitously and reached a low point a few moments after she stopped drinking. At no time did the temperature of the retieulum drop below 32 C, in spite of the fact that the water temperature was 4-5 C. Within another few moments after the low point was reached the contents of the reticulum began to increase in temperature. tIowever, it took approximately an hour and a half for the temperature to return to the predrinking level. These data agree with the findings of other investigators (1-3, 7). A similar drop in stomach temperature has been noted in the dolphin, by Mackay (6), when this mammal ingests a cold fish. Here again, about an hour elapses before the temperature returns to norreal. In all cases the maximum temperature of the reticulmn of the cows was reached in the
~
PARARECTAL
~k~-
MAX
~34
MIN
W O.
36 35
RETICULUM
34 53
TIME
FIG. 2. Four-day diurnal temperature record of Cow 115. late evening and early morning. The period of least fluctuation also occurred during this time. Animal-to-animal variations. Although the ~verage daily temperature for each of the areas recorded remained within a small variation, there were times when an animal deviated greatly
from this average. I t is felt; that these digressions are important, because averages are not too meaningful without some knowledge of the over-all pattern. To more completely explain this, a short discussion of the variations from the average within an individual cow follows. As seen in Figure 3, Cow 102 (Holstein)
5 9
_
38
_
_
PARARECTAL
37
MAX
~3
6 7
8
9 I 0 II 12 I A M
3
5
TIME
7
9
II
IPM
3
8
:F;G. 3. Four-day diurnal temperature ;'ecord of Cow 102. showed the same over-all patterns as Cow 990. t-Iowever, the pararectal temperatures showed less variation and the pattern was not as distinctly diphasic. Tile average pararectal ternperature was 38.4 ± .3 C. The consistent drop in pararectal temperature between 6 p~ and 7:30 p~ was probably due to the ingestion of water. A decrease was also apparent in the subcutaneous temperature. The average subcutaneous tmnperature was 35.6 ± .8 C. A sharp decrease occurred when the cow was turned out. The three separate low points in reticulum temperature reflect the fact that morning feeding and other management practices were started at three different times. However, the start of the evening barn management routine was much more consistent, as noted by the fact that the low points all occurred at the same time. Cow 102 was observed to have her major drinking periods only during and after eating, and this is reflected in the temperature record. The average retieulum temperature was 38.8 -~ 1.2 C. Cow 104 (Ayrshire) also showed a consistent pararectal temperature pattern, with an average of 38.2 ± .3 C (Figure 4). The over-all pattern was more diphasic than that of Cow 102, but not as clearly diphasie as that of Cow 990. The subcutaneous temperature was more variable than that of Cows 990 and 102, but showed an over-all diphasic pattern. The average sub-
TEMPERATURE
4O
39
5[
PARARECTAL
37
MAX G 3E
~ 36
SUBCUTANEOUS
~40' 39 38 57 36 35 34
6 7' 8
9 I0 I1 12 IAM
3
5 "f TIME
9
,
i
II
,
i
,
IPM
,
3
,
i 5
"FIG. 4. Four-day diurnal temperature record of Cow 104. cutaneous temperature was 37.7 ± .6 C. The retieulum temperature was also more variable than for the previous two cows. Again, each low point occurred when the cow drank w a t e r - all at different times. The average temperature of the retieulum was 39.3 ± 1.2 C, higher than that of the previous two cows. Cow 115 (Guernsey) showed more variation in her parareetal and subcutaneous temperatures than any other cow within the group (Figure 2). H e r pararectal temperature averaged 37.2 ~-.8 C and bet subcutaneous temperature 34.0 ~ .6 C~ several degrees below the other cows. The average temperature of the reticulum was 38.5 ± 1.0 C. Cow 115 drank more often throughout the day than did the other cows. In general, this cow had a more nervous temperament than the other three, which may help to explain why her temperature varied from day to day. Results of this investigation are similar to those obtained by conventional methods. However, radio telemetry techniques, when used for studying body temperature, have the distinct advantage that the animal is unrestrained and can be kept in as natural a condition as possible. Results also confirm that there are many variations between animals as regards their body temperatures. These data show consid-
1493
PATTERNS
erable variation in temperatures from hour to hour throughout the day and also considerable variation frmn location to location within the body. Because of this variation, one would have to determine whether a constant temperature was necessary when making in vivo observations on a particular organ system. F o r example, these data show that the reticulum temperature was constant for only a relatively short period of the day (late night and early morning). Thus, if constant temperature were an important factor in an investigation, observations would have to be made during this time. Furthermore~ a complete study of temperatures of a particular organ system must take into account factors which influence adjacent body temperatures. I~EFERENCES (1) CUNNINGHA~f, M. D., MARTZ, F.
A., AND
ME~ILAN, C. P. 1964. Effect of DrinkingWater Temperature upon Ruminant Digestion, Intrarumlnal Temperature, and Water Consumption of Nonlactating Dairy Cows. J. Dairy Sci., 47: 382. (2) DALE, H. E., STEXVART,R. E., ADD Bt~0DY, S.
1954. Rumen Temperature. 1. Temperature Gradients During Feeding and Fasting. Cornell Vet., 44: 368. (3) DRACY, A. E., ESSLER, W. O., AND JAHN, J. R. 1963. Recording Intrareticular Temperatures by Radiosond6 Equipment. J. Dairy
Sci., 46: 241. (4) DaACY, A. E., AND J~HN, J. R. ]964. Use of Electro-cardiographic Radio Telemetry to Determine I-Ieart Rate in Ruminants. J. Dairy ScL, 47: 561. (5) KLEIT~AN, N. 1949. Biological Rhythms and Cycles. Physiol. Revs., 29" 1. (6) MACKAY,R. S. 1964. Deep Body Temperature of Untethered Dolphin Recorded by Ingested Radio Transmitter. Science, 144: 864. (7) VEERARAGI~AVAN,G., AND MENDEL, V. E. 1963.
A Study of Diurnal Temperature Patterns in Sheep. J. Animal Sci., 22: 865. (8) WaENN, T. R., BIT~AN, J., AND SYKES, J. F. 1961. Diurnal Patterns of Bovine Body Temperature. J. DaSry Sci., 44: 2077.
TEMPERATURE
PATTERNS
IN
UNRESTRAINED
COWS ~
K. I~OGERS SIMMONS, ARTHUR E. DRACY,~ AND W. O. ESSLER 8 Department of Animal and Dairy Science, University of Vermont, Burlington ABSTRACT
Radio telemetry was used to measure the temperature in three different locations within the bodies of unmolested cows. The diurnal temperature pattern was measured over a four-day period in the reticulum, the crop area, and in a pararectal area. The reticular temperature of four mature cows varied from 32.2 C after drinking water, to a high of 40.5 C prior to feeding. Usually 60-90 rain were required for the temperature to reach the predrinking level. I-Iowever, other than at drinking time, reticular temperatures were between 39 and 40 C. The subcutaneous temperatures varied from 31.9 to 38.4 C and dropped rapidly when the animals were turned out for" exercise dm'ing outdoor temperatures of approximately 10 C. The pararectal temperatures were most constant, but ranged between 34.4 and 39.2 C, reaching a peak during feeding. When the a.nimals were lying down, pararectal temperatures dropped but the subcutaneous temperatures rose until they approached or exceeded the pararectal temperatures.
Most studies of the body temperature of animals have employed either thermometers or thermocouples (2, 5, 7, 8). These devices irapose a certain degree of irritation on an animal. I n addition, tile presence of an investigator may induce a state of nervousness in the animal which may adversely affect the body temperature. These disadvantages can be effeetively eliminated by the use of radio telemetry. With this method the animal is not connected directly to any recording device; the animal does not need to be restrained; and it can be kept in as normal a state as husbandry practices permit. Furthermore, the investigator does not have to be in the immediate area. A block diagram o~' the physical arrangements for using radio techniques has been described by Draey and Jahn (4). A number of experiments have been reported showing diurnal temperature variations in isolated portions of the animal body (5, 7, 8). Most temperature patterns thus far recorded have been based on temperatures taken from 2- to 4-hr periods. W r e n n et al. (S), however, measured the vaginal temperatures continuously in calves and nonpregnant and pregnant cows. The purpose of the present investigation was to determine the cow's diurnal temperature pattern using radio telemetry, and to compare this with previous work where conventional methods were
used. Further, the temperature was determined simultaneously at several points in an animal's body and compared with the pararectal ternperature. E X P E R I M E N T A L PROCEDURE
Three transmitters were implanted in each of four (two Ayrshires, (me Guernsey, one Holstein) mature, lactating cows. By surgery a temperature-sensitive transmitter was placed in a pararectal position. Another was located in the region of the crops, behind the left shoulder. A third was placed in the rumen via the esophagus. It was actually recovered from the reticulure when the animal was sacrificed at the end of this investigation. The transmitter located in the retieulum was 2.5 cm in diameter and 7.5 cm in length. I t was heavy enough to remain in the reti(,ulum. The transmitter located subcutaneously in the region of the crops was 1.2 cm in diameter and 4 cm in length. The parareetal transmitter was the same diameter but was 9 cm in length. When in position the temperature-sensitive end was located at a depth of approximately 10 cm from the skin and lateral to the rectal wall. All surgical implantations were completed under aseptic conditions. Actual trials were begun between 1 and 2 wk after the transmitters were implanted. This allowed for any localized tissue reaction to subside. Received for publication May 24, ~965. The trials were conducted in the late winter ~Universi~y of Vermont Agricultural Experi- and early spring. During this time the cows n~ent Station Journal Article no. 161. were tied in individual stalls. They were fed Present address: Centro De Ensenanza E In- morning and evening after milking. They had water ad lib. and were turned oat one-half vestigacion, Turrialba, Costa Rica. College of Technology, University of Vermont. hour for exercise in the morning before feeding. 1490
TEMPERATURE
The transmitting devices were designed and built in the Electrical Engineering Department at the University of Vermont. The eomponent parts, mounted on a piece of plastic, were inserted in a glass tube which was plugged and then coated with tygon to make the device water-proof. All of the transmitters had a temperature-sensitive condenser which varied the frequency of transmission. Transmission was over a range of 180-350 KC. The design of all transmitters of this type is a compromise of three factors--size, range of transmission, and battery life. An increase in any one of these factors is at the expense of the other two. The two smaller-sized devices had a transmitting life of about three or four months, whereas the intraretieular device would broadeast for a year. The signal from these devices was picked up by a commercial radio receiver (Hallicrafter WR-3000) at a distance of approximately 20 ft. The transmitters were calibrated in a water bath before being placed in the animals. They were recalibrated after recovery. The drift over this period of time was negligible. Each device within a given animal was designed to broadcast over a different range of frequencies so that the signal from one transmitter would not be confused with that of another. Furthermore, the signal from a given transmitter was identified by bringing the receiver close to the transmitter. This procedure increased the intensity of the signal and positively identified the transmitter. The frequencies transmitted were received, converted to temperature, and recorded every half hour for a period of four days for each cow. Each animal was also continuously observed through two drinking and eating periods. During this time the tempersture of the retieulure was recorded every 2 rain. The inside air temperature of the barn was recorded every half hour. The outside air temperature was recorded during the exercise periods. The water temperature was recorded immediately after the cow finished drinking. R E S U L T S AND D I S C U S S I O N
Results of these observations are best considered in several categories. These are most easily presented under the following subtopics: Pararectal temperatures. Results of this investigation show a diphasic pattern for the pararectaI temperatures. This is in agreement with the work of W r e n n et al. (8). By way of illustration (Figure 1) the data for Cow 990 (Ayrshire) show the most typical diphasic pattern for parareetal temperature.
1491
PATTERNS
39 58
37 36
PARARECTAL
~
MAX
~
MIN
1-38 37
7
IB 9
I0 II 12
IAM
3
FI6. ]. Four-day diurnal temperature record of Cow 990. The graph represents the data collected over a four-day period. The heavy line is the fourday average. The upper line represents the maximmn recorded temperature at any given time and the lower line represents the mininmm recorded temperature. Likewise, for the subcutaneous and reticular temperatures, the heavy line is the four-day average, the top line the maximum, and the bottom line the minimum. Note that the over-all pattern of parareetal temperature is diphasie. Two peaks occur, one between 5 and 7 eM, and the other between 6 and 9 AM; there are two low periods between the peaks. The two elevated portions in the diurnal temperature record occurred when the animals were eating and most probably represent the heat increment of eating. The average pararectal temperature of Cow 990 was 38.0 +-.5 C. This particular cow's parareetal temperature was most erratic in the evening and very early morning when she was continually changing between standing and lying down. The parareetal temperature rose when she stood, and decreased when she lay down. This same type of change was true for all four cows. The parareetal temperatures of the four cows dropped below the subcutaneous temperatures 11 times. I n all eases the cows were lying very still or appeared to be asleep when this occurred. The pararectal temperatures were generally lower after the cows drank quantities of water. This may be the result of a total cooling effect, since the water consumed ranged between 4 and 8 C. Subcutaneous temperatures. Generally, the subcutaneous temperature patterns were diphasic, except for that of Cow 990 (Figure 1), which was monophasic. Observations showed that when the cows were lying down the subcutaneous temperatures rose and the pararectal temperatures decreased. Occasionally, the sub-
]492
K. ~. SIMMONS ~T AL
cutaneous temperature exceeded the pararectal temperature while a cow was lying down and apparently asleep. When the cows were standing, the subcutaneous temperature never equaled the pararectal temperatures. When the cows stood, the subcutaneous temperature gradually dropped and reached a minimum when the animals were outdoors for exercise. This was especially noticeable in Cow 115 (Figure 2) when her subcutaneous temperature dropped to 32 C. Reticulum temperature. As mentioned previously, at least two of the drinking periods for each animal were monitored at 2-rain intervals. As soon as a cow started drinking, the temperature of the reticulum dropped precipitously and reached a low point a few moments after she stopped drinking. At no time did the temperature of the retieulum drop below 32 C, in spite of the fact that the water temperature was 4-5 C. Within another few moments after the low point was reached the contents of the reticulum began to increase in temperature. tIowever, it took approximately an hour and a half for the temperature to return to the predrinking level. These data agree with the findings of other investigators (1-3, 7). A similar drop in stomach temperature has been noted in the dolphin, by Mackay (6), when this mammal ingests a cold fish. Here again, about an hour elapses before the temperature returns to norreal. In all cases the maximum temperature of the reticulmn of the cows was reached in the
~
PARARECTAL
~k~-
MAX
~34
MIN
W O.
36 35
RETICULUM
34 53
TIME
FIG. 2. Four-day diurnal temperature record of Cow 115. late evening and early morning. The period of least fluctuation also occurred during this time. Animal-to-animal variations. Although the ~verage daily temperature for each of the areas recorded remained within a small variation, there were times when an animal deviated greatly
from this average. I t is felt; that these digressions are important, because averages are not too meaningful without some knowledge of the over-all pattern. To more completely explain this, a short discussion of the variations from the average within an individual cow follows. As seen in Figure 3, Cow 102 (Holstein)
5 9
_
38
_
_
PARARECTAL
37
MAX
~3
6 7
8
9 I 0 II 12 I A M
3
5
TIME
7
9
II
IPM
3
8
:F;G. 3. Four-day diurnal temperature ;'ecord of Cow 102. showed the same over-all patterns as Cow 990. t-Iowever, the pararectal temperatures showed less variation and the pattern was not as distinctly diphasic. Tile average pararectal ternperature was 38.4 ± .3 C. The consistent drop in pararectal temperature between 6 p~ and 7:30 p~ was probably due to the ingestion of water. A decrease was also apparent in the subcutaneous temperature. The average subcutaneous tmnperature was 35.6 ± .8 C. A sharp decrease occurred when the cow was turned out. The three separate low points in reticulum temperature reflect the fact that morning feeding and other management practices were started at three different times. However, the start of the evening barn management routine was much more consistent, as noted by the fact that the low points all occurred at the same time. Cow 102 was observed to have her major drinking periods only during and after eating, and this is reflected in the temperature record. The average retieulum temperature was 38.8 -~ 1.2 C. Cow 104 (Ayrshire) also showed a consistent pararectal temperature pattern, with an average of 38.2 ± .3 C (Figure 4). The over-all pattern was more diphasic than that of Cow 102, but not as clearly diphasie as that of Cow 990. The subcutaneous temperature was more variable than that of Cows 990 and 102, but showed an over-all diphasic pattern. The average sub-
TEMPERATURE
4O
39
5[
PARARECTAL
37
MAX G 3E
~ 36
SUBCUTANEOUS
~40' 39 38 57 36 35 34
6 7' 8
9 I0 I1 12 IAM
3
5 "f TIME
9
,
i
II
,
i
,
IPM
,
3
,
i 5
"FIG. 4. Four-day diurnal temperature record of Cow 104. cutaneous temperature was 37.7 ± .6 C. The retieulum temperature was also more variable than for the previous two cows. Again, each low point occurred when the cow drank w a t e r - all at different times. The average temperature of the retieulum was 39.3 ± 1.2 C, higher than that of the previous two cows. Cow 115 (Guernsey) showed more variation in her parareetal and subcutaneous temperatures than any other cow within the group (Figure 2). H e r pararectal temperature averaged 37.2 ~-.8 C and bet subcutaneous temperature 34.0 ~ .6 C~ several degrees below the other cows. The average temperature of the reticulum was 38.5 ± 1.0 C. Cow 115 drank more often throughout the day than did the other cows. In general, this cow had a more nervous temperament than the other three, which may help to explain why her temperature varied from day to day. Results of this investigation are similar to those obtained by conventional methods. However, radio telemetry techniques, when used for studying body temperature, have the distinct advantage that the animal is unrestrained and can be kept in as natural a condition as possible. Results also confirm that there are many variations between animals as regards their body temperatures. These data show consid-
1493
PATTERNS
erable variation in temperatures from hour to hour throughout the day and also considerable variation frmn location to location within the body. Because of this variation, one would have to determine whether a constant temperature was necessary when making in vivo observations on a particular organ system. F o r example, these data show that the reticulum temperature was constant for only a relatively short period of the day (late night and early morning). Thus, if constant temperature were an important factor in an investigation, observations would have to be made during this time. Furthermore~ a complete study of temperatures of a particular organ system must take into account factors which influence adjacent body temperatures. I~EFERENCES (1) CUNNINGHA~f, M. D., MARTZ, F.
A., AND
ME~ILAN, C. P. 1964. Effect of DrinkingWater Temperature upon Ruminant Digestion, Intrarumlnal Temperature, and Water Consumption of Nonlactating Dairy Cows. J. Dairy Sci., 47: 382. (2) DALE, H. E., STEXVART,R. E., ADD Bt~0DY, S.
1954. Rumen Temperature. 1. Temperature Gradients During Feeding and Fasting. Cornell Vet., 44: 368. (3) DRACY, A. E., ESSLER, W. O., AND JAHN, J. R. 1963. Recording Intrareticular Temperatures by Radiosond6 Equipment. J. Dairy
Sci., 46: 241. (4) DaACY, A. E., AND J~HN, J. R. ]964. Use of Electro-cardiographic Radio Telemetry to Determine I-Ieart Rate in Ruminants. J. Dairy ScL, 47: 561. (5) KLEIT~AN, N. 1949. Biological Rhythms and Cycles. Physiol. Revs., 29" 1. (6) MACKAY,R. S. 1964. Deep Body Temperature of Untethered Dolphin Recorded by Ingested Radio Transmitter. Science, 144: 864. (7) VEERARAGI~AVAN,G., AND MENDEL, V. E. 1963.
A Study of Diurnal Temperature Patterns in Sheep. J. Animal Sci., 22: 865. (8) WaENN, T. R., BIT~AN, J., AND SYKES, J. F. 1961. Diurnal Patterns of Bovine Body Temperature. J. DaSry Sci., 44: 2077.