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Energy Use and Performance of Young Turkeys Kept Under Various Constant and Cycling Environmental Temperatures1
Energy Use and Performance of Young Turkeys Kept Under Various Constant and Cycling Environmental Temperatures1 SHMUEL HURWITZ and ILAN BENGAL Institute of Animal Science, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel (Received for publication October 19, 1981) ABSTRACT Performance of young male turkeys held under cyclic temperatures was compared with that of others kept at the upper and lower limits of the cycle and at the constant average temperature. Performance and amount of energy used for maintenance in turkeys kept at cycling temperature with a high of up to 30 C were similar to those of others kept at the average temperature. When the upper temperature was above 35 C, performance of the cycled birds was inferior to that of birds kept at the avarage temperature but superior to that obtained at the upper temperature. Similar results were obtained when the cycle range (difference between upper and lower temperatures) was 10 or 20 C. (Key words: environmental temperature, turkey, diurnal cycles, energy requirements)
INTRODUCTION
Growth rate and the energy requirement for maintenance vary nonlinearly with environmental temperature in both chickens and turkeys. This results in a nonlinear function of amino acid requirements on temperature (Hurwitz et al, 1980). In practice, under a wide range of environmental temperatures, the quantitation of the changes in nutrient requirements as a function of temperature is essential for economic diet formulation. The ability to predict growth and feed intake, influenced primarily by the maintenance requirement for various temperatures, is also important for decisions such as the determination of optimal environment in temperature-controlled houses and marketing age.
documented for chicks. Deaton et al. (1972) concluded that at the upper temperature range, performance at cyclic temperature was similar to that obtained at the constant average temperature, but that at the lower ranges (10 to 21 C), small diurnal cycles were superior to constant temperature. However, Harris et al. (1974) found a decrease in broiler performance with the increasing range of the cyclic temperature. Siegel and Drury (1970), in a very careful study, observed growth depression whenever the daily temperature cycle was above 11 C with little difference between the constant temperature and the 5.5 C cycle. However, this study had been started with day-old chicks, which have special temperature sensitivity due to immature thermoregulation.
In a previous paper, equations were given to calculate energy intake at various temperatures (Hurwitz et al, 1980). However, the parameters used in these equations had been obtained from experimentation under constant temperature conditions, whereas in practice, birds are kept under daily cycling temperatures. The effects of diurnal cycles have been
In the present study, performance of turkeys kept under diurnal cycles was compared with that of others kept constantly at high, low, or average temperatures. Experiments were conducted at different temperature ranges and with cycles of 10 or 20 C. Energy allocation into growth and maintenance under the various environmental conditions has been evaluated using a model published previously (Hurwitz et al., 1978b) and validated experimentally (Hurwitz et al, 1980).
1 Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, 1981 series, No. 247-E. Supported by The Poultry Marketing Board of Israel and by a grant from the United States - Israel Binational Agricultural Research and Development Fund (BARD).
MATERIALS AND METHODS
Day-old BUT male turkeys were obtained from a commercial hatchery and raised in battery brooders situated in a temperature controlled room maintained at 24 C. During
1082
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
1982 Poultry Science 61:1082-1086
TURKEYS IN CYCLIC TEMPERATURES
1083
growth, D, were calculated using the equation developed previously (Hurwitz et al, 1978b; 1980):
this period, they were fed a commercial diet. At the age of 4 to 4.5 weeks, die birds were weighed, and 20 were assigned to each treatment group on the basis of body weight; this was done to equalize both average weight and weight distribution within the group. The birds were then transferred to individual cages in the respective temperature chambers and fed the experimental diet. Measurements began after about 1 week of acclimatization. During 4-week experiments, individual body weights and feed intakes were recorded twice weekly. The temperature chambers used (Hurwitz et al, 1980) were equipped with two thermostatic controls so that temperatures could either be kept constant or alternated on a 12-hr. basis. For each condition, the room temperature was calibrated with thermometers on the cages. For the cycling environment, the temperature change was effected within 1 hr. Humidity was not controlled in the rooms, but measurements indicated relative humidity varied between 60 and 70%. Fluorescent lights provided constant illumination in all experiments. The diet fed contained (kg/ton): soybean oil meal (45% protein), 508; fish meal, 20; milo, 244; yellow corn, 100; soybean oil, refined, 82.5; sodium chloride, 3; dicalcium phosphate, 22; limestone, 13; DL-methionine, 1.4; vitamin and trace mineral mixture (Hurwitz et al, 1978a), 5.5. The diet was calculated according to recommendations of National Research Council (1977) to contain 3000 kcal/kg. The energy content of the diet has been verified experimentally (Hurwitz et al, 1980). The energy use for maintenance, M, and
TEC/G = M • BW 2 / 3 / G + D
TABLE 1. Effect of constant and alternating temperature, at the lower range, on turkey performance* Environmental temperature ,c 18
24
12
1558 a 2529 a 5490 a .462 b
1508 a 2498 a 5513 a .45 3 b
1589 a 248 3 a 4847 b .514 a
1526 a 2304 b 5597 a .412 c
ab
ab
Parameter
12-24'
Body weight, g initial Weight gain, g/4 weeks Feed intake, g/4 weeks Feed efficiency Maintenance expenditure, kcal/g2/* Growth expenditure, kcal/g
2.17 1.8 a
2.27 1.6a
2.06
b
1.2 a
a,b Means with different superscript letters are significantly different (P<.05). 1
Cycled, 12 hr at each temperature.
2.35 1.8a
SE
a
27 63 115 .009 .07 .2
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
where TEC is the energy intake per day during the period of measurement and obtained by multiplying the feed intake by the energy concentration of the diet, BW is the average body weight obtained by averaging the body weights recorded at the beginning and end of the measurement period, and G is the daily weight gain. TEC/G is plotted against BW 2 / 3 /G for values obtained twice weekly. D is then obtained from the intercept and M from the slope of the function. The regressions have been computed separately for each bird. The parameters M and D represent the averages for each treatment group. Performance in each experiment was subjected to analysis of variance. This and linear regressions were computed according to standard procedures (Snedecor and Cochran, 1968). The results were processed automatically using a CDC Cyber computer. Each experiment consisted of four temperature treatments. Treatment 1 consisted of 12 hr low temperature and 12 hr high temperature; treatment 2 was the average temperature for 24 hr/day; and treatments 3 and 4 represented 24 hr of the high and low constant temperatures per days, respectively. In additional experiments, the same cycle magnitude was repeated twice, at a lower and upper temperature ranges.
HURWITZ AND BENGAL
1084 RESULTS
Trial 2. In this trial a cycling temperature at a higher range than in trial 1, with a difference of 10 C was tested. The treatments were: 1) 25 to 35 C cycling temperature (12 hr/day on each treatment); 2) 30 C constant; 3) 25 C constant; and 4) 3 5 C constant. The results of this trial are given in Table 2. Weight gain was highest at 25 C with a progressive decrease at 30 and 35 C. Weight gain for the alternating temperature was somewhat lower than that observed at the constant 30 C but intermediate between 25 and 35 C. Feed intake was highest at 25 and lowest at 35 C. At
30 C and at the cycling temperatures of 25 to 35 C, feed intake was similar and intermediate. Feed efficiency was highest at 30 C and was not significantly different in all other treatments. Maintenance energy expediture was higher at 25 C and similar at all other treatments. There were no consistent differences in the growth expenditure among the temperature treatments. Trial 3. The purpose of this trial was to evaluate the effect of the environmental temperature cycling between 10 and 30 C. The trial included four treatments: 1) 10 to 30 C alternating temperature, 12 hr/day on each; 2) 20 C constant temperature; 3) 30 C constant temperature; and 4) 10 C constant temperature. The results of this trial are given in Table 3. Weight gain was significantly depressed at 30 C compared with the lower temperatures; there was no significant difference among the other three treatments. However, weight gain at 10 C appeared to be lower than at 20 C constant and 10 to 30 C cycling temperatures with little difference between the latter. Feed intake was highest at 10, and lowest at 30, and'intermediate at 20 C or at 10 to 30 C. There was no significant difference between the latter two treatments. Feed efficiency was highest at 30 C, similar for both 10 to 30 C and 20 C, and lowest for 10 C. Similarly, energy intake for maintenance was highest at 10 and lowest at 30 C, intermediate at 10 to 30 C and 20 C, with little difference between them. Energy intake for growth did not vary significantly. Trial 4. The purpose of this trial was to evaluate the effect of a cycle of 20 C at the
TABLE 2. Effect of upper range constant and alternating temperatures on the performance of turkey poults* Environmental temperature, C Parameter
25-35
Body weight, initial g Weight gain, g/4 weeks Feed intake, g/4 weeks Feed efficiency Maintenance expenditure, kcal/g 2 / 3 Growth expenditure, kcal/g
1305 a 2116bc 3917 b .539ab
30
25
35
SE
1282 a 2275ab 4005b .569 a
1325 a 2310 a 4428 a .523 b
1285 a 1992 c 3665 c .544 a b
19 64 73
1.80 b
2.01ab
2.24 a
1.93 b
.10
1.0*
.9a
.8a
.7 a
.2
a,b ' Means with different superscript letters are significantly different (P<.05). 1
.013
Cycled, 12 hr at each temperature.
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
Trial 1. In this trial, the effect of cycling temperatures was studied at the lower range of temperatures with a high-low difference of 12 C. Accordingly, the treatments were 12 to 24 C alternating; 18, 24, and 12 C constant. The results of this trial are given in Table 1. Body weight gain was significantly lower at 12 C than at 24 or 18 C. No significant difference was noted between the latter two treatments and the 12 to 24 alternating temperature. Feed intake was significantly lower at 24 C than at all other temperatures with little difference among the latter. Feed efficiency was highest at 24 C and lowest at 12 C. Feed efficiencies for the average temperature of 18 C and the alternating 12 to 24 C were very similar. As expected, the energy expenditure for maintenance was highest at 12 C and lowest at 24 C. The values for 18 C constant and 12 to 24 C alternating temperatures were similar and intermediate. The energy requirement for growth was not affected by the temperature treatments.
TURKEYS IN CYCLIC TEMPERATURES
1085
TABLE 3. Effect of constant and alternating temperatures within a 20 C range on turkey
performance1
Environmental temperature, C Parameter
10-301
Body weight, initial g Weight gain, g/4 weeks Feed intake, g/4 weeks Feed efficiency Maintenance expenditure, kcal/g 2 / 3 Growth expenditure, kcal/g
1399 a 2355a 4488 b .524 b
a
20
30
10
1389 a 2422a 4666 b .520 b
1344a 2150 b 3915 c .550 a
1436 a 2293ab 5042 a .455 c
SE 28 72 79 '.008
2.17a
2.25 a
1.78 b
2.31 a
.09
l.oa
l.ia
1.4a
1.3a
.2
' ' Means with different superscript letters are significantly different (P<.05).
1
Cycled, 12 hr at each temperature.
DISCUSSION
Consistent with our previous study (Hurwitz et al, 1980) and the results of de Albuquerque
et al. (1978), weight gain in young turkeys was highest around 20 C with an asymmetrical decrease on either side of this temperature. However, in the previous study, feed efficiency also decreased when the temperature exceeded 27 C due to an increase in the energy used for maintenance, whereas in the present study feed efficiency improved between 25 and 35 C. When the environmental temperatures were cycled below 30 C (trials 1 and 3), weight gain on the cycling temperatures were similar to that obtained on the corresponding average temperatures. In these cases, weight gain on both average and cycling temperatures slightly exceeded that obtained on the low or high constant temperatures. These results obtained with turkeys agree with those of Siegel and Drury (1970), who found no significant difference between constant temperatures and those fluctuating 11 C (difference between maximum and minimum). In contrast, our results do not show deleterious effects of
TABLE 4. The effect of a wide range (20 C) in constant and alternating temperatures at the upper range on turkey performance1 Experimental temperature, C Parameter
15-35 1
Body weight, initial, g Weight gain, g/4 weeks Feed intake, g/4 weeks Feed efficiency
1195a 2335b 4099c .570a
25
35
15
SE
1204a 2737a 4674b .585 a
1172a 1819 c 3069 d .588 a
1179a 2497 b 5048 a .492
21 71 96
a,b,c Means with different superscript letters are significantly different (P<.05). 1
Cycled, 12 hr at each temperature.
.011
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
upper temperature range. The experimental treatments were: 1)15 to 35 C alternating, 2) 25 C constant, 3) 35 C constant, and 4) 15 C constant. The results are presented in Table 4. Weight gain was highest at 25 and lowest at 35 C. The weight gains at 15 C and at 15 to 35 C were similar, and both were higher than at 35 C. Feed intake was lowest at 35 C and highest at 15 C but not significantly different at 15 to 3 5 C compared with 25 C. Feed efficiency was similar at 15 to 35, 25, and 35 C, and significantly lower at 15 C. Due to only slight variations in the TEC/G within birds and treatments, the results were not suitable for regression analysis. Therefore, calorie intakes for maintenance and growth have not been calculated.
1086
HURWITZ AND BENGAL
REFERENCES de Albuquerque, K., A. T. Leighton, Jr., J. P. Mason, Sr., and L. M. Potter, 1978. The effects of
environmental temperature, sex and dietary energy levels on growth performance of Large White turkeys. Poultry Sci. 57:353-362. Deaton, J. W., F. N. Reece, B. D. Lott, L. F. Kubena, and J. D. May, 1972. The efficiency of cooling broilers in summer as measured by growth and feed utilization. Poultry Sci. 51:69—71. Deaton, J. W., F. N. Reece, B. D. Lott, L. F. Kubena, J. D. May, and T. H. Vardaman, 1973. The effect of low versus moderate rearing temperature on broiler performance. Poultry Sci. 52:1175— 1181. Griffin, J. G., and T. H. Vardaman, 1970. Diurnal cyclic versus constant temperature for broiler performance. Poultry Sci. 49:387-392. Harris, G. D., Jr., W. H. Dodgen, and G. S. Nelson, 1974. Effect of diurnal cyclic temperatures on broiler performance. Poultry Sci. 53:2204-2208. Hurwitz, S., D. Sklan, and I. Bartov, 1978b. New formal approaches to the determination of energy and amino acid requirements for chicks. Poultry Sci. 57:197-205. Hurwitz, S., D. Dubrov, W. Eisner, G. Risenfeld, and A. Bar, 1978a. Phosphate absorption and excretion in the young turkey, as influenced by calcium intake. J. Nutr. 108:1321-1335. Hurwitz, S., M. Weisselberg, U. Eisner, I. Bartov, G. Risenfeld, M. Sharvit, A. Niv, and S. Bornstein, 1980. The energy requirements and performance of growing chickens and turkeys as affected by environmental temperature. Poultry Sci. 59: 2290-2299. National Research Council, 1977. Nutrient Requirements of Poultry. Natl. Acad. Sci. Washington, DC. Siegel, H. S., and L. N. Drury, 1970. Broiler growth in diurnally cyclic temperature environments. Poultry Sci. 49:238-244. Snedecor, G. W., and W. G. Cochran, 1968. Statistical Methods. 6th ed. Iowa State Univ. Press, Ames, IA.
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
temperature cycles of 20 C. These results are in agreement also with those of Griffin and Vardaman (1970) and with Deaton et al. (1973). However, when the birds are heat-stressed with maximun temperature above 30 C (trials 2 and 4), the performance on the cycling temperature is poorer than at the respective constant average temperatures and ranks between the performances on the high and low temperatures. The energy used for maintenance appeared to be similar for the cyclic and the average temperatures. The main purpose of this study has been to evaluate the applicability of performance results obtained under laboratory constant temperatures in predicting performance under field conditions. As was also suggested by Deaton et al. (1973) on the basis of experiments with chickens, the present results indicate the possibility of predicting performance, under field conditions, from a knowledge of the typical average temperature; however, care should be excercised whenever the maximum temperature exceeds 30 C. This information is useful in applying nutrient requirements for different temperatures, as obtained from experimentation at constant temperatures (Hurwitz et al, 1980), to least cost formulation of practical diets.
INTRODUCTION
Growth rate and the energy requirement for maintenance vary nonlinearly with environmental temperature in both chickens and turkeys. This results in a nonlinear function of amino acid requirements on temperature (Hurwitz et al, 1980). In practice, under a wide range of environmental temperatures, the quantitation of the changes in nutrient requirements as a function of temperature is essential for economic diet formulation. The ability to predict growth and feed intake, influenced primarily by the maintenance requirement for various temperatures, is also important for decisions such as the determination of optimal environment in temperature-controlled houses and marketing age.
documented for chicks. Deaton et al. (1972) concluded that at the upper temperature range, performance at cyclic temperature was similar to that obtained at the constant average temperature, but that at the lower ranges (10 to 21 C), small diurnal cycles were superior to constant temperature. However, Harris et al. (1974) found a decrease in broiler performance with the increasing range of the cyclic temperature. Siegel and Drury (1970), in a very careful study, observed growth depression whenever the daily temperature cycle was above 11 C with little difference between the constant temperature and the 5.5 C cycle. However, this study had been started with day-old chicks, which have special temperature sensitivity due to immature thermoregulation.
In a previous paper, equations were given to calculate energy intake at various temperatures (Hurwitz et al, 1980). However, the parameters used in these equations had been obtained from experimentation under constant temperature conditions, whereas in practice, birds are kept under daily cycling temperatures. The effects of diurnal cycles have been
In the present study, performance of turkeys kept under diurnal cycles was compared with that of others kept constantly at high, low, or average temperatures. Experiments were conducted at different temperature ranges and with cycles of 10 or 20 C. Energy allocation into growth and maintenance under the various environmental conditions has been evaluated using a model published previously (Hurwitz et al., 1978b) and validated experimentally (Hurwitz et al, 1980).
1 Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, 1981 series, No. 247-E. Supported by The Poultry Marketing Board of Israel and by a grant from the United States - Israel Binational Agricultural Research and Development Fund (BARD).
MATERIALS AND METHODS
Day-old BUT male turkeys were obtained from a commercial hatchery and raised in battery brooders situated in a temperature controlled room maintained at 24 C. During
1082
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
1982 Poultry Science 61:1082-1086
TURKEYS IN CYCLIC TEMPERATURES
1083
growth, D, were calculated using the equation developed previously (Hurwitz et al, 1978b; 1980):
this period, they were fed a commercial diet. At the age of 4 to 4.5 weeks, die birds were weighed, and 20 were assigned to each treatment group on the basis of body weight; this was done to equalize both average weight and weight distribution within the group. The birds were then transferred to individual cages in the respective temperature chambers and fed the experimental diet. Measurements began after about 1 week of acclimatization. During 4-week experiments, individual body weights and feed intakes were recorded twice weekly. The temperature chambers used (Hurwitz et al, 1980) were equipped with two thermostatic controls so that temperatures could either be kept constant or alternated on a 12-hr. basis. For each condition, the room temperature was calibrated with thermometers on the cages. For the cycling environment, the temperature change was effected within 1 hr. Humidity was not controlled in the rooms, but measurements indicated relative humidity varied between 60 and 70%. Fluorescent lights provided constant illumination in all experiments. The diet fed contained (kg/ton): soybean oil meal (45% protein), 508; fish meal, 20; milo, 244; yellow corn, 100; soybean oil, refined, 82.5; sodium chloride, 3; dicalcium phosphate, 22; limestone, 13; DL-methionine, 1.4; vitamin and trace mineral mixture (Hurwitz et al, 1978a), 5.5. The diet was calculated according to recommendations of National Research Council (1977) to contain 3000 kcal/kg. The energy content of the diet has been verified experimentally (Hurwitz et al, 1980). The energy use for maintenance, M, and
TEC/G = M • BW 2 / 3 / G + D
TABLE 1. Effect of constant and alternating temperature, at the lower range, on turkey performance* Environmental temperature ,c 18
24
12
1558 a 2529 a 5490 a .462 b
1508 a 2498 a 5513 a .45 3 b
1589 a 248 3 a 4847 b .514 a
1526 a 2304 b 5597 a .412 c
ab
ab
Parameter
12-24'
Body weight, g initial Weight gain, g/4 weeks Feed intake, g/4 weeks Feed efficiency Maintenance expenditure, kcal/g2/* Growth expenditure, kcal/g
2.17 1.8 a
2.27 1.6a
2.06
b
1.2 a
a,b Means with different superscript letters are significantly different (P<.05). 1
Cycled, 12 hr at each temperature.
2.35 1.8a
SE
a
27 63 115 .009 .07 .2
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
where TEC is the energy intake per day during the period of measurement and obtained by multiplying the feed intake by the energy concentration of the diet, BW is the average body weight obtained by averaging the body weights recorded at the beginning and end of the measurement period, and G is the daily weight gain. TEC/G is plotted against BW 2 / 3 /G for values obtained twice weekly. D is then obtained from the intercept and M from the slope of the function. The regressions have been computed separately for each bird. The parameters M and D represent the averages for each treatment group. Performance in each experiment was subjected to analysis of variance. This and linear regressions were computed according to standard procedures (Snedecor and Cochran, 1968). The results were processed automatically using a CDC Cyber computer. Each experiment consisted of four temperature treatments. Treatment 1 consisted of 12 hr low temperature and 12 hr high temperature; treatment 2 was the average temperature for 24 hr/day; and treatments 3 and 4 represented 24 hr of the high and low constant temperatures per days, respectively. In additional experiments, the same cycle magnitude was repeated twice, at a lower and upper temperature ranges.
HURWITZ AND BENGAL
1084 RESULTS
Trial 2. In this trial a cycling temperature at a higher range than in trial 1, with a difference of 10 C was tested. The treatments were: 1) 25 to 35 C cycling temperature (12 hr/day on each treatment); 2) 30 C constant; 3) 25 C constant; and 4) 3 5 C constant. The results of this trial are given in Table 2. Weight gain was highest at 25 C with a progressive decrease at 30 and 35 C. Weight gain for the alternating temperature was somewhat lower than that observed at the constant 30 C but intermediate between 25 and 35 C. Feed intake was highest at 25 and lowest at 35 C. At
30 C and at the cycling temperatures of 25 to 35 C, feed intake was similar and intermediate. Feed efficiency was highest at 30 C and was not significantly different in all other treatments. Maintenance energy expediture was higher at 25 C and similar at all other treatments. There were no consistent differences in the growth expenditure among the temperature treatments. Trial 3. The purpose of this trial was to evaluate the effect of the environmental temperature cycling between 10 and 30 C. The trial included four treatments: 1) 10 to 30 C alternating temperature, 12 hr/day on each; 2) 20 C constant temperature; 3) 30 C constant temperature; and 4) 10 C constant temperature. The results of this trial are given in Table 3. Weight gain was significantly depressed at 30 C compared with the lower temperatures; there was no significant difference among the other three treatments. However, weight gain at 10 C appeared to be lower than at 20 C constant and 10 to 30 C cycling temperatures with little difference between the latter. Feed intake was highest at 10, and lowest at 30, and'intermediate at 20 C or at 10 to 30 C. There was no significant difference between the latter two treatments. Feed efficiency was highest at 30 C, similar for both 10 to 30 C and 20 C, and lowest for 10 C. Similarly, energy intake for maintenance was highest at 10 and lowest at 30 C, intermediate at 10 to 30 C and 20 C, with little difference between them. Energy intake for growth did not vary significantly. Trial 4. The purpose of this trial was to evaluate the effect of a cycle of 20 C at the
TABLE 2. Effect of upper range constant and alternating temperatures on the performance of turkey poults* Environmental temperature, C Parameter
25-35
Body weight, initial g Weight gain, g/4 weeks Feed intake, g/4 weeks Feed efficiency Maintenance expenditure, kcal/g 2 / 3 Growth expenditure, kcal/g
1305 a 2116bc 3917 b .539ab
30
25
35
SE
1282 a 2275ab 4005b .569 a
1325 a 2310 a 4428 a .523 b
1285 a 1992 c 3665 c .544 a b
19 64 73
1.80 b
2.01ab
2.24 a
1.93 b
.10
1.0*
.9a
.8a
.7 a
.2
a,b ' Means with different superscript letters are significantly different (P<.05). 1
.013
Cycled, 12 hr at each temperature.
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
Trial 1. In this trial, the effect of cycling temperatures was studied at the lower range of temperatures with a high-low difference of 12 C. Accordingly, the treatments were 12 to 24 C alternating; 18, 24, and 12 C constant. The results of this trial are given in Table 1. Body weight gain was significantly lower at 12 C than at 24 or 18 C. No significant difference was noted between the latter two treatments and the 12 to 24 alternating temperature. Feed intake was significantly lower at 24 C than at all other temperatures with little difference among the latter. Feed efficiency was highest at 24 C and lowest at 12 C. Feed efficiencies for the average temperature of 18 C and the alternating 12 to 24 C were very similar. As expected, the energy expenditure for maintenance was highest at 12 C and lowest at 24 C. The values for 18 C constant and 12 to 24 C alternating temperatures were similar and intermediate. The energy requirement for growth was not affected by the temperature treatments.
TURKEYS IN CYCLIC TEMPERATURES
1085
TABLE 3. Effect of constant and alternating temperatures within a 20 C range on turkey
performance1
Environmental temperature, C Parameter
10-301
Body weight, initial g Weight gain, g/4 weeks Feed intake, g/4 weeks Feed efficiency Maintenance expenditure, kcal/g 2 / 3 Growth expenditure, kcal/g
1399 a 2355a 4488 b .524 b
a
20
30
10
1389 a 2422a 4666 b .520 b
1344a 2150 b 3915 c .550 a
1436 a 2293ab 5042 a .455 c
SE 28 72 79 '.008
2.17a
2.25 a
1.78 b
2.31 a
.09
l.oa
l.ia
1.4a
1.3a
.2
' ' Means with different superscript letters are significantly different (P<.05).
1
Cycled, 12 hr at each temperature.
DISCUSSION
Consistent with our previous study (Hurwitz et al, 1980) and the results of de Albuquerque
et al. (1978), weight gain in young turkeys was highest around 20 C with an asymmetrical decrease on either side of this temperature. However, in the previous study, feed efficiency also decreased when the temperature exceeded 27 C due to an increase in the energy used for maintenance, whereas in the present study feed efficiency improved between 25 and 35 C. When the environmental temperatures were cycled below 30 C (trials 1 and 3), weight gain on the cycling temperatures were similar to that obtained on the corresponding average temperatures. In these cases, weight gain on both average and cycling temperatures slightly exceeded that obtained on the low or high constant temperatures. These results obtained with turkeys agree with those of Siegel and Drury (1970), who found no significant difference between constant temperatures and those fluctuating 11 C (difference between maximum and minimum). In contrast, our results do not show deleterious effects of
TABLE 4. The effect of a wide range (20 C) in constant and alternating temperatures at the upper range on turkey performance1 Experimental temperature, C Parameter
15-35 1
Body weight, initial, g Weight gain, g/4 weeks Feed intake, g/4 weeks Feed efficiency
1195a 2335b 4099c .570a
25
35
15
SE
1204a 2737a 4674b .585 a
1172a 1819 c 3069 d .588 a
1179a 2497 b 5048 a .492
21 71 96
a,b,c Means with different superscript letters are significantly different (P<.05). 1
Cycled, 12 hr at each temperature.
.011
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
upper temperature range. The experimental treatments were: 1)15 to 35 C alternating, 2) 25 C constant, 3) 35 C constant, and 4) 15 C constant. The results are presented in Table 4. Weight gain was highest at 25 and lowest at 35 C. The weight gains at 15 C and at 15 to 35 C were similar, and both were higher than at 35 C. Feed intake was lowest at 35 C and highest at 15 C but not significantly different at 15 to 3 5 C compared with 25 C. Feed efficiency was similar at 15 to 35, 25, and 35 C, and significantly lower at 15 C. Due to only slight variations in the TEC/G within birds and treatments, the results were not suitable for regression analysis. Therefore, calorie intakes for maintenance and growth have not been calculated.
1086
HURWITZ AND BENGAL
REFERENCES de Albuquerque, K., A. T. Leighton, Jr., J. P. Mason, Sr., and L. M. Potter, 1978. The effects of
environmental temperature, sex and dietary energy levels on growth performance of Large White turkeys. Poultry Sci. 57:353-362. Deaton, J. W., F. N. Reece, B. D. Lott, L. F. Kubena, and J. D. May, 1972. The efficiency of cooling broilers in summer as measured by growth and feed utilization. Poultry Sci. 51:69—71. Deaton, J. W., F. N. Reece, B. D. Lott, L. F. Kubena, J. D. May, and T. H. Vardaman, 1973. The effect of low versus moderate rearing temperature on broiler performance. Poultry Sci. 52:1175— 1181. Griffin, J. G., and T. H. Vardaman, 1970. Diurnal cyclic versus constant temperature for broiler performance. Poultry Sci. 49:387-392. Harris, G. D., Jr., W. H. Dodgen, and G. S. Nelson, 1974. Effect of diurnal cyclic temperatures on broiler performance. Poultry Sci. 53:2204-2208. Hurwitz, S., D. Sklan, and I. Bartov, 1978b. New formal approaches to the determination of energy and amino acid requirements for chicks. Poultry Sci. 57:197-205. Hurwitz, S., D. Dubrov, W. Eisner, G. Risenfeld, and A. Bar, 1978a. Phosphate absorption and excretion in the young turkey, as influenced by calcium intake. J. Nutr. 108:1321-1335. Hurwitz, S., M. Weisselberg, U. Eisner, I. Bartov, G. Risenfeld, M. Sharvit, A. Niv, and S. Bornstein, 1980. The energy requirements and performance of growing chickens and turkeys as affected by environmental temperature. Poultry Sci. 59: 2290-2299. National Research Council, 1977. Nutrient Requirements of Poultry. Natl. Acad. Sci. Washington, DC. Siegel, H. S., and L. N. Drury, 1970. Broiler growth in diurnally cyclic temperature environments. Poultry Sci. 49:238-244. Snedecor, G. W., and W. G. Cochran, 1968. Statistical Methods. 6th ed. Iowa State Univ. Press, Ames, IA.
Downloaded from http://ps.oxfordjournals.org/ at NERL on June 16, 2015
temperature cycles of 20 C. These results are in agreement also with those of Griffin and Vardaman (1970) and with Deaton et al. (1973). However, when the birds are heat-stressed with maximun temperature above 30 C (trials 2 and 4), the performance on the cycling temperature is poorer than at the respective constant average temperatures and ranks between the performances on the high and low temperatures. The energy used for maintenance appeared to be similar for the cyclic and the average temperatures. The main purpose of this study has been to evaluate the applicability of performance results obtained under laboratory constant temperatures in predicting performance under field conditions. As was also suggested by Deaton et al. (1973) on the basis of experiments with chickens, the present results indicate the possibility of predicting performance, under field conditions, from a knowledge of the typical average temperature; however, care should be excercised whenever the maximum temperature exceeds 30 C. This information is useful in applying nutrient requirements for different temperatures, as obtained from experimentation at constant temperatures (Hurwitz et al, 1980), to least cost formulation of practical diets.