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Performance of Turkeys Subjected to Day and Night Feeding Programs During Heat Stress1
81992Applied Poultq Science. Inc
PERFORMANCE OF TURKEYS SUBJECTED TO DAYAND NIGHT FEEDING PROGRAMS DURING HEATSTRESS’
Primarv Audience: Turkev Producers. Nutritionists. Veterinarians
DESCRIPTION OF PROBLEM Heat stress often causes excessive losses in broilers and turkeys during the summer months in the southeastern United States [l]. In addition to the use of evaporative cooling, insulation, and improved ventilation systems, management practices have been employed in order to reduce the deleterious effects of heat stress on livability and feed efficiency. One practice that has been used by some broiler companies is withdrawing feed in the morning so that birds are fasted during the hottest part of the day [2]. The basic premise is that feed removal prior to acute heat stress reduces overall metabolic activity and subsequent heat 1 Supported
production of the birds during this period. As a result of the physiological changes, the bird is more capable of tolerating heat stress. Research on this subject with chickens is limited and for turkeys, it is essentially nonexistent. Studies with chickens under acute heat stress suggest that longer survival times and decreased mortalities may be benefits of fasting during heat stress [3, 4, 51. In addition, fasting broilers during heat stress may stimulate behaviors that increase survival rates [6]. However, significant reductions in body weight gain due to fasting during heat stress have been reported [6]. Thus, from an eco-
by State and Hatch funds allocated to the Georgia Agricultural Stations of the University of Georgia 2 To whom correspondence should be addressed
Downloaded from http://japr.oxfordjournals.org/ at University of Hawaii - Manoa on June 9, 2015
M.MAMPUTU, D. L. CUNNINGHAM2and R. J. BUHR Department of PouIhy Science, The Universityof Georgia,Athens, GA 30602 Phone: (404) 542-1325 F M : (404) 542-8383
Research Report 297
MAMPUTU et al.
During the first week, additional jar-type drinkers and feeder lids were used. The diets were standard University of Georgia starting, growing and finishing turkey diets. At 9 weeks of age, the number of poults in each pen was made equal by assigning 26 turkeys to each of the treatment pens. In addition, the thermostats in the furnaces were set at 90°F between 0800 and 1700 to simulate daytime heat stress conditions. The furnaces were turned off during the evening hours to allow normal nighttime cooling conditions. This approach resulted in temperatures ranging from 60°F to 92°F during the day. Performance data were evaluated for growth rate, feed usage and mortality. Growth rates were determined by weighing all birds in each replicate group every three weeks starting at 9 weeks of age. Feed usage was recorded for each replicate on a three week basis. Mortality was recorded daily. Income per bird was computed for each replicate by using average 18 week body weights x $0.836/kg ($0.38/lb) of weight. Feed costs were determined by using a value of $0.187/kg ($170/ton) x average feed usage for each replicate. A value of $1.65 was used for determining poult costs for each replicate.
MATERIALS AND METHODS Three hundred twelve Large White male turkeys from each of two commercial strains (Nicholas and B.U.T.) were used in this study. They were housed in 24 floor pens (9 ft x 10 ft) in an environmentally controlled growing facility. Each strain was subjected to two feeding programs (full feeding or fasting) from 9 to 18 weeks of age under heat stress conditions. The experimental design consisted of two strain and two feeding programs in a 2 x 2 factorial arrangement [7]. Full-fed turkeys had feed available 24 hours each day, while fasted birds had feed removed from 0800 to 1700 each day. The poults were brooded using a combination of gas hoover heaters and forced air furnaces. Standard brooding temperatures were used for the first three weeks; thereafter, artificial heating was terminated. The lighting program consisted of 23 hours of incandescent light followed by one hour of darkness. Feed and water were provided by two tube-type feeders and one bell-type drinker for each pen.
STRAIN
FEEDING PROGRAM
Nicholas
Differences between day and night feeding programs were not present for 18 week body weights or for the 9th to the 18th week weight gains (Table 1). Significant differences (P e .Ol) were observed between strains for 18 week body weights and for the 9th to the 18th week weight gains regardless of the feeding program used. The B.U.T. strain of turkeys weighed 9.4% more at 18 weeks (13.9 kg vs. 12.7 kg) than did the Nicholas strain. Because body weights were essentially the same be-
BODY WEIGHT (kgbird) 9th Week
B.U.T.
RESULTS AND DISCUSSION
WEIGHT GAIN (kghird)
LIVABILITY
(%I
18th Week
Day and Night
S.14a
13.91a
8.7?
92.g
Night
5.1.Sa
13.88a
8.70a
95SX
Day and Night
5.46a
12.94b
7.48b
87.8'
Night
5.28a
12.46b
7.Mb
91.v
Downloaded from http://japr.oxfordjournals.org/ at University of Hawaii - Manoa on June 9, 2015
nomic standpoint, any gains achieved by reduced mortalities would have to more than offset any losses realized through reduced finishing weights. Significant mortality losses for turkeys as a result of heat stress occur from 10 to 20 weeks of age, when the birds are achieving their heaviest weights. This also represents the time period when the investment per bird is greatest. A program to reduce mortalities at this age without significantly reducing performance characteristics could prove to be extremely valuable to turkey growers. This study investigated production and economic performance of two commercial strains of Large White male turkeys subjected to feed withdrawal during chronic daily heat stress.
JAPR HEAT STRESS IN TURKEYS
298
SIRAIN
B.U.T. Nicholas
FEEDING PROGRAM
FEED USAGE (kglbird)
FEED CONVERSION (kg feed/kg wt gain)
Day and Night
29.90a
3.41a
Night
30.60a
3Sla
Day and Night
25.57b
3.42a
Night
24.82‘
3.4sa
I
IabMeans with different superscripts within columns are significantlydifferent (P < W).
SIXAIN
FEEDING PROGRAM
B.U.T. Nicholas
INCOME($)*/ POULT HOUSED A T 9TH WEEK
Day and Night
10.81a
Night
costs for the Nicholas strain and for day feeding were significantly higher due to the differences in livability rates for these two factors. Night feeding reduced poult costs by $O.M/poult compared to the day feeding program, while poult costs for B.U.T. birds were $O.lO/poult less than for the Nicholas strain. In the final analysis, the only differences for net income per poult housed were between the two strains. Night feeding significantly reduced 9 to 18 week mortality rates for both strains of turkey employed in this study, but did not affect body weight gains, feed usage or feed conversion ratios. These performance results are similar to those reported for broiler chickens [3],suggesting that feed restriction during the hours of highest ambient temperatures is beneficial in reducing heat stress and related mortalities. McCorrnick [4] found that fasting birds for 24, 48 and 72 hours resulted in a significant increase in survival time ( P < .OS). Kohne [5] reported slightly longer survivaltimes for adult turkeys fasted 24 hours before exposure to extremely high temperatures (49.SoF),but not significantly different (P > .05) from survival times of heat stressed-full fed birds. Benefits achieved from reduced mortality levels using
POULT
POULT HOUSED AT 9TH WEEK
COST($)‘
NET INCOME($)/ POULT HOUSED AT 9TH WEEK
5.20a
1.78Y
3.83a
FEED
11.13a
5.50a
1.72’
3.91a
Day and Night
9SOb
4.20‘
1.88x
3.42b
Night
9.48b
4.22b
l.82y
3.ab
Downloaded from http://japr.oxfordjournals.org/ at University of Hawaii - Manoa on June 9, 2015
tween the two strains at the 9th week, the weight differentials observed in this study were achieved during the 9th to the 18th week period. Night feeding significantly reduced mortality for both strains (2.6% and 3.2% reductions for B.U.T. and Nicholas, respectively). Feed usage and feed conversion values by strain and feeding program are presented in Table 2. Day or night feedings did not affect either feed usage or feed conversion performances. Not surprisingly, feed usage values were significantly greater for the B.U.T. strain than for the Nicholas strain. However, feed conversion ratios were identical for the two strains. Income, feed costs, poult costs and net incomes by strain and feeding program are presented in Table 3. Because of the differences in frnal body weights and livability rates, income values were significantly different between the strains. Night or day feeding had no significant effect on incomes. Feed costs were greater for the B.U.T. strain due to increased feed usage levels, but were not significantly affected by night or day feeding programs. However, poult costs were affected by both strain of birds and feeding program. Poult
Research Report 299
MAMPUTUefal. this approach need to be cost effective to be of value to the producer. The results of the present study indicate that no significant differences for net returns per bird were achieved with this feeding program. However, night feeding during heat stress improves the well
being of the birds without reducing net returns. Because important performance values were unaffected by the night feeding program, and mortality rates were significantly reduced, further studies under commercial conditions will be of value.
CONCLUSIONS AND APPLICATIONS 1. Night feeding increased livability rates significantly ( P < .Ol) for both strains of turkeys
(B.U.T. and Nicholas) subjected to heat stress.
=-
3. Night feeding was not economically beneficial for net return values per poult [net return = income (poult + feed cost)]. 4. Net returns per bird were significantly greater for B.U.T. due to increased livability rates and body weight gains.
-
REFERENCES AND NOTES 1. Brown, R H., 1986. Heat wave reduces broiler, turkey population in Southeast. Feedstuffs 58:34:10.
adult turkey hens under conditions of acute thermal stress. Poultry Sci. 52:1780-1783.
2. Pierce, R, 1980. Don’t wait until broilers start to die from heat stress. Poultry Dig. 39:298-300.
6. Ouart, M. D., B. L.Damron, F. B. Malher and J. E Marion, 1989. Effects of short-term fasting and diurnal heat stress on broiler performance and behavior. Poultry Sci. 6855-60. 7. Steele, R G. D., and J. H. Harris, 1960. PnnclDles d-pf-. McGraw-Hill Book Co.,Inc. New York, New York.
3. Teeter, R G., 1988. Enhancingbroiler productivity duringchronicand acute heatstress. MonsantoNutrition Update, Vol. 6, No. 1. 4. McCormick, C. C., J. D. GarUch and F. W. Edens, 1979. Fasting and diet affects the tolerance of young chickens exposed to acute heat stress. J. Nutr. 10917971809. 5. Kohne, H. J., M. A. Boone, and J. E Jones, 1973. The effect of feed consumption on the survival time of
8. The authors are thankful to Lynda Jones, Ariel and Maria Elena Rolon for assistance in flock management.
Downloaded from http://japr.oxfordjournals.org/ at University of Hawaii - Manoa on June 9, 2015
2. Body weight gain, feed usage, and feed conversion ratios within strains of turkeys were not significantly affected (P .05) by the feeding program used.
PERFORMANCE OF TURKEYS SUBJECTED TO DAYAND NIGHT FEEDING PROGRAMS DURING HEATSTRESS’
Primarv Audience: Turkev Producers. Nutritionists. Veterinarians
DESCRIPTION OF PROBLEM Heat stress often causes excessive losses in broilers and turkeys during the summer months in the southeastern United States [l]. In addition to the use of evaporative cooling, insulation, and improved ventilation systems, management practices have been employed in order to reduce the deleterious effects of heat stress on livability and feed efficiency. One practice that has been used by some broiler companies is withdrawing feed in the morning so that birds are fasted during the hottest part of the day [2]. The basic premise is that feed removal prior to acute heat stress reduces overall metabolic activity and subsequent heat 1 Supported
production of the birds during this period. As a result of the physiological changes, the bird is more capable of tolerating heat stress. Research on this subject with chickens is limited and for turkeys, it is essentially nonexistent. Studies with chickens under acute heat stress suggest that longer survival times and decreased mortalities may be benefits of fasting during heat stress [3, 4, 51. In addition, fasting broilers during heat stress may stimulate behaviors that increase survival rates [6]. However, significant reductions in body weight gain due to fasting during heat stress have been reported [6]. Thus, from an eco-
by State and Hatch funds allocated to the Georgia Agricultural Stations of the University of Georgia 2 To whom correspondence should be addressed
Downloaded from http://japr.oxfordjournals.org/ at University of Hawaii - Manoa on June 9, 2015
M.MAMPUTU, D. L. CUNNINGHAM2and R. J. BUHR Department of PouIhy Science, The Universityof Georgia,Athens, GA 30602 Phone: (404) 542-1325 F M : (404) 542-8383
Research Report 297
MAMPUTU et al.
During the first week, additional jar-type drinkers and feeder lids were used. The diets were standard University of Georgia starting, growing and finishing turkey diets. At 9 weeks of age, the number of poults in each pen was made equal by assigning 26 turkeys to each of the treatment pens. In addition, the thermostats in the furnaces were set at 90°F between 0800 and 1700 to simulate daytime heat stress conditions. The furnaces were turned off during the evening hours to allow normal nighttime cooling conditions. This approach resulted in temperatures ranging from 60°F to 92°F during the day. Performance data were evaluated for growth rate, feed usage and mortality. Growth rates were determined by weighing all birds in each replicate group every three weeks starting at 9 weeks of age. Feed usage was recorded for each replicate on a three week basis. Mortality was recorded daily. Income per bird was computed for each replicate by using average 18 week body weights x $0.836/kg ($0.38/lb) of weight. Feed costs were determined by using a value of $0.187/kg ($170/ton) x average feed usage for each replicate. A value of $1.65 was used for determining poult costs for each replicate.
MATERIALS AND METHODS Three hundred twelve Large White male turkeys from each of two commercial strains (Nicholas and B.U.T.) were used in this study. They were housed in 24 floor pens (9 ft x 10 ft) in an environmentally controlled growing facility. Each strain was subjected to two feeding programs (full feeding or fasting) from 9 to 18 weeks of age under heat stress conditions. The experimental design consisted of two strain and two feeding programs in a 2 x 2 factorial arrangement [7]. Full-fed turkeys had feed available 24 hours each day, while fasted birds had feed removed from 0800 to 1700 each day. The poults were brooded using a combination of gas hoover heaters and forced air furnaces. Standard brooding temperatures were used for the first three weeks; thereafter, artificial heating was terminated. The lighting program consisted of 23 hours of incandescent light followed by one hour of darkness. Feed and water were provided by two tube-type feeders and one bell-type drinker for each pen.
STRAIN
FEEDING PROGRAM
Nicholas
Differences between day and night feeding programs were not present for 18 week body weights or for the 9th to the 18th week weight gains (Table 1). Significant differences (P e .Ol) were observed between strains for 18 week body weights and for the 9th to the 18th week weight gains regardless of the feeding program used. The B.U.T. strain of turkeys weighed 9.4% more at 18 weeks (13.9 kg vs. 12.7 kg) than did the Nicholas strain. Because body weights were essentially the same be-
BODY WEIGHT (kgbird) 9th Week
B.U.T.
RESULTS AND DISCUSSION
WEIGHT GAIN (kghird)
LIVABILITY
(%I
18th Week
Day and Night
S.14a
13.91a
8.7?
92.g
Night
5.1.Sa
13.88a
8.70a
95SX
Day and Night
5.46a
12.94b
7.48b
87.8'
Night
5.28a
12.46b
7.Mb
91.v
Downloaded from http://japr.oxfordjournals.org/ at University of Hawaii - Manoa on June 9, 2015
nomic standpoint, any gains achieved by reduced mortalities would have to more than offset any losses realized through reduced finishing weights. Significant mortality losses for turkeys as a result of heat stress occur from 10 to 20 weeks of age, when the birds are achieving their heaviest weights. This also represents the time period when the investment per bird is greatest. A program to reduce mortalities at this age without significantly reducing performance characteristics could prove to be extremely valuable to turkey growers. This study investigated production and economic performance of two commercial strains of Large White male turkeys subjected to feed withdrawal during chronic daily heat stress.
JAPR HEAT STRESS IN TURKEYS
298
SIRAIN
B.U.T. Nicholas
FEEDING PROGRAM
FEED USAGE (kglbird)
FEED CONVERSION (kg feed/kg wt gain)
Day and Night
29.90a
3.41a
Night
30.60a
3Sla
Day and Night
25.57b
3.42a
Night
24.82‘
3.4sa
I
IabMeans with different superscripts within columns are significantlydifferent (P < W).
SIXAIN
FEEDING PROGRAM
B.U.T. Nicholas
INCOME($)*/ POULT HOUSED A T 9TH WEEK
Day and Night
10.81a
Night
costs for the Nicholas strain and for day feeding were significantly higher due to the differences in livability rates for these two factors. Night feeding reduced poult costs by $O.M/poult compared to the day feeding program, while poult costs for B.U.T. birds were $O.lO/poult less than for the Nicholas strain. In the final analysis, the only differences for net income per poult housed were between the two strains. Night feeding significantly reduced 9 to 18 week mortality rates for both strains of turkey employed in this study, but did not affect body weight gains, feed usage or feed conversion ratios. These performance results are similar to those reported for broiler chickens [3],suggesting that feed restriction during the hours of highest ambient temperatures is beneficial in reducing heat stress and related mortalities. McCorrnick [4] found that fasting birds for 24, 48 and 72 hours resulted in a significant increase in survival time ( P < .OS). Kohne [5] reported slightly longer survivaltimes for adult turkeys fasted 24 hours before exposure to extremely high temperatures (49.SoF),but not significantly different (P > .05) from survival times of heat stressed-full fed birds. Benefits achieved from reduced mortality levels using
POULT
POULT HOUSED AT 9TH WEEK
COST($)‘
NET INCOME($)/ POULT HOUSED AT 9TH WEEK
5.20a
1.78Y
3.83a
FEED
11.13a
5.50a
1.72’
3.91a
Day and Night
9SOb
4.20‘
1.88x
3.42b
Night
9.48b
4.22b
l.82y
3.ab
Downloaded from http://japr.oxfordjournals.org/ at University of Hawaii - Manoa on June 9, 2015
tween the two strains at the 9th week, the weight differentials observed in this study were achieved during the 9th to the 18th week period. Night feeding significantly reduced mortality for both strains (2.6% and 3.2% reductions for B.U.T. and Nicholas, respectively). Feed usage and feed conversion values by strain and feeding program are presented in Table 2. Day or night feedings did not affect either feed usage or feed conversion performances. Not surprisingly, feed usage values were significantly greater for the B.U.T. strain than for the Nicholas strain. However, feed conversion ratios were identical for the two strains. Income, feed costs, poult costs and net incomes by strain and feeding program are presented in Table 3. Because of the differences in frnal body weights and livability rates, income values were significantly different between the strains. Night or day feeding had no significant effect on incomes. Feed costs were greater for the B.U.T. strain due to increased feed usage levels, but were not significantly affected by night or day feeding programs. However, poult costs were affected by both strain of birds and feeding program. Poult
Research Report 299
MAMPUTUefal. this approach need to be cost effective to be of value to the producer. The results of the present study indicate that no significant differences for net returns per bird were achieved with this feeding program. However, night feeding during heat stress improves the well
being of the birds without reducing net returns. Because important performance values were unaffected by the night feeding program, and mortality rates were significantly reduced, further studies under commercial conditions will be of value.
CONCLUSIONS AND APPLICATIONS 1. Night feeding increased livability rates significantly ( P < .Ol) for both strains of turkeys
(B.U.T. and Nicholas) subjected to heat stress.
=-
3. Night feeding was not economically beneficial for net return values per poult [net return = income (poult + feed cost)]. 4. Net returns per bird were significantly greater for B.U.T. due to increased livability rates and body weight gains.
-
REFERENCES AND NOTES 1. Brown, R H., 1986. Heat wave reduces broiler, turkey population in Southeast. Feedstuffs 58:34:10.
adult turkey hens under conditions of acute thermal stress. Poultry Sci. 52:1780-1783.
2. Pierce, R, 1980. Don’t wait until broilers start to die from heat stress. Poultry Dig. 39:298-300.
6. Ouart, M. D., B. L.Damron, F. B. Malher and J. E Marion, 1989. Effects of short-term fasting and diurnal heat stress on broiler performance and behavior. Poultry Sci. 6855-60. 7. Steele, R G. D., and J. H. Harris, 1960. PnnclDles d-pf-. McGraw-Hill Book Co.,Inc. New York, New York.
3. Teeter, R G., 1988. Enhancingbroiler productivity duringchronicand acute heatstress. MonsantoNutrition Update, Vol. 6, No. 1. 4. McCormick, C. C., J. D. GarUch and F. W. Edens, 1979. Fasting and diet affects the tolerance of young chickens exposed to acute heat stress. J. Nutr. 10917971809. 5. Kohne, H. J., M. A. Boone, and J. E Jones, 1973. The effect of feed consumption on the survival time of
8. The authors are thankful to Lynda Jones, Ariel and Maria Elena Rolon for assistance in flock management.
Downloaded from http://japr.oxfordjournals.org/ at University of Hawaii - Manoa on June 9, 2015
2. Body weight gain, feed usage, and feed conversion ratios within strains of turkeys were not significantly affected (P .05) by the feeding program used.