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The Effect of Delayed Placement and Day-Old Debeaking on the Performance of White Leghorn Pullets
The Effect of Delayed Placement and Day-Old Debeaking on the Performance of White Leghorn Pullets J. R. CARSON
Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907 (Received for publication January 13, 1975)
POULTRY SCIENCE 54: 1581-1584, 1975
A
NDRADE and Carson (1975) showed that debeaking of S.C. White Leghorn pullets at one day of age by the early precision block-type method significantly reduced feed consumption through 20 weeks of age and 35-week body weight, but had no effect on mortality, egg size or egg production. They felt that debeaking at day-old had much to recommend it for use in the field. However, an objection was raised that day-old debeaking could be catastrophic especially if chicks were held several days in chick boxes before being placed on feed and water. This raised a reasonable question about the effect of imposing two stresses at the same time on day-old chicks. With this in mind an experiment was set up to test the hypothesis that delaying the placement of chicks for
Journal Paper No. 5765 of the Purdue University Agricultural Experiment Station, West Lafayette, Indiana 47907.
1 or 2 days and then debeaking would have undesirable effects on their performance. The purpose of this paper is to present the results of this study. PROCEDURE Experimental Design. Two hundred Single Comb White Leghorn, Heisdorf and Nelson "Nick" chicks were placed on experiment on each of three placement days: 0 days (upon receipt from hatchery), 1 day and 2 days after receipt from hatchery. One-half of each day's placements was debeaked by a precision type debeaking as described by Bramhall (1967). The remainder served as controls. Each of the 6 treatment combinations was replicated 4 times with 25 chicks per replicate. Management. Chicks were delivered on August 15 about 1400 hours and those that were to be fed and watered on that day were placed in battery brooders between 1600 and
1581
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on May 21, 2015
ABSTRACT S.C. White Leghorn pullets were placed on feed and water on the day of hatching or 1 or 2 days after the day of hatching. Precision block type debeaking was performed with a Lyon's electric debeaker immediately before feeding and watering. Debeaking at the time of placement significantly reduced body weight at 25 days, 22, and 51 weeks of age. The fact that the reduction in body weight persisted through 51 weeks of age would indicate that it was a permanent effect. Age at first egg was significantly delayed in the debeaked pullets. No effect was noted on egg size or egg production. Delaying placement for 2 days produced a significant reduction in body weight at 25 days of age that was equal to the debeaking effect. However, as the pullets grew older the placement effect grew less pronounced so that at 22 weeks of age the chicks delayed in placement by 2 days were only 3% lighter than their controls. At 51 weeks of age there was no difference between these groups. Delayed placement pullets did not differ from their controls in days to sexual maturity, egg weight or egg production. Neither debeaking, delayed placement or a combination of the two increased mortality. Non-debeaked controls housed two to a cage had significantly more mortality than debeaked pullets. The placing of 2 stresses on White Leghorn pullets did not increase mortality, but the double stress was noticeable in 3 week and 22 week body weights. The birds which were debeaked and placed 2 days after hatching were lighter in body weights than any other combination groups. The two effects were additive.
1582
J. R. CARSON
a 20% Chick Starter; 8 to 20 weeks, a 15% Pullet Developer; and in the laying house, a 16% Layer Mash. Analysis of variance using replicate means was used to identify significance of main effects and interaction. RESULTS The means for the treatment combination groups for all traits are given in Table 1. Also included in this table are the degrees of freedom and mean squares for the analyses of variance for various traits. In each case the mean squares appear at the bottom of each column of treatment means for each trait. The first body weights were taken at 25 days of age. At this age the debeaked groups were 9.2 grams lighter than the non-debeaked controls (P < 0.01). Similarly, delaying placement produced a significant reduction (P < 0.01) in body weight. The longer placement was delayed, the greater was the reduction in body weight. Those birds that were not placed until 2 days after hatching were 11.2 gms. lighter than their controls. The double stressed groups were 20.3 gms. lighter than those groups that had neither stress applied, which would indicate that the two effects were additive. At 22 weeks of age, after the pullets had been moved from the brooder house to laying cages, the reduction in body weight due to debeaking was 98.7 gms. or about 7.6%. If this is compared to the 4.6% loss identified in 25 day weights, it is apparent that debeaked groups had not made up any of their earlier loss but continued to fall behind the controls. The effect of a 2 day delay in placement was a 36.8 gm. reduction in body weight. This was a 3% reduction and when compared to the 5% decrease measured at 25 days of age indicates that the effect of delaying placement was waning as the birds became older. This effect was seen primarily in the
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on May 21, 2015
1700 hours. The remainder of the chicks were held in chick boxes in the brooder room and processed at the appropriate time. Debeaking and placement were done at approximately the same time each day. The temperature on the afternoon the chicks were received was approximately 34° C. (93° F.) with high humidity making conditions in the chick boxes extremely uncomfortable. Most chicks were panting and in two sections of 25 there were 18 and 5 chicks dead. Other than this, all were in good condition and started eating and drinking as soon as they were placed. Debeaking was done each day just before the chicks were placed on feed and water. Chicks were debeaked with a Lyon's electric debeaker using a cam attachment which held the cutting blade down for 2 seconds after cutting for cauterization of the beak tissue. The larger of the three holes on the baby chick attachment plate with a diameter of 4.37 mm. (11/64 in.) was used to guide the beak and determine the amount removed. About 1/2 to 2 / 3 of the chick's beak was removed by this means. No further debeaking was done throughout the experiment. Each day after debeaking had been done, the control and debeaked chicks were placed in Petersime starting batteries. The 4 control replicates for the day were assigned at random to 4 deck levels and the 4 debeaked replicates were similarly placed at random. Each rep of 25 chicks was assigned to one deck of a battery. At the end of 5 days all chicks were taken from battery brooders and placed in floor pens, the debeaked birds going into one floor pen; the controls in another. At 22 weeks of age, the pullets were transferred from their floor pens to a cage house. One-third were placed in individual cages; and 2 / 3 , two birds to a cage. The rations were custom mixed according to Purdue formulations and the feeding program was as follows: 0 to 8 weeks of age,
1583
DELAYED PLACEMENT AND DAY-OLD DEBEAKING TABLE 1.-
-Means and analyses of variance for body weight, mortality and egg production traits by treatment Body weight at
ANOV Source Debeaking (D) Placement (T) D x T Error
d.f. 1 2 2 18
Days to first egg days
25 days gms.
22 weeks gms.
51 weeks gms.
0-22 wks.
22-51 wks.
%
%
205.5 200.9 194.3
1340.9 1281.2 1272.4
1756.7 1725.4 1706.2
6.5 5.6 6.3
15.3 18.0 17.3
181.4 183.1 181.4
60.5 60.9 59.9
195.1 192.9 185.2
1202.5 1198.8 1197.3
1654.1 1654.5 1657.0
2.0 5.2 6.0
7.0 11.5 6.5
192.8 189.9 185.2
61.2 59.2 58.8
M.S. 58390.3** 3187.6* 2402.7 718.8
M.S. 33071.0** 1165.5 1443.9 1040.0
M.S. 324.1** 33.7 29.6 17.0
M.S. 2.7 4.8 3.1 2.9
M.S. 506** 232.6**' 2.8 21.6
M.S. 549.1** 37.1 45.1 60.6
Egg weight gms.
**Significant at 1% level. *Significant at 5% level.
control group with little difference noted in the debeaked groups. The double stressed birds were still 143.6 gms. lighter than the controls. Analysis of variance of 22 week body weights indicated the debeaking effect was significant at the 1% level and the delayed placement effect was significant at the 5% level. At 51 weeks of age, by which time final body size has been attained in White Leghorns, the difference between the debeaked and control birds had been modified somewhat but was still significant (P < 0.01). The reduction in body size was 74.2 grams. The means of the delayed placement pullets still reflect a small effect, but analyses of variance indicated that this was non-significant. Mortality. One area of primary interest was early mortality for it was felt that a double stress placed on newly hatched chicks would have a profound effect on this trait. The percent mortality through 22 weeks of age for all groups was 6%. The differences in
treatment means appear to be random and no analysis of variance was run. There was very little mortality during the first 3 weeks in any group. The main point which should be made is that the double stressed pullets lived as well as their controls. Mortality in the laying house (22 through 51 weeks of age) was 8.3% for the debeaked birds versus 16.9% for the non-debeaked controls. This difference of 7.6% was highly significant. Delayed placement had no effect on this trait. It is logical to assume that the reduction in mortality in the debeaked birds was greatly influenced by the control of cannibalism due to debeaking, although data on causes of mortality were not kept. Egg Production Traits. The means for days to first egg are shown in Table 1. Debeaking at day-old delayed sexual maturity by about 7 days. This agrees with the 5 day delay in sexual maturity obtained by Andrade and Carson (1975) in Leghorns debeaked at 1 day of age. The effect of day of placement is noticeable in the debeaked groups but not
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on May 21, 2015
Non-debeaked Placed on day 0 1 2 Debeaked Placed on day 0 1 2
Mortality
1584
J. R.
DISCUSSION Under the conditions of this experiment delaying the placement on feed and water of newly hatched chicks and debeaking just before placement did not produce adverse effects on mortality at any age, egg size or egg production. However, significant reductions in body weight occurred, the largest of which was in those birds debeaked and placed 2 days after hatching. The magnitude of the reduction in the double stressed birds was equal to the sum of the two individual effects. Reduction in body weight from delayed placement remained significant through 22 weeks of age, but had disappeared by 51 weeks of age. By contrast, the body weight reduction from debeaking before placement was of a permanent nature and was highly significant at 51 weeks of age.
In egg type chickens a reduction in adult body size, if it did not affect egg size or numbers, and an increase in days to sexual maturity would be considered desirable by commercial egg producers. It is reasoned here that none of the effects produced by debeaking and delayed placement, either singly or in combination with each other, were undesirable. This should not be construed as an endorsement of imposing these two stresses on newly hatched chicks. The fact that the effects of debeaking and delayed placement were additive would lead one to expect that a third stress imposed at the same time as the two investigated here might add enough to overwhelm the defenses of the chick completely. Since the effects on body weight at 25 days of the two treatments were roughly equal, it could be argued that debeaking merely delayed by one or two days eating and drinking by newly hatched chicks. Thus the effect of debeaking is one which results from a reduction of feed and water intake. This does not seem likely because as growth of the treated birds is traced through 22 and 51 weeks of age, it is apparent that the delayed placement effect had diminished by 22 weeks of age and completely disappears by 51 weeks. On the other hand, debeaking effect increased by 22 weeks and persisted through 51 weeks. It seems that the effects of debeaking are more profound than a mere deprivation of feed and water and probably include a physiologic reaction to the shock of debeaking. REFERENCES Andrade, A. N., and J. R. Carson, 1975. The effect of age at- and methods of debeaking on future performance of White Leghorn pullets. Poultry Sci. 54: 666-674. Bramhall, E. L., 1967. Development of precision debeaking for week-old chicks. Poultry Sci. 46: 1237.
MARCH 1-5, 1976. WORLD CONFERENCE ON OILSEED AND VEGETABLE OIL PROCESSING TECHNOLOGY, AMSTERDAM, THE NETHERLANDS
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on May 21, 2015
significant. The double stressed birds matured at essentially the same time as their controls. It is interesting to note that the greatest difference in sexual maturity between debeaked and non-debeaked birds was in those placed on the day they hatched and the least on day 2. Egg weight data were taken at 40 weeks of age. Analysis of variance of egg weight data indicated that none of the treatment effects were significant. In this experiment as in our previous one, the significant reduction in body weight at 22 weeks of age which persisted through 51 weeks of age in the debeaked pullets was not accompanied by a significant reduction in egg weight. Egg production data for the period 22 weeks through 51 weeks of age showed no significant differences in any of the treatment means for total eggs produced from the date of first egg through the first seven months in the laying house or in the rate of production for this period.
CARSON
Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907 (Received for publication January 13, 1975)
POULTRY SCIENCE 54: 1581-1584, 1975
A
NDRADE and Carson (1975) showed that debeaking of S.C. White Leghorn pullets at one day of age by the early precision block-type method significantly reduced feed consumption through 20 weeks of age and 35-week body weight, but had no effect on mortality, egg size or egg production. They felt that debeaking at day-old had much to recommend it for use in the field. However, an objection was raised that day-old debeaking could be catastrophic especially if chicks were held several days in chick boxes before being placed on feed and water. This raised a reasonable question about the effect of imposing two stresses at the same time on day-old chicks. With this in mind an experiment was set up to test the hypothesis that delaying the placement of chicks for
Journal Paper No. 5765 of the Purdue University Agricultural Experiment Station, West Lafayette, Indiana 47907.
1 or 2 days and then debeaking would have undesirable effects on their performance. The purpose of this paper is to present the results of this study. PROCEDURE Experimental Design. Two hundred Single Comb White Leghorn, Heisdorf and Nelson "Nick" chicks were placed on experiment on each of three placement days: 0 days (upon receipt from hatchery), 1 day and 2 days after receipt from hatchery. One-half of each day's placements was debeaked by a precision type debeaking as described by Bramhall (1967). The remainder served as controls. Each of the 6 treatment combinations was replicated 4 times with 25 chicks per replicate. Management. Chicks were delivered on August 15 about 1400 hours and those that were to be fed and watered on that day were placed in battery brooders between 1600 and
1581
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on May 21, 2015
ABSTRACT S.C. White Leghorn pullets were placed on feed and water on the day of hatching or 1 or 2 days after the day of hatching. Precision block type debeaking was performed with a Lyon's electric debeaker immediately before feeding and watering. Debeaking at the time of placement significantly reduced body weight at 25 days, 22, and 51 weeks of age. The fact that the reduction in body weight persisted through 51 weeks of age would indicate that it was a permanent effect. Age at first egg was significantly delayed in the debeaked pullets. No effect was noted on egg size or egg production. Delaying placement for 2 days produced a significant reduction in body weight at 25 days of age that was equal to the debeaking effect. However, as the pullets grew older the placement effect grew less pronounced so that at 22 weeks of age the chicks delayed in placement by 2 days were only 3% lighter than their controls. At 51 weeks of age there was no difference between these groups. Delayed placement pullets did not differ from their controls in days to sexual maturity, egg weight or egg production. Neither debeaking, delayed placement or a combination of the two increased mortality. Non-debeaked controls housed two to a cage had significantly more mortality than debeaked pullets. The placing of 2 stresses on White Leghorn pullets did not increase mortality, but the double stress was noticeable in 3 week and 22 week body weights. The birds which were debeaked and placed 2 days after hatching were lighter in body weights than any other combination groups. The two effects were additive.
1582
J. R. CARSON
a 20% Chick Starter; 8 to 20 weeks, a 15% Pullet Developer; and in the laying house, a 16% Layer Mash. Analysis of variance using replicate means was used to identify significance of main effects and interaction. RESULTS The means for the treatment combination groups for all traits are given in Table 1. Also included in this table are the degrees of freedom and mean squares for the analyses of variance for various traits. In each case the mean squares appear at the bottom of each column of treatment means for each trait. The first body weights were taken at 25 days of age. At this age the debeaked groups were 9.2 grams lighter than the non-debeaked controls (P < 0.01). Similarly, delaying placement produced a significant reduction (P < 0.01) in body weight. The longer placement was delayed, the greater was the reduction in body weight. Those birds that were not placed until 2 days after hatching were 11.2 gms. lighter than their controls. The double stressed groups were 20.3 gms. lighter than those groups that had neither stress applied, which would indicate that the two effects were additive. At 22 weeks of age, after the pullets had been moved from the brooder house to laying cages, the reduction in body weight due to debeaking was 98.7 gms. or about 7.6%. If this is compared to the 4.6% loss identified in 25 day weights, it is apparent that debeaked groups had not made up any of their earlier loss but continued to fall behind the controls. The effect of a 2 day delay in placement was a 36.8 gm. reduction in body weight. This was a 3% reduction and when compared to the 5% decrease measured at 25 days of age indicates that the effect of delaying placement was waning as the birds became older. This effect was seen primarily in the
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on May 21, 2015
1700 hours. The remainder of the chicks were held in chick boxes in the brooder room and processed at the appropriate time. Debeaking and placement were done at approximately the same time each day. The temperature on the afternoon the chicks were received was approximately 34° C. (93° F.) with high humidity making conditions in the chick boxes extremely uncomfortable. Most chicks were panting and in two sections of 25 there were 18 and 5 chicks dead. Other than this, all were in good condition and started eating and drinking as soon as they were placed. Debeaking was done each day just before the chicks were placed on feed and water. Chicks were debeaked with a Lyon's electric debeaker using a cam attachment which held the cutting blade down for 2 seconds after cutting for cauterization of the beak tissue. The larger of the three holes on the baby chick attachment plate with a diameter of 4.37 mm. (11/64 in.) was used to guide the beak and determine the amount removed. About 1/2 to 2 / 3 of the chick's beak was removed by this means. No further debeaking was done throughout the experiment. Each day after debeaking had been done, the control and debeaked chicks were placed in Petersime starting batteries. The 4 control replicates for the day were assigned at random to 4 deck levels and the 4 debeaked replicates were similarly placed at random. Each rep of 25 chicks was assigned to one deck of a battery. At the end of 5 days all chicks were taken from battery brooders and placed in floor pens, the debeaked birds going into one floor pen; the controls in another. At 22 weeks of age, the pullets were transferred from their floor pens to a cage house. One-third were placed in individual cages; and 2 / 3 , two birds to a cage. The rations were custom mixed according to Purdue formulations and the feeding program was as follows: 0 to 8 weeks of age,
1583
DELAYED PLACEMENT AND DAY-OLD DEBEAKING TABLE 1.-
-Means and analyses of variance for body weight, mortality and egg production traits by treatment Body weight at
ANOV Source Debeaking (D) Placement (T) D x T Error
d.f. 1 2 2 18
Days to first egg days
25 days gms.
22 weeks gms.
51 weeks gms.
0-22 wks.
22-51 wks.
%
%
205.5 200.9 194.3
1340.9 1281.2 1272.4
1756.7 1725.4 1706.2
6.5 5.6 6.3
15.3 18.0 17.3
181.4 183.1 181.4
60.5 60.9 59.9
195.1 192.9 185.2
1202.5 1198.8 1197.3
1654.1 1654.5 1657.0
2.0 5.2 6.0
7.0 11.5 6.5
192.8 189.9 185.2
61.2 59.2 58.8
M.S. 58390.3** 3187.6* 2402.7 718.8
M.S. 33071.0** 1165.5 1443.9 1040.0
M.S. 324.1** 33.7 29.6 17.0
M.S. 2.7 4.8 3.1 2.9
M.S. 506** 232.6**' 2.8 21.6
M.S. 549.1** 37.1 45.1 60.6
Egg weight gms.
**Significant at 1% level. *Significant at 5% level.
control group with little difference noted in the debeaked groups. The double stressed birds were still 143.6 gms. lighter than the controls. Analysis of variance of 22 week body weights indicated the debeaking effect was significant at the 1% level and the delayed placement effect was significant at the 5% level. At 51 weeks of age, by which time final body size has been attained in White Leghorns, the difference between the debeaked and control birds had been modified somewhat but was still significant (P < 0.01). The reduction in body size was 74.2 grams. The means of the delayed placement pullets still reflect a small effect, but analyses of variance indicated that this was non-significant. Mortality. One area of primary interest was early mortality for it was felt that a double stress placed on newly hatched chicks would have a profound effect on this trait. The percent mortality through 22 weeks of age for all groups was 6%. The differences in
treatment means appear to be random and no analysis of variance was run. There was very little mortality during the first 3 weeks in any group. The main point which should be made is that the double stressed pullets lived as well as their controls. Mortality in the laying house (22 through 51 weeks of age) was 8.3% for the debeaked birds versus 16.9% for the non-debeaked controls. This difference of 7.6% was highly significant. Delayed placement had no effect on this trait. It is logical to assume that the reduction in mortality in the debeaked birds was greatly influenced by the control of cannibalism due to debeaking, although data on causes of mortality were not kept. Egg Production Traits. The means for days to first egg are shown in Table 1. Debeaking at day-old delayed sexual maturity by about 7 days. This agrees with the 5 day delay in sexual maturity obtained by Andrade and Carson (1975) in Leghorns debeaked at 1 day of age. The effect of day of placement is noticeable in the debeaked groups but not
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on May 21, 2015
Non-debeaked Placed on day 0 1 2 Debeaked Placed on day 0 1 2
Mortality
1584
J. R.
DISCUSSION Under the conditions of this experiment delaying the placement on feed and water of newly hatched chicks and debeaking just before placement did not produce adverse effects on mortality at any age, egg size or egg production. However, significant reductions in body weight occurred, the largest of which was in those birds debeaked and placed 2 days after hatching. The magnitude of the reduction in the double stressed birds was equal to the sum of the two individual effects. Reduction in body weight from delayed placement remained significant through 22 weeks of age, but had disappeared by 51 weeks of age. By contrast, the body weight reduction from debeaking before placement was of a permanent nature and was highly significant at 51 weeks of age.
In egg type chickens a reduction in adult body size, if it did not affect egg size or numbers, and an increase in days to sexual maturity would be considered desirable by commercial egg producers. It is reasoned here that none of the effects produced by debeaking and delayed placement, either singly or in combination with each other, were undesirable. This should not be construed as an endorsement of imposing these two stresses on newly hatched chicks. The fact that the effects of debeaking and delayed placement were additive would lead one to expect that a third stress imposed at the same time as the two investigated here might add enough to overwhelm the defenses of the chick completely. Since the effects on body weight at 25 days of the two treatments were roughly equal, it could be argued that debeaking merely delayed by one or two days eating and drinking by newly hatched chicks. Thus the effect of debeaking is one which results from a reduction of feed and water intake. This does not seem likely because as growth of the treated birds is traced through 22 and 51 weeks of age, it is apparent that the delayed placement effect had diminished by 22 weeks of age and completely disappears by 51 weeks. On the other hand, debeaking effect increased by 22 weeks and persisted through 51 weeks. It seems that the effects of debeaking are more profound than a mere deprivation of feed and water and probably include a physiologic reaction to the shock of debeaking. REFERENCES Andrade, A. N., and J. R. Carson, 1975. The effect of age at- and methods of debeaking on future performance of White Leghorn pullets. Poultry Sci. 54: 666-674. Bramhall, E. L., 1967. Development of precision debeaking for week-old chicks. Poultry Sci. 46: 1237.
MARCH 1-5, 1976. WORLD CONFERENCE ON OILSEED AND VEGETABLE OIL PROCESSING TECHNOLOGY, AMSTERDAM, THE NETHERLANDS
Downloaded from http://ps.oxfordjournals.org/ at University of North Dakota on May 21, 2015
significant. The double stressed birds matured at essentially the same time as their controls. It is interesting to note that the greatest difference in sexual maturity between debeaked and non-debeaked birds was in those placed on the day they hatched and the least on day 2. Egg weight data were taken at 40 weeks of age. Analysis of variance of egg weight data indicated that none of the treatment effects were significant. In this experiment as in our previous one, the significant reduction in body weight at 22 weeks of age which persisted through 51 weeks of age in the debeaked pullets was not accompanied by a significant reduction in egg weight. Egg production data for the period 22 weeks through 51 weeks of age showed no significant differences in any of the treatment means for total eggs produced from the date of first egg through the first seven months in the laying house or in the rate of production for this period.
CARSON