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Methods of Feeding Ducks*
Methods of Feeding Ducks" R O Y E.
ROBERTS
Agricultural Experiment Station, Purdue University, Lafayette, Indiana (Received for Publication March 5, 1934)
T
tion as a moist mash and as a dry mash. Nor is information available concerning the value of feeding a moist mash at intervals as compared to leaving it before the ducks at all times. To obtain such data experiments were conducted in which the same ration was fed as a dry mash available at all times, as a moist mash fed four times daily, and as a moist mash available at all times. Three experiments involving nine lots of Pekin ducks (Table 1) were run. The dayold ducklings were divided into equal lots according to weight. They were toe marked at the start and bands were placed in the wings at four weeks of age. Individual weights were taken at the start and at the ages of four, eight, and ten weeks. Experiment 1 was started March 30, 1932; Experiment 2, May 16, 1932; and Experiment 3, April 12,1933. During the first four to five weeks the ducklings were brooded in a permanent brooder house. This house was equipped with hovers heated by hot water pipes and had a concrete platform in front. Ground corn cobs (Experiment 1) and uncut straw (Experiments 2 and 3) were used for litter. The ducklings were given access to the concrete platform outside at from ten days to three weeks of age in the different experiments, depending upon weather conditions. At the end of four to five weeks the ducklings were transferred to outside yards where they had no heat. In Experiment 1 protection from the rain and sun was provided by a wooden platform with one side raised about three feet * Published with the approval of the Director and the other resting on the ground. In Exof the Agricultural Experiment Station, Purdue periment 2 shelter was provided by apple University. [338]
Downloaded from http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
HE common recommendation for feeding ducks is that the ration be fed as a moist mash. Lee (1932) states that "all duck rations are fed as a moist mash." Horton (1932) says that "the duck is quite particular in that it wants a mash that sticks together fairly well." Pardee (1930) recommends that "all feeds for ducks and ducklings should be fed moist (crumbly) but not sloppy." He states that the ducks' bills "are so constructed that it is difficult for them to pick up small grain so it is necessary to moisten the ground grain and form it into lumps or have it crumbly so they can readily pick it up." According to the different recommendations the ducklings should be given this moist mash four or five times daily during the first week, four times daily until three or four weeks old, and then three times daily until marketed. In some instances nothing is said regarding the amount of feed to give or the length of the feeding period. Pardee also states that the last feeding of the day should be heaviest with a little feed left over, if the ducklings have access to it at night, and that for the other feedings they be given what they will clean up in 20 minutes, any feed which is not consumed at the end of this time to be removed. The use of a moist ration requires extra labor in mixing and also in removing the unconsumed feed after each feeding, where such a practice is followed. So far as is known, no data have been presented to show the relative merits of feeding the same ra-
3
2
1
Experiment
Moist mash—• ad libitum
9
48
50
47
118
Moist mash— four times daily
8 39
55
54
118
Dry mash— ad libitum
7
118
48
6
39
Moist mash— four times daily
5
92
37
SO
Moist mash— ad libitum
92
Dry mash— ad libitum
4
22
21
19
20
42
46
Moist mash— ad libitum
3
16
19
48
46
Moist mash— four times daily
2
9
&
Finished
Ducklings
92
46
Dry mash— ad libitum
Started
1
Lot
Method of feeding
' 52 53
809+11
673+ 9
603 + 11 806 + 12
622 + 12
626+12
52
53 53
789+17
787 + 18
47
48
52
704+15
676+17
47
742 + 15
746+19
2003 ± 2 3
726+16
47
46
47
gms. 1956 ± 3 9
gms. 1977 ±30
gms. 870 ±19
2717 + 25 (6.0 lbs.)
2177 ± 1 8 2180 ± 2 3
2604 + 21 (5.7 lbs.)
2530+19 (5.6 lbs.)
2598 + 24 (5.7 lbs.) 2090 ± 1 8 2018 + 22
2421 ± 2 3 (5.3 lbs.)
2545 + 23 (5.6 lbs.) 1939 ± 2 0
1921 ±22
2319 + 29 (5.1 lbs.)
2487 + 35 (5.5 lbs.) 2048 ± 3 0
2111 + 35
2104+31 (4.6 lbs.)
2387 + 26 (5.3 lbs.)
2189 + 32 (4.8 lbs.)
2139±27 (4.7 lbs.)
2450 + 31 (5.4 lbs.)
2477 + 30 ' (5.5 lbs.)
2086 + 32 (4.6 lbs.)
2298 + 32 (5.1 lbs.)
1925 ±27
1839 + 28
1964+25
gms. 2128 + 34 (4.7 lbs.)
9
gms. 2274 + 32 (5.0 lbs.)
&
10
2062 + 30
1968 ± 2 4
2176±29
1939 ± 3 5
9
8
&
9
839 + 13
4
850+18
704+12
41
44 41
gms. 835 + 23
gms. 43
gms. 43
43
&
9
c?
Initial
Age in weeks
TABLE 1.—Average weights of males and females that lived through the experiments
m http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
340
POULTRY
trees, while in Experiment 3 tall trees in a woods furnished ample shade but gave little protection from rain. All three lots in each experiment received a ration which has proved quite satisfactory for starting chicks and which consisted of:
In each experiment one lot received this ration as a moist mash ad libitum during the first three days and after that as a dry mash ad libitum; one lot received a moist mash fed four times daily (unconsumed feed removed after each feeding); and the other lot received a moist mash ad libitum. In mixing the moist mash sufficient water was used to make the mash crumbly but not sloppy. In all lots drinking water was always available. In no case did the ducks have water in which to swim. RESULTS
The average weights of the ducks that lived through the experiments are given in Table 1. At ten weeks of age the differences in the average weights of the ducks which received the dry mash ad libitum and those which were fed the moist mash four times daily were as follows: Differences (grams) Males Females 1 +24±4S — 42±47 2 - f °0±40 + 85±4S 3 -)-53±33 -j-109±35 The plus sign ( + ) indicates a difference in favor of the moist mash.
differences may be considered significant only for the females in Experiment 3 and possibly for the males in Experiment 2. Comparing the dry mash ad libitum and the moist mash ad libitum the differences (all in favor of the moist mash) were as follows: Experiment 1 2 3
In all cases the differences were in favor of the moist mash ad libitum and, with the exception of the females in Experiment 1, these differences are probably significant. The differences between the moist mash fed four times daily and the same ration fed ad libitum (all in favor of the latter) were as follows: 'iment
Differences (grams) Males Females 152±45 53±42 10±46 130±43 119±3S 74±28
1 2 3
While there was a difference of only 10 grams for the males in Experiment 2 and no significant difference for the females in Experiment 1, the increase produced by the moist mash ad libitum over that of the moist mash fed four times daily was greater than that of the latter over the dry mash ad libitum. The mortality rates for the dry mash, moist mash fed four times daily, and moist mash ad libitum were as follows for the different experiments:
Experiment
While all of the differences, except for the females in Experiment 1, were in favor of the moist mash fed four times daily, these
Differences (grams) Males Females +176±45 + 11±43 +100±44 +215±42 +172±34 -j-183±31
Exp. 1 2 3
. Dry mash— Moist mash— Moist mash— ad libitum 4ts. daily ad libitum 23.9 15.2 6.5 5.4 2.2 5.4 7.6
17.8
26.3
The differences in mortality can scarcely be attributed to the method of feeding, because the differences were not consistent for any one ration in the three experiments. Also in Experiment 3, 13 ducklings in lot 2
Downloaded from http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
Percent Ground yellow dorn 46 or 46.75 Wheat bran IS Wheat middlings IS Meat and bone scraps (50% protein) 15 Dried skimmilk 5 Alfalfa leaf meal 3 Sardine oil or concentrated cod liver oil* 1 or 0.2 S * Replaced by corn when ducklings were let outside on platform (at age of 10 days to 3 weeks).
SCIENCE
NOVEMBER,
1934.
VOL.
X I I I ,
No.
341
6
TABLE 2.—Average grams (or lbs.) of feed consumed per gram (or lb.) of gain Experiment
1
3
Method of feeding
0to4 weeks
4 to 8 weeks
8 to 10 weeks
Total OtolO weeks
1
Dry mash— ad libitum
2.7
4.8
11.5
4.8
2
Moist mash—• four times daily
2.4
4.2.
9.0
4.1
3
Moist mash— ad libitum
2.5
3.9
11.7
4.2
4
Dry mash— ad libitum
2.9
4.4
6.8
4.3
5
Moist mash— four times daily
2.5
3.8
7.0
3.8
6
Moist mash— ad libitum
2.4
4.1
9.1
4.2
7
Dry mash— ad libitum
3.0
3.9
5.8
4.1
8
Moist mash— four times daily
2.7
3.8
6.2
4.0
9
Moist mash— ad libitum
2.5
4.3
7.2
4.3
and 12 in lot 3 were killed by rats. Most of the mortality occurred during the first week of the experiments. In Experiment 1, 20 ducklings out of a total mortality of 21, in Experiment 2, 9 out of 12, and in Experiment 3, 26 out of 36 (not including loss from rats) died during the first week. Perhaps some of this early mortality was caused by chilling, since it was difficult during cold nights to maintain the temperature under the hovers. That the temperature may have been responsible is indicated by the fact that the mortality was lower in Experiment 2 (started May 16) than in Experiment 1 (started March 30) and in Experiment 3 (started April 12). The feed consumed per gram of gain is given in Table 2. With the exception of the dry mash lot in Experiment 1, where 4.8 grams of feed were required to produce a gram of gain, the grams of feed per gram of gain varied between 3.8 and 4.3, a variation of one-half gram. There was a con-
sistent, although slight, advantage in all three trials in favor of the moist mash fed four times daily. DISCUSSION
In these trials the all-mash chick starting ration, with the same method of feeding that is commonly employed for chicks, namely, dry mash available at all times with water given ad libitum, proved satisfactory for growing ducks during the first 10 weeks. Considering the three experiments there was only a slight advantage in favor of the moist mash fed four times daily over the dry mash ad libitum. However, the moist mash ad libitum did have an appreciable advantage over the other two rations. On the basis of these results it is doubtful whether with a small flock of ducks, such as is usually kept on a general farm, the increased gains resulting from the feeding of the ration moist rather than dry would pay for the extra labor involved in mixing the
Downloaded from http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
2
Lot
342
SCIENCE
stock as those used in Experiment 1 and the other third similar to those used in Experiment 3. The large increase in weight secured in Experiment 3 emphasizes the importance of the effect of breeding on the final weights obtained. SUMMARY
The all-mash chick starting ration which was fed produced satisfactory gains when fed ad libitum to ducklings as a dry mash. The same ration fed as a moist mash four times daily gave only a slight increase over the dry mash. When the ration was fed as a moist mash ad libitum it apparently produced a significant increase in the rate of growth as compared to the other two methods of feeding. There were only slight differences in the amount of feed required to produce a unit of gain with the different methods of feeding. There were no apparent differences in mortality which could be attributed to the different methods of feeding. REFERENCES
Horton, D. Hart, 1932. A comparison of feeding a twelve percent and a nineteen percent protein ration to White Pekin ducklings. Poul. Sri., 11:106-109. Lee, Alfred R., 1932. Duck raising. TJ. S. D. A., Farmers' Bui. 697 :l-22. Pardee, Roy E., 1930. Raising Ducks for Profit, 48 pp. Cory-Keim Co., Springfield, Ohio.
Downloaded from http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
moistened ration. Where a large number of ducks are to be fed it would probably be advisable to feed ad libitum a moistened ration, which would probably give somewhat greater gains and would save the labor of removing the unconsumed feed after each feeding. The satisfactory gains made by the ducks which received the dry mash indicate that they are able to eat sufficient quantities of ground grains in the dry form. The slight variations in the amount of feed required to produce a unit of gain with the different methods of feeding show that ducks apparently use feed as efficiently and with no more wastage when it is fed dry than when it is moistened. There was apparently no difference in mortality resulting from the different methods of feeding. In all experiments the greater part of the mortality occurred during the first week. The differences in the average weight of the ducks in the different trials are no doubt due primarily to the quality of ducks used. The ducks used in Experiment 1 were from breeding stock obtained from a farm flock where apparently little attention had been given to selection for size. In Experiment 3 the ducks were from stock obtained from a commercial duck plant where breeders have been selected for size for a number of years. In Experiment 2 about twothirds of the ducks were from the same
POULTRY
ROBERTS
Agricultural Experiment Station, Purdue University, Lafayette, Indiana (Received for Publication March 5, 1934)
T
tion as a moist mash and as a dry mash. Nor is information available concerning the value of feeding a moist mash at intervals as compared to leaving it before the ducks at all times. To obtain such data experiments were conducted in which the same ration was fed as a dry mash available at all times, as a moist mash fed four times daily, and as a moist mash available at all times. Three experiments involving nine lots of Pekin ducks (Table 1) were run. The dayold ducklings were divided into equal lots according to weight. They were toe marked at the start and bands were placed in the wings at four weeks of age. Individual weights were taken at the start and at the ages of four, eight, and ten weeks. Experiment 1 was started March 30, 1932; Experiment 2, May 16, 1932; and Experiment 3, April 12,1933. During the first four to five weeks the ducklings were brooded in a permanent brooder house. This house was equipped with hovers heated by hot water pipes and had a concrete platform in front. Ground corn cobs (Experiment 1) and uncut straw (Experiments 2 and 3) were used for litter. The ducklings were given access to the concrete platform outside at from ten days to three weeks of age in the different experiments, depending upon weather conditions. At the end of four to five weeks the ducklings were transferred to outside yards where they had no heat. In Experiment 1 protection from the rain and sun was provided by a wooden platform with one side raised about three feet * Published with the approval of the Director and the other resting on the ground. In Exof the Agricultural Experiment Station, Purdue periment 2 shelter was provided by apple University. [338]
Downloaded from http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
HE common recommendation for feeding ducks is that the ration be fed as a moist mash. Lee (1932) states that "all duck rations are fed as a moist mash." Horton (1932) says that "the duck is quite particular in that it wants a mash that sticks together fairly well." Pardee (1930) recommends that "all feeds for ducks and ducklings should be fed moist (crumbly) but not sloppy." He states that the ducks' bills "are so constructed that it is difficult for them to pick up small grain so it is necessary to moisten the ground grain and form it into lumps or have it crumbly so they can readily pick it up." According to the different recommendations the ducklings should be given this moist mash four or five times daily during the first week, four times daily until three or four weeks old, and then three times daily until marketed. In some instances nothing is said regarding the amount of feed to give or the length of the feeding period. Pardee also states that the last feeding of the day should be heaviest with a little feed left over, if the ducklings have access to it at night, and that for the other feedings they be given what they will clean up in 20 minutes, any feed which is not consumed at the end of this time to be removed. The use of a moist ration requires extra labor in mixing and also in removing the unconsumed feed after each feeding, where such a practice is followed. So far as is known, no data have been presented to show the relative merits of feeding the same ra-
3
2
1
Experiment
Moist mash—• ad libitum
9
48
50
47
118
Moist mash— four times daily
8 39
55
54
118
Dry mash— ad libitum
7
118
48
6
39
Moist mash— four times daily
5
92
37
SO
Moist mash— ad libitum
92
Dry mash— ad libitum
4
22
21
19
20
42
46
Moist mash— ad libitum
3
16
19
48
46
Moist mash— four times daily
2
9
&
Finished
Ducklings
92
46
Dry mash— ad libitum
Started
1
Lot
Method of feeding
' 52 53
809+11
673+ 9
603 + 11 806 + 12
622 + 12
626+12
52
53 53
789+17
787 + 18
47
48
52
704+15
676+17
47
742 + 15
746+19
2003 ± 2 3
726+16
47
46
47
gms. 1956 ± 3 9
gms. 1977 ±30
gms. 870 ±19
2717 + 25 (6.0 lbs.)
2177 ± 1 8 2180 ± 2 3
2604 + 21 (5.7 lbs.)
2530+19 (5.6 lbs.)
2598 + 24 (5.7 lbs.) 2090 ± 1 8 2018 + 22
2421 ± 2 3 (5.3 lbs.)
2545 + 23 (5.6 lbs.) 1939 ± 2 0
1921 ±22
2319 + 29 (5.1 lbs.)
2487 + 35 (5.5 lbs.) 2048 ± 3 0
2111 + 35
2104+31 (4.6 lbs.)
2387 + 26 (5.3 lbs.)
2189 + 32 (4.8 lbs.)
2139±27 (4.7 lbs.)
2450 + 31 (5.4 lbs.)
2477 + 30 ' (5.5 lbs.)
2086 + 32 (4.6 lbs.)
2298 + 32 (5.1 lbs.)
1925 ±27
1839 + 28
1964+25
gms. 2128 + 34 (4.7 lbs.)
9
gms. 2274 + 32 (5.0 lbs.)
&
10
2062 + 30
1968 ± 2 4
2176±29
1939 ± 3 5
9
8
&
9
839 + 13
4
850+18
704+12
41
44 41
gms. 835 + 23
gms. 43
gms. 43
43
&
9
c?
Initial
Age in weeks
TABLE 1.—Average weights of males and females that lived through the experiments
m http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
340
POULTRY
trees, while in Experiment 3 tall trees in a woods furnished ample shade but gave little protection from rain. All three lots in each experiment received a ration which has proved quite satisfactory for starting chicks and which consisted of:
In each experiment one lot received this ration as a moist mash ad libitum during the first three days and after that as a dry mash ad libitum; one lot received a moist mash fed four times daily (unconsumed feed removed after each feeding); and the other lot received a moist mash ad libitum. In mixing the moist mash sufficient water was used to make the mash crumbly but not sloppy. In all lots drinking water was always available. In no case did the ducks have water in which to swim. RESULTS
The average weights of the ducks that lived through the experiments are given in Table 1. At ten weeks of age the differences in the average weights of the ducks which received the dry mash ad libitum and those which were fed the moist mash four times daily were as follows: Differences (grams) Males Females 1 +24±4S — 42±47 2 - f °0±40 + 85±4S 3 -)-53±33 -j-109±35 The plus sign ( + ) indicates a difference in favor of the moist mash.
differences may be considered significant only for the females in Experiment 3 and possibly for the males in Experiment 2. Comparing the dry mash ad libitum and the moist mash ad libitum the differences (all in favor of the moist mash) were as follows: Experiment 1 2 3
In all cases the differences were in favor of the moist mash ad libitum and, with the exception of the females in Experiment 1, these differences are probably significant. The differences between the moist mash fed four times daily and the same ration fed ad libitum (all in favor of the latter) were as follows: 'iment
Differences (grams) Males Females 152±45 53±42 10±46 130±43 119±3S 74±28
1 2 3
While there was a difference of only 10 grams for the males in Experiment 2 and no significant difference for the females in Experiment 1, the increase produced by the moist mash ad libitum over that of the moist mash fed four times daily was greater than that of the latter over the dry mash ad libitum. The mortality rates for the dry mash, moist mash fed four times daily, and moist mash ad libitum were as follows for the different experiments:
Experiment
While all of the differences, except for the females in Experiment 1, were in favor of the moist mash fed four times daily, these
Differences (grams) Males Females +176±45 + 11±43 +100±44 +215±42 +172±34 -j-183±31
Exp. 1 2 3
. Dry mash— Moist mash— Moist mash— ad libitum 4ts. daily ad libitum 23.9 15.2 6.5 5.4 2.2 5.4 7.6
17.8
26.3
The differences in mortality can scarcely be attributed to the method of feeding, because the differences were not consistent for any one ration in the three experiments. Also in Experiment 3, 13 ducklings in lot 2
Downloaded from http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
Percent Ground yellow dorn 46 or 46.75 Wheat bran IS Wheat middlings IS Meat and bone scraps (50% protein) 15 Dried skimmilk 5 Alfalfa leaf meal 3 Sardine oil or concentrated cod liver oil* 1 or 0.2 S * Replaced by corn when ducklings were let outside on platform (at age of 10 days to 3 weeks).
SCIENCE
NOVEMBER,
1934.
VOL.
X I I I ,
No.
341
6
TABLE 2.—Average grams (or lbs.) of feed consumed per gram (or lb.) of gain Experiment
1
3
Method of feeding
0to4 weeks
4 to 8 weeks
8 to 10 weeks
Total OtolO weeks
1
Dry mash— ad libitum
2.7
4.8
11.5
4.8
2
Moist mash—• four times daily
2.4
4.2.
9.0
4.1
3
Moist mash— ad libitum
2.5
3.9
11.7
4.2
4
Dry mash— ad libitum
2.9
4.4
6.8
4.3
5
Moist mash— four times daily
2.5
3.8
7.0
3.8
6
Moist mash— ad libitum
2.4
4.1
9.1
4.2
7
Dry mash— ad libitum
3.0
3.9
5.8
4.1
8
Moist mash— four times daily
2.7
3.8
6.2
4.0
9
Moist mash— ad libitum
2.5
4.3
7.2
4.3
and 12 in lot 3 were killed by rats. Most of the mortality occurred during the first week of the experiments. In Experiment 1, 20 ducklings out of a total mortality of 21, in Experiment 2, 9 out of 12, and in Experiment 3, 26 out of 36 (not including loss from rats) died during the first week. Perhaps some of this early mortality was caused by chilling, since it was difficult during cold nights to maintain the temperature under the hovers. That the temperature may have been responsible is indicated by the fact that the mortality was lower in Experiment 2 (started May 16) than in Experiment 1 (started March 30) and in Experiment 3 (started April 12). The feed consumed per gram of gain is given in Table 2. With the exception of the dry mash lot in Experiment 1, where 4.8 grams of feed were required to produce a gram of gain, the grams of feed per gram of gain varied between 3.8 and 4.3, a variation of one-half gram. There was a con-
sistent, although slight, advantage in all three trials in favor of the moist mash fed four times daily. DISCUSSION
In these trials the all-mash chick starting ration, with the same method of feeding that is commonly employed for chicks, namely, dry mash available at all times with water given ad libitum, proved satisfactory for growing ducks during the first 10 weeks. Considering the three experiments there was only a slight advantage in favor of the moist mash fed four times daily over the dry mash ad libitum. However, the moist mash ad libitum did have an appreciable advantage over the other two rations. On the basis of these results it is doubtful whether with a small flock of ducks, such as is usually kept on a general farm, the increased gains resulting from the feeding of the ration moist rather than dry would pay for the extra labor involved in mixing the
Downloaded from http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
2
Lot
342
SCIENCE
stock as those used in Experiment 1 and the other third similar to those used in Experiment 3. The large increase in weight secured in Experiment 3 emphasizes the importance of the effect of breeding on the final weights obtained. SUMMARY
The all-mash chick starting ration which was fed produced satisfactory gains when fed ad libitum to ducklings as a dry mash. The same ration fed as a moist mash four times daily gave only a slight increase over the dry mash. When the ration was fed as a moist mash ad libitum it apparently produced a significant increase in the rate of growth as compared to the other two methods of feeding. There were only slight differences in the amount of feed required to produce a unit of gain with the different methods of feeding. There were no apparent differences in mortality which could be attributed to the different methods of feeding. REFERENCES
Horton, D. Hart, 1932. A comparison of feeding a twelve percent and a nineteen percent protein ration to White Pekin ducklings. Poul. Sri., 11:106-109. Lee, Alfred R., 1932. Duck raising. TJ. S. D. A., Farmers' Bui. 697 :l-22. Pardee, Roy E., 1930. Raising Ducks for Profit, 48 pp. Cory-Keim Co., Springfield, Ohio.
Downloaded from http://ps.oxfordjournals.org/ at Michigan State University on April 6, 2015
moistened ration. Where a large number of ducks are to be fed it would probably be advisable to feed ad libitum a moistened ration, which would probably give somewhat greater gains and would save the labor of removing the unconsumed feed after each feeding. The satisfactory gains made by the ducks which received the dry mash indicate that they are able to eat sufficient quantities of ground grains in the dry form. The slight variations in the amount of feed required to produce a unit of gain with the different methods of feeding show that ducks apparently use feed as efficiently and with no more wastage when it is fed dry than when it is moistened. There was apparently no difference in mortality resulting from the different methods of feeding. In all experiments the greater part of the mortality occurred during the first week. The differences in the average weight of the ducks in the different trials are no doubt due primarily to the quality of ducks used. The ducks used in Experiment 1 were from breeding stock obtained from a farm flock where apparently little attention had been given to selection for size. In Experiment 3 the ducks were from stock obtained from a commercial duck plant where breeders have been selected for size for a number of years. In Experiment 2 about twothirds of the ducks were from the same
POULTRY