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Rate of Feathering and Ten-Week Body Weight Observations in Strains Differing in Shank Length*
Rate of Feathering and Ten-Week Body Weight Observations in Strains Differing in Shank Length* EDWARD W. GLAZENER AND MORLEY A. JULL
Department of Poultry Husbandry, Maryland Agricultural Experiment Station, College Park, Maryland (Received for publication April 4, 1946)
I
NCREASED competition in -the production and marketing of broilers of superior quality is inevitable. To face this competition the most successful producers will have to place well-finished, high quality broilers with an attractive appearance on the market. Birds with "barebacks" and undeveloped feathers are not only unattractive to the live buyer, but dress poorly, giving carcasses with pin feathers and bluish spots. Darrow and Warren (1944) found that the number of visible secondaries at hatching time is a good measure of the degree of feathering at ten days, six weeks, and eight weeks of age. Individual variations in time of hatching had only a slight effect upon the number of secondaries but greatly influenced the length of day-old wing feathers. As early as 1922, Serebrovsky, reported that a sex-linked gene affects the rate of feathering. Warren (1925) confirmed the findings of Serebrovsky and demonstrated that slow-feathering is controlled by a sexlinked dominant gene by crossing White Leghorn males and Jersey Black Giant females. The Fx males were slow-feathering, and the Fi females fast feathering. In the reciprocal croS'l, both sexes were slow feathering. Martin (1929), Jaap and Mor-
ris (1937), Radi and Warren (1938), Hays and Sanborn (1942), and Darrow and Warren (1944) have observed sexual dimorphism in rate of feathering, the females feathering more rapidly than the males. Jaap and Morris (1937) concluded from a covariance analysis that sex was relatively more important than any other heritable factor influencing rate of feathering. Several workers have observed that body growth and feathering appeared related. Martin (1929) reported that the rate of feathering over the back of the Barred Plymouth Rock was related to rate of growth, the heavier birds feathering more rapidly. Gericke and Piatt (1932) further confirmed the observation in a protein-diet study, using Barred Plymouth Rocks. The higher protein diets tended to produce better growth and feathering than the lower protein diets. Schnetzler (1936), Jaap and Morris (1937), Radi and Warren (1938), and Hoffman and Tomhave (1944) also observed that the better feathered birds were heavier at broiler age. Warren and Payne (1945), in four lots of chicks, found the early feathering chicks to be heavier at twelve weeks of age than the slow feathering chicks.
* Scientific paper No. A129. Contribution No. 2017 of the Maryland Agricultural Experiment Station. (Department of Poultry Husbandry.) 433
MATERIALS AND PROCEDURE
Three hatches of chicks from one pen each of short-shanked Barred Plymouth
434
EDWARD W. GLAZENER AND M O R L E Y A. JTJLL
Rocks and New Hampshires and one pen each of long-shanked Barred Plymouth Rocks and New Hampshires were examined at hatching time, ten days of age, and a t eight weeks for feathering. All chicks were started in batteries and fed the University of Maryland Station mash ad libitum. When the chickens were six weeks old, they were transferred to growing batteries. Each chicken was weighed biweekly. FIG. 2. A ten-week Barred Plymouth Rock cockerel with back and sides bare of feathers.
FIG. 1. A ten-week Barred Plymouth Rock cockerel with body fully feathered.
At hatching time, the chicks were banded and the number of secondaries counted in the right wing. At ten days of age the chickens were classified into two arbitrary groups: (1) those with tail feathering, and (2) those with no tail feather development. Only those chickens having tail feathers at least one-half inch long were classified as having tail feathers. At eight weeks of age body feathering in the chickens was classified into three groups: (1) body fully feathered, (2) back feathered, but hips and sides bare, and (3) bare backs and bare sides. These degrees of feather development are illustrated in Figures 1, 2, and 3, respectively. In addition to the short-shanked and long-shanked strains of New Hampshires, four more strains of New Hampshires, one of Rhode Island Reds, and one of Barred Plymouth Rocks from private
breeders were observed for feathering. Feather development was analyzed separately for each sex. Ten-day tail feathering and eight-week body feathering were compared with the number of seer ondaries a t hatching time, and eight-week body feathering was compared with tenday tail feathering. Mean body weights of the birds a t ten weeks of age were classified according to the degree of feathering a t hatching time, ten days, and eight weeks of age. RESULTS AND DISCUSSION As is seen in Table 1, ten-day tail feathering is related to the number of secondaries a t hatching time. In both
FIG. 3. A ten-week Barred Plymouth Rock cockerel with back covered with feathers, but side and hip bare.
435
RATE OF FEATHERING AND GROWTH OF STRAINS TABLE 1.—Ten-day tail feathering in relation to the number
of secondaries at hatching time Females
Males Number of secondaries a t hatching time
Number
Percent with tail feathers
Number
Percent with tail feathers
Short-shanked
6 or more
84
38
63
38
New Hampshire
5 or less
43
16
37
13
Long-shanked
6 or more
40
0
27
0
New Hampshire
5 or less
26
0
33
0
Short-shanked
6 or more
26
15
47
55
Barred Plymouth Rock
5 or less
53
6
59'
25
Long-shanked
6 or more
2
0
5
0
Barred Plymouth Rock
5 or less
46
0
36
0
Breed and strain
sexes of the short-shanked New Hamp- Rocks did not have a single chick in three shires and Barred Plymouth Rocks, the lots that had tail feather development. percentage of chicks having tail feathers Table 2 shows the relationship between is over twice as high in the "6 or more" the degree of feathering at eight weeks classification than in the "5 or less" classi- and the number of secondaries at hatching fication. The long-shanked strains of both time. As the Table shows, chicks having New Hampshires and Barred Plymouth 6 or more secondaries in both sexes and in TABLE 2.—Eight-week feathering in relation to the number
of secondaries at hatching time Males
Males Breed and strain
Short-shanked
Percent Number with of secondback aries a t Percent hatching Number fully feathtime feathered ered, sides bare 6 or more
New Hampshire 5 or less Long-shanked
6 or more
Percent with back feathered, sides bare
Percent with back and sides bare
40
54
6
Percent with Percent back fully Number and feathered sides bare
84
26
64
10
63
43
8
42
30
37
14
67
19
25
75
0
27
34
66
0
40
New Hampshire 5 or less
26
4
89
7
33
15
85
0
Short-shanked
26
50
46
4
47
52
48
0
53
32
57
11
59
41
59
0
2
50
50
0
5
60
40
0
46
9
63
28
36
33
67
0
6 or more
Barred Plymouth Rock 5 or less Long-shanked
6 or more
Barred Plymouth Rock 5 or less
436
EDWARD W. GLAZENKR AND MORLEY A. JULL TABLE 3.—Eight-week feathering in relation to 10-day feathering Males
Breed and strain
Ten-day tail feather development
Females
PerPercent Percent Per- with Per- with cent cent back Num- cent back with Numfully feathfully feath- back ber ber feathfeath- ered, and ered, ered sides ered sides sides bare bare bare
Percent with back and sides bare
Short-shanked
Tail feathers
39
30
67
3
29
55
45
0
New Hampshire
No tail feathers
88
15
66
19
71
25
66
9
Long-shanked
. Tail feathers
New Hampshire
No tail feathers
Short-shanked
Tail feathers
Barred Plymouth Rock
No tail feathers
Long-shanked
Tail feathers
Barred Plymouth Rock
No tail feathers
0
0
66
17
80
3
60
30
70
0
7
57
43
0
42
45
55
0
72
39
54
7
64
46
54
0
29
71
0
0
0 48
all strains tended to be better feathered than those having 5 or less secondaries. The females in both classifications tended to be better feathered than the males. These observations are in accord with the findings of Darrow and Warren (1944). In the first hatch, the length of the primaries and the length of the secondaries were observed in addition to counting the number of secondaries at hatching time. After the first hatch, however, only the secondaries were counted. As other workers have observed, the length of the feathers was found to vary appreciably with the hatching time. Table 3 shows the relationship between eight-week feathering and ten-day tail feathering. The birds with the development of tail feathers at ten days were better feathered at eight weeks than those not having tail feathers. As previously mentioned, however, this applies only to the short-shanked strains. In comparing the short-shanked strains in Tables 2 and 3, it is observed that in general, eight-week body feathering has a
17
56
27
41
somewhat higher degree of relationship with ten-day tail feathering than with the number of secondaries at hatching time. In considering all strains, the number of secondaries at hatching time appears to be a better measure for observing early feathering than ten-day tail feather ob^ servations. Most of the chicks obtained from the private breeders contained very little tail feather development at ten days. It seems that good feathering might be secured in these strains by careful selection on the basis of the number of secondaries at hatching time. Upon comparing these data, a sex difference in feathering is evident, as previous workers have found. Part of this sex difference might be explained by a differential in the activity of the thyroid gland. Preliminary work at this station indicates that there is a sex difference in the thyroid gland secretion. Furthermore, Schultze and Turner (1945) found that the rate of thyroxine secretion at five weeks of age was somewhat higher in females than in males. That thyroxine has
437
RATE OF FEATHERING AND GROWTH OF STRAINS TABLE 4.—Ten-week body weights in relation to the number of secondaries at hatching time
Breed and strain
Number of secondaries at hatching time
Short-shanked
Females
Males Number
Ten-week mean body weight in grams
Number
Ten-week mean body weight in grams
6 or more
84
1039.29 ±12.37
63
891.45±12.26
New Hampshire
5 or less
43
980.28 ±11.12
37
864.06±15.30
Long-shanked
6 or more
40
1157.37 + 16.53
27
966.86±23.04
New Hampshire
5 or less
26
1075.65 + 26.89
33
897.88±16.16
Short-shanked
6 or more
2,6
1157.92±23.49
47
930.08± 16.86
Barred Plymouth Rock
5 or less
53
1042.67 ±17.19
59
960.47 ±13.47
Long-shanked
6 or more
Barred Plymouth Rock
5 or less
2 46
an effect upon feathering was demonstrated by Radi and Warren (1938). In comparing the mean ten-week body weight (with standard errors) of the chickens with the degree of feathering at the various stages, hatching time, ten days, and eight weeks, it is observed that the better feathered chickens within a strain have a tendency to be heavier; see Tables 4, 5, and 6. From this limited data, it appears that the relative differences in mean TABLE 5.-—Ten-week
1071.50 1081.14±17.96
5 36
997.62±20.69
body weights are greater in the males than in the females, indicating that probably the sex-linked and modifying genes involved for feathering may have a cumulative effect on growth. Warren and Payne (1945) suggested that probably a genetic or physiological linkage existed between early feathering and rapid growth. Apparently, the number of secondaries at hatching time is the most effective method of determining rate of feathering.
body weights in relation to 10-day tail feather development Females
Males Breed and strain
1091.00
Ten-day tail feather development
Number
Ten-week mean body weight in grams
Number
Ten-week mean body weight in grams
Short-shanked
Tail feathers
39
1029.19 ±13.58
29
862.25±22.45
New Hampshire
No tail feathers
88
1002.29 ±20.52
71
889.03±12.10
Long-shanked
Tail feathers
New Hampshire
No tail feathers
Short-shanked
Tail feathers
Barred Plymouth Rock
No tail feathers
Long-shanked
Tail feathers
Barred Plymouth Rock
No tail feathers
0 66 7 72
0 1140.59± 13.93
60
906.58±19.01
1177.16
42
945.43±18.62
1066.69 ±14.77
64
950.57±13.13
0 48
0 1093.28±17.94
41
999.90±20.60
438
E D W A R D W. G L A Z E N E R AND M O R L E Y A. J U L L
TABLE 6.—Ten-week body weights in relation to eight-week feathering Ten-week mean weights in grams Breed and strain
Long-shanked New Hampshire Short-shanked Barred Plymouth Rock
Males
Short-shanked New Hampshire
No.
Fully feathered
No.
Back feathered, sides bare
No.
Back and sides bare
25
1046.76 ±19.74
83
1027.84 ±14.61
19
960.22 + 22.48
11
1127.72
53
1115.80 + 15.14
2
625.00
33
1098.27 + 15.51
41
1080.58 ± 1 9 . 5 3
5
935.00
1108.25
27
1108.48±23.65
13
962.23
Long-shanked Barred Plymouth Rock
8
Long-shanked New Hampshire Short-shanked Barred Plymouth Rock Long-shanked Barred Plymouth Rock
Females
Short-shanked New Hampshire
36
914.86+16.33
57
866.70±12.98
7
940.21
18
1040.41 + 16.99
42
907.14±13.72
0
—
49
985.73 + 10.77
57
909.84±16.76
0
—
12
1082.50 ±28.01
29
950.72±24.35
0
—
With the aid of proper lighting conditions, the count is made readily. It seems that at hatching time the degree of feathering is least affected by environmental factors. Although feather development appears to be somewhat related to body growth, excellent body weight was obtained in some of the poorly feathered birds, indicating that probably there are separate genes for feathering and growth. In observing the poorly feathered birds at eight weeks of age, some appeared to be poorly feathered because of poor growth; whereas, others apparently did not carry as many specific genes for feathering or respond as satisfactorily to the environment. To secure the desired bird, probably both body weight and feathering should be considered in the growing stages. SUMMARY The degree of feathering at eight weeks and at ten days of age was related to the degree of feathering at hatching time.
The number of secondaries at hatching time appeared to be a better criterion of early feathering than ten-day tail feather observations in considering strain and environmental differences. The females tended to feather better than the males. Within each strain the chicks having 6 or more secondaries at hatching time were heavier at ten weeks of age than those containing 5 or less secondaries, and the better feathered birds at eight weeks were the heavier birds at ten weeks of age. Although body weight and feathering appeared somewhat related, some of the "barebacks" had good weight at ten weeks. REFERENCES
Darrow, M. I., and D. C. Warren, 1944. The influence of age on expression of genes controlling rate of chick feathering. Poultry Sci. 23:199-212. Gericke, A. M., and C. S. Piatt, 1932. Feather development in Barred Plymouth Rock chicks. New Jersey Agric. Expt. Sta. Bui. 543.
N E W S AND N O T E S
Hays, F. A., and Ruby Sanborn, 1942. Breeding Rhode Island Reds for rapid feathering. Mass. Agric. Expt. Sta. Bui. 396. Hoffman, Edmund, and A. E. Tomhave, 1944. Superior strains for broiler production. U. S. Egg and Poultry Magazine 50:30-32. Jaap, R. G., and L. Morris, 1937. Genetic differences in eight week weight and feathering. Poultry Sci. 16:44-48. Martin, J. H., 1929. Rate of feather growth in the Barred Plymouth Rock chicks. Poultry Sci. 8: 167-183. Radi, M. H., and D. C. Warren, 1938. Studies on the physiology and inheritance of feathering in the growing chick. Jour. Agri. Res. 56:679-706.
439
Schnetzler, E. E., 1936. Inheritance of rate of growth in Barred Plymouth Rocks. Poultry Sci., 15:369-376. Schultze, A. B., and C. W. Turner, 1945. The determination of the rate of thyroxine secretion by certain domestic animals. Mo. Agric. Expt. Sta. Bui. 392. Serebrovsky, H. S., 1922. Crossing over involving three sex-linked genes in chickens. Amer. Nat. 56:571-572. Warren, D. C., 1925. Inheritance of rate of feathering in poultry. Jour, of Hered. 16:13-18. Warren, D. C , and L. F. Payne, 1945. Influence of the early-feathering gene upon a chick's growth. Poultry Sci. 24:191-192.
News and Notes ANNUAL M E E T I N G
AWARDS
The annual meeting of the Poultry Science Association was held in St. Louis, July 22-23, with approximately 300 members in attendance. The officers elected for 1946-47 were as follows: President—C. W. Upp, University, Louisiana 1st Vice-Pres.—W. A. Maw, Macdonald College, Quebec 2nd Vice-Pres.—H. M. Scott, Storrs, Conn. Secretary-Treas.—E. M. Funk, Columbia, Mo. Directors for 1945-47 G. T. Klein, Amherst, Mass. W. M. Insko, Lexington, K y . J. H . Bruckner, Ithaca, N . Y. Directors for 1946-48 R. M. Bethke, Wooster, Ohio T. C. Byerly, Beltsville, M d .
The Borden Award for distinctive contributions to the advancement of poultry
FELLOW
D R . F. B. H U T T
Dr. G. F . Heuser of Cornell University was elected Fellow of Poultry Science Association in recognition of his services to the poultry industry.
Winner of 1946 Borden Award
science was awarded to D r . F. B . H u t t of Cornell University. The award of $1000 and a gold medal were presented to Dr.
(Continued on page 450)
Department of Poultry Husbandry, Maryland Agricultural Experiment Station, College Park, Maryland (Received for publication April 4, 1946)
I
NCREASED competition in -the production and marketing of broilers of superior quality is inevitable. To face this competition the most successful producers will have to place well-finished, high quality broilers with an attractive appearance on the market. Birds with "barebacks" and undeveloped feathers are not only unattractive to the live buyer, but dress poorly, giving carcasses with pin feathers and bluish spots. Darrow and Warren (1944) found that the number of visible secondaries at hatching time is a good measure of the degree of feathering at ten days, six weeks, and eight weeks of age. Individual variations in time of hatching had only a slight effect upon the number of secondaries but greatly influenced the length of day-old wing feathers. As early as 1922, Serebrovsky, reported that a sex-linked gene affects the rate of feathering. Warren (1925) confirmed the findings of Serebrovsky and demonstrated that slow-feathering is controlled by a sexlinked dominant gene by crossing White Leghorn males and Jersey Black Giant females. The Fx males were slow-feathering, and the Fi females fast feathering. In the reciprocal croS'l, both sexes were slow feathering. Martin (1929), Jaap and Mor-
ris (1937), Radi and Warren (1938), Hays and Sanborn (1942), and Darrow and Warren (1944) have observed sexual dimorphism in rate of feathering, the females feathering more rapidly than the males. Jaap and Morris (1937) concluded from a covariance analysis that sex was relatively more important than any other heritable factor influencing rate of feathering. Several workers have observed that body growth and feathering appeared related. Martin (1929) reported that the rate of feathering over the back of the Barred Plymouth Rock was related to rate of growth, the heavier birds feathering more rapidly. Gericke and Piatt (1932) further confirmed the observation in a protein-diet study, using Barred Plymouth Rocks. The higher protein diets tended to produce better growth and feathering than the lower protein diets. Schnetzler (1936), Jaap and Morris (1937), Radi and Warren (1938), and Hoffman and Tomhave (1944) also observed that the better feathered birds were heavier at broiler age. Warren and Payne (1945), in four lots of chicks, found the early feathering chicks to be heavier at twelve weeks of age than the slow feathering chicks.
* Scientific paper No. A129. Contribution No. 2017 of the Maryland Agricultural Experiment Station. (Department of Poultry Husbandry.) 433
MATERIALS AND PROCEDURE
Three hatches of chicks from one pen each of short-shanked Barred Plymouth
434
EDWARD W. GLAZENER AND M O R L E Y A. JTJLL
Rocks and New Hampshires and one pen each of long-shanked Barred Plymouth Rocks and New Hampshires were examined at hatching time, ten days of age, and a t eight weeks for feathering. All chicks were started in batteries and fed the University of Maryland Station mash ad libitum. When the chickens were six weeks old, they were transferred to growing batteries. Each chicken was weighed biweekly. FIG. 2. A ten-week Barred Plymouth Rock cockerel with back and sides bare of feathers.
FIG. 1. A ten-week Barred Plymouth Rock cockerel with body fully feathered.
At hatching time, the chicks were banded and the number of secondaries counted in the right wing. At ten days of age the chickens were classified into two arbitrary groups: (1) those with tail feathering, and (2) those with no tail feather development. Only those chickens having tail feathers at least one-half inch long were classified as having tail feathers. At eight weeks of age body feathering in the chickens was classified into three groups: (1) body fully feathered, (2) back feathered, but hips and sides bare, and (3) bare backs and bare sides. These degrees of feather development are illustrated in Figures 1, 2, and 3, respectively. In addition to the short-shanked and long-shanked strains of New Hampshires, four more strains of New Hampshires, one of Rhode Island Reds, and one of Barred Plymouth Rocks from private
breeders were observed for feathering. Feather development was analyzed separately for each sex. Ten-day tail feathering and eight-week body feathering were compared with the number of seer ondaries a t hatching time, and eight-week body feathering was compared with tenday tail feathering. Mean body weights of the birds a t ten weeks of age were classified according to the degree of feathering a t hatching time, ten days, and eight weeks of age. RESULTS AND DISCUSSION As is seen in Table 1, ten-day tail feathering is related to the number of secondaries a t hatching time. In both
FIG. 3. A ten-week Barred Plymouth Rock cockerel with back covered with feathers, but side and hip bare.
435
RATE OF FEATHERING AND GROWTH OF STRAINS TABLE 1.—Ten-day tail feathering in relation to the number
of secondaries at hatching time Females
Males Number of secondaries a t hatching time
Number
Percent with tail feathers
Number
Percent with tail feathers
Short-shanked
6 or more
84
38
63
38
New Hampshire
5 or less
43
16
37
13
Long-shanked
6 or more
40
0
27
0
New Hampshire
5 or less
26
0
33
0
Short-shanked
6 or more
26
15
47
55
Barred Plymouth Rock
5 or less
53
6
59'
25
Long-shanked
6 or more
2
0
5
0
Barred Plymouth Rock
5 or less
46
0
36
0
Breed and strain
sexes of the short-shanked New Hamp- Rocks did not have a single chick in three shires and Barred Plymouth Rocks, the lots that had tail feather development. percentage of chicks having tail feathers Table 2 shows the relationship between is over twice as high in the "6 or more" the degree of feathering at eight weeks classification than in the "5 or less" classi- and the number of secondaries at hatching fication. The long-shanked strains of both time. As the Table shows, chicks having New Hampshires and Barred Plymouth 6 or more secondaries in both sexes and in TABLE 2.—Eight-week feathering in relation to the number
of secondaries at hatching time Males
Males Breed and strain
Short-shanked
Percent Number with of secondback aries a t Percent hatching Number fully feathtime feathered ered, sides bare 6 or more
New Hampshire 5 or less Long-shanked
6 or more
Percent with back feathered, sides bare
Percent with back and sides bare
40
54
6
Percent with Percent back fully Number and feathered sides bare
84
26
64
10
63
43
8
42
30
37
14
67
19
25
75
0
27
34
66
0
40
New Hampshire 5 or less
26
4
89
7
33
15
85
0
Short-shanked
26
50
46
4
47
52
48
0
53
32
57
11
59
41
59
0
2
50
50
0
5
60
40
0
46
9
63
28
36
33
67
0
6 or more
Barred Plymouth Rock 5 or less Long-shanked
6 or more
Barred Plymouth Rock 5 or less
436
EDWARD W. GLAZENKR AND MORLEY A. JULL TABLE 3.—Eight-week feathering in relation to 10-day feathering Males
Breed and strain
Ten-day tail feather development
Females
PerPercent Percent Per- with Per- with cent cent back Num- cent back with Numfully feathfully feath- back ber ber feathfeath- ered, and ered, ered sides ered sides sides bare bare bare
Percent with back and sides bare
Short-shanked
Tail feathers
39
30
67
3
29
55
45
0
New Hampshire
No tail feathers
88
15
66
19
71
25
66
9
Long-shanked
. Tail feathers
New Hampshire
No tail feathers
Short-shanked
Tail feathers
Barred Plymouth Rock
No tail feathers
Long-shanked
Tail feathers
Barred Plymouth Rock
No tail feathers
0
0
66
17
80
3
60
30
70
0
7
57
43
0
42
45
55
0
72
39
54
7
64
46
54
0
29
71
0
0
0 48
all strains tended to be better feathered than those having 5 or less secondaries. The females in both classifications tended to be better feathered than the males. These observations are in accord with the findings of Darrow and Warren (1944). In the first hatch, the length of the primaries and the length of the secondaries were observed in addition to counting the number of secondaries at hatching time. After the first hatch, however, only the secondaries were counted. As other workers have observed, the length of the feathers was found to vary appreciably with the hatching time. Table 3 shows the relationship between eight-week feathering and ten-day tail feathering. The birds with the development of tail feathers at ten days were better feathered at eight weeks than those not having tail feathers. As previously mentioned, however, this applies only to the short-shanked strains. In comparing the short-shanked strains in Tables 2 and 3, it is observed that in general, eight-week body feathering has a
17
56
27
41
somewhat higher degree of relationship with ten-day tail feathering than with the number of secondaries at hatching time. In considering all strains, the number of secondaries at hatching time appears to be a better measure for observing early feathering than ten-day tail feather ob^ servations. Most of the chicks obtained from the private breeders contained very little tail feather development at ten days. It seems that good feathering might be secured in these strains by careful selection on the basis of the number of secondaries at hatching time. Upon comparing these data, a sex difference in feathering is evident, as previous workers have found. Part of this sex difference might be explained by a differential in the activity of the thyroid gland. Preliminary work at this station indicates that there is a sex difference in the thyroid gland secretion. Furthermore, Schultze and Turner (1945) found that the rate of thyroxine secretion at five weeks of age was somewhat higher in females than in males. That thyroxine has
437
RATE OF FEATHERING AND GROWTH OF STRAINS TABLE 4.—Ten-week body weights in relation to the number of secondaries at hatching time
Breed and strain
Number of secondaries at hatching time
Short-shanked
Females
Males Number
Ten-week mean body weight in grams
Number
Ten-week mean body weight in grams
6 or more
84
1039.29 ±12.37
63
891.45±12.26
New Hampshire
5 or less
43
980.28 ±11.12
37
864.06±15.30
Long-shanked
6 or more
40
1157.37 + 16.53
27
966.86±23.04
New Hampshire
5 or less
26
1075.65 + 26.89
33
897.88±16.16
Short-shanked
6 or more
2,6
1157.92±23.49
47
930.08± 16.86
Barred Plymouth Rock
5 or less
53
1042.67 ±17.19
59
960.47 ±13.47
Long-shanked
6 or more
Barred Plymouth Rock
5 or less
2 46
an effect upon feathering was demonstrated by Radi and Warren (1938). In comparing the mean ten-week body weight (with standard errors) of the chickens with the degree of feathering at the various stages, hatching time, ten days, and eight weeks, it is observed that the better feathered chickens within a strain have a tendency to be heavier; see Tables 4, 5, and 6. From this limited data, it appears that the relative differences in mean TABLE 5.-—Ten-week
1071.50 1081.14±17.96
5 36
997.62±20.69
body weights are greater in the males than in the females, indicating that probably the sex-linked and modifying genes involved for feathering may have a cumulative effect on growth. Warren and Payne (1945) suggested that probably a genetic or physiological linkage existed between early feathering and rapid growth. Apparently, the number of secondaries at hatching time is the most effective method of determining rate of feathering.
body weights in relation to 10-day tail feather development Females
Males Breed and strain
1091.00
Ten-day tail feather development
Number
Ten-week mean body weight in grams
Number
Ten-week mean body weight in grams
Short-shanked
Tail feathers
39
1029.19 ±13.58
29
862.25±22.45
New Hampshire
No tail feathers
88
1002.29 ±20.52
71
889.03±12.10
Long-shanked
Tail feathers
New Hampshire
No tail feathers
Short-shanked
Tail feathers
Barred Plymouth Rock
No tail feathers
Long-shanked
Tail feathers
Barred Plymouth Rock
No tail feathers
0 66 7 72
0 1140.59± 13.93
60
906.58±19.01
1177.16
42
945.43±18.62
1066.69 ±14.77
64
950.57±13.13
0 48
0 1093.28±17.94
41
999.90±20.60
438
E D W A R D W. G L A Z E N E R AND M O R L E Y A. J U L L
TABLE 6.—Ten-week body weights in relation to eight-week feathering Ten-week mean weights in grams Breed and strain
Long-shanked New Hampshire Short-shanked Barred Plymouth Rock
Males
Short-shanked New Hampshire
No.
Fully feathered
No.
Back feathered, sides bare
No.
Back and sides bare
25
1046.76 ±19.74
83
1027.84 ±14.61
19
960.22 + 22.48
11
1127.72
53
1115.80 + 15.14
2
625.00
33
1098.27 + 15.51
41
1080.58 ± 1 9 . 5 3
5
935.00
1108.25
27
1108.48±23.65
13
962.23
Long-shanked Barred Plymouth Rock
8
Long-shanked New Hampshire Short-shanked Barred Plymouth Rock Long-shanked Barred Plymouth Rock
Females
Short-shanked New Hampshire
36
914.86+16.33
57
866.70±12.98
7
940.21
18
1040.41 + 16.99
42
907.14±13.72
0
—
49
985.73 + 10.77
57
909.84±16.76
0
—
12
1082.50 ±28.01
29
950.72±24.35
0
—
With the aid of proper lighting conditions, the count is made readily. It seems that at hatching time the degree of feathering is least affected by environmental factors. Although feather development appears to be somewhat related to body growth, excellent body weight was obtained in some of the poorly feathered birds, indicating that probably there are separate genes for feathering and growth. In observing the poorly feathered birds at eight weeks of age, some appeared to be poorly feathered because of poor growth; whereas, others apparently did not carry as many specific genes for feathering or respond as satisfactorily to the environment. To secure the desired bird, probably both body weight and feathering should be considered in the growing stages. SUMMARY The degree of feathering at eight weeks and at ten days of age was related to the degree of feathering at hatching time.
The number of secondaries at hatching time appeared to be a better criterion of early feathering than ten-day tail feather observations in considering strain and environmental differences. The females tended to feather better than the males. Within each strain the chicks having 6 or more secondaries at hatching time were heavier at ten weeks of age than those containing 5 or less secondaries, and the better feathered birds at eight weeks were the heavier birds at ten weeks of age. Although body weight and feathering appeared somewhat related, some of the "barebacks" had good weight at ten weeks. REFERENCES
Darrow, M. I., and D. C. Warren, 1944. The influence of age on expression of genes controlling rate of chick feathering. Poultry Sci. 23:199-212. Gericke, A. M., and C. S. Piatt, 1932. Feather development in Barred Plymouth Rock chicks. New Jersey Agric. Expt. Sta. Bui. 543.
N E W S AND N O T E S
Hays, F. A., and Ruby Sanborn, 1942. Breeding Rhode Island Reds for rapid feathering. Mass. Agric. Expt. Sta. Bui. 396. Hoffman, Edmund, and A. E. Tomhave, 1944. Superior strains for broiler production. U. S. Egg and Poultry Magazine 50:30-32. Jaap, R. G., and L. Morris, 1937. Genetic differences in eight week weight and feathering. Poultry Sci. 16:44-48. Martin, J. H., 1929. Rate of feather growth in the Barred Plymouth Rock chicks. Poultry Sci. 8: 167-183. Radi, M. H., and D. C. Warren, 1938. Studies on the physiology and inheritance of feathering in the growing chick. Jour. Agri. Res. 56:679-706.
439
Schnetzler, E. E., 1936. Inheritance of rate of growth in Barred Plymouth Rocks. Poultry Sci., 15:369-376. Schultze, A. B., and C. W. Turner, 1945. The determination of the rate of thyroxine secretion by certain domestic animals. Mo. Agric. Expt. Sta. Bui. 392. Serebrovsky, H. S., 1922. Crossing over involving three sex-linked genes in chickens. Amer. Nat. 56:571-572. Warren, D. C., 1925. Inheritance of rate of feathering in poultry. Jour, of Hered. 16:13-18. Warren, D. C , and L. F. Payne, 1945. Influence of the early-feathering gene upon a chick's growth. Poultry Sci. 24:191-192.
News and Notes ANNUAL M E E T I N G
AWARDS
The annual meeting of the Poultry Science Association was held in St. Louis, July 22-23, with approximately 300 members in attendance. The officers elected for 1946-47 were as follows: President—C. W. Upp, University, Louisiana 1st Vice-Pres.—W. A. Maw, Macdonald College, Quebec 2nd Vice-Pres.—H. M. Scott, Storrs, Conn. Secretary-Treas.—E. M. Funk, Columbia, Mo. Directors for 1945-47 G. T. Klein, Amherst, Mass. W. M. Insko, Lexington, K y . J. H . Bruckner, Ithaca, N . Y. Directors for 1946-48 R. M. Bethke, Wooster, Ohio T. C. Byerly, Beltsville, M d .
The Borden Award for distinctive contributions to the advancement of poultry
FELLOW
D R . F. B. H U T T
Dr. G. F . Heuser of Cornell University was elected Fellow of Poultry Science Association in recognition of his services to the poultry industry.
Winner of 1946 Borden Award
science was awarded to D r . F. B . H u t t of Cornell University. The award of $1000 and a gold medal were presented to Dr.
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