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Inheritance of Rate of Growth in Bronze Turkeys
INHERITANCE OE RATE OE GROWTH IN TURKEYS chicks for growth and protein utilization. Poultry Sci. 27: 674. Peeler, H. T., R. F. Miller, C. W. Carlson, L. C. Norris and G. F. Heuser, 1951. Studies of the effect of vitamin B12 on hatchability. Poultry Sci. 30: 11-17. Richardson, L. R., L. G. Blaylock and C. M. Lyman, 1953. Influence of level of vitamins in the diet on the concentration of free amino acids in the plasma of chicks. J. Nutrition, 49: 21-28.
411
Rubin, M., and H. R. Bird, 1947. A chick growth factor in cow manure. V. Relation to quantity and quality of soybean oil meal in the diet. J. Nutrition, 34: 233-245. Stern, J. R., and J. McGinnis, 1951. Toxicity of glycine for vitamin B i 2 deficient chicks. Proc. Soc. Exp. Biol. Med. 76: 233-234. Yacowitz, H., R. F. Miller, L. C. Norris and G. F. Heuser, 1952. Vitamin Bi2 studies with the hen. Poultry Sci. 31: 89-94.
V. S. ASMUNDSON AND C. F. PUN University of California, Davis (Received for publication August 10, 1953)
I
T HAS been shown that much of the difference in percentage rate of growth of large and small strains and varieties of chickens occurs during the earlier months of the birds' post hatching life. Thus Asmundson and Lerner (1934) found that Barred Plymouth Rocks grew more rapidly than Single Comb White Leghorns up to 16 weeks of age but not thereafter. Inherited differences in percentage rate of growth have been demonstrated between breeds of chickens (Lerner and Asmundson, 1932) and within breeds and varieties (Asmundson and Lerner, 1933). Inherited differences in weight have been shown for chickens based on mature weights (Waters, 1931) and about 8 weeks of age (Schnetzler, 1936). The inheritance of differences in gain and in weight at 8 weeks in turkeys has been reported by Abplanalp and Kosin (1952). They, Knox and Marsden (1944) and Asmundson (1948) have reported inherited differences in the weight of 24week-old turkeys. The present paper presents data on the differences in percentage rate of growth of two of the strains of Bronze turkeys (reported on by Asmundson, 1948) and crosses between them; also the interrelation between early growth
and weight at 24 weeks and the inheritance of difference in early rate of growth. MATERIALS AND METHODS Strains 1 and 3 were used, the former being relatively small and narrowbreasted, while the latter are larger and broad breasted. Both are Bronze. Fi and backcross progeny were raised in 1946 and 1948 and F2 progeny in 1946. The birds were weighed when removed from the incubator on the 29th day, at 2, 4, 8, 12, 20, and 28 weeks. Percentage rate of growth was calculated by the modified formula of Minot (Brody, 1927)
where W2 is the weight at the end and Wi the weight at the beginning of the period for which the rate was calculated. Rate of growth for the various periods to 28 weeks of age (Table 3) was calculated from the average weights in Tables 1 and 2 and corrected for differences in time interval by dividing the rate of growth by 2 or 4 to show the rate of growth for one week. Rate of growth from 2 to 8 weeks of age was calculated for each individual.
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Inheritance of Rate of Growth in Bronze Turkeys
412
V. S. ASMUNDSON AND C. F. PUN TABLE 1.—Mean weight in kilos of turkeys in 1946 No. of birds
12th 16th 20th 24th 28th 8th 4th 2nd 0 week week week week week week week week week Females
Strain 1 Fi 9 9XStrain Fi (Strain 3 9 9 Fi (Strain 1 9 9 F2 Fi 9 9 XStrain Strain 3
36 17 28 8 82 12 28
ldd X Strain l d d ) X Strain 3 d d ) 3d"d
.113 .137 .133 .141 .130 .130 .128
.042 .051 .048 .041 .049 .048 .051
5.00 5.53 6.14 6.18 5.82 6.10 6.40
.•258 .342 .350 .359 .343 .350 .340
.69 .89 1.01 1.06 .92 1.04 1.05
1.49 1.94 2.11 2.18 1.91 2.17 2.15
2.49 2.90 3.36 3.48 3.01 3.39 3.36
3.61 4.04 4.56 4.55 4.16 4.53 4.58
4.33 4.83 5.39 5.37 5.06 5.37 5.56
.306 .376 .423 .403 .368 .394 .383
.75 1.13 1.26 1.34 1.05 1.29 1.30
1.64 2.62 2.78 2.91 2.24 2.77 2.67
2.94 4.14 4.75 4.63 3.76 4.53 4.26
4.46 5.84 6.94 6.41 5.54 6.35 6.05
5.99 7.21 7.56 9.34 8.86 10.38 8.29 10.00 7.27 8.81 8.32 9.53 8.04 9.67
Males 22 10 17 8 49 18 25
ldd" X Strain l d d 1 ) XStrain 3c?d") 3dd
.124 .145 .160 .138 .142 .147 .136
.043 .050 .050 .041 .048 .047 .052
WEIGHT CHANGES
Mean weights of females and males in 1946 and 1948 are in Tables 1 and 2. The average weights of the males and females as grouped in these tables did not differ significantly when hatched (p = > .05) but by two weeks of age the differences were statistically significant (/>=<.01). Differences in the weight of males and females at day old and all subsequent ages reported by Kodinetz (1940) indicate that the differences be-
tween the weights of day old turkeys are similar to those reported for day old male and female chicks by Munro and Kosin (1940). After hatching, the differences between males and females become increasingly pronounced. This is shown by the weight of the female as a percentage of the weight of the male (Figure 1). Differences in mean weight between strain 1 and strain 3 birds were apparent from day old. A difference in initial (hatching) weight was expected since the hens
TABLE 2.—Mean weight of tut'keys ini kilos, 1948 No. of birds
8th 0 2nd 4th 12th 16th 20th 24th 28th week week week week week week week week week Females
Strain 1 F! 9 9 X S t r a i n l d d Fi (Strain 39 9 XStrain l d d ) Fj (Strain 19 9 XStrain 3 d d ) Fi 9 9 XStrain 3 d d Strain 3
33 12 20 18 39 64
.051 .058 .056 .045 .055 .054
.129 .138 .140 .141 .147 .139
.325 .366 .392 .382 .393 .365
.97 1.07 1.21 1.28 1.28 1.22
1.85 2.10 2.40 2.44 2.51 2.43
2.99 3.29 3.68 3.33 3.77 3.66
3.90 4.35 4.67 4.73 4.87 4.97
4.56 5.11 5.35 5.39 5.67 5.85
5.11 5.69 6.04 5.97 6.33 6.61
.335 .432 .432 .400 .426 .381
1.09 1.38 1.39 1.45 1.49 1.38
2.20 2.76 2.89 2.96 3.00 2.87
3.79 4.49 4.70 4.87 4.80 4.64
5.47 6.53 6.76 6.88 6.78 6.67
6.87 8.15 8.38 8.57 8.57 8.47
8.39 9.97 10.56 10.45 10.45 10.21
Males Strain 1 F, 9 9 XStrain l d d 1 Fi (Strain 39 9 XStrain Id1 d ) Fj (Strain 19 9 XStrain 3 d d ) Fi 9 9 XStrain 3 d d Strain 3
34 20 23 19 44 85
.052 .058 .056 .045 .055 .054
.129 .157 .152 .142 .153 .140
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Strain 1 Fi 9 9XStrain Fi (Strain 3 9 9 F : (Strain 1 9 9 F2 Fi 9 9 XStrain Strain 3
413
INHERITANCE OF RATE OF GROWTH IN TURKEYS 100 ^
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14 16 18 AGE IN WEEKS
i ,.,
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FIG. 1. Weight of the female turkey as a percentage of the weight of the male.
of strain 1 were smaller and laid smaller cross progeny out of Fi females X strain 1 eggs than those of strain 3. The Fis also males were intermediate between strains differed in initial weight according to 1 and 3. The F 2 progeny in 1946 (Table 1) which way the cross was made, but these were also intermediate between strains 1 differences in day old weight, which pre- and 3, indicating loss of heterosis and segsumably were not related to genetic regation of genes for smaller size. The greater size of the Fis over the differences in rate of growth of the Fis, had larger (strain 3) from 2-16 weeks may be little or no effect on subsequent weight. due to heterosis. Partial dominance of These results agree with expectation on genes for large size seems likely. However, the basis of work reported by Funk in dealing with a quantitative character (1930) and others. such as this, the dominance of its controlThe average weights of the Fi progeny ling genes is difficult to determine. There exceeded those of the corresponding largwere no consistent differences in weight er strain 3 parent in all or most cases between reciprocal crosses, hence no indifrom 2 to 16 weeks; after 16 weeks the cation of sex-linkage or maternal effects. average weights of the Fi females were less, those of the males, more than the PERCENTAGE RATE OF GROWTH average weights of corresponding strain A statistical analysis of the data in 3 groups. The weights of the backcross Tables 3 and 4 showed that the differences progeny out of Fi females X strain 3 males in rate of growth between females and followed closely those of the Fis relative males from 0 to 2 weeks were significant to strain 3. On the other hand, the back-
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414
V . S. ASMUNDSON AND C. F . PUN TABLE 3.—Rate of growth of turkeys in percent per week, 1946 0-2 4-8 8-12 12-16 16-20 20-24 24-28 2-4 week week week week week week week week
No. birds
Females Strain 1 FL 9 9 XStrain lc?c? Fi (Strain 1 9 9 XStrain 3c? c?) Fi (Strain 3 9 9 XStrain lc?c?) F2 Fi 9 9 XStrain 3c? c? Strain 3
46.1 45.5 46.7 55.0 45.9 42.9 45.6
36 17 28 8 82 12 28
22.1 22.2 24.7 24.2 24.8 25.5 22.9
18.2 18.6 17.3 17.7 17.6 17.2 17.4
12.6 10.0 11.5 11.4 11.0 11.0 11.3
9.1 8.2 6.7 7.6 7.2 7.7 8.0
4.6 4.5 4.1 4.2 4.7 4.8 4.9
3.8 3.4 3.5 3.3 2.7 3.5 3.5
42.3 21.1 44.4 25.0 49.0 26.9 45.1 24.9 44.4 19.1 45.7 26.7 47.6 27.3
18.5 19.9 18.1 18.8 18.5 18.2 17.2
14.2 11.3 11.4 17.8 12.7 12.1 11.5
10.3 8.6 8.1 9.4 9.6 8.4 8.7
7.3 6.4 6.4 6.1 6.8 6.7 7.1
4.6 5.2 4.7 4.0 4.8 3.4 4.6
40.7 42.9 43.5 44.8 45.8 45.3 45.0
Males 22 10 17 8 49 18 25
48.9 48.7 53.9 52.4 49.8 51.5 44.6
{p = .013). After 2 weeks the males continued to grow more rapidly than the females and this difference in favor of the males continued up to 28 weeks. From 2 to 8 weeks of age the birds in strain 3 grew more rapidly than those of strain 1. Thereafter the birds of strain 1 grew slightly faster (1946—Table 3) or at about the same rate (1948—Table 4) as those in strain 3. I t thus appears that most of the differences between these strains are confined to a relatively short
period of time early in the growing period. Since most of the difference in rate of growth between strains 1 and 3 was confined to the period from 2 to 8 weeks of age, the rate of growth for each individual was calculated and summarized in Table 5. The Fi progeny did not differ in rate of growth according to which way the cross was made, thus indicating that the differences in rate of growth of these strains are determined by autosomal genes. The Fi progeny and the backcross progeny
TABLE 4.—Rate of growth in percent per week 1948 No. birds
2-4 0-2 4-8 8-12 12-16 16-20 20-24 24-28 week week week week week week week week Female
Strain 1 F, 9 9 XStrain F, (Strain 3 9 9 F, (Strain 19 9 Fi 9 9 XStrain Strain 3
lc?c? XStrain lc?c?) XStrain 3c? c?) 3c?c?
33 12 20 18 39 64
42.8 41.0 43.2 51.7 45.3 44.1
43.2 45.3 48.4 46.0 45.6 44.9
24.8 25.2 25.5 27.1 26.6 26.9
15.7 16.2 16.6 15.5 16.1 16.6
11.7 11.0 10.5 10.4 10.0 10.2
6.6 6.9 5.9 5.9 6.4 7.6
3.9 4.0 3.4 3.2 3.8 4.0
2.8 2.4 3.0 2.6 2.8 3.1
44.4 26.5 46.6 26.2 47.8 26.3 47.5 28.3 47.2 27.7 46.4 28.4
16.8 16.7 17.5 17.2 16.9 17.5
13.3 11.9 11.9 12.2 11.5 11.8
9.1 9.3 9.0 8.6 8.6 9.0
5.7 5.5 5.4 5.4 5.8 5.9
5.0 5.0 5.8 5.0 5.0 4.7
Male Strain 1 Fi 9 9 XStrain lc?c? Fi (Strain 3 9 9 XStrain lc?c?) Fi (Strain 1 9 9 XStrain 3c?c?) Fi 9 9 XStrain 3c?c? Strain 3
34 20 23 19 44 85
43.0 45.8 46.2 51.9 47.4 44.4
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Strain 1 Fi 9 9 XStrain lc?c? Fi (Strain 1 9 9 XStrain 3c? c?) Fi (Strain 3 9 9 XStrain lc?c?) F2 Fi 9 9 XStrain 3c? c? Strain 3
415
INHERITANCE OF RATE OF GROWTH IN TURKEYS TABLE 5.—Rate of growth in percent from 2-8 weeks by sex and by year Females
Strain 1 F , 9 9 XStrain 1 tfc? Fi (Strain 3 9 9 X Strain
Fi Fi 9 9 XStrain 3 &d> Strain 3
Males
1946
1948
1946
1948
142.0 143.8
152.5 154.5
139.2 155.1
157.3 159.0
151.6
158.1
153.5
160.5
151.2 148.2 154.9 155.6
160.5
162.1 150.4 157.7 160.5
164.0
Fi (Strain 1 9 9 XStrain
158.1 158.6
162.3 163.1
from Fi females X strain 3 males grew at about the same rate as, or slightly more slowly than, the larger parental strain (strain 3) while the rate of growth of the progeny from the backcross on strain 1 was intermediate. The rate of growth of the F2 progeny was also intermediate. The following analysis of variance shows that the differences between groups were statistically significant (p=<.01).
Even if the somewhat higher values of r for weight at 8 weeks are omitted, the general conclusion remains that over half the variation in weight between groups
Females Source of variation
Total Between Groups Within Groups F
Males
1946
1946
1948
1948
D/F
Mean square
D/F
Mean square
D/F
Mean square
D/F
Mean square
210 6 204
154.11 879.45 132.78 6.62
185 5 180
30.02 238.72 24.22 9.86
146 6 140
305.69 1,145.01 269.72 4.25
224 5 219
22.84 221.66 18.30 12.15
RELATION BETWEEN RATE OF GROWTH AND WEIGHT
The differences in weight between the parental strains, FiS backcrosses and F2s
is determined by differences in early rate of growth, while within groups 25 percent or less of the differences between birds are so determined. These data suggest
TABLE 6.—Coefficients of correlation for rate of growth from 2-8 weeks and weights at 8, 24 and 28 weeks Degrees 01
8 weeks
24 weeks
28 weeks
freedom
1946
1948
1946
1948
1946
1948
Total Between groups Within groups
146 6 140
.701 .963 .643
Males .517 .799 .428
.427 .839 .458
.521 .886 .386
.522 .719 .423
.396 .814 .237
Total Between groups Within groups
210 6 204
.698 .822 .913
Females .566 .949 .370
.595 .857 .536
.406 .862 .191
.526 .960 .427
.387 .841 .144
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at 24 to 28 weeks and rate of growth from 2-8 weeks are similar. The question then arises as to what extent weight at different ages is determined by rate of growth from 2 to 8 weeks of age. Correlation between rate of growth and weight at 8, 24 and 28 weeks is summarized in Table 6. The data indicate that much of the difference in weight between groups (the coefficient of determination r 2 =.52 to .93 or 52 to 93 percent) is determined by differences in rate of growth. Much less of the differences in weight within groups, or from 3.6 to 41 percent is apparently determined by differences in rate of growth from 2 to 8 weeks.
416
NEWS AND NOTES
that early rate of growth has a significant effect on weight at 24 and 28 weeks but less than would be expected if the differences at 8 weeks were fully reflected in the later weights. SUMMARY
REFERENCES Abplanalp, H., and I. L. Kosin, 1952. Heritability of
NEWS AND NOTES {Continued from page 400) CALIFORNIA NOTES
WASHINGTON NOTES
J. Kimber, President of Kimber Farms, Niles, California has estabhshed a scholarship of $500 for a poultry husbandry student at the University of California, Davis. The award is open to a high school, junior college, or college undergraduate student. A second scholarship of $2,000-$3,000 has been estabhshed for graduate work in poultry genetics.
The State College of Washington has received a grant for research from E. I. duPont de Nemours Company of $2500 to the Department of Poultry Science, Pullman, for research on methionine for laying hens and turkeys; from Dr. Hess and Clark, Inc., of $1,000 to the Department of Veterinary Science, Puyallup, for evaluation of formulations for
{Continued on page 421)
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Two strains of Bronze turkeys differing in weight at 24 and 28 weeks and in rate of growth from 2-8 weeks were crossed. Data were obtained for Fi progeny from reciprocal crosses between the strains; also F2 and backcross progeny. The weights of the Fi progeny tended to exceed those of the larger parents to 16 weeks of age after which the Fi males weighed more, the Fi females less, than the larger parents. The backcrosses on the smaller parent strain and the F 2 progeny were intermediate in weight and rate of growth. Correlations between rate of growth and weight at 24 and 28 weeks show that over half the differences in weight between groups were determined by differences in rate of growth from 2 to 8 weeks, but only 25 percent or less of the differences in weight within groups were so determined.
body measurements in turkeys. Poultry Sci. 31: 781-791. Asmundson, V. S., 1948. Inherited differences in weight and conformation of Bronze turkeys. Poultry Sci. 27:695-708. Asmundson, V. S., and I. M. Lerner, 1933. Inheritance of rate of growth in domestic fowl. II. Genetic variation in growth of Leghorns. Poultry Sci. 12: 250-255. Asmundson, V. S., and I. M. Lerner, 1934. Inheritance of rate of growth in domestic fowl. III. Comparative rates of growth of Leghorns and Rocks. Poultry Sci. 13: 348-352. Brody, S., 1927. Growth and development with special reference to domestic animals. III. Growth rates, their evaluation and significance. Missouri Res. Bui. 97. Funk, E. M., 1930. Rate of growth in Bronze and White Holland turkeys. Poultry Sci. 9: 343-355. Knox, C. W., and S. J. Marsden, 1944. The inheritance of some quantitative characteristics in turkeys. J. Heredity, 35: 89-97. Kodinetz, G., 1940. Beitrag zur Kenntnis der Rasse und der Entwicklung des Zagorianer Truthuhnes (Meleagris gallopavo). Zeitschr. f. Tierzuchtung u. Zuchtungsbiol. 47: 140-165. Lerner, I. M., and V. S. Asmundson, 1932. Inheritance of rate of growth in domestic fowl. 1. Methods and preliminary report on results obtained with two breeds. Sci. Agric. 12: 652-664. Munro, S. S., and I. L. Kosin, 1940. The existence of a sex difference in the weight of day-old chicks, with further data on the egg weight-chick weight relationship. Sci. Agric. 20: 586-591. Schnetzler, E. E., 1936. Inheritance of rate of growth in Barred Plymouth Rocks. Poultry Sci. 15:369376. Waters, N. F., 1931. Inheritance of body weight in domestic fowl. Rhode Island Bui. 228.
411
Rubin, M., and H. R. Bird, 1947. A chick growth factor in cow manure. V. Relation to quantity and quality of soybean oil meal in the diet. J. Nutrition, 34: 233-245. Stern, J. R., and J. McGinnis, 1951. Toxicity of glycine for vitamin B i 2 deficient chicks. Proc. Soc. Exp. Biol. Med. 76: 233-234. Yacowitz, H., R. F. Miller, L. C. Norris and G. F. Heuser, 1952. Vitamin Bi2 studies with the hen. Poultry Sci. 31: 89-94.
V. S. ASMUNDSON AND C. F. PUN University of California, Davis (Received for publication August 10, 1953)
I
T HAS been shown that much of the difference in percentage rate of growth of large and small strains and varieties of chickens occurs during the earlier months of the birds' post hatching life. Thus Asmundson and Lerner (1934) found that Barred Plymouth Rocks grew more rapidly than Single Comb White Leghorns up to 16 weeks of age but not thereafter. Inherited differences in percentage rate of growth have been demonstrated between breeds of chickens (Lerner and Asmundson, 1932) and within breeds and varieties (Asmundson and Lerner, 1933). Inherited differences in weight have been shown for chickens based on mature weights (Waters, 1931) and about 8 weeks of age (Schnetzler, 1936). The inheritance of differences in gain and in weight at 8 weeks in turkeys has been reported by Abplanalp and Kosin (1952). They, Knox and Marsden (1944) and Asmundson (1948) have reported inherited differences in the weight of 24week-old turkeys. The present paper presents data on the differences in percentage rate of growth of two of the strains of Bronze turkeys (reported on by Asmundson, 1948) and crosses between them; also the interrelation between early growth
and weight at 24 weeks and the inheritance of difference in early rate of growth. MATERIALS AND METHODS Strains 1 and 3 were used, the former being relatively small and narrowbreasted, while the latter are larger and broad breasted. Both are Bronze. Fi and backcross progeny were raised in 1946 and 1948 and F2 progeny in 1946. The birds were weighed when removed from the incubator on the 29th day, at 2, 4, 8, 12, 20, and 28 weeks. Percentage rate of growth was calculated by the modified formula of Minot (Brody, 1927)
where W2 is the weight at the end and Wi the weight at the beginning of the period for which the rate was calculated. Rate of growth for the various periods to 28 weeks of age (Table 3) was calculated from the average weights in Tables 1 and 2 and corrected for differences in time interval by dividing the rate of growth by 2 or 4 to show the rate of growth for one week. Rate of growth from 2 to 8 weeks of age was calculated for each individual.
Downloaded from http://ps.oxfordjournals.org/ at University of Arizona on June 10, 2016
Inheritance of Rate of Growth in Bronze Turkeys
412
V. S. ASMUNDSON AND C. F. PUN TABLE 1.—Mean weight in kilos of turkeys in 1946 No. of birds
12th 16th 20th 24th 28th 8th 4th 2nd 0 week week week week week week week week week Females
Strain 1 Fi 9 9XStrain Fi (Strain 3 9 9 Fi (Strain 1 9 9 F2 Fi 9 9 XStrain Strain 3
36 17 28 8 82 12 28
ldd X Strain l d d ) X Strain 3 d d ) 3d"d
.113 .137 .133 .141 .130 .130 .128
.042 .051 .048 .041 .049 .048 .051
5.00 5.53 6.14 6.18 5.82 6.10 6.40
.•258 .342 .350 .359 .343 .350 .340
.69 .89 1.01 1.06 .92 1.04 1.05
1.49 1.94 2.11 2.18 1.91 2.17 2.15
2.49 2.90 3.36 3.48 3.01 3.39 3.36
3.61 4.04 4.56 4.55 4.16 4.53 4.58
4.33 4.83 5.39 5.37 5.06 5.37 5.56
.306 .376 .423 .403 .368 .394 .383
.75 1.13 1.26 1.34 1.05 1.29 1.30
1.64 2.62 2.78 2.91 2.24 2.77 2.67
2.94 4.14 4.75 4.63 3.76 4.53 4.26
4.46 5.84 6.94 6.41 5.54 6.35 6.05
5.99 7.21 7.56 9.34 8.86 10.38 8.29 10.00 7.27 8.81 8.32 9.53 8.04 9.67
Males 22 10 17 8 49 18 25
ldd" X Strain l d d 1 ) XStrain 3c?d") 3dd
.124 .145 .160 .138 .142 .147 .136
.043 .050 .050 .041 .048 .047 .052
WEIGHT CHANGES
Mean weights of females and males in 1946 and 1948 are in Tables 1 and 2. The average weights of the males and females as grouped in these tables did not differ significantly when hatched (p = > .05) but by two weeks of age the differences were statistically significant (/>=<.01). Differences in the weight of males and females at day old and all subsequent ages reported by Kodinetz (1940) indicate that the differences be-
tween the weights of day old turkeys are similar to those reported for day old male and female chicks by Munro and Kosin (1940). After hatching, the differences between males and females become increasingly pronounced. This is shown by the weight of the female as a percentage of the weight of the male (Figure 1). Differences in mean weight between strain 1 and strain 3 birds were apparent from day old. A difference in initial (hatching) weight was expected since the hens
TABLE 2.—Mean weight of tut'keys ini kilos, 1948 No. of birds
8th 0 2nd 4th 12th 16th 20th 24th 28th week week week week week week week week week Females
Strain 1 F! 9 9 X S t r a i n l d d Fi (Strain 39 9 XStrain l d d ) Fj (Strain 19 9 XStrain 3 d d ) Fi 9 9 XStrain 3 d d Strain 3
33 12 20 18 39 64
.051 .058 .056 .045 .055 .054
.129 .138 .140 .141 .147 .139
.325 .366 .392 .382 .393 .365
.97 1.07 1.21 1.28 1.28 1.22
1.85 2.10 2.40 2.44 2.51 2.43
2.99 3.29 3.68 3.33 3.77 3.66
3.90 4.35 4.67 4.73 4.87 4.97
4.56 5.11 5.35 5.39 5.67 5.85
5.11 5.69 6.04 5.97 6.33 6.61
.335 .432 .432 .400 .426 .381
1.09 1.38 1.39 1.45 1.49 1.38
2.20 2.76 2.89 2.96 3.00 2.87
3.79 4.49 4.70 4.87 4.80 4.64
5.47 6.53 6.76 6.88 6.78 6.67
6.87 8.15 8.38 8.57 8.57 8.47
8.39 9.97 10.56 10.45 10.45 10.21
Males Strain 1 F, 9 9 XStrain l d d 1 Fi (Strain 39 9 XStrain Id1 d ) Fj (Strain 19 9 XStrain 3 d d ) Fi 9 9 XStrain 3 d d Strain 3
34 20 23 19 44 85
.052 .058 .056 .045 .055 .054
.129 .157 .152 .142 .153 .140
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Strain 1 Fi 9 9XStrain Fi (Strain 3 9 9 F : (Strain 1 9 9 F2 Fi 9 9 XStrain Strain 3
413
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14 16 18 AGE IN WEEKS
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FIG. 1. Weight of the female turkey as a percentage of the weight of the male.
of strain 1 were smaller and laid smaller cross progeny out of Fi females X strain 1 eggs than those of strain 3. The Fis also males were intermediate between strains differed in initial weight according to 1 and 3. The F 2 progeny in 1946 (Table 1) which way the cross was made, but these were also intermediate between strains 1 differences in day old weight, which pre- and 3, indicating loss of heterosis and segsumably were not related to genetic regation of genes for smaller size. The greater size of the Fis over the differences in rate of growth of the Fis, had larger (strain 3) from 2-16 weeks may be little or no effect on subsequent weight. due to heterosis. Partial dominance of These results agree with expectation on genes for large size seems likely. However, the basis of work reported by Funk in dealing with a quantitative character (1930) and others. such as this, the dominance of its controlThe average weights of the Fi progeny ling genes is difficult to determine. There exceeded those of the corresponding largwere no consistent differences in weight er strain 3 parent in all or most cases between reciprocal crosses, hence no indifrom 2 to 16 weeks; after 16 weeks the cation of sex-linkage or maternal effects. average weights of the Fi females were less, those of the males, more than the PERCENTAGE RATE OF GROWTH average weights of corresponding strain A statistical analysis of the data in 3 groups. The weights of the backcross Tables 3 and 4 showed that the differences progeny out of Fi females X strain 3 males in rate of growth between females and followed closely those of the Fis relative males from 0 to 2 weeks were significant to strain 3. On the other hand, the back-
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414
V . S. ASMUNDSON AND C. F . PUN TABLE 3.—Rate of growth of turkeys in percent per week, 1946 0-2 4-8 8-12 12-16 16-20 20-24 24-28 2-4 week week week week week week week week
No. birds
Females Strain 1 FL 9 9 XStrain lc?c? Fi (Strain 1 9 9 XStrain 3c? c?) Fi (Strain 3 9 9 XStrain lc?c?) F2 Fi 9 9 XStrain 3c? c? Strain 3
46.1 45.5 46.7 55.0 45.9 42.9 45.6
36 17 28 8 82 12 28
22.1 22.2 24.7 24.2 24.8 25.5 22.9
18.2 18.6 17.3 17.7 17.6 17.2 17.4
12.6 10.0 11.5 11.4 11.0 11.0 11.3
9.1 8.2 6.7 7.6 7.2 7.7 8.0
4.6 4.5 4.1 4.2 4.7 4.8 4.9
3.8 3.4 3.5 3.3 2.7 3.5 3.5
42.3 21.1 44.4 25.0 49.0 26.9 45.1 24.9 44.4 19.1 45.7 26.7 47.6 27.3
18.5 19.9 18.1 18.8 18.5 18.2 17.2
14.2 11.3 11.4 17.8 12.7 12.1 11.5
10.3 8.6 8.1 9.4 9.6 8.4 8.7
7.3 6.4 6.4 6.1 6.8 6.7 7.1
4.6 5.2 4.7 4.0 4.8 3.4 4.6
40.7 42.9 43.5 44.8 45.8 45.3 45.0
Males 22 10 17 8 49 18 25
48.9 48.7 53.9 52.4 49.8 51.5 44.6
{p = .013). After 2 weeks the males continued to grow more rapidly than the females and this difference in favor of the males continued up to 28 weeks. From 2 to 8 weeks of age the birds in strain 3 grew more rapidly than those of strain 1. Thereafter the birds of strain 1 grew slightly faster (1946—Table 3) or at about the same rate (1948—Table 4) as those in strain 3. I t thus appears that most of the differences between these strains are confined to a relatively short
period of time early in the growing period. Since most of the difference in rate of growth between strains 1 and 3 was confined to the period from 2 to 8 weeks of age, the rate of growth for each individual was calculated and summarized in Table 5. The Fi progeny did not differ in rate of growth according to which way the cross was made, thus indicating that the differences in rate of growth of these strains are determined by autosomal genes. The Fi progeny and the backcross progeny
TABLE 4.—Rate of growth in percent per week 1948 No. birds
2-4 0-2 4-8 8-12 12-16 16-20 20-24 24-28 week week week week week week week week Female
Strain 1 F, 9 9 XStrain F, (Strain 3 9 9 F, (Strain 19 9 Fi 9 9 XStrain Strain 3
lc?c? XStrain lc?c?) XStrain 3c? c?) 3c?c?
33 12 20 18 39 64
42.8 41.0 43.2 51.7 45.3 44.1
43.2 45.3 48.4 46.0 45.6 44.9
24.8 25.2 25.5 27.1 26.6 26.9
15.7 16.2 16.6 15.5 16.1 16.6
11.7 11.0 10.5 10.4 10.0 10.2
6.6 6.9 5.9 5.9 6.4 7.6
3.9 4.0 3.4 3.2 3.8 4.0
2.8 2.4 3.0 2.6 2.8 3.1
44.4 26.5 46.6 26.2 47.8 26.3 47.5 28.3 47.2 27.7 46.4 28.4
16.8 16.7 17.5 17.2 16.9 17.5
13.3 11.9 11.9 12.2 11.5 11.8
9.1 9.3 9.0 8.6 8.6 9.0
5.7 5.5 5.4 5.4 5.8 5.9
5.0 5.0 5.8 5.0 5.0 4.7
Male Strain 1 Fi 9 9 XStrain lc?c? Fi (Strain 3 9 9 XStrain lc?c?) Fi (Strain 1 9 9 XStrain 3c?c?) Fi 9 9 XStrain 3c?c? Strain 3
34 20 23 19 44 85
43.0 45.8 46.2 51.9 47.4 44.4
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Strain 1 Fi 9 9 XStrain lc?c? Fi (Strain 1 9 9 XStrain 3c? c?) Fi (Strain 3 9 9 XStrain lc?c?) F2 Fi 9 9 XStrain 3c? c? Strain 3
415
INHERITANCE OF RATE OF GROWTH IN TURKEYS TABLE 5.—Rate of growth in percent from 2-8 weeks by sex and by year Females
Strain 1 F , 9 9 XStrain 1 tfc? Fi (Strain 3 9 9 X Strain
Fi Fi 9 9 XStrain 3 &d> Strain 3
Males
1946
1948
1946
1948
142.0 143.8
152.5 154.5
139.2 155.1
157.3 159.0
151.6
158.1
153.5
160.5
151.2 148.2 154.9 155.6
160.5
162.1 150.4 157.7 160.5
164.0
Fi (Strain 1 9 9 XStrain
158.1 158.6
162.3 163.1
from Fi females X strain 3 males grew at about the same rate as, or slightly more slowly than, the larger parental strain (strain 3) while the rate of growth of the progeny from the backcross on strain 1 was intermediate. The rate of growth of the F2 progeny was also intermediate. The following analysis of variance shows that the differences between groups were statistically significant (p=<.01).
Even if the somewhat higher values of r for weight at 8 weeks are omitted, the general conclusion remains that over half the variation in weight between groups
Females Source of variation
Total Between Groups Within Groups F
Males
1946
1946
1948
1948
D/F
Mean square
D/F
Mean square
D/F
Mean square
D/F
Mean square
210 6 204
154.11 879.45 132.78 6.62
185 5 180
30.02 238.72 24.22 9.86
146 6 140
305.69 1,145.01 269.72 4.25
224 5 219
22.84 221.66 18.30 12.15
RELATION BETWEEN RATE OF GROWTH AND WEIGHT
The differences in weight between the parental strains, FiS backcrosses and F2s
is determined by differences in early rate of growth, while within groups 25 percent or less of the differences between birds are so determined. These data suggest
TABLE 6.—Coefficients of correlation for rate of growth from 2-8 weeks and weights at 8, 24 and 28 weeks Degrees 01
8 weeks
24 weeks
28 weeks
freedom
1946
1948
1946
1948
1946
1948
Total Between groups Within groups
146 6 140
.701 .963 .643
Males .517 .799 .428
.427 .839 .458
.521 .886 .386
.522 .719 .423
.396 .814 .237
Total Between groups Within groups
210 6 204
.698 .822 .913
Females .566 .949 .370
.595 .857 .536
.406 .862 .191
.526 .960 .427
.387 .841 .144
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at 24 to 28 weeks and rate of growth from 2-8 weeks are similar. The question then arises as to what extent weight at different ages is determined by rate of growth from 2 to 8 weeks of age. Correlation between rate of growth and weight at 8, 24 and 28 weeks is summarized in Table 6. The data indicate that much of the difference in weight between groups (the coefficient of determination r 2 =.52 to .93 or 52 to 93 percent) is determined by differences in rate of growth. Much less of the differences in weight within groups, or from 3.6 to 41 percent is apparently determined by differences in rate of growth from 2 to 8 weeks.
416
NEWS AND NOTES
that early rate of growth has a significant effect on weight at 24 and 28 weeks but less than would be expected if the differences at 8 weeks were fully reflected in the later weights. SUMMARY
REFERENCES Abplanalp, H., and I. L. Kosin, 1952. Heritability of
NEWS AND NOTES {Continued from page 400) CALIFORNIA NOTES
WASHINGTON NOTES
J. Kimber, President of Kimber Farms, Niles, California has estabhshed a scholarship of $500 for a poultry husbandry student at the University of California, Davis. The award is open to a high school, junior college, or college undergraduate student. A second scholarship of $2,000-$3,000 has been estabhshed for graduate work in poultry genetics.
The State College of Washington has received a grant for research from E. I. duPont de Nemours Company of $2500 to the Department of Poultry Science, Pullman, for research on methionine for laying hens and turkeys; from Dr. Hess and Clark, Inc., of $1,000 to the Department of Veterinary Science, Puyallup, for evaluation of formulations for
{Continued on page 421)
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Two strains of Bronze turkeys differing in weight at 24 and 28 weeks and in rate of growth from 2-8 weeks were crossed. Data were obtained for Fi progeny from reciprocal crosses between the strains; also F2 and backcross progeny. The weights of the Fi progeny tended to exceed those of the larger parents to 16 weeks of age after which the Fi males weighed more, the Fi females less, than the larger parents. The backcrosses on the smaller parent strain and the F 2 progeny were intermediate in weight and rate of growth. Correlations between rate of growth and weight at 24 and 28 weeks show that over half the differences in weight between groups were determined by differences in rate of growth from 2 to 8 weeks, but only 25 percent or less of the differences in weight within groups were so determined.
body measurements in turkeys. Poultry Sci. 31: 781-791. Asmundson, V. S., 1948. Inherited differences in weight and conformation of Bronze turkeys. Poultry Sci. 27:695-708. Asmundson, V. S., and I. M. Lerner, 1933. Inheritance of rate of growth in domestic fowl. II. Genetic variation in growth of Leghorns. Poultry Sci. 12: 250-255. Asmundson, V. S., and I. M. Lerner, 1934. Inheritance of rate of growth in domestic fowl. III. Comparative rates of growth of Leghorns and Rocks. Poultry Sci. 13: 348-352. Brody, S., 1927. Growth and development with special reference to domestic animals. III. Growth rates, their evaluation and significance. Missouri Res. Bui. 97. Funk, E. M., 1930. Rate of growth in Bronze and White Holland turkeys. Poultry Sci. 9: 343-355. Knox, C. W., and S. J. Marsden, 1944. The inheritance of some quantitative characteristics in turkeys. J. Heredity, 35: 89-97. Kodinetz, G., 1940. Beitrag zur Kenntnis der Rasse und der Entwicklung des Zagorianer Truthuhnes (Meleagris gallopavo). Zeitschr. f. Tierzuchtung u. Zuchtungsbiol. 47: 140-165. Lerner, I. M., and V. S. Asmundson, 1932. Inheritance of rate of growth in domestic fowl. 1. Methods and preliminary report on results obtained with two breeds. Sci. Agric. 12: 652-664. Munro, S. S., and I. L. Kosin, 1940. The existence of a sex difference in the weight of day-old chicks, with further data on the egg weight-chick weight relationship. Sci. Agric. 20: 586-591. Schnetzler, E. E., 1936. Inheritance of rate of growth in Barred Plymouth Rocks. Poultry Sci. 15:369376. Waters, N. F., 1931. Inheritance of body weight in domestic fowl. Rhode Island Bui. 228.