A Test of Crossbred Chickens, Single Comb White Leghorns and Rhode Island Reds

A Test of Crossbred Chickens, Single Comb White Leghorns and Rhode Island Reds CHARLES W. KNOX AND MARLOW W. OLSEN

Bureau of Animal Industry, U. S. Department of Agriculture, Beltsville, Maryland (Presented at annual meeting, August, 1937; received for publication August 13, 1937)

N THE fields of plant and animal gen- between the pheasant and Golden Campine etics, there has been a considerable fowl. Tiniakoff (1933 and 1934) obtained amount of experimental work crossing dif- a hybrid from a cross of a peacock with the ferent inbred lines, distantly related indi- domestic hen. viduals, and, in some cases, crossing indiIn recent years, many rumors have been viduals of different genera, species, or sub- encountered of successful hybrids that were species. Hybridization has been and may obtained from crossing turkeys with chickbe accomplished in three ways: ens. However, Warren and Scott (1935) 1. Crossing individuals of different gen- and Quinn, Burrows, and Byerly (1937) in the only authentic reports available were era, species, or subspecies. 2. Crossing inbred individuals of differ- unable to hatch any of the hybrid embryos. In addition to this they found that the ferent inbred lines. 3. Crossing individuals of different breeds tility obtained from this cross was exceedingly low. From the results of these and the and varieties. other wide crosses mentioned there appears The progeny of genera, species, and subto' be slight hope of producing successful species crosses in the plant kingdom have hybrids for economic uses by making crosses been used with some degree of success in involving different genera, species, or subthe formation of new types of plants. Howspecies. ever, in the animal kingdom, progeny from wide crosses in large animals, whenever they The production of hybrids by crossing inare obtained, usually prove to be without dividuals from different inbred lines has economic value- although the mule is an been very successful in the field of plant outstanding exception. Many crosses have genetics. Corn breeders have produced their been made between birds of different spe- successful economic hybrids by this method cies and subspecies and in a few be- of crossing. Although the crossing of inbreds tween individuals from different genera. has proven to be highly successful in plant However, such hybrids that were obtained breeding, it has not been tried with poultry were of no practical value. to any extent because of the great difficutly in obtaining successful inbred lines. There Phillips (1913, 1915, 1916, and 1921) have been no published reports of systemcrossed different genera, species, and subatic well-organized attempts to test the few species among ducks and pheasants. Smith successful lines of inbred chickens that have and Haig-Thomas (1913) crossed various been obtained. It appears, therefore, that species of pheasants. Cutler (1918) obone of the most promising means of productained only male hybrids from a cross made

I

[193]

194

CHARLES W. KNOX AND MARLOW W. OLSEN

ing successful hybrids has been sadly neglected thus far by the majority of scientists. Jull (1930 and 1933) intercrossed inbred lines of White Leghorns that had been inbred for three years. The results from these intercrosses, compared with the results from inbreeding, were decreased fertility, increased hatchability, increased viability of the chicks, decreased age in days that laying commenced, increased rate of production, and increased total first-year production. One of the latest developments in poultry breeding is the creation of superior progeny by the crossing of different breeds and varieties of domestic fowl. Hybrids obtained in this manner are not to be confused with the manner in which successful hybrids are produced by corn breeders. Many rumors as to the success and extent of breed crosses in the United States and England have been circulated with but little foundation upon facts. Only a few meager reports have been published on the crossing of poultry for the production of successful economic hybrids. This manuscript is mainly concerned with this latter method of obtaining hybrids and comparing them with progeny from standardbred Single Comb White Leghorns and Single Comb Rhode Island Reds. Pearl and Surface (1910) published the first extensive report of crossing different breeds of the domestic fowl. Reciprocal crosses were made between Barred Plymouth Rocks and Dark Cornish and records were kept on many factors including mortality of chicks, hatchability, and winter egg production. The mortality of the chicks was about equal for each of the groups. In regard to hatchability they found that the crossbred embryos hatched better than the standardbred Barred Plymouth Rock embryos or the Dark Cornish embryos. Without question the difference in hatchability, approximately 22 percent, is signifi-

cant and it can be stated that the hatchability of the hybrid embryos was superior to those of the standardbred parental stock. However, the hatchability of the parental stock is exceedingly low and it is to be expected that there would be an increase in the hatchability of the hybrid embryos. Byerly, Knox, and Jull (1934) stated that it has been shown that crossing pure breeds is likely to increase hatchability over that characteristic of the parental breeds in the inverse proportion to the hatchability of the parental breeds. In other words, if the hatchability of the eggs from the pure breeds is low, the crossbreeding of such parental stock would increase the hatchability of the hybrid embryos. This probably accounts for the results in regard to hatchability reported by Pearl and Surface, as only about 48 percent of the purebred embryos hatched. However, Byerly, Knox, and Jull (1934) state also that crossing breeds with a hatchability above 80 percent lowered hatchability about as often as it increased it among the flocks used in their experiments at Beltsville, Maryland. Pearl and Surface (1910) also found that the hybrid pullets were more or less intermediate in the production of eggs from November 1 to March 1. They chose the winter period of production from November 1 to March 1 on the assumption that this was a truer measure of production than the annual egg record as the winter period was influenced less by environmental factors. The results of recent investigations by Knox, Jull, and Quinn (1935) show that the number of eggs laid from date of first egg to March 1 is highly and significantly correlated with the date of hatch, date of first egg, and sexual maturity. When these correlations are considered it is evident that any adequate genetic or statistical studies of total egg production using production to March 1 is not only difficult but hazardous.

A TEST OF CROSSBRED CHICKENS

195

It is to be regretted that the published and the diversity of results thus far obrecords of Pearl and Surface did not include tained, the experiment now reported was undertaken at the National Agricultural Rethe annual records. Warren (1927) reported that the F1 hy- search Center. It was desired to test crossbrids resulting from crossing the Single bred stock from different parts of the counComb White Leghorn and the Jersey Black try against White Leghorns bred in difGiant hatched better, grew faster, and pro- ferent parts of the United States and against duced more eggs than did the parental the Beltsville Rhode Island Reds. Therestocks. He also stated that they showed a fore, approximately 100 eggs were obtained lower mortality and that the adult size of from each of the various breeders of White the hybrid birds was intermediate between Leghorns and from poultrymen selling eggs the two breeds crossed. In a later report from different breed crosses. Warren (1930) showed that similar results The results from such a project would be were obtained from crosses of Single Comb a partial answer at least to many queries White Leghorns and Rhode Island Reds made by poultrymen in regard to the rewith the hybrids showing more broodiness sults that might be expected from hybrid than the parental stock. Warren found that progeny. No attempt is made in this study the hybrids produced eggs that were equal to use similar parental stock to produce the in weight to those laid by the two breeds. standardbred and hybrid progeny. In crosses among Single Comb White LegThe eggs, with the exception of the Rhode horns, Rhode Island Reds, and Barred Island Red eggs, were set and hatched in Plymouth Rocks he also found that the Fx the same forced draft machine in two hybrids grew faster up to 10 weeks of age hatches, one week apart, and the chicks and that there was considerably less mor- were brooded in a long brooder house in 12 tality among the hybrids than among chicks pens which were identical in respect to type of any of the parent stock. and kind of equipment. The Rhode Island Knox1 found that the Fx hybrids from Red eggs were hatched in similar incubators crosses between (1) Single Comb White and hatched in six weekly hatches. The Leghorns and Rhode Island Reds, and (2) chicks and adult stock of the different White Plymouth Rocks and White Wyan- groups were given the same diets and were dottes did not attain the production of the otherwise kept under similar conditions of Leghorns or Reds. Early growth and via- housing and management. All the data of bility of these hybrids seemed to be better any cross or standardbred stock were disbut the pullet progeny laid small eggs and carded if the number of chicks or adult had a greater incidence of broodiness than stock from any breeder became too small the parental stocks. The strains of Leg- to be regarded as an adequate sample. horns and Reds used in these crosses were The data in Table 1 are summarized for very good as far as egg production was each cross and for each breeder (each breedconcerned. The Reds averaged somewhat er's stock is identified by a letter) as to better than 200 eggs and the Leghorns ap- annual average egg production, average egg proximately 225. weight, the average number of points, hatchBecause of the interest in crossbreeding ability of eggs set and of fertile eggs, average body weight for males at 10 weeks of age and for females at 10, 20, and ap1 Unpublished data, Iowa Agricultural Experiproximately 50 weeks (mature pullet ment Station, 1924-1931.

53.5

203.3

B

189.7

67.0 52.1 79.8 77.8 46.1 83.7 73.2 65.2 51.6

63.1

69.9 77.9 71.0 43.0 65.5

55.3 69.8 62.8 66.7 72.2 76.0 65.2 65.1 56.4 65.5

percent

of total eggs set

72.8 63.0 79.8 77.8 50.4 85.8 76.5 70.0

79.1 81.2 78.9 58.9 74.5

82.3 83.6 70.5 79.4 75.5 77.8 74.7 67.7 59.8 74.6

percent

of fertile eggs set

Hatchability

589.8

577.1 629.0 646.1 700.2 637.1 550.7 587.8 608.7

556.6 541.3 552.0 625.0 568.7

718.9

** **

741.7 876.7 693.9 629.0 782.8 623.5 679.5

grams

males 10 wks.

545.4

519.0 556.2 568.7 604.2 556.5 469.4 532.6 535.8

552.9 476.3 507.3 480.1 504.2

646.5 764.6 710.5 632.2 717.5 678.9 622.9 623.9 599.0 666.2

grams

10 wks.

1434

1187 1194 1184 1356 1211 1140 1224 1202

1322 1142 1216 1208 1222

1482 1616 1562 1624 1612 1532 1606 1392 1498 1547

grams

20 wks.

females

Average body weight

2471

1769 1894 1914 2010 1956 1666 1893 1825

2042 1753 1946 1852 1898

2243 2599 •2456 2436 2663 2078 2535 2314 2325 2405

grams

mature

220

193 182 199 189 196 190 189 192

211 206 210 218 211

213 212 209 214 232 213 205 233 217 216

days

egg

Age at first

5

6 0 0 0 6 11 0 3

42 0 17 42 25

44 40 39 29 12 75 50 46 73 45

Percent broody

* The different variety names are abbreviated and the variety of the male is given first. The Rhode Island Reds used were the Single Comb variety. ** Males from this cross were discarded as day old chicks. t Three-way crosses involving Rhode Island Reds, White Wyandottes and Light Sussex.

R.I.R. AVERAGE

F

JL

225.2 220.1 217.8 193.8 185.3 183.4 136.4 192.9

56.1 55.4 57.0 56.9 56.0 49.1 54.4 54.7

228.1 226.2 216.5 193.0 188.0 217.9 143.3 201.3

I H K G

S.C.W.L. S.C.W.L. S.C.W.L. S.C.W.L. S.C.W.L. S.C.W.L. S.C.W.L. AVERAGE

144.5 147.2 131.2 106.2 131.8

56.4 55.3 54.7 49.9 54.1

145.4 151.6 136.9 123.7 139.4

D D D E

W.L.XR.LR. W.L.XB.M. W.L.XW.P.R. W.P.R.XW.L. AVERAGE

186.2 185.3 180.3 174.6 162.1 160.2 141.0 135.4 124.7 161.2

number

Points

56.0 54.9 54.6 58.7 56.2 53.0 55.7 55.7 53.5 55.4

grams

number

189.0 192.5 188.5 167.6 163.8 173.6 144.0 138.3 133.6 165.7

Egg weight

Egg prod.

B A C B C B B D D

-D1CCU.C1

"RrpfHpr

R.I.R.XW.W. B.P.R.XR.I.R. B.P.R.XR.I.R. fW.W.XF, R.-Sx. R.I.R.XB.P.R. R.-L.XSx. fSx.XFi R.-W.W. R.I.R.XB.P.R. R.I.R.XW.W. AVERAGE

Variety and variety crosses*

Annual average

TABLE 1.—Summary of a breeding test ofS. C. White Leghorns, S. C. Rhode Island Reds, and crossbred chickens

W

2

o

> a

zo

f H

8 > w

o

A TEST OF CROSSBRED CHICKENS

weight) of age, average age at first egg, and the percentage of pullets that were broody in their first laying year. Averages for these characteristics are also given for all of the crossbred progeny from parental crosses of the general purpose breeds, for all of the pullets from parental crosses involving Single Comb White Leghorn as one of the parental breeds, for the Single Comb White Leghorn progeny, and for the Rhode Island Red progeny. The number of individuals in each of the groups reported is large enough to make the differences noted statistically sound. It is quite obvious that a comparison of as many chaarcteristics as are shown in Table 1 will be quite complicated. It will be noted that some crosses are duplicated, as the stock was obtained from different breeders, and that these crosses produced different results. This was anticipated and the breeders were grouped into three classes, R.O.P. breeders or their equivalent, breeders of trap-nested stock, and breeders of non-trap-nested stock. Each breeder was identified by a code letter. A, B, C, G, H, I, K, and L were of the first classification, breeders F and J of the second class, and breeders D and E of the last class. The influence of the quality of the parental stock used in the crosses is shown by the results obtained from the progeny of similar crosses from different breeders. There were two such groups, one a cross between Rhode Island Red males and White Wyandotte females from breeders B and D and the other was a cross between Rhode Island Red males and Barred Plymouth Rock females from breeders C and D. In each case the crossbred progeny from the better breeder's stock gave better results than those from the other breeder. The progeny from the crosses of general purpose breeds, on an average, were better than the progeny from crosses involving the Single Comb White Leghorn in egg produc-

197

tion, egg weight, number of points, body weight at 10 and 20 weeks and at maturity. However, when the crosses involving breeder D's general purpose stock and the Leghorn crosses are compared, the Leghorn hybrids, on an average, produced more eggs and more points and better hatchability than the hybrids from these crosses of general purpose breeds. The eggs from the females in the crossed matings were equal in hatchability to the eggs from the females in standardbred matings. The crossbred progeny were older at first egg and had almost twice as much broodiness as the progeny from the acquired parental stock. It is interesting to note that the percentage of broodiness in the nonbroody lines, Single Comb White Leghorns, Rhode Island Reds, and the cross of two non-broody lines, White Leghorn with Black Minorca, was 3 percent, 5 percent, and 0 percent, respectively. However, hybrid progeny from crosses between the Barred Plymouth Rock and Rhode Island Reds and between the White Leghorn and White Plymouth Rocks had a greater incidence of broodiness and their reciprocal crosses gave different results. The progeny of Barred Plymouth Rock males crossed with Rhode Island Red pullets obtained from breeders A and C had 40 and 39 percent incidence of broodiness, respectively, and the reciprocal cross obtained from breeders C and D had 12 and 46 percent incidence of broodiness. The progeny of the White Leghorn males with the White Plymouth Rock females had an incidence of broodiness of 12 percent whereas the progeny from the reciprocal cross had 42 percent broodiness. The lack of broodiness in the non-broody breeds, non-broody strains, and crosses of the non-broody breeds and the different results cited from the progeny of reciprocal crosses between non-broody and broody breeds indicate that sex-linkage is involved, at least in part, in the inheritance

198

CHARLES W. KNOX AND MARLOW W. OLSEN

of broodiness. These results are similar to those obtained by Roberts and Card (1933). Two groups of progeny from three-way crosses are included in the results given in Table 1. Both groups involved the Rhode Island Reds, White Wyandottes, and Light Sussex. One group of progeny was obtained from a mating of White Wyandotte males to F a progeny from a cross between Rhode Island Red males and Light Sussex females. The other group was obtained from a mating of Light Sussex males to F± progeny from a cross between Rhode Island Red males and White Wyandotte pullets. Neither of these groups had as good egg production or early rate of growth as the F1 Red-Wyandotte hybrids, nor were they enough better in respect to the other characteristics to warrant their use in preference to the F1 hybrids.

crosses. The Leghorn progeny were slightly heavier in body weight at 10 weeks but weighed slightly less at 20 weeks of age and at maturity. The Rhode Island Red eggs had poorer hatchability but were incubated in a different incubator which was operated by a different operator, which might account for this difference, as the percentage of hatchability found at this time was considerably lower than usually observed in this stock. The Red progeny were not as heavy in body weight at 10 and 20 weeks as the crossbred progeny from the utility crosses but were slightly heavier at maturity. However, it is probable that the difference may be due to heterosis for early rate of growth usually found in crossbred progeny. The age at which the first egg was laid was later in the Rhode Island Reds than it was in either of the crossbred groups.

The crossbred chicks, on the average, had 13.3 percent better viability, calculated from the time that the chicks were a day old to the end of the first laying year, than the standardbred Leghorns. The best hybrids for egg production and early rate of growth were those obtained from crosses between the Rhode Island Reds and White Wyandottes and between Rhode Island Reds and Barred Rocks. As a matter of fact, these crosses when obtained from the better breeders are practically as good in respect to egg production, egg weight, and hatchability as the average of the Single Comb White Leghorn and Rhode Island Red pullets and better than the Single Comb White Leghorn stock in respect to body weight at all ages. The standardbred White Leghorn and Rhode Island Red progeny produced more eggs, more points, and had much less broodiness than the average of their crossbred progeny. The White Leghorn progeny had a better average egg weight than the Leghorn crossbred progeny and slightly less than the average of the general purpose

Although the results of this experiment do not verify previous opinions of the results of crossbreeding it does not mean that this method of approach for the production of superior commercial stock should be discarded. When compared to the many unsuccessful crosses discarded in corn breeding work it is only a very small beginning in crossbreeding of poultry. It is quite possible that the stock used in these crosses lacked the essential factors for producing successful hybrids. However, this investigation does show that considerable experience, skill, and intelligence is necessary for the production of successful hybrids. This work indicates also that much of the success depends upon the quality of the standardbred chickens used as parental stock in the cross and that the use of inferior parental standardbred stock merely produces another hybrid of doubtful quality and use. SUMMARY

1. The quality of the.parental stock has considerable influence upon the quality of the hybrid progeny.

A TEST OF CROSSBRED CHICKENS

2. Different strains of the same varieties of chickens may produce different results in the hybrid progeny obtained. 3. The results from the parental crosses studied in this investigation indicate that the average hybrid was superior only in the case of early body weight. 4. The results showed that the average hybrid chicken from purchased stock did not do so well in regard to egg production as did the average of the White Leghorn and Rhode Island Red stock. Reciprocal crosses between broody and non-broody breeds and strains gave different results indicating sex-linked broody factors. 5. The best hybrid progeny were obtained from crosses between Rhode Island Reds and Barred Plymouth Rocks and between Rhode Island Reds and White Wyandottes. These crosses obtained from good quality parental stock produced practically as well as the standardbred White Leghorns and Rhode Island Reds. 6. The viability of the hybrids was superior to that of the standardbred chickens. 7. The hybrids had a considerably greater incidence of broodiness than either the White Leghorns or Rhode Island Reds. REFERENCES

Axelson, Joel, 1932. Variation and heredity of some characters in White Leghorns, Rhode Island Reds, and Barnevelders. Lunds Univ. Arsskrift, N. F. Avd. 1(28):4-196. Byerly, Theodore, C , C. W. Knox, and Morley A. Jull, 1934. Some genetic aspects of hatchability. Poultry Sci. 13 :230-238. Chodat, R., 1921. Genetics in crossing of poultry. Soc. Phys. et Hist. Nat. Geneva Compt. Rend. 38:17-21. Cutler, D. W., 1918. On the sterility of hybrids between the pheasant and the Gold Campine fowl. Jour. Gen. 7 :155-165. Gericke, A. M., 1933. Crossing different breeds of poultry for table purposes. Fuig. S. Africa 8: 113-114. Jull, M. A., 1930. Studies in hatchability. IV. The effect of intercrossing inbred strains of chickens on fertility and hatchability. Poultry Sci. 9:1491S6.

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, 1933. Inbreeding and intercrossing in poultry. Jour. Hered. 24:93-101. Knox, C. W., M. A. Jull and J. P. Quinn, 1935. Correlation studies of egg production and possible genetic interpretation. Jour. Agr. Res. 50:573589. . Langen, H. R. van, 1930. Die Legetatigkeit der F 3 Generation aus der Kreusung schwarzer Rheinlander mit weissen Leghorn. Arch. f. Gefliigelkunde 4:40-41. Lippincott, W. A., 1920. Improving mongrel farm flocks through standardbred cockerels. Kan. Agr. Expt. Sta. Bull. 223. May, Henry, G., and Nelson F. Waters, 1927. The inheritance of body weight in the BrahmaLeghorn cross in the domestic fowl. Proc. World's Third Poultry Congress, 118-122. Pearl, Raymond, and F. M. Surface, 1910. Studies on hybrid poultry poultry. Me. Agr. Expt. Sta. Bull. 179. Phillips, J. C , 1913. Reciprocal crosses between Reeve's Pheasant and the common ring-neck pheasant producing unlike hybrids. Amer. Nat. 47 :701-704. , 1915. Experimental studies of hybridization among ducks and pheasants. Jour. Expt. Zool. 18:69-112. , 1916. Two pheasant crosses. Jour. Hered. 7:12. , 1921. A further report on species crosses in birds. Genetics 6:366-383. Quinn, J. P., W. H. Burrows, and T. C. Byerly, 1937. Turkey-chicken hybridization. Jour. Hered. 28:169-173. Roberts, E., and L. E. Card, 1933. Inheritance of broodiness in the domestic fowl. Proc. World's Fifth Poultry Congress 1 :l-6. Serebrovsky, A. S., 1929. Untersuchungen iiber Artbastarde bei Hiihnern. Jour. Gent. 21:327-340. Smith, G., and R. Haig-Thomas, 1913. On sterile and hybrid pheasants. Jour. Genetics 3:39-52. Tiniakoff, G. G., 1933. Hybrid of peacock and hen. (Russian with English summary.) Verhandl. d. landwirtsch. Instituts f. Bastardierung u. Acclimatisation in Ascania Nova. 1:85-98. , 1934. Peacock and hen hybrids and a comparative analysis of their parents. Jour. Biol. 3 :41-63. Warren, D. C , 1927. Hybrid vigor in poultry. Poultry Sci. 7 :l-8. , 1930. Crossbred poultry. Kan. Agr. Expt. Sta. Bull. 252. , and H. M. Scott, 1935. An attempt to produce turkey-chicken hybrids. Jour. Hered. 26:105-107.