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A Comparison of the Performance of Four Varieties of Turkeys During the Breeding Season
A Comparison of the Performance of Four Varieties of Turkeys During the Breeding Season DONALD WHITSON, STANLEY J. MARSDEN, AND HARRY W. TITUS Bureau of Animal Industry, Agricultural Research Administration, United States Department of Agriculture, Beltsville Research Center, Beltsville, Maryland
ALTHOUGH there are a number of re•*• *• ports on the egg production of turkey hens, very few data are available for making a comparison of the different varieties. Marble and Margolf (1936) found somewhat higher egg production, to July 31, for Bronze than for White Holland turkeys. A report by Wilcke (1939) on the use of lights and heat for breeding turkeys indicates a slightly better egg production, to June 15 or June 30, for Bronze than for White Holland turkeys. Scott and Payne (1937) reported egg production, to May 25, for Narragansett turkeys. Mussehl (1926), Albright and Thompson (1933), Asmundson and Lloyd (1935), Marsden (1936 B), Asmundson (1938), and Thompson (1943) also have reported on the egg production of Bronze turkeys. Weight losses of turkeys during the breeding season have been reported by Purdue University (1934), Marsden (1936 A), Scott (1937), Charles, Wilcox, Flagg, and Tepper (1938), Asmundson and Jukes (1939), and Scott and Payne (1941). MATERIALS AND METHODS
In 1941 and 1942, breeding pens of standardbred Bronze, White Holland, and Broad Breasted Bronze turkeys, as well as of Beltsville Small White turkeys, were maintained at the Beltsville Research Center, Beltsville, Maryland. The data on date of first egg (sexual maturity), egg
production, feed consumption, live-weight changes, egg weight, fertility, and hatchability reported in this paper are for those pens of turkeys. One pen of each variety was included each of the two years, except 1942, in which year three pens of Beltsville Small White turkeys were included. The standardbred Bronze, the White Holland, and the Broad Breasted Bronze turkeys on which data were obtained in 1941 were hatched April 26, 1940, from eggs purchased from commercial breeders. Those on which data were obtained in 1942 were hatched April 23, 1941, and were the offspring of those that were hatched April 26, 1940. The Beltsville Small White turkeys were a part of the breeding flock maintained at the Beltsville Research Center; those on which data were obtained in 1941 and 1942 were hatched in several lots between April 10 and May 14, 1940, and between April 1 and May 29, 1941, respectively. Each breeding unit consisted of 19 to 21 young hens and one young torn and was kept in a pen, 14 feet by 14 feet, in an open front house. Each pen had two range lots, 14 feet by 200 feet, with a good bluegrass sod. The turkeys had access first to one range lot for 4 weeks and then to the other for the same length of time, from January 15 to June 1. Lights were started January 1, both years, on the toms; arid Janu-
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(Received for publication January 15, 1944)
COMPARISON OF THE BREEDING PERFORMANCE OF FOUR VARIETIES OF TURKEYS
Ground yellow corn Standard wheat middlings Ground oats Wheat bran Alfalfa leaf meal Dried skimmilk Meat scrap Fish meal Pulverized oystershell Salt Vitamin-A-and-D feeding oil Total
30 23 20 5 5 5 4 3 4 0.5 0.5 100.0
The "date of first egg" has been shown by Asmundson (1938) to be the most satisfactory measure of sexual maturity in turkeys. He used as a numerical measure of the date of first egg the number of days from December 31 to the day on which the first egg was laid. All hens were trapnested from January 15 to June 1. Those that were found to be nesting elsewhere than in the trapnests and those that were in laying condition but had not been on the trapnests were suitably banded and then, on several mornings, placed in the nests. Hens that were found in the nests on 3 successive days and had not laid were considered as broody. Broody hens were placed in broody coops with wire-mesh floors for seven days. This treatment was very effective in stopping the broodiness. Only the records of the hens that survived to June 1 were used in computing the egg production, date of first egg, live weight
changes, egg weight, fertility, and hatchability. "Floor" eggs were credited to the survivors in proportion to the number of "trapnest" eggs they produced. The live weights of all the turkeys were recorded every two weeks. These recorded live weights of the individual hens were used in estimating the maximum differences (losses) between the maximum weights attained in January or February and the minimum weights reached in April or May. However, the changes in weight were rapid, and so, the estimates of the maximum differences may be considerably less than they would have been if more frequent weighings had been made. "The feed consumed by each pen from January 15 to June 1 and the number of days each bird, including the torn, was in the pen were used in calculating the feed consumption per bird per day. Eggs were set at irregular intervals, the length of which depended on the rate of lay and the number of poults desired at one time. Eggs being held for incubation were stored at a temperature of 55°F. The maximum length of the holding or storage period was 5 weeks; the usual length was from 1 to 2 weeks. Records were kept of the fertility and hatchability of all the eggs that were incubated. Fertility was ascertained by candling on the eighth day of incubation. Hatchability was measured in two ways: First, by the number of strong vigorous poults; and, second, by the total number of poults. Throughout this paper "total poults" includes weak poults and "helpouts," but does not include crippled poults. During March and April the weights of 10 to 15 eggs from each hen were obtained. An unweighted ayerage egg weight for each pen was calculated by taking the average of the average egg weights for the individual hens in the pen.
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ary 15,1941, and January 16,1942, on the hens. The toms were put into the breeding pens January 22 and were observed at that time to ascertain whether they mated satisfactorily. It is recognized that these data are for one commercially available strain of each variety and therefore may or may not be representative of that variety. All pens received the same all-mash breeding diet. It was compounded as follows:
315
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D. WHITSON, S. J. MARSDEN, AND H. W. TITUS RESULTS
varieties and between 1941 and 1942. The White Hollands matured the earliest each year, they were significantly earlier than the Broad Breasted Bronzes and the Beltsville Small Whites in 1941, and significantly earlier than the other three varieties in 1942. The Broad Breasted Bronzes were significantly later maturing each year than the standardbred Bronzes or White Hollands, even though all three varieties were hatched at the same time and were fed and managed in the same manner.
TABLE 1.—Average egg production and average date of first «gg of the four varieties of turkeys
Variety of turkey
Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
Average number of eggs laid per hen to June l 1 1941
1942 Average
74.2 57.7 56.8 56.1
77.9 68.7 60.2 68.1
76.1 63.2 58.5 62.1
Average date of first egg2'3 1941 Feb. Feb. Feb. Feb.
8(39.3) 6 (36.5) 12 (42.7) 14 (45.4)
1942 Feb. Feb. Feb. Feb.
6(36.8) 2 (32.5) 9 (40.4) 8(39.2)
Average Feb. Feb. Feb. Feb.
7 4 11 11
(38.0) (34.5) (41.6) (42.3)
1
The least significant difference (odds of 19 to 1) between two pens is 10.66 eggs. The numerical measure of "date of first egg" is the number of days from December 31 to the day on which the first egg is laid. 3 The least significant difference (odds of 19 to 1) between two pens is 2.92 days. 2
ference in average egg production between them and the Broad Breasted Bronze turkeys was statistically significant. The pen of Beltsville Small White turkeys used in the 1941 comparison was not so good as other pens of that variety kept at this station under similar conditions that year. This particular pen had a lower egg production and a significantly later date of first egg than other pens of that variety kept at this station under similar conditions that year. The Beltsville Small White turkeys used in 1942 evidently were more typical of the variety in egg production and date of first egg than those used in 1941. The analysis of variance also showed that there were highly significant differences in date of first egg among the four
The coefficient of correlation between egg production and date of first egg was calculated and found to be —0.387. This value, although not large, -is highly significant (odds greater than 99:1). A summary of the changes in live weight is presented in Table 2. The average net losses in live weight between January 15 and May 21 in 1941, and January 16 and May 22 in 1942, are given for the females and for one male of each variety. In the case of the males, all losses in weight are those of individuals, except the 1942 loss of Beltsville Small White toms, which is y
the average loss of three individuals. Most of the birds reached their maximum weight in late January or February and then lost weight until about June 1. The average differences between the indi-
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Table 1 gives the average egg production per hen surviving to June 1, and the average date of first egg for each of the four varieties. An analysis of the variance of the data showed that there were highly significant differences in egg production among the four varieties and between 1941 and 1942. Also, it showed that the least significant difference in egg production between any two pens is 10.66 eggs. The standardbred Bronze turkeys were the best egg producers both years and the dif-
COMPARISON OF THE BREEDING PERFORMANCE OF FOUR VARIETIES OF TURKEYS TABLE 2 . --Averages
317
changes in live weight of the four varieties of turkeys Average difference between the individual maximum weights and the individual minimum weights 1
Average net loss in weight between January 15-16 and May 21-22 1 Sex and variety of turkey Absolute 1941
1942
Absolute
Relative
Relative
1941
1942
1941
Percent Percent Pounds
Pounds
Percent
1941
1942
1942 Percent
Pounds
2.02 1.25 2.12 1.34
1.27 1.09 .78 ,932
13.2 10.0 11.9 12.8
8.9 8.8 4.9 9.0 2
2.59 2.29 3.52 2.46
2.54 1.99 2.79 1.872
16.3 17.1 18.3 21.8
16.1 15.0 14.9 17.0 2
Male 3 Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
2.65 4.95 7.20 1.75
3.70 2.35 7.15 3.822
10.4 20.8 22.1 89
13.5 9-9 22.0 17.2 2
4.25 6.35 11.85 3.45
3.75 4.45 8.20 4.552
16.4 25:2 32.3 16.5
13.7 18.8 25.3 20.2 2
1 2 3
In the 18 week period that began January 15 in 1941 and January 16 in 1942. This is an average for |3 pens. There was only one male in each pen.
vidual maximum weights (in January or February) and the individual minimum weights (in April or May) also are shown in Table 2. The females of all four varieties lost 5 to 13 percent of their mid-January live weight by the 21st or the 22nd of May. The differences between the maximum weights and the corresponding minimum weights were from 15 to. 22 percent of the former. These differences were greater than the net losses in live weight, because many of the females gained for 2 to 4 weeks at the beginning of the period —a few for as long as 6 weeks—and several gained toward the end of the period. There was a small but significant (odds of 19 to 1) negative correlation between percent of change from maximum to minimum live weight and egg production (r=-0.168). The feed consumption per bird per day for the period between January 15 and June 1 is shown in Table 3. Considerable differences among the four varieties were observed. These differences, however, are greatly reduced when converted to pounds of feed per day per pound of live weight.
The large size of the Broad Breasted Bronze turkey probably accounts for its smaller consumption of feed per pound of live weight. TABLE 3. Average feed consumption of the four varieties of turkeys between January 15 and June 1 Average weight of feed consumed 1 Variety of turkey
Per bird per day 1941
Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
1942
Per pound of live weight per day 1941
1942
Pound Pound Pound
Pound
0.53 .44
0.48 .43
0.033 .032
0.031 .032
.57
.51
.030
.027
.38
.36
.032
.031
1 These averages are for pens in which there were 19 to 21 hens and 1 torn.
The average mortality among the females was about 10 percent and is summarized in Table 4. It resulted from several causes, among which blackhead and trichomoniasis were the most important.
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Pounds Female Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
318
D. WHITSON, S. J," MAESDEN, AND H. W. TITUS TABLE 4. Mortality among the females of the four varieties of turkeys between January 15 and June 1 Mortality Variety of turkey
Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
1941
1942
Percent 31.6 10.5 10.5 4.8
Percent 15.8 21.0 5.3 9.5
small but highly significant correlation (r = .354) was found between the hatchability of the fertile eggs set and egg production. As shown by the data in Table 5, there were more weak and "helpout" poults among the Broad Breasted Bronze poults than among those of the other varities. Inasmuch as the percent of total poults from all eggs set includes weak and "helpout" poults, it may be considered as the maximum hatchability obtainable under ordinary conditions. However, it is probable that the irregular schedule according to which the eggs were incubated may have caused a reduction in apparent fertility and hatchability. DISCUSSION
The observations reported here show that there were significant differences among the four varieties of turkeys, especially in date of first egg (date of sexual
TABLE 5.—Average weight, fertility, and hatchability of the eggs of the four varieties of turkeys
Variety of turkey
Average weight per egg1
1 2 3 4 6 6
6 Hatchability 3 Hatchability 3 Total poults from all of all of fertile eggs set eggs set6 eggs set4
1941
1942
1941
1942
1941
1942
1941
1942
Grams Grams Percent 83.3 83.9 95.2 89.2 89.3 96.9 88.7 90.9 75.5 76.2 77.6 97.3
Percent 93.9 96.7 87.6 88.3
Percent 70.0 66.2 45.2 73.0
Percent 76.8 77.5 52.5 82.9
Percent 66.8 64.3 34.9 71.0
Percent 72.0 75.1 47.6 73.3
Percent 68.2 66.9 42.2 71.5
Percent 73.8 80.1 57.7 75.8
1941
Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
Fertility 2
1942
Least significant difference (odds of 19 to 1), in average weight per egg, between pens is 8 grams. Least significant difference (odds of 19 to 1), in fertility, between pens is 9.58 percent. Does not include weak, "helpout," or crippled poults. Least significant difference (odds of 19 to 1), in hatchability of fertile eggs, between pens is 9.83 percent. Least significant difference (odds of 19 to 1), in hatchability of all eggs, between pens is 11.54 percent. Includes weak and "helpout" poults, but not crippled poults.
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The average weight, fertility, and hatchability of the eggs are shown in Table 5. The eggs produced by the White Holland and the Broad Breasted Bronze were significantly heavier than the eggs of the Beltsville Small White; the eggs of the standardbred Bronze were intermediate in size. In the White Holland variety the weights of the eggs were appreciably heavier in proportion to the live weights of the hens than in the other varieties. The fertility of the eggs of the Broad Breasted Bronze was significantly poorer than that of the other varieties in 1941. There were no significant differences in the fertility of the four varieties in 1942. There was no appreciable correlation between egg production and fertility of the eggs (r = .O20). The data in Table 5 show that the Broad Breasted Bronze turkeys had a significantly lower hatchability each year, both of fertile eggs set and of all eggs set, than the other varieties. There were no significant differences in hatchability among the other varieties in either 1941 or 1942. The hatchability of fertile eggs set was higher for each variety in 1942 than in 1941, and for the White Holland and Beltsville Small White turkeys the differences between the two years were statistically significant. A
COMPARISON OF THE BREEDING PERFORMANCE OF FOUR VARIETIES OF TURKEYS
When 19 to 21 females of the standardbred Bronze, White Holland or Beltsville Small White varieties were mated with one male, 92 to 98 percent of their eggs were fertile. However, in 1942 in one of the 3 pens of Beltsville Small Whites the fertility was only 78 percent, the torn in that pen was found to be almost completely sterile and was replaced March 3. The low fertility in that pen accounts for the low average fertility shown in Table 5 for this variety in 1942. In contrast with the high fertility in these varieties, that in the Broad Breasted Bronze was distinctly low. It is possible that the fertility of the Broad Breasted Bronze would have been higher if a smaller number of females had been mated with one male. The loss of weight by all four varieties of turkeys, the larger losses of weight by the males than by the females, and the negative correlation between loss of weight and egg production in the females, all indicate that the loss in weight is essentially a seasonal phenomenon. SUMMARY A two-year study was made of the date of first egg (date of sexual maturity), feed
consumption, changes in live weight, egg production, egg weight, fertility, and hatchability of a commercially available strain of standardbred Bronze, White Holland, Broad Breasted Bronze, and Beltsville Small White turkeys. Analyses of variance showed that there were highly significant differences among the four varieties in egg production and in date of first egg. Egg production to June 1 averaged 76, 63, 59, and 62 eggs for the standardbred Bronze, White Holland, Broad Breasted Bronze, and Beltsville Small White turkeys, respectively. The Broad Breasted Bronze was significantly later in maturing each year than the standardbred Bronze or White Holland varieties under the same conditions. The average dates of sexual maturity of the standardbred Bronze, White Holland, Broad Breasted Bronze and Beltsville Small White turkeys were February 7, 4, 11, and 11, respecively. All turkeys lost weight between January IS and June 1, the males about 16 percent, and the females about 10 percent. Feed consumption was directly proportional to the maximum live weights of the four varieties, being approximately .031 pounds of feed per day per pound of live weight. The Broad Breasted Bronze had a significantly lower hatchability of fertile eggs than the other varieties each year. The hatchability of all eggs set averaged 67, 64, 35, and 71 percent in 1941, and 72, 75, 48, and 73 percent in .1942, for the standardbred Bronze, White Holland, Broad Breasted Bronze, and Beltsville Small White turkeys, respectively. REFERENCES
Albright, W. P., and R. B. Thompson, 1933. Securing early turkeys by stimulated egg production. Poultry Sci. 12:124-128. Asmundson, V. S., and W. E. Lloyd, 1935. Effect of age on the reproduction of the turkey hen. Poultry Sci. 14:259-266.
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maturity) and in egg production to June 1. This suggests that selection for early maturity should result in an increase in egg production in both the Broad Breasted Bronze and the Beltsville Small White. And, inasmuch as there is some correlation between hatchability and egg production, the rather low hatchability of the eggs of the Broad Breasted Bronze might increase simultaneously with any appreciable decrease in the number of days between January 1 and the date of the first egg. The late maturity of the Broad Breasted Bronze also suggests that the earlier use of lights, and the use of more hours of light per day, might be helpful in bringing about an increase in egg production in this variety.
319
320
BOOK R E V I E W S
Mussehl, F. E., 1926. Turkey production. Nebraska Agr. Expt. Sta. Cir. 34. Purdue University Agr. Expt. Sta. Report of Director, 1934. Variations in the weights of mature turkeys. Scott, H. M., 1937. Turkey production in Kansas. Kansas Agr. Expt. Sta. Bui. 276. , and L. F. Payne, 1937. Light in relation to the experimental modification of the breeding season of turkeys. Poultry Sci. 16:90-96. , 1941. The influence of restricted food intake of the reproductive performance of breeding turkeys. Poultry Sci. 20:395-401. Thompson, J. N., 1943. With Broad Breasts its balance. Turkey World 18 (9): 14-16, 39-40. Wilcke, H. L., 1939. The use of artificial lights for turkeys. Poultry Sci. 18: 236-243.
Book Reviews Haynes, Sheppard K n a p p . Practical Pigeon Production. New York: Orange Judd Publishing Company, 1944. 263 p p . 55 illustrations. Price $2.00. T h e title clearly describes this most recent text on squab raising. T h e primary purpose of t h e a u t h o r in t h e preparation of this book was to present t h e necessary essentials for successful squab production. The book is brief and clearly written. I t is well indexed and illustrated, although many of t h e illustrations show different breeds a n d varieties of pigeons. T h e use of additional illustrations in such chapters as the one discussing diseases would add much to t h e understanding of t h e reader. Numbering of t h e illustrations would help if t h e book was used for classroom work. Special emphasis is given to problems of production and marketing since these fields are of major importance to t h e commercial pigeon raiser. D . R. M .
Campbell, D . M . (Lt. Col. U.S.A.V.C.) 1944. Veterinary Service a t an Army Post. Veterinary Magazine Corporation, Chicago. 64 p p . (Reprinted from Vet. Med. 39(3): 81-142, 1943). This is a compilation of a series of 16 articles b y t h e a u t h o r on t h e various functions of the U. S. Army Veterinary Corps. I t is concerned with t h e functions other t h a n those relating to the care of horses, which is now a very small p a r t of the duties of the Veterinary Corps. Chapters of interest to Readers of POULTRY S C I E N C E
include " S t a n d a r d s of Army Food I n spection," " P o u l t r y Slaughtering," " I n spection of Poultry and Egg H o u s e , " "Shell E g g s , " a n d " E g g Powder." Other chapters relate to the Dairy a n d Produce Inspection duties of a Post Veterinarian. W. R. H .
Downloaded from http://ps.oxfordjournals.org/ at UNIVERSITY OF ARIZONA on April 19, 2015
Asmundson, V. S., 1938. The influence of various factors on egg production in turkeys. Jour. Agr. Res. 56:387-393. — , and T. H. Jukes, 1939. Turkey production in California. California Agricultural Extension Circular 110. Charles T. B., P. A. Wilcox, D. W. Flagg, and A. E. Tepper, 1938. Confinement versus open range for Bronze turkey breeders. Poultry Sci. 17:248-252. Marble, D. R., and P. H. Margolf, 1936. The selection and management of turkey breeders. Poultry Sci. 15:225-229. Marsden, S. J., 1936A. Feed consumption and cost of feeding of Bronze turkey breeding stock. Poultry Sci. 15:400-404. , 1936B. A study of egg production in Bronze turkeys. Poultry Sci. 15:439-445.
ALTHOUGH there are a number of re•*• *• ports on the egg production of turkey hens, very few data are available for making a comparison of the different varieties. Marble and Margolf (1936) found somewhat higher egg production, to July 31, for Bronze than for White Holland turkeys. A report by Wilcke (1939) on the use of lights and heat for breeding turkeys indicates a slightly better egg production, to June 15 or June 30, for Bronze than for White Holland turkeys. Scott and Payne (1937) reported egg production, to May 25, for Narragansett turkeys. Mussehl (1926), Albright and Thompson (1933), Asmundson and Lloyd (1935), Marsden (1936 B), Asmundson (1938), and Thompson (1943) also have reported on the egg production of Bronze turkeys. Weight losses of turkeys during the breeding season have been reported by Purdue University (1934), Marsden (1936 A), Scott (1937), Charles, Wilcox, Flagg, and Tepper (1938), Asmundson and Jukes (1939), and Scott and Payne (1941). MATERIALS AND METHODS
In 1941 and 1942, breeding pens of standardbred Bronze, White Holland, and Broad Breasted Bronze turkeys, as well as of Beltsville Small White turkeys, were maintained at the Beltsville Research Center, Beltsville, Maryland. The data on date of first egg (sexual maturity), egg
production, feed consumption, live-weight changes, egg weight, fertility, and hatchability reported in this paper are for those pens of turkeys. One pen of each variety was included each of the two years, except 1942, in which year three pens of Beltsville Small White turkeys were included. The standardbred Bronze, the White Holland, and the Broad Breasted Bronze turkeys on which data were obtained in 1941 were hatched April 26, 1940, from eggs purchased from commercial breeders. Those on which data were obtained in 1942 were hatched April 23, 1941, and were the offspring of those that were hatched April 26, 1940. The Beltsville Small White turkeys were a part of the breeding flock maintained at the Beltsville Research Center; those on which data were obtained in 1941 and 1942 were hatched in several lots between April 10 and May 14, 1940, and between April 1 and May 29, 1941, respectively. Each breeding unit consisted of 19 to 21 young hens and one young torn and was kept in a pen, 14 feet by 14 feet, in an open front house. Each pen had two range lots, 14 feet by 200 feet, with a good bluegrass sod. The turkeys had access first to one range lot for 4 weeks and then to the other for the same length of time, from January 15 to June 1. Lights were started January 1, both years, on the toms; arid Janu-
13141
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(Received for publication January 15, 1944)
COMPARISON OF THE BREEDING PERFORMANCE OF FOUR VARIETIES OF TURKEYS
Ground yellow corn Standard wheat middlings Ground oats Wheat bran Alfalfa leaf meal Dried skimmilk Meat scrap Fish meal Pulverized oystershell Salt Vitamin-A-and-D feeding oil Total
30 23 20 5 5 5 4 3 4 0.5 0.5 100.0
The "date of first egg" has been shown by Asmundson (1938) to be the most satisfactory measure of sexual maturity in turkeys. He used as a numerical measure of the date of first egg the number of days from December 31 to the day on which the first egg was laid. All hens were trapnested from January 15 to June 1. Those that were found to be nesting elsewhere than in the trapnests and those that were in laying condition but had not been on the trapnests were suitably banded and then, on several mornings, placed in the nests. Hens that were found in the nests on 3 successive days and had not laid were considered as broody. Broody hens were placed in broody coops with wire-mesh floors for seven days. This treatment was very effective in stopping the broodiness. Only the records of the hens that survived to June 1 were used in computing the egg production, date of first egg, live weight
changes, egg weight, fertility, and hatchability. "Floor" eggs were credited to the survivors in proportion to the number of "trapnest" eggs they produced. The live weights of all the turkeys were recorded every two weeks. These recorded live weights of the individual hens were used in estimating the maximum differences (losses) between the maximum weights attained in January or February and the minimum weights reached in April or May. However, the changes in weight were rapid, and so, the estimates of the maximum differences may be considerably less than they would have been if more frequent weighings had been made. "The feed consumed by each pen from January 15 to June 1 and the number of days each bird, including the torn, was in the pen were used in calculating the feed consumption per bird per day. Eggs were set at irregular intervals, the length of which depended on the rate of lay and the number of poults desired at one time. Eggs being held for incubation were stored at a temperature of 55°F. The maximum length of the holding or storage period was 5 weeks; the usual length was from 1 to 2 weeks. Records were kept of the fertility and hatchability of all the eggs that were incubated. Fertility was ascertained by candling on the eighth day of incubation. Hatchability was measured in two ways: First, by the number of strong vigorous poults; and, second, by the total number of poults. Throughout this paper "total poults" includes weak poults and "helpouts," but does not include crippled poults. During March and April the weights of 10 to 15 eggs from each hen were obtained. An unweighted ayerage egg weight for each pen was calculated by taking the average of the average egg weights for the individual hens in the pen.
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ary 15,1941, and January 16,1942, on the hens. The toms were put into the breeding pens January 22 and were observed at that time to ascertain whether they mated satisfactorily. It is recognized that these data are for one commercially available strain of each variety and therefore may or may not be representative of that variety. All pens received the same all-mash breeding diet. It was compounded as follows:
315
316
D. WHITSON, S. J. MARSDEN, AND H. W. TITUS RESULTS
varieties and between 1941 and 1942. The White Hollands matured the earliest each year, they were significantly earlier than the Broad Breasted Bronzes and the Beltsville Small Whites in 1941, and significantly earlier than the other three varieties in 1942. The Broad Breasted Bronzes were significantly later maturing each year than the standardbred Bronzes or White Hollands, even though all three varieties were hatched at the same time and were fed and managed in the same manner.
TABLE 1.—Average egg production and average date of first «gg of the four varieties of turkeys
Variety of turkey
Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
Average number of eggs laid per hen to June l 1 1941
1942 Average
74.2 57.7 56.8 56.1
77.9 68.7 60.2 68.1
76.1 63.2 58.5 62.1
Average date of first egg2'3 1941 Feb. Feb. Feb. Feb.
8(39.3) 6 (36.5) 12 (42.7) 14 (45.4)
1942 Feb. Feb. Feb. Feb.
6(36.8) 2 (32.5) 9 (40.4) 8(39.2)
Average Feb. Feb. Feb. Feb.
7 4 11 11
(38.0) (34.5) (41.6) (42.3)
1
The least significant difference (odds of 19 to 1) between two pens is 10.66 eggs. The numerical measure of "date of first egg" is the number of days from December 31 to the day on which the first egg is laid. 3 The least significant difference (odds of 19 to 1) between two pens is 2.92 days. 2
ference in average egg production between them and the Broad Breasted Bronze turkeys was statistically significant. The pen of Beltsville Small White turkeys used in the 1941 comparison was not so good as other pens of that variety kept at this station under similar conditions that year. This particular pen had a lower egg production and a significantly later date of first egg than other pens of that variety kept at this station under similar conditions that year. The Beltsville Small White turkeys used in 1942 evidently were more typical of the variety in egg production and date of first egg than those used in 1941. The analysis of variance also showed that there were highly significant differences in date of first egg among the four
The coefficient of correlation between egg production and date of first egg was calculated and found to be —0.387. This value, although not large, -is highly significant (odds greater than 99:1). A summary of the changes in live weight is presented in Table 2. The average net losses in live weight between January 15 and May 21 in 1941, and January 16 and May 22 in 1942, are given for the females and for one male of each variety. In the case of the males, all losses in weight are those of individuals, except the 1942 loss of Beltsville Small White toms, which is y
the average loss of three individuals. Most of the birds reached their maximum weight in late January or February and then lost weight until about June 1. The average differences between the indi-
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Table 1 gives the average egg production per hen surviving to June 1, and the average date of first egg for each of the four varieties. An analysis of the variance of the data showed that there were highly significant differences in egg production among the four varieties and between 1941 and 1942. Also, it showed that the least significant difference in egg production between any two pens is 10.66 eggs. The standardbred Bronze turkeys were the best egg producers both years and the dif-
COMPARISON OF THE BREEDING PERFORMANCE OF FOUR VARIETIES OF TURKEYS TABLE 2 . --Averages
317
changes in live weight of the four varieties of turkeys Average difference between the individual maximum weights and the individual minimum weights 1
Average net loss in weight between January 15-16 and May 21-22 1 Sex and variety of turkey Absolute 1941
1942
Absolute
Relative
Relative
1941
1942
1941
Percent Percent Pounds
Pounds
Percent
1941
1942
1942 Percent
Pounds
2.02 1.25 2.12 1.34
1.27 1.09 .78 ,932
13.2 10.0 11.9 12.8
8.9 8.8 4.9 9.0 2
2.59 2.29 3.52 2.46
2.54 1.99 2.79 1.872
16.3 17.1 18.3 21.8
16.1 15.0 14.9 17.0 2
Male 3 Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
2.65 4.95 7.20 1.75
3.70 2.35 7.15 3.822
10.4 20.8 22.1 89
13.5 9-9 22.0 17.2 2
4.25 6.35 11.85 3.45
3.75 4.45 8.20 4.552
16.4 25:2 32.3 16.5
13.7 18.8 25.3 20.2 2
1 2 3
In the 18 week period that began January 15 in 1941 and January 16 in 1942. This is an average for |3 pens. There was only one male in each pen.
vidual maximum weights (in January or February) and the individual minimum weights (in April or May) also are shown in Table 2. The females of all four varieties lost 5 to 13 percent of their mid-January live weight by the 21st or the 22nd of May. The differences between the maximum weights and the corresponding minimum weights were from 15 to. 22 percent of the former. These differences were greater than the net losses in live weight, because many of the females gained for 2 to 4 weeks at the beginning of the period —a few for as long as 6 weeks—and several gained toward the end of the period. There was a small but significant (odds of 19 to 1) negative correlation between percent of change from maximum to minimum live weight and egg production (r=-0.168). The feed consumption per bird per day for the period between January 15 and June 1 is shown in Table 3. Considerable differences among the four varieties were observed. These differences, however, are greatly reduced when converted to pounds of feed per day per pound of live weight.
The large size of the Broad Breasted Bronze turkey probably accounts for its smaller consumption of feed per pound of live weight. TABLE 3. Average feed consumption of the four varieties of turkeys between January 15 and June 1 Average weight of feed consumed 1 Variety of turkey
Per bird per day 1941
Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
1942
Per pound of live weight per day 1941
1942
Pound Pound Pound
Pound
0.53 .44
0.48 .43
0.033 .032
0.031 .032
.57
.51
.030
.027
.38
.36
.032
.031
1 These averages are for pens in which there were 19 to 21 hens and 1 torn.
The average mortality among the females was about 10 percent and is summarized in Table 4. It resulted from several causes, among which blackhead and trichomoniasis were the most important.
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Pounds Female Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
318
D. WHITSON, S. J," MAESDEN, AND H. W. TITUS TABLE 4. Mortality among the females of the four varieties of turkeys between January 15 and June 1 Mortality Variety of turkey
Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
1941
1942
Percent 31.6 10.5 10.5 4.8
Percent 15.8 21.0 5.3 9.5
small but highly significant correlation (r = .354) was found between the hatchability of the fertile eggs set and egg production. As shown by the data in Table 5, there were more weak and "helpout" poults among the Broad Breasted Bronze poults than among those of the other varities. Inasmuch as the percent of total poults from all eggs set includes weak and "helpout" poults, it may be considered as the maximum hatchability obtainable under ordinary conditions. However, it is probable that the irregular schedule according to which the eggs were incubated may have caused a reduction in apparent fertility and hatchability. DISCUSSION
The observations reported here show that there were significant differences among the four varieties of turkeys, especially in date of first egg (date of sexual
TABLE 5.—Average weight, fertility, and hatchability of the eggs of the four varieties of turkeys
Variety of turkey
Average weight per egg1
1 2 3 4 6 6
6 Hatchability 3 Hatchability 3 Total poults from all of all of fertile eggs set eggs set6 eggs set4
1941
1942
1941
1942
1941
1942
1941
1942
Grams Grams Percent 83.3 83.9 95.2 89.2 89.3 96.9 88.7 90.9 75.5 76.2 77.6 97.3
Percent 93.9 96.7 87.6 88.3
Percent 70.0 66.2 45.2 73.0
Percent 76.8 77.5 52.5 82.9
Percent 66.8 64.3 34.9 71.0
Percent 72.0 75.1 47.6 73.3
Percent 68.2 66.9 42.2 71.5
Percent 73.8 80.1 57.7 75.8
1941
Standardbred Bronze White Holland Broad Breasted Bronze Beltsville Small White
Fertility 2
1942
Least significant difference (odds of 19 to 1), in average weight per egg, between pens is 8 grams. Least significant difference (odds of 19 to 1), in fertility, between pens is 9.58 percent. Does not include weak, "helpout," or crippled poults. Least significant difference (odds of 19 to 1), in hatchability of fertile eggs, between pens is 9.83 percent. Least significant difference (odds of 19 to 1), in hatchability of all eggs, between pens is 11.54 percent. Includes weak and "helpout" poults, but not crippled poults.
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The average weight, fertility, and hatchability of the eggs are shown in Table 5. The eggs produced by the White Holland and the Broad Breasted Bronze were significantly heavier than the eggs of the Beltsville Small White; the eggs of the standardbred Bronze were intermediate in size. In the White Holland variety the weights of the eggs were appreciably heavier in proportion to the live weights of the hens than in the other varieties. The fertility of the eggs of the Broad Breasted Bronze was significantly poorer than that of the other varieties in 1941. There were no significant differences in the fertility of the four varieties in 1942. There was no appreciable correlation between egg production and fertility of the eggs (r = .O20). The data in Table 5 show that the Broad Breasted Bronze turkeys had a significantly lower hatchability each year, both of fertile eggs set and of all eggs set, than the other varieties. There were no significant differences in hatchability among the other varieties in either 1941 or 1942. The hatchability of fertile eggs set was higher for each variety in 1942 than in 1941, and for the White Holland and Beltsville Small White turkeys the differences between the two years were statistically significant. A
COMPARISON OF THE BREEDING PERFORMANCE OF FOUR VARIETIES OF TURKEYS
When 19 to 21 females of the standardbred Bronze, White Holland or Beltsville Small White varieties were mated with one male, 92 to 98 percent of their eggs were fertile. However, in 1942 in one of the 3 pens of Beltsville Small Whites the fertility was only 78 percent, the torn in that pen was found to be almost completely sterile and was replaced March 3. The low fertility in that pen accounts for the low average fertility shown in Table 5 for this variety in 1942. In contrast with the high fertility in these varieties, that in the Broad Breasted Bronze was distinctly low. It is possible that the fertility of the Broad Breasted Bronze would have been higher if a smaller number of females had been mated with one male. The loss of weight by all four varieties of turkeys, the larger losses of weight by the males than by the females, and the negative correlation between loss of weight and egg production in the females, all indicate that the loss in weight is essentially a seasonal phenomenon. SUMMARY A two-year study was made of the date of first egg (date of sexual maturity), feed
consumption, changes in live weight, egg production, egg weight, fertility, and hatchability of a commercially available strain of standardbred Bronze, White Holland, Broad Breasted Bronze, and Beltsville Small White turkeys. Analyses of variance showed that there were highly significant differences among the four varieties in egg production and in date of first egg. Egg production to June 1 averaged 76, 63, 59, and 62 eggs for the standardbred Bronze, White Holland, Broad Breasted Bronze, and Beltsville Small White turkeys, respectively. The Broad Breasted Bronze was significantly later in maturing each year than the standardbred Bronze or White Holland varieties under the same conditions. The average dates of sexual maturity of the standardbred Bronze, White Holland, Broad Breasted Bronze and Beltsville Small White turkeys were February 7, 4, 11, and 11, respecively. All turkeys lost weight between January IS and June 1, the males about 16 percent, and the females about 10 percent. Feed consumption was directly proportional to the maximum live weights of the four varieties, being approximately .031 pounds of feed per day per pound of live weight. The Broad Breasted Bronze had a significantly lower hatchability of fertile eggs than the other varieties each year. The hatchability of all eggs set averaged 67, 64, 35, and 71 percent in 1941, and 72, 75, 48, and 73 percent in .1942, for the standardbred Bronze, White Holland, Broad Breasted Bronze, and Beltsville Small White turkeys, respectively. REFERENCES
Albright, W. P., and R. B. Thompson, 1933. Securing early turkeys by stimulated egg production. Poultry Sci. 12:124-128. Asmundson, V. S., and W. E. Lloyd, 1935. Effect of age on the reproduction of the turkey hen. Poultry Sci. 14:259-266.
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maturity) and in egg production to June 1. This suggests that selection for early maturity should result in an increase in egg production in both the Broad Breasted Bronze and the Beltsville Small White. And, inasmuch as there is some correlation between hatchability and egg production, the rather low hatchability of the eggs of the Broad Breasted Bronze might increase simultaneously with any appreciable decrease in the number of days between January 1 and the date of the first egg. The late maturity of the Broad Breasted Bronze also suggests that the earlier use of lights, and the use of more hours of light per day, might be helpful in bringing about an increase in egg production in this variety.
319
320
BOOK R E V I E W S
Mussehl, F. E., 1926. Turkey production. Nebraska Agr. Expt. Sta. Cir. 34. Purdue University Agr. Expt. Sta. Report of Director, 1934. Variations in the weights of mature turkeys. Scott, H. M., 1937. Turkey production in Kansas. Kansas Agr. Expt. Sta. Bui. 276. , and L. F. Payne, 1937. Light in relation to the experimental modification of the breeding season of turkeys. Poultry Sci. 16:90-96. , 1941. The influence of restricted food intake of the reproductive performance of breeding turkeys. Poultry Sci. 20:395-401. Thompson, J. N., 1943. With Broad Breasts its balance. Turkey World 18 (9): 14-16, 39-40. Wilcke, H. L., 1939. The use of artificial lights for turkeys. Poultry Sci. 18: 236-243.
Book Reviews Haynes, Sheppard K n a p p . Practical Pigeon Production. New York: Orange Judd Publishing Company, 1944. 263 p p . 55 illustrations. Price $2.00. T h e title clearly describes this most recent text on squab raising. T h e primary purpose of t h e a u t h o r in t h e preparation of this book was to present t h e necessary essentials for successful squab production. The book is brief and clearly written. I t is well indexed and illustrated, although many of t h e illustrations show different breeds a n d varieties of pigeons. T h e use of additional illustrations in such chapters as the one discussing diseases would add much to t h e understanding of t h e reader. Numbering of t h e illustrations would help if t h e book was used for classroom work. Special emphasis is given to problems of production and marketing since these fields are of major importance to t h e commercial pigeon raiser. D . R. M .
Campbell, D . M . (Lt. Col. U.S.A.V.C.) 1944. Veterinary Service a t an Army Post. Veterinary Magazine Corporation, Chicago. 64 p p . (Reprinted from Vet. Med. 39(3): 81-142, 1943). This is a compilation of a series of 16 articles b y t h e a u t h o r on t h e various functions of the U. S. Army Veterinary Corps. I t is concerned with t h e functions other t h a n those relating to the care of horses, which is now a very small p a r t of the duties of the Veterinary Corps. Chapters of interest to Readers of POULTRY S C I E N C E
include " S t a n d a r d s of Army Food I n spection," " P o u l t r y Slaughtering," " I n spection of Poultry and Egg H o u s e , " "Shell E g g s , " a n d " E g g Powder." Other chapters relate to the Dairy a n d Produce Inspection duties of a Post Veterinarian. W. R. H .
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Asmundson, V. S., 1938. The influence of various factors on egg production in turkeys. Jour. Agr. Res. 56:387-393. — , and T. H. Jukes, 1939. Turkey production in California. California Agricultural Extension Circular 110. Charles T. B., P. A. Wilcox, D. W. Flagg, and A. E. Tepper, 1938. Confinement versus open range for Bronze turkey breeders. Poultry Sci. 17:248-252. Marble, D. R., and P. H. Margolf, 1936. The selection and management of turkey breeders. Poultry Sci. 15:225-229. Marsden, S. J., 1936A. Feed consumption and cost of feeding of Bronze turkey breeding stock. Poultry Sci. 15:400-404. , 1936B. A study of egg production in Bronze turkeys. Poultry Sci. 15:439-445.