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RESEARCH NOTES
TABLE 1.—Linkage data for "shaker"* and other sex-linked genes Classification of pullet progeny Genes tested
Sire
New Parental combinations
Crossing over, %
17 12 7 10 6
K and sh
Total
REFERENCES 23
26.4 35.3
2
11
6
B and sh
1 2
6 10
7 5
16
12
42.8-
17
0
0.0
S and K
2
* For the purpose of convenience for the present and future authors, the symbol sh is herewith assigned to indicate the gene for "shaker" and Sh for the normal allele.
tests of Sh with the mutant genes for naked (Hutt and Sturkie, 1938), albino
Bohren, B. B., 1950. A sex-linked nervous disorder in the fowl and its linkage relationship. Genetics, 35: 655. Hutt, F. B., 1949. Genetics of the fowl. New York. McGraw-Hill Book Company, Inc. Hutt, F. B., and P. D. Sturkie, 1938. Genetics of the fowl. IX. Naked, a new sex-linked mutation. J. Hered. 29: 370-379. Mueller, C. D., and F. B. Hutt, 1941. Genetics of the fowl. 12. Sex-linked, imperfect albinism. J. Hered. 32:71-80. Punnett, R. C , 1940. Genetic studies in poultry. X. Linkage data for the sex chromosome. J. Genet. 39: 335-342. Scott, H. M., C. C. Morrill, J. O. Alberts and Elmer Roberts, 1950. The "shaker" fowl—A sex-linked semi-lethal nervous disorder. J. Hered. 41: 254257.
EFFECT OF PENICILLIN ON THE GROWTH AND FEED EFFICIENCY OF CHICKS FED UREA. S. J. SLINGER, W. F. PEPPER, D. C. HILL AND H. D. BRANION Departments of Poultry Husbandry and Nutrition, Ontario Agricultural College, Guelph, Canada (Received for publication August 22, 1952)
Urea has been found unsatisfactory as a source of protein in chick diets (Ackerson el al., 1940; Bice and Dean, 1942). However, the possibility suggests itself that an increased utilization of urea might occur when antibiotics are included in the diet. Reported herein are three experiments designed to test this hypothesis. In experiment 1 each diet was fed to a group of 10 male and 10 female chicks composed of equal numbers of Columbian Rock and Columbian Rock X New Hamp-
shire chicks. In experiment 2, 20 male Columbian Rock chicks were used per group and in experiment 3, 9 male and 9 female Columbian Rock chicks. All chicks were one day old when placed on experiment. Basal diets used are given in Table 1 and the experimental data are given in Table 2. For experiment 1 urea was added at low levels to avoid possible toxic effects. On a nitrogen basis 0.38% and 0.76%
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64
S and sh
Total
(Mueller and Hutt, 1941) and dwarfism (Hutt, 1949) would be helpful. Two "shaker" pullets which reached sexual maturity were mated by artificial insemination to a carrier "jittery" male obtained from Dr. B. B. Bohren, Purdue University. The few eggs produced were infertile so that no stock was obtained which might be heterozygous for both genes.
1107
RESEARCH NOTES TABLE 1.—Composition of basal diets per 100 pounds Experiment No. Ingredient 1
2
3
Ground yellow corn 31.0 lbs. 77.0 lbs. 74.0 lbs. Ground oats 31.0 lbs. — — lbs. Ground wheat 30.0 lbs. 4.3 lbs. 10.25 Fish meal 13.0 lbs. 10.0 lbs. — Dried buttermilk 3.0 lbs. 3.0 lbs. — Dehydrated alfalfa 2.25 lbs. 1.0 lbs. 1.0 lbs. Limestone 1.0 lbs. 1.0 lbs. 1.0 lbs. Steamed bone meal 4.0 lbs. — — Iodized salt 0.5 lbs. 0.2 lbs. 0.25 lbs. Fish oil 0.25 lbs. 0.5 lbs. 0.5 lbs. Riboflavin 100 mg. 150 mg. 150 mg. Niacin 400 mg. 1.0 gm. 900 mg. Calcium pantothenate 200 mg. 300 mg. 300 mg. Vitamin Bis 1.0 mg. — gm. 17.5 — gm. Choline chloride 17.5 — Manganese sulfate 5.7 gm. 11.4 gm. 10.0 gm. Calculated protein (NX6.25) 10.5% 17.0% 15.5%
TABLE 2.—Effect
SUMMARY
Chick weights were not improved by
of penicillin on the utilization of urea by chicks Mean weight (gm.)2
Experiment
Supplement to basal 1
Feed: gain ratio
No penicillin
Plus penicillin3
No penicillin
Plus penicillin3
% decrease due to penicillin
1
none 0.38% urea 0.76% urea
715 685 726
733 702 776
2.65 2.61 2.94
2.50 2.53 2.48
5.7 3.1 15.6
2
none 1% urea 4 % urea 27% soybean oil meal
108 106 90 407
113 118 114 408
6.80 6.96 7.44 2.91
6.11 5.93 5.98 2.87
10.1 14.8 19.6 1.4
3
none 1% urea 2 % urea 3 % urea 12% soybean oil meal
415 423 432 401 575
449 474 434 436 620
2.48 2.47 2.58 2.80 2.27
2.56 2.54 2.65 2.58 2.26
-3.2 -2.8 -2.7 7.9 0.4
1 In experiments 1 and 3, supplements replaced an equal weight of corn, in experiment 2 an equal weight of wheat. 2 Mean weights for experiments 1, 2 and 3 are those at 7 weeks, 5 weeks and 38 days respectively. 3 10 p.p.m. procaine penicillin G, supplied through the courtesy of Merck and Co. Ltd., Montreal, Quebec.
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urea are equivalent to 1% and 2% of protein respectively. The results from experiment 1 may be summarized as follows. With no penicillin in the diet there was little effect on growth from added urea, but an increase in the feed: gain ratio from 2.65 to 2.94 occurred when 0.76% urea was used. With penicillin in the diet there is an indication that the addition of 0.76% urea increased growth. However, the feed:gain ratio remained relatively constant at all levels of urea. In the case of each diet, penicillin decreased the ratio. In experiment 2 the protein content of the basal diet was lowered to approxi-
mately 10.5% and higher levels of urea were used. A diet containing 2.7% soybean oil meal was included as a check on the growth potential of the birds. This experiment produced no evidence that urea was utilized for growth either in the presence or absence of penicillin. However, as in experiment 1, an increase occurred in the feed:gain ratio in the absence of penicillin but not in its presence. Again the addition of penicillin decreased the ratio for all diets. A third experiment, for which the basal diet contained approximately 15.5% protein, gave results which for the most part agreed with those from experiments 1 and 2. Thus, there was no evidence that urea was utilized for growth, but there was an increasing feed:gain ratio in the absence of penicillin and a relatively stable ratio in its presence. In this experiment a decrease in the ratio when penicillin was added was not obtained in every case. With three diets the ratio was increased, resulting in the negative values shown in Table 2.
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RESEARCH NOTES
the addition of urea to diets suboptimal in protein level either in the presence or the absence of penicillin in the diet. In the absence of penicillin the feed:gain ratio tended to be higher at higher levels of urea. However, in the presence of penicillin this effect was not observed.
REFERENCES Ackerson, C. W., W. E. Ham and F. E. Mussehl, 1940. The utilization of food elements by growing chicks. I X . The nitrogen of urea. Nebraska-Agric. Expt. Sta. Res. Bui. 120. Bice, G. M., and L. A. Dean, 1942. Utilization of urea nitrogen by growing chicks. Poultry Sci. 21: 15-17.
EVIDENCE OF BREED AND SEX DIFFERENCES IN THE WEIGHT OF CHICKS HATCHED FROM EGGS OF SIMILAR WEIGHTS 1 EDWARD F. GODFREY University of Tennessee, Knoxville
Ohio State University, Columbus (Received for publication September 8, 1952)
It has been demonstrated that breed differences exist in rate of embryonic growth (Byerly, 1930; Blunn and Gregory, 1935; Kaufman, 1936; and others), but differences in body weight are usually not present at hatching due to the effects of egg size. During a study of the genetic control of growth in the fowl, a difference between breeds and sexes was noted for chick weight, as expressed by "the percentage chick weight is of original egg weight" (percentage utilization). Baby chicks from Rose Comb Black Bantams (RCB), White and Barred Plymouth Rocks (WPR and BPR), and reciprocal crossbreeds between the large and small breeds were compared. In the case of the Bantam X Barred Plymouth Rock matings, all eggs were individually weighed prior to incubation and the chicks were individually hatched. The eggs and chicks were weighed and identified only^ according to kind in the Bantam X White Plymouth Rock series of 1 Published with the approval of the Director, Tennessee Agricultural Experiment Station.
matings. The use of reciprocal crossbreds allowed one parental kind and one crossbred kind to hatch from a large egg (laid by Plymouth Rock dams) and the other parental and crossbred kind to hatch from a small egg (laid by Bantam dams). The data for differences in percentage utilization of the egg between the kinds indicated that the Bantams utilized less of the egg than the larger parents (Table 1). Also, a " t " test for paired comparisons based upon egg weight demonstrated a statistically highly significant difference ( P = < . 0 1 ) between the weight of purebred Plymouth Rock and the Bantam X Plymouth Rock chicks. The purebreds utilized 1.84% more of the egg in the case of the BPR series, while the difference amounted to 2.09% in the Bantam-White Plymouth Rock series. There were no statistically significant differences in percentage utilization between the kinds hatched from Bantam eggs. In addition, there were no differences between the kinds in length of the incubation period. The males of three kinds of chicks in the Bantam-Barred Plymouth Rock series
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AND R. GEORGE JAAP