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The Effect of Length of Daily Light Periods on Reproduction in Female Chickens1
ULTRASONIC TREATMENT AND EGG QUALITY
the ultrasonic treatment on the porosity of the egg shell, or on the physical movement of bacteria through the shell membrane. ACKNOWLEDGMENTS Appreciation is expressed to HermesSonic Corporation, New York, New York, for supplying ultrasonic equipment, and to the Big Dutchman Automatic Poultry Equipment Company, Zeeland, Michigan, for other egg washing equipment used in this study. REFERENCES Almquist, H. J., and W. F. Hoist, 1931. Variability of shell porosity in the hen's egg. Hilgardia, 6: 61-71. Carlin, B., 1949. Ultrasonics, McGraw-Hill Book Co., Inc., New York. Crawford, A. E., 1955. Ultrasonic Engineering with Particular Reference to High Power Applications. Butterworth's Scientific Publications, London, England. Dawson, L. E., C. W. Hall and E. H. Farmer, 1961. The use of ultrasonic energy for cleaning eggs.
1161
Poultry Sci. 41: 620-626. Fromm, D., and R. J. Munroe, 1960. Interior physical quality and bacterial contamination of market eggs as influenced by egg shell permeability. Food Technol. 14:401-403. Johnson, C. H., 1929. The lethal effects of ultrasonic radiation. J. Physiol. 67: 356-359. Kilpatrick, L., A. W. Brant and H. L. Shrader, 1958. Equipment and methods for measuring egg quality. A.M.S. No. 246, U.S.D.A. Agricultural Marketing Service, Washington 25, D.C. Kramer, A., 1960. A rapid method for determining significance of differences from rank sums. Food Technol. 14:576-581. Murdock, A., Jr., 1956. Ultrasonics . . . How it works and what it does. American Machine, 100: 97-104. Stuart, L. S., and E. H. McNally, 1943. Bacteriological studies on the egg shell. U. S. Egg Poultry Mag. 49:28-31,45-47. Thomas, R. W., 1961. Ultrasonic cleaning: its theory and some factors affecting its application. General Motors Engineering Journal, April-MayJune, 23-28. Walden, C. C , I. V. Allen and P. C. Trussell, 1956. The role of the egg shell and shell membrane in restraining the entry of microorganisms. Poultry Sci. 35:1190-1196.
The Effect of Length of Daily Light Periods on Reproduction in Female Chickens1 W. H. MCCLUSKEY AND J. E. PARKER Department of Poultry Science, Oregon State University, Corvallis, Oregon (Received for publication March 13. 1963)
A
LTHOUGH numerous studies conL cerned with photoperiodism on the sexual development of female chickens have been reported, most of them have involved Leghorn type birds and have been limited to the influence of lights during the rearing period. Also, most studies have limited light restriction to 6 or 8 hours although Rider (1938) and King (1961, 1
Technical Paper No. 1658. Agricultural Experiment Station, Oregon State University, Corvallis, Oregon.
1962) reported pullets reared in darkness would come into egg production. Parker and McCluskey (1961) reported onset of semen production in cockerels on as little as a 1 hour single light period per day. This study involved heavy breed pullets reared and maintained on light periods as short as 1 hour per day. MATERIALS AND METHODS
Chicks used in this experiment consisted of 21 Delaware pullets per treatment
1162
W. H. MCCLUSKEY AND J. E. PARKER
TABLE 1.—Egg production of Delaware pullets reared and maintained on different lengths of daily light Hours of daily light Age at 10% production (days) Age at 50% production (wks.) Highest monthly egg production—% Average production 1st 10 months—% Average production for 5 months following light increase—%
1
3
9
13
155 30 54.8 33.7
148 29 48.8 28.2
145 25 67.4 54.1
140 24 66.3 42.8
44.5
41.6
26.7
32.1
hatched November 11, 1961, from a flock maintained at the Oregon Agricultural Experiment Station. They were reared from time of hatch on 1, 3, 9 and 13 hours of daily light and maintained on these schedules until they had been in production for a period of approximately 10 months. Following this period, the light periods were increased to 13 hours daily in the 1-, 3- and 9-hour groups and to 15 hours daily in the 13-hour group. This light schedule was maintained for 5 months before the experiment was terminated. Light was provided by a 25-watt incandescent lamp suspended in the center of the pens and gave intensities of light in each pen ranging from approximately 2.6 to .75 foot candles at bird height. All birds were immunized at 7 days of age for coccidiosis. The feed used was a commercial mash fed free choice and flowing water was provided in a vee trough. Entries into the pen by all workers were restricted to the period when the lights were on. Sexual maturity was measured by age in days to reach 10 percent production. Fertility was determined by incubating eggs collected over an 8-day sequence at 10 different periods during the laying year. RESULTS
The first egg produced was in the 9-hour light group but the pen receiving 13 hours of daily light was the first to reach both 10 and 50 percent lay (Table 1). The pen receiving 1-hour of daily light required ap-
proximately 6 weeks longer to reach 50 percent production. All groups peaked during the same four-week period (Fig. 1) but the 1- and 3-hour light treatments did not peak as high as the pens receiving the longer daily light periods. During the first 10 months after the onset of lay, females on 9 and 13 hours of daily light produced at a higher average rate than did the 1- and 3-hour treatments. Following the increase in length of daily light periods, females previously exposed to 1- and 3-hours of light greatly increased their rates of lay and maintained a much higher level of production for the last five months of the experiment. Those females previously given 9 and 13 hours of daily light were not influenced appreciably by the increased light periods. The results indicate that layers on 1 and 3 hours of daily light do not produce at their full potential and that they can be further stimulated by increasing the daily light period many months after the onset of egg laying. These observations are in accord with those of Sykes (1956) who reported that layers on 6 hours of daily light did not lay as well as those on 13 hours and that increasing the daily light of the 6-hour group resulted in increased egg production. Fertility data from natural matings of pullets and cockerels2 reared and maintained under the four light schedules are 2
Two cockerels in each mating.
1163
L I G H T AND SEXUAL D E V E L O P M E N T DAILY
LIGHT
PERIODS
First 10 months
Following 5 months
I
13
% PRODUCTION
3
80 -
13
9 13
, I
13 15 Light schedule changed '<— Feb. 6, 1962
60
40
20
Apr
May
June July
Aug Sept
Oct
1961
Nov
Dec
Jan
Feb
Mar
Apr
May June
1962
FIG. 1. Egg production of meat type females reared and maintained under different lengths of daily light periods. shown in Figure 2. Fertility of pullets exposed to 9 and 13 hours of light daily was high throughout the study. Pullets on 3 hours of daily light were less fertile during the first two months of the testing period b u t subsequently approached the levels of pullets on the longer light periods. Pullets on 1 hour of light daily averaged less t h a n one percent fertile eggs during the first ten months of lay. Following the increase in light the fertility of these birds increased to 93.2 percent, comparable to t h a t of the other treatments (Fig. 2). Increasing the light periods did not increase fertility in the 3-, 9- or 13-hour treatments. To determine the factors contributing to the low fertility of the group receiving 1-hour daily light, a series of ma tings were made using both natural and artificial mating methods. To determine if the males were capable of producing viable
semen, the two males in the 1-hour pen were ejaculated and the semen used to inseminate Leghorn females housed in cages and exposed to 14 hours of daily light. Semen from males exposed to 13 hours of light was also used in the same manner so t h a t the males from the two light treatments could be compared. The results are shown in Table 2. These results show t h a t males under both light treatments produced semen capable of fertilizing females. To determine if the females under the 1-hour daily light period were capable of being fertilized, they were inseminated two times, 10 days apart, with semen from males maintained under 13 hours of daily light. Leghorn females in cages were inseminated a t the same time to provide a comparison. Fertility levels were established for eggs laid 2 to 9 days following
1164 %
W. H. MCCLUSKEY AND J. E. PARKER FERTILITY
100 r-
x
^x-
/ // ;
80
601-
\
_.. .%—
x
A-
x
—x-^-^x '"'—x
xJI-
/
Light schedule changed t— Feb. 6, 1962
/
40 -
DAILY LIGHT PERIODS First 10 months | Following 5 months .
20
x
x
X
X
I 3
I I
13 13 13 15
9 13
h;—$77—h—*.. Apr " May "June'july K ' Aug *?—:i-z-ri-z—i~—*-. 'Sept'Oct ' Nov 'Dec ' 1961
Jan rJ' ' Feb' Mar 1962
Apr
May June
FIG. 2. Fertility of meat type females reared and maintained under different lengths of daily light periods.
insemination with .05 ml. of undiluted semen. The results are shown in Table 3. The results indicate that the females exposed to 1 hour daily light periods were capable of being fertilized. Since the males and females exposed to 1 hour daily light periods had relatively high fertility in the artificial insemination trials, it seems evident that the abnormally low fertility of the flock mating was TABLE 2.—Fertilizing capacity of semen from Delaware males exposed to 1 and 13 hours daily of light as determined by artificially inseminating White Leghorn pullets with .05 ml. undiluted semen Light period 1 hour 3 hours
Pullets insem.
Eggs set
Eggs fert.
(No.) 14 10
(No.) 75 55
(No.) 56 42
Fert;H
(%)
74.7 76.4
J
due to a lack of desire to mate on the part of either the males, the females or both. To investigate this possibility, two Delaware males maintained under 13 hours of daily light were placed with the 1-hour females each day during the 1 hour light period. The first fertile egg was produced 4 days after the start but fertility for the first 20 days was only 9.7 percent. Fertility during the second 20 day period was 35.5 percent. These relatively low rates of fertility TABLE 3.—Fertility of Delaware females exposed to 1 hour of daily light as compared to White Leghorn females exposed to 14 hours of daily light ^
Delaware W. Leghorn
Daily light
Eggs set
Eggs fertile
Fertility
(No.) 1 hour 14 hours
(No.) 59 112
(No.) 44 92
74.6 83.0
(%)
LIGHT AND SEXUAL DEVELOPMENT
suggest a lack of libido of the females reared and maintained under the 1-hour daily light period. The fact that fertility was much higher with the 13-hour males than the 1-hour males indicates that the males exposed to 1 hour of daily light also were lacking in libido under the conditions of this experiment. SUMMARY
Female chickens of the Delaware breed developed sexually on 1 hour of daily light but required six weeks longer to reach 50 percent production than those on 13-hours of daily light. As compared to pullets on 9 and 13 hours of light daily those on 1 and 3 hours did not reach as high a peak and maintained a lower level of egg production during the first 10 months of lay. Following an increase in daily light after 10 months production, females previously on 1 and 3 hours of light exhibited a substantial increase in rate of lay whereas those previously on 9 and 13 hours failed to respond to an increase in daily light. Fertility from natural mating of males and females reared and continued on 9 and 13 hours of light daily was relatively
1165
high throughout the trial. Three hours of light depressed fertility during the first 2 months and 1 hour of light caused abnormally low fertility, averaging less than 1 percent. The fertility of the 1-hour group increased to approximately 93 percent when the light exposure was increased to 13 hours. The abnormally low fertility of both males and females reared and maintained under 1 hour daily light periods was shown to be related to a lack of mating as both sexes were capable of contributing to a relatively normal level of fertility when used in artificially inseminated matings. REFERENCES King, D. F., 1961. Effects of increasing, decreasing, and constant light treatments on growing pullets. Poultry Sci. 40:479-484. King, D. F., 1962. Egg production of chickens raised and kept in darkness. Poultry Sci. 41: 1499-1503. Parker, J. E., and W. H. McCluskey, 1961. The effect of length of daily light periods on the sexual development of chickens. Poultry Sci. 40: 14411442. Rider, P. L., 1938. The influence of light on growth and reproduction of the domestic fowl. Unpublished M.S. Thesis, Ohio State University. Sykes, A. H., 1956. Short day-lengths and egg production in the fowl. J. Agric. Sci. 47: 429-434.
NEWS AND NOTES {Continued from page 1130) Dr. E. L. R. Stokstad has joined the Department of Nutritional Sciences at the University of California. Dr. Stokstad spent some 20 years in research with the American Cyanamid Company and in its Lederle Laboratories. U.S.D.A. NOTES Dr. Edward C. Miller, who received a B.S. degree, a M.S. degree and a Ph.D. degree at the University of Wisconsin in 1952, 1954 and 1957, respectively, joined the staff of specialists of the Cooperative State Experiment Station Service, United States Department of Agriculture, Washington 25, D.C., as Biochemist on April 1. He will be associated
with the Animal Science Group under the leadership of Director J. O. Grandstaff. Since 1956 Dr. Miller has been Biochemist in Poultry Nutrition Investigations, A.R.S., Beltsville, Maryland. Dr. Stanley P. Wilson, for the past two years engaged in postdoctoral research in animal genetics at Purdue University, became Coordinator of the North Central Poultry Breeding Project, NC-47, on March 3. He succeeds Dr. James R. Carson who became a member of the staff of Purdue University. After completion of an assignment in Mexico and Venezuela with the Food and Agriculture Organization of the United Nations, Dr. C. D. Gordon is now Research Geneticist with the Southeast Poultry
{Continued on page 1171)
the ultrasonic treatment on the porosity of the egg shell, or on the physical movement of bacteria through the shell membrane. ACKNOWLEDGMENTS Appreciation is expressed to HermesSonic Corporation, New York, New York, for supplying ultrasonic equipment, and to the Big Dutchman Automatic Poultry Equipment Company, Zeeland, Michigan, for other egg washing equipment used in this study. REFERENCES Almquist, H. J., and W. F. Hoist, 1931. Variability of shell porosity in the hen's egg. Hilgardia, 6: 61-71. Carlin, B., 1949. Ultrasonics, McGraw-Hill Book Co., Inc., New York. Crawford, A. E., 1955. Ultrasonic Engineering with Particular Reference to High Power Applications. Butterworth's Scientific Publications, London, England. Dawson, L. E., C. W. Hall and E. H. Farmer, 1961. The use of ultrasonic energy for cleaning eggs.
1161
Poultry Sci. 41: 620-626. Fromm, D., and R. J. Munroe, 1960. Interior physical quality and bacterial contamination of market eggs as influenced by egg shell permeability. Food Technol. 14:401-403. Johnson, C. H., 1929. The lethal effects of ultrasonic radiation. J. Physiol. 67: 356-359. Kilpatrick, L., A. W. Brant and H. L. Shrader, 1958. Equipment and methods for measuring egg quality. A.M.S. No. 246, U.S.D.A. Agricultural Marketing Service, Washington 25, D.C. Kramer, A., 1960. A rapid method for determining significance of differences from rank sums. Food Technol. 14:576-581. Murdock, A., Jr., 1956. Ultrasonics . . . How it works and what it does. American Machine, 100: 97-104. Stuart, L. S., and E. H. McNally, 1943. Bacteriological studies on the egg shell. U. S. Egg Poultry Mag. 49:28-31,45-47. Thomas, R. W., 1961. Ultrasonic cleaning: its theory and some factors affecting its application. General Motors Engineering Journal, April-MayJune, 23-28. Walden, C. C , I. V. Allen and P. C. Trussell, 1956. The role of the egg shell and shell membrane in restraining the entry of microorganisms. Poultry Sci. 35:1190-1196.
The Effect of Length of Daily Light Periods on Reproduction in Female Chickens1 W. H. MCCLUSKEY AND J. E. PARKER Department of Poultry Science, Oregon State University, Corvallis, Oregon (Received for publication March 13. 1963)
A
LTHOUGH numerous studies conL cerned with photoperiodism on the sexual development of female chickens have been reported, most of them have involved Leghorn type birds and have been limited to the influence of lights during the rearing period. Also, most studies have limited light restriction to 6 or 8 hours although Rider (1938) and King (1961, 1
Technical Paper No. 1658. Agricultural Experiment Station, Oregon State University, Corvallis, Oregon.
1962) reported pullets reared in darkness would come into egg production. Parker and McCluskey (1961) reported onset of semen production in cockerels on as little as a 1 hour single light period per day. This study involved heavy breed pullets reared and maintained on light periods as short as 1 hour per day. MATERIALS AND METHODS
Chicks used in this experiment consisted of 21 Delaware pullets per treatment
1162
W. H. MCCLUSKEY AND J. E. PARKER
TABLE 1.—Egg production of Delaware pullets reared and maintained on different lengths of daily light Hours of daily light Age at 10% production (days) Age at 50% production (wks.) Highest monthly egg production—% Average production 1st 10 months—% Average production for 5 months following light increase—%
1
3
9
13
155 30 54.8 33.7
148 29 48.8 28.2
145 25 67.4 54.1
140 24 66.3 42.8
44.5
41.6
26.7
32.1
hatched November 11, 1961, from a flock maintained at the Oregon Agricultural Experiment Station. They were reared from time of hatch on 1, 3, 9 and 13 hours of daily light and maintained on these schedules until they had been in production for a period of approximately 10 months. Following this period, the light periods were increased to 13 hours daily in the 1-, 3- and 9-hour groups and to 15 hours daily in the 13-hour group. This light schedule was maintained for 5 months before the experiment was terminated. Light was provided by a 25-watt incandescent lamp suspended in the center of the pens and gave intensities of light in each pen ranging from approximately 2.6 to .75 foot candles at bird height. All birds were immunized at 7 days of age for coccidiosis. The feed used was a commercial mash fed free choice and flowing water was provided in a vee trough. Entries into the pen by all workers were restricted to the period when the lights were on. Sexual maturity was measured by age in days to reach 10 percent production. Fertility was determined by incubating eggs collected over an 8-day sequence at 10 different periods during the laying year. RESULTS
The first egg produced was in the 9-hour light group but the pen receiving 13 hours of daily light was the first to reach both 10 and 50 percent lay (Table 1). The pen receiving 1-hour of daily light required ap-
proximately 6 weeks longer to reach 50 percent production. All groups peaked during the same four-week period (Fig. 1) but the 1- and 3-hour light treatments did not peak as high as the pens receiving the longer daily light periods. During the first 10 months after the onset of lay, females on 9 and 13 hours of daily light produced at a higher average rate than did the 1- and 3-hour treatments. Following the increase in length of daily light periods, females previously exposed to 1- and 3-hours of light greatly increased their rates of lay and maintained a much higher level of production for the last five months of the experiment. Those females previously given 9 and 13 hours of daily light were not influenced appreciably by the increased light periods. The results indicate that layers on 1 and 3 hours of daily light do not produce at their full potential and that they can be further stimulated by increasing the daily light period many months after the onset of egg laying. These observations are in accord with those of Sykes (1956) who reported that layers on 6 hours of daily light did not lay as well as those on 13 hours and that increasing the daily light of the 6-hour group resulted in increased egg production. Fertility data from natural matings of pullets and cockerels2 reared and maintained under the four light schedules are 2
Two cockerels in each mating.
1163
L I G H T AND SEXUAL D E V E L O P M E N T DAILY
LIGHT
PERIODS
First 10 months
Following 5 months
I
13
% PRODUCTION
3
80 -
13
9 13
, I
13 15 Light schedule changed '<— Feb. 6, 1962
60
40
20
Apr
May
June July
Aug Sept
Oct
1961
Nov
Dec
Jan
Feb
Mar
Apr
May June
1962
FIG. 1. Egg production of meat type females reared and maintained under different lengths of daily light periods. shown in Figure 2. Fertility of pullets exposed to 9 and 13 hours of light daily was high throughout the study. Pullets on 3 hours of daily light were less fertile during the first two months of the testing period b u t subsequently approached the levels of pullets on the longer light periods. Pullets on 1 hour of light daily averaged less t h a n one percent fertile eggs during the first ten months of lay. Following the increase in light the fertility of these birds increased to 93.2 percent, comparable to t h a t of the other treatments (Fig. 2). Increasing the light periods did not increase fertility in the 3-, 9- or 13-hour treatments. To determine the factors contributing to the low fertility of the group receiving 1-hour daily light, a series of ma tings were made using both natural and artificial mating methods. To determine if the males were capable of producing viable
semen, the two males in the 1-hour pen were ejaculated and the semen used to inseminate Leghorn females housed in cages and exposed to 14 hours of daily light. Semen from males exposed to 13 hours of light was also used in the same manner so t h a t the males from the two light treatments could be compared. The results are shown in Table 2. These results show t h a t males under both light treatments produced semen capable of fertilizing females. To determine if the females under the 1-hour daily light period were capable of being fertilized, they were inseminated two times, 10 days apart, with semen from males maintained under 13 hours of daily light. Leghorn females in cages were inseminated a t the same time to provide a comparison. Fertility levels were established for eggs laid 2 to 9 days following
1164 %
W. H. MCCLUSKEY AND J. E. PARKER FERTILITY
100 r-
x
^x-
/ // ;
80
601-
\
_.. .%—
x
A-
x
—x-^-^x '"'—x
xJI-
/
Light schedule changed t— Feb. 6, 1962
/
40 -
DAILY LIGHT PERIODS First 10 months | Following 5 months .
20
x
x
X
X
I 3
I I
13 13 13 15
9 13
h;—$77—h—*.. Apr " May "June'july K ' Aug *?—:i-z-ri-z—i~—*-. 'Sept'Oct ' Nov 'Dec ' 1961
Jan rJ' ' Feb' Mar 1962
Apr
May June
FIG. 2. Fertility of meat type females reared and maintained under different lengths of daily light periods.
insemination with .05 ml. of undiluted semen. The results are shown in Table 3. The results indicate that the females exposed to 1 hour daily light periods were capable of being fertilized. Since the males and females exposed to 1 hour daily light periods had relatively high fertility in the artificial insemination trials, it seems evident that the abnormally low fertility of the flock mating was TABLE 2.—Fertilizing capacity of semen from Delaware males exposed to 1 and 13 hours daily of light as determined by artificially inseminating White Leghorn pullets with .05 ml. undiluted semen Light period 1 hour 3 hours
Pullets insem.
Eggs set
Eggs fert.
(No.) 14 10
(No.) 75 55
(No.) 56 42
Fert;H
(%)
74.7 76.4
J
due to a lack of desire to mate on the part of either the males, the females or both. To investigate this possibility, two Delaware males maintained under 13 hours of daily light were placed with the 1-hour females each day during the 1 hour light period. The first fertile egg was produced 4 days after the start but fertility for the first 20 days was only 9.7 percent. Fertility during the second 20 day period was 35.5 percent. These relatively low rates of fertility TABLE 3.—Fertility of Delaware females exposed to 1 hour of daily light as compared to White Leghorn females exposed to 14 hours of daily light ^
Delaware W. Leghorn
Daily light
Eggs set
Eggs fertile
Fertility
(No.) 1 hour 14 hours
(No.) 59 112
(No.) 44 92
74.6 83.0
(%)
LIGHT AND SEXUAL DEVELOPMENT
suggest a lack of libido of the females reared and maintained under the 1-hour daily light period. The fact that fertility was much higher with the 13-hour males than the 1-hour males indicates that the males exposed to 1 hour of daily light also were lacking in libido under the conditions of this experiment. SUMMARY
Female chickens of the Delaware breed developed sexually on 1 hour of daily light but required six weeks longer to reach 50 percent production than those on 13-hours of daily light. As compared to pullets on 9 and 13 hours of light daily those on 1 and 3 hours did not reach as high a peak and maintained a lower level of egg production during the first 10 months of lay. Following an increase in daily light after 10 months production, females previously on 1 and 3 hours of light exhibited a substantial increase in rate of lay whereas those previously on 9 and 13 hours failed to respond to an increase in daily light. Fertility from natural mating of males and females reared and continued on 9 and 13 hours of light daily was relatively
1165
high throughout the trial. Three hours of light depressed fertility during the first 2 months and 1 hour of light caused abnormally low fertility, averaging less than 1 percent. The fertility of the 1-hour group increased to approximately 93 percent when the light exposure was increased to 13 hours. The abnormally low fertility of both males and females reared and maintained under 1 hour daily light periods was shown to be related to a lack of mating as both sexes were capable of contributing to a relatively normal level of fertility when used in artificially inseminated matings. REFERENCES King, D. F., 1961. Effects of increasing, decreasing, and constant light treatments on growing pullets. Poultry Sci. 40:479-484. King, D. F., 1962. Egg production of chickens raised and kept in darkness. Poultry Sci. 41: 1499-1503. Parker, J. E., and W. H. McCluskey, 1961. The effect of length of daily light periods on the sexual development of chickens. Poultry Sci. 40: 14411442. Rider, P. L., 1938. The influence of light on growth and reproduction of the domestic fowl. Unpublished M.S. Thesis, Ohio State University. Sykes, A. H., 1956. Short day-lengths and egg production in the fowl. J. Agric. Sci. 47: 429-434.
NEWS AND NOTES {Continued from page 1130) Dr. E. L. R. Stokstad has joined the Department of Nutritional Sciences at the University of California. Dr. Stokstad spent some 20 years in research with the American Cyanamid Company and in its Lederle Laboratories. U.S.D.A. NOTES Dr. Edward C. Miller, who received a B.S. degree, a M.S. degree and a Ph.D. degree at the University of Wisconsin in 1952, 1954 and 1957, respectively, joined the staff of specialists of the Cooperative State Experiment Station Service, United States Department of Agriculture, Washington 25, D.C., as Biochemist on April 1. He will be associated
with the Animal Science Group under the leadership of Director J. O. Grandstaff. Since 1956 Dr. Miller has been Biochemist in Poultry Nutrition Investigations, A.R.S., Beltsville, Maryland. Dr. Stanley P. Wilson, for the past two years engaged in postdoctoral research in animal genetics at Purdue University, became Coordinator of the North Central Poultry Breeding Project, NC-47, on March 3. He succeeds Dr. James R. Carson who became a member of the staff of Purdue University. After completion of an assignment in Mexico and Venezuela with the Food and Agriculture Organization of the United Nations, Dr. C. D. Gordon is now Research Geneticist with the Southeast Poultry
{Continued on page 1171)