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Studies in Coccidiosis in Chickens
Studies in Coccidiosis in Chickens CALCIUM CARBONATE A D D I T I O N S AND COCCIDIA C. E. HOLMES Department of Poultry
Husbandry
AND C. A. HEREICK AND G. L . OTT Departments of Zoology and of Veterinary Science Wisconsin Experiment Station, Madison, Wisconsin (Presented at Annual Meeting, August, 1936; received for publication August 14, 1936)
E
XPERIENCE at the Wisconsin Experiment Station has shown that when chicks are hopper-fed chick size limestone grit or chick size oyster shell the consumption will vary from 1 to 4 percent of the ration. Chicks receiving an insufficient amount of vitamin D will consume more calcium carbonate grit than will those having access to direct sunshine or those receving an ample amount of vitamin D as supplied by cod liver oil or other vitamin D oils. Halpin (1926) reported that chicks reared inside, fed rations containing and addition of approximately 3.6 percent limestone, weighed 509 grams at ten weeks whereas those receiving no limestone averaged only 353 grams. Later experience, however, demonstrated that 2 percent of a calcium carbonate carrier in the usual chick ration was sufficient. Herrick, Ott, Halpin, and Holmes (1935) reported preliminary results which indicated that rations, high in calcium carbonate, increased the susceptibility of chickens to coccidiosis. The experiments reported here are a continuation of the preliminary studies mentioned above. The Single Comb White Leghorn chicks used in this study were from stock maintained at the Wisconsin Agricultural Experiment Station. The chicks were placed in sterilized brooders and were fed
"sterilized"1 rations under conditions that made coccidia infection impossible as described by Herrick, Ott, and Holmes (1936). In the first trial the chicks were fed a sterilized ration consisting of ground yellow corn 45, wheat bran 15, standard middlings 15, dried skimmilk 12, meat scrap 6, alfalfa leaf meal 3, chick size oyster shell 3, iodized stock salt 0.5, and cod liver oil 0.5. At four weeks of age the chicks were evenly divided into three lots and fed the following sterilized experimental rations for a period of two weeks. Lot 1 received the basal ration which consisted of ground yellow corn 45, wheat bran 15, standard wheat middlings 15, dried skimmilk 12, meat scrap 6, alfalfa leaf meal 3, iodized stock salt 0.5, and cod liver oil 0.5. Lot 2 received basal ration 97 percent and chick size oyster shell 3 percent; Lot 3 received basal ration 94 percent and chick size oyster shell 6 percent. After two weeks on the experimental rations the three lots of chicks were fed by pipette the same dosage of sporulated oocysts of a pure culture of Eimeria tenella. Approximately 200,000 sporulated oocysts were given to each chicken. Death loss and general conditions of the groups were noted. The results of the first trial are given in Table 1. The results of the first trial seemed to 1 Heated to 170°F. for 30 minutes—a temperature sufficient to kill oocysts of coccidia (Fish, 1931).
[33S]
336
POULTRY
indicate that the addition of 6 percent chick size oyster shell to the basal ration resulted in a marked lowering of resistance to coccidiosis as evidenced by the extremely heavy mortality in lot 3. In this trial there was no significant difference in mortality rate obtained in the groups receiving 0 and 3 percent chick size oyster shell. In the second trial the day-old chicks were placed in sterile brooders and were fed the same experimental rations as were used in the first trial. The three lots of chicks were infected when two weeks old. They were, however, given the same dosage of sporulated oocysts of the same pure culture of Eimeria tenella as used in the first trial. Death loss and general conditions of the groups were noted. The results of the second trial are given in Table 2. It is evident that when 3 and 6 percent chick size oyster, shell was added the chicks were more seriously affected by coccidia as evidenced by the greater mortality in these groups. In the third trial the day-old chicks were placed in sterile brooders and were given the same sterilized experimental rations as the preceding trials but were infected at four weeks of age with the same dosage of sporulated oocyts of the same pure culture
SCIENCE
of Eimeria tenella as used in the previous trials. The results (Table 3) show that the mortality from coccidiosis in the three lots was 46,8, 60.0, and 77.8 percent respectively when 0, 3, and 6 percent oyster shell was fed, showing that the addition of calcium carbonate in the form of chick size oyster shell increased the susceptibility of chickens to coccidiosis. In the last two trials the lowest mortality from coccidiosis was experienced when no chick size oyster shell (source of calcium carbonate) was added to the ration. In the first and third trials the heaviest mortality from coccidiosis occurred in the lots receiving 6 percent of chick size oyster shell. The results of the three trials summarized in Table 4 indicate that with the higher levels of calcium carbonate, as supplied by chick size oyster shell, more deaths occurred after infection with coccidiosis. Chemical analyses of the three experimental rations for calcium and phosphorous content were made. The calcium, phosphorous, and calcium to phosphorous ratio for the three experimental rations is given in Table 5. It will be noted that when no addition of chick size oyster shell was made to the basal ration there was a calcium con-
TABLE 1.—Results of first trial
Average* SurNumber weight at 6 weeks vivors
Ration
grams Lot 1 Basal
100
Lot 2 Basal Chick size oyster shell
97
Lot 3 Basal Chick size oyster shell
94
3
6
Average Deaths weight of from survivors coccidiosis at 7 weeks (percent)
Deaths from coccidiosis 5th day
6th day
7th day
Average weight at death grams
grams
42
249.1
27
287.4
35.7
0
14
1
254.5
39
225.0
27
266.0
30.8
0
10
2
245.1
39
251.4
11
272.9
71.8
5
20
3
256.6
* Infected at six weeks of age.
SEPTEMBER,
1937.
VOL.
XVI,
No.
TABLE 2 .—Results
of second trial
Average Deaths Deaths from weight from Average Average coccidiosis Num- weight Average* Sur- of sur- coccidiweight weight ber at start at 2 wks. vivors vivors at osis 3rd 4th 5th 6th 7th at 3 weeks (percent) day day day day day death
Ration
Lot 1 Basal
337
5
grams
grams
grams
grams
100
43
40.5
78.0
19
90.7
55.8
3
1
8
11
1
77.7
Lot 2 Basal 97 Chick size oyster shell 3
44
42.4
81.3
14
88.1
68.2
3
0
10
16
1
84.4
Lot 3 Basal 94 94 Chick size oyster shell 6
45
41.3
75.3
16
79.8
64.4
7
2
8
11
1
68.3
* Infected at two weeks of age.
tent of 0.8714 percent and a ratio of 1 part of calcium to 1.07 parts of phosphorus; when 3 percent of chick size oyster shell was fed there was a calcium content of 1.293 percent and a ratio of 1 part of calcium to 0.74 parts of phosphorus; when 6 percent of chick size oyster shell was fed there was a calcium content of 2.471 percent and a ratio of 1 part of calcium to 0.354 parts of phosphorus. These trials are in agreement with the preliminary results reported by Herrick, Ott, Halpin, and Holmes (1935) and seem TABLE 3
Lot 1 Basal
—Results of third trial
Num- Average Average* Surweight weight ber at start at 4 weeks vivors
Ration
grams
grams
to indicate that excessive mineral additions are likely to be detrimental to growing chicks when sporulated coccidia oocysts are fed in measured amounts. These trials were repeated with an attempt to maintain rations with the same calcium to phosphorus ratio. The calcium to phosphorus ratio was adjusted by adding sufficient disodium phosphate (Na2 HP0 4 • 12H 2 0) to maintain the same ratio in all three lots. The same basal ration was used as in the three previous trials. The general plan of the rations was: lot 1—
Deaths from Average Average Deaths from coccidiosis weight weight coccidiosis, 5th 6th 7th at death at 5 weeks (percent) day day day grams
grams
100
47
40.1
149.4
25
166.2
46.8
1
19
2
155.7
Lot 2 Basal 97 Chick size oyster shell 3
40
40.3
165.4
16
169.6
60.0
0
21
3
164.7
Lot 3 Basal 94 Chick size oyster shell 6
45
41.4
155.8
10
168.8
77.8
1
31
3
149.0
* Infected at four weeks of age.
338
POULTRY
basal, no additions; lot 2—basal plus 3 percent chick size oyster shell and disodium phosphate; lot 3—basal plus 6 percent chick size oyster shell and disodium phosphate. To adjust the calcium to phosphorus ratios 863.5 and 3,620.4 grams of disodium phosphate were added to each 100 pounds of ration of lots 2 and 3 respectively. The trials were started with day-old chicks in sterile brooders fed the sterilized experimental rations. The chicks in lots 2 and 3 would not eat their rations readily and a majority of the chicks in these two lots died of starvation. The remaining chicks in lots 2 and 3 made little growth. The experiment was completed, but because only a few very badly stunted chicks remained in lots 2 and 3 at the time of infection, no significant results were obtained as to the resistance to coccidiosis at different levels of calcium carbonate when the calcium to phosphorus ratio was held constant. One group of day-old chicks was placed in a battery brooder. They were given the Wisconsin 2 A starting ration in one feed trough and in the other feed trough the same ration as lot 3: 3,620.4 grams of disodium phosphate in 100 pounds of ration. Wisconsin 2A consists of ground yellow corn 45, wheat bran 15, standard wheat middlings 15, dried skimmilk 12, meat scrap
Ration
Percent Deaths mortalfrom ity from coccid- coccidioiosis sis
100
132
61
46.2
Basal 97 Chick size oyster shell 3
123
66
53.6
Basal 94 Chick size oyster shell 6
129
92
71.3
Basal
TABLE 5.—Calcium and phosphorus contents of rations
Ration
Basal
100
Basal Chick size oyster shell
97
Basal Chick size oyster shell
94
3
6
Calcium Phosphorus percent percent
Calcium to phosphorus ratio
0.8714
0.9343
1.0:1.07
1.293
0.9636
1.0:0.74
2.471
0.8862
1.0:0.354
6, alfalfa leaf meal 3, chick size oyster shell 3, iodized stock salt 0.5, and cod liver oil 0.5. The feed troughs were interchanged frequently in order to overcome any influence of difference in light intensity or habit on food consumption. In the twentytwo-day period the chicks had consumed only 452 grams of the ration containing the additional disodium phosphate and had consumed in the same time 7,432 grams of the Wisconsin 2 A starting ration that contained no addition of disodium phosphate. Rations containing the amounts of disodium phosphate used in these trials are unpalatable and if studies are to be made with different levels of calcium carbonate holding the calcium to phosphorus ratio constant some other source of phosphorus must be used. SUMMARY
TABLE 4.—Summary of three trials Number of chicks infected
SCIENCE
1. In two trials more deaths occurred after infection with coccidiosis when 6 percent of chick size oyster shell was added to a basal diet containing 0.8714 and 0.9343 percent calcium and phosphorus respectively. 2. The results of the three trials indicate that with the higher levels of calcium carbonate more deaths occurred after infection with coccidiosis. 3. Attempts to determine the effects of different levels of calcium carbonate on
SEPTEMBER,
1937.
VOL.
XVI,
mortality from coccidiosis holding the calcium to phosphorous ratio constant by means of disodium phosphate were not successful due probably to unpalatability of the rations containing this phosphorus supplement. REFERENCES
Fish, F., 1931. The effects of physical and chemical agents on the oocysts of Eimeria tenella. Science, 73 :292-293.
No.
S
339
Halpin, J. G., 1926. Minerals influence rate of growth of chicks. Wisconsin Agricultural Experiment Station Bulletin 388:111. Herrick, C. A., G. L. Ott, J. G. Halpin, and C. E. Holmes, 1935. Extra calcium in ration increases susceptibility of chicks to coccidiosis. Wisconsin Agricultural Station Bulletin 430:97. Herrick, C. A., G. L. Ott, and C. E. Holmes, 1936. The chicken as a carrier of the oocysts of the coccidia, Eimeria tenella. Poultry Science, 15:322-325.
News and Notes At the recent annual meeting of the Poultry Science Association at Madison, Wisconsin, R. E. Jones of Storrs, Connecticut, was elected President for the year 1937-38. Berley Winton of Washington, D.C., was elected 1st Vice-President and L. W. Taylor of Berkeley, California, was elected 2nd Vice-President. W. A. Maw of Macdonald College, Quebec, Canada, was reelected Secretary-Treasurer. The directors elected for the period 1937-39 were R. B. Thompson of Stillwater, Oklahoma, and M. 0. North of Laramie, Wyoming. G. W. Sprague of Washington, D.C., was elected an associate editor of POULTRY SCIENCE. The Executive Committee of the Poultry Science Association decided to hold the next annual meeting of the Association at Washington State College, Pullman, Washington, after a guiding vote indicating the preference of the members present at the annual
meeting, had been taken. The Seventh World's Poultry Congress will be held in Cleveland, Ohio, where excellent facilities are available for housing the Congress. It is expected that the Congress will be held sometime during the period covering the last week in July and the first week in August. Dr. Victor Heiman, Assistant Professor of Poultry Husbandry, Washington State College, has resigned to become associated with Kasco Mills, Inc., Waverly, New York, on August 1 as director of research. Dr. Lawrence L. Lachat has resigned from the Minnesota State Department of Agriculture, effective August IS, to head the new Feed Testing and Control Laboratory of the Great Atlantic & Pacific Tea Company. Dr. Lachat will have his headquarters at Minneapolis, Minnesota.
Husbandry
AND C. A. HEREICK AND G. L . OTT Departments of Zoology and of Veterinary Science Wisconsin Experiment Station, Madison, Wisconsin (Presented at Annual Meeting, August, 1936; received for publication August 14, 1936)
E
XPERIENCE at the Wisconsin Experiment Station has shown that when chicks are hopper-fed chick size limestone grit or chick size oyster shell the consumption will vary from 1 to 4 percent of the ration. Chicks receiving an insufficient amount of vitamin D will consume more calcium carbonate grit than will those having access to direct sunshine or those receving an ample amount of vitamin D as supplied by cod liver oil or other vitamin D oils. Halpin (1926) reported that chicks reared inside, fed rations containing and addition of approximately 3.6 percent limestone, weighed 509 grams at ten weeks whereas those receiving no limestone averaged only 353 grams. Later experience, however, demonstrated that 2 percent of a calcium carbonate carrier in the usual chick ration was sufficient. Herrick, Ott, Halpin, and Holmes (1935) reported preliminary results which indicated that rations, high in calcium carbonate, increased the susceptibility of chickens to coccidiosis. The experiments reported here are a continuation of the preliminary studies mentioned above. The Single Comb White Leghorn chicks used in this study were from stock maintained at the Wisconsin Agricultural Experiment Station. The chicks were placed in sterilized brooders and were fed
"sterilized"1 rations under conditions that made coccidia infection impossible as described by Herrick, Ott, and Holmes (1936). In the first trial the chicks were fed a sterilized ration consisting of ground yellow corn 45, wheat bran 15, standard middlings 15, dried skimmilk 12, meat scrap 6, alfalfa leaf meal 3, chick size oyster shell 3, iodized stock salt 0.5, and cod liver oil 0.5. At four weeks of age the chicks were evenly divided into three lots and fed the following sterilized experimental rations for a period of two weeks. Lot 1 received the basal ration which consisted of ground yellow corn 45, wheat bran 15, standard wheat middlings 15, dried skimmilk 12, meat scrap 6, alfalfa leaf meal 3, iodized stock salt 0.5, and cod liver oil 0.5. Lot 2 received basal ration 97 percent and chick size oyster shell 3 percent; Lot 3 received basal ration 94 percent and chick size oyster shell 6 percent. After two weeks on the experimental rations the three lots of chicks were fed by pipette the same dosage of sporulated oocysts of a pure culture of Eimeria tenella. Approximately 200,000 sporulated oocysts were given to each chicken. Death loss and general conditions of the groups were noted. The results of the first trial are given in Table 1. The results of the first trial seemed to 1 Heated to 170°F. for 30 minutes—a temperature sufficient to kill oocysts of coccidia (Fish, 1931).
[33S]
336
POULTRY
indicate that the addition of 6 percent chick size oyster shell to the basal ration resulted in a marked lowering of resistance to coccidiosis as evidenced by the extremely heavy mortality in lot 3. In this trial there was no significant difference in mortality rate obtained in the groups receiving 0 and 3 percent chick size oyster shell. In the second trial the day-old chicks were placed in sterile brooders and were fed the same experimental rations as were used in the first trial. The three lots of chicks were infected when two weeks old. They were, however, given the same dosage of sporulated oocysts of the same pure culture of Eimeria tenella as used in the first trial. Death loss and general conditions of the groups were noted. The results of the second trial are given in Table 2. It is evident that when 3 and 6 percent chick size oyster, shell was added the chicks were more seriously affected by coccidia as evidenced by the greater mortality in these groups. In the third trial the day-old chicks were placed in sterile brooders and were given the same sterilized experimental rations as the preceding trials but were infected at four weeks of age with the same dosage of sporulated oocyts of the same pure culture
SCIENCE
of Eimeria tenella as used in the previous trials. The results (Table 3) show that the mortality from coccidiosis in the three lots was 46,8, 60.0, and 77.8 percent respectively when 0, 3, and 6 percent oyster shell was fed, showing that the addition of calcium carbonate in the form of chick size oyster shell increased the susceptibility of chickens to coccidiosis. In the last two trials the lowest mortality from coccidiosis was experienced when no chick size oyster shell (source of calcium carbonate) was added to the ration. In the first and third trials the heaviest mortality from coccidiosis occurred in the lots receiving 6 percent of chick size oyster shell. The results of the three trials summarized in Table 4 indicate that with the higher levels of calcium carbonate, as supplied by chick size oyster shell, more deaths occurred after infection with coccidiosis. Chemical analyses of the three experimental rations for calcium and phosphorous content were made. The calcium, phosphorous, and calcium to phosphorous ratio for the three experimental rations is given in Table 5. It will be noted that when no addition of chick size oyster shell was made to the basal ration there was a calcium con-
TABLE 1.—Results of first trial
Average* SurNumber weight at 6 weeks vivors
Ration
grams Lot 1 Basal
100
Lot 2 Basal Chick size oyster shell
97
Lot 3 Basal Chick size oyster shell
94
3
6
Average Deaths weight of from survivors coccidiosis at 7 weeks (percent)
Deaths from coccidiosis 5th day
6th day
7th day
Average weight at death grams
grams
42
249.1
27
287.4
35.7
0
14
1
254.5
39
225.0
27
266.0
30.8
0
10
2
245.1
39
251.4
11
272.9
71.8
5
20
3
256.6
* Infected at six weeks of age.
SEPTEMBER,
1937.
VOL.
XVI,
No.
TABLE 2 .—Results
of second trial
Average Deaths Deaths from weight from Average Average coccidiosis Num- weight Average* Sur- of sur- coccidiweight weight ber at start at 2 wks. vivors vivors at osis 3rd 4th 5th 6th 7th at 3 weeks (percent) day day day day day death
Ration
Lot 1 Basal
337
5
grams
grams
grams
grams
100
43
40.5
78.0
19
90.7
55.8
3
1
8
11
1
77.7
Lot 2 Basal 97 Chick size oyster shell 3
44
42.4
81.3
14
88.1
68.2
3
0
10
16
1
84.4
Lot 3 Basal 94 94 Chick size oyster shell 6
45
41.3
75.3
16
79.8
64.4
7
2
8
11
1
68.3
* Infected at two weeks of age.
tent of 0.8714 percent and a ratio of 1 part of calcium to 1.07 parts of phosphorus; when 3 percent of chick size oyster shell was fed there was a calcium content of 1.293 percent and a ratio of 1 part of calcium to 0.74 parts of phosphorus; when 6 percent of chick size oyster shell was fed there was a calcium content of 2.471 percent and a ratio of 1 part of calcium to 0.354 parts of phosphorus. These trials are in agreement with the preliminary results reported by Herrick, Ott, Halpin, and Holmes (1935) and seem TABLE 3
Lot 1 Basal
—Results of third trial
Num- Average Average* Surweight weight ber at start at 4 weeks vivors
Ration
grams
grams
to indicate that excessive mineral additions are likely to be detrimental to growing chicks when sporulated coccidia oocysts are fed in measured amounts. These trials were repeated with an attempt to maintain rations with the same calcium to phosphorus ratio. The calcium to phosphorus ratio was adjusted by adding sufficient disodium phosphate (Na2 HP0 4 • 12H 2 0) to maintain the same ratio in all three lots. The same basal ration was used as in the three previous trials. The general plan of the rations was: lot 1—
Deaths from Average Average Deaths from coccidiosis weight weight coccidiosis, 5th 6th 7th at death at 5 weeks (percent) day day day grams
grams
100
47
40.1
149.4
25
166.2
46.8
1
19
2
155.7
Lot 2 Basal 97 Chick size oyster shell 3
40
40.3
165.4
16
169.6
60.0
0
21
3
164.7
Lot 3 Basal 94 Chick size oyster shell 6
45
41.4
155.8
10
168.8
77.8
1
31
3
149.0
* Infected at four weeks of age.
338
POULTRY
basal, no additions; lot 2—basal plus 3 percent chick size oyster shell and disodium phosphate; lot 3—basal plus 6 percent chick size oyster shell and disodium phosphate. To adjust the calcium to phosphorus ratios 863.5 and 3,620.4 grams of disodium phosphate were added to each 100 pounds of ration of lots 2 and 3 respectively. The trials were started with day-old chicks in sterile brooders fed the sterilized experimental rations. The chicks in lots 2 and 3 would not eat their rations readily and a majority of the chicks in these two lots died of starvation. The remaining chicks in lots 2 and 3 made little growth. The experiment was completed, but because only a few very badly stunted chicks remained in lots 2 and 3 at the time of infection, no significant results were obtained as to the resistance to coccidiosis at different levels of calcium carbonate when the calcium to phosphorus ratio was held constant. One group of day-old chicks was placed in a battery brooder. They were given the Wisconsin 2 A starting ration in one feed trough and in the other feed trough the same ration as lot 3: 3,620.4 grams of disodium phosphate in 100 pounds of ration. Wisconsin 2A consists of ground yellow corn 45, wheat bran 15, standard wheat middlings 15, dried skimmilk 12, meat scrap
Ration
Percent Deaths mortalfrom ity from coccid- coccidioiosis sis
100
132
61
46.2
Basal 97 Chick size oyster shell 3
123
66
53.6
Basal 94 Chick size oyster shell 6
129
92
71.3
Basal
TABLE 5.—Calcium and phosphorus contents of rations
Ration
Basal
100
Basal Chick size oyster shell
97
Basal Chick size oyster shell
94
3
6
Calcium Phosphorus percent percent
Calcium to phosphorus ratio
0.8714
0.9343
1.0:1.07
1.293
0.9636
1.0:0.74
2.471
0.8862
1.0:0.354
6, alfalfa leaf meal 3, chick size oyster shell 3, iodized stock salt 0.5, and cod liver oil 0.5. The feed troughs were interchanged frequently in order to overcome any influence of difference in light intensity or habit on food consumption. In the twentytwo-day period the chicks had consumed only 452 grams of the ration containing the additional disodium phosphate and had consumed in the same time 7,432 grams of the Wisconsin 2 A starting ration that contained no addition of disodium phosphate. Rations containing the amounts of disodium phosphate used in these trials are unpalatable and if studies are to be made with different levels of calcium carbonate holding the calcium to phosphorus ratio constant some other source of phosphorus must be used. SUMMARY
TABLE 4.—Summary of three trials Number of chicks infected
SCIENCE
1. In two trials more deaths occurred after infection with coccidiosis when 6 percent of chick size oyster shell was added to a basal diet containing 0.8714 and 0.9343 percent calcium and phosphorus respectively. 2. The results of the three trials indicate that with the higher levels of calcium carbonate more deaths occurred after infection with coccidiosis. 3. Attempts to determine the effects of different levels of calcium carbonate on
SEPTEMBER,
1937.
VOL.
XVI,
mortality from coccidiosis holding the calcium to phosphorous ratio constant by means of disodium phosphate were not successful due probably to unpalatability of the rations containing this phosphorus supplement. REFERENCES
Fish, F., 1931. The effects of physical and chemical agents on the oocysts of Eimeria tenella. Science, 73 :292-293.
No.
S
339
Halpin, J. G., 1926. Minerals influence rate of growth of chicks. Wisconsin Agricultural Experiment Station Bulletin 388:111. Herrick, C. A., G. L. Ott, J. G. Halpin, and C. E. Holmes, 1935. Extra calcium in ration increases susceptibility of chicks to coccidiosis. Wisconsin Agricultural Station Bulletin 430:97. Herrick, C. A., G. L. Ott, and C. E. Holmes, 1936. The chicken as a carrier of the oocysts of the coccidia, Eimeria tenella. Poultry Science, 15:322-325.
News and Notes At the recent annual meeting of the Poultry Science Association at Madison, Wisconsin, R. E. Jones of Storrs, Connecticut, was elected President for the year 1937-38. Berley Winton of Washington, D.C., was elected 1st Vice-President and L. W. Taylor of Berkeley, California, was elected 2nd Vice-President. W. A. Maw of Macdonald College, Quebec, Canada, was reelected Secretary-Treasurer. The directors elected for the period 1937-39 were R. B. Thompson of Stillwater, Oklahoma, and M. 0. North of Laramie, Wyoming. G. W. Sprague of Washington, D.C., was elected an associate editor of POULTRY SCIENCE. The Executive Committee of the Poultry Science Association decided to hold the next annual meeting of the Association at Washington State College, Pullman, Washington, after a guiding vote indicating the preference of the members present at the annual
meeting, had been taken. The Seventh World's Poultry Congress will be held in Cleveland, Ohio, where excellent facilities are available for housing the Congress. It is expected that the Congress will be held sometime during the period covering the last week in July and the first week in August. Dr. Victor Heiman, Assistant Professor of Poultry Husbandry, Washington State College, has resigned to become associated with Kasco Mills, Inc., Waverly, New York, on August 1 as director of research. Dr. Lawrence L. Lachat has resigned from the Minnesota State Department of Agriculture, effective August IS, to head the new Feed Testing and Control Laboratory of the Great Atlantic & Pacific Tea Company. Dr. Lachat will have his headquarters at Minneapolis, Minnesota.