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Speed of Hatching and the Resistance of Chickens to Ascaridia Galli
Speed of Hatching and the Resistance of Chickens to Ascaridia Galli BERNARD B. R I E D E L Disease Research, Poultry Department, University of Georgia, Athens, Georgia (Received for publication March 17, 1950)
E
VIDENCE has been presented which indicated that the resistance of chickens to infection by the large roundworm may be affected by several factors. Among these factors are genetic constitution (Ackert and Wilmoth, 1934; and Ackert et al., 1935a) and diet (Ackert and Beach, 1933; Ackert et al.-, 1927; Ackert and Spindler, 1929; and Riedel and Ackert, 1950a). Age as a factor of resistance was reported by Herrick (1926); Ackert et al. (1935b); and Riedel and Ackert (1950b). Histological studies made by Ackert and Edgar (1938) disclosed a progressive increase of goblet cells in the chicken duodenum. This increase of the number of goblet cells correlated with the increase of age resistance established formerly by Herrick (1926). The mucus secreted by the goblet cells was tested (Ackert, Todd and Tanner, 1938; and Frick and Ackert, 1948) and the results showed that the growth of young Ascaridia was retarded when placed in nutrient media containing autoclaved mucin from older chickens. Hydrogen-ion concentration as a factor in age resistance to the fowl ascarid was studied by Riedel and Ackert (1947). The fact that the worm habitat in chickens 17 to 35 weeks of age had about the same hydrogen-ion concentration as did that of young birds one to 8 weeks of age eliminated hydrogen-ion concentration as a factor of age resistance. Recently, Henderson and Champion
(1948) found that within breeds there was a tendency for chicks which hatched earliest to be the largest at the end of an 8-week period. As a result of their observations an investigation was undertaken to note if speed of hatching may influence the resistance of the chick toward infection by Ascaridia galli. METHODS
The chicks used in this investigation were selected from several hatchings of Rhode Island Reds after separating each hatch into an early, intermediary, and late period. To make certain that the speed of hatching between the early and late chicks varied considerably, the intermedial period, from which no chickens were taken, was always of 10 or more hours duration. The chickens in each experiment were banded and weighed within one week after hatching. The chicks were individually infected with 300 embryonated Ascaridia galli ova and autopsied 21 days later. The nematodes harbored in the intestinal lumen of each chick were collected and counted and the numbers of worms harbored by each bird were used as the criterion in determining the correlation between the degree of resistance to infection by Ascaridia galli and speed of hatching. RESULTS AND DISCUSSION
The data in Tables 1 and 2 show the effect of speed of hatching upon the weight 703
704
BERNARD B. RIEDEL TABLE 1.—The effect of early and late hatching upon the weight records and the numbers of "Ascardia galli" harbored in younger chickens Number of birds harboring worms
Av. weight (gms.)
G
™P**
1 2
SSr
At start
At finish
Total worm number
Av. worm number harbored
30 31
60
52
Experiment 1 238 247
16 14
460 360
15.3 11.9
26 20
64 69
Experiment Z 20 240 19 253
826 856
31.8 42.8
29 24
58 60
Experiment 3 247 25 21 259
728 555
25.1 23.1
23 23
65 68
Experiment 4 244 21 260 20
644 578
28.0 25.1
22 23
69 71
Experiment 5 251 21 262 12
129 29
5.9 1.3
25 24
62 65
Experiment 6 17 239 15 253
58 96
2.3 4.0
2,845 2,474
18.4 17.1
Totals 1 2 ;
155 145
63 66
245 257
120 101
Group 1 hatched late, Group 2 hatched early.
records and the average numbers of Ascaridia galli harbored by growing chickens. In the first part of this investigation in which the chicks were infected at less than 10 days of age and autopsied 21 days later (Table 1), a consistent correlation existed between the speed of hatching and the average weight records. The chickens which hatched the earliest (Group 2) had a total, average weight of 12 grams higher than that of the chicks which hatched late (Group 1). With respect to Ascaridia the results were inconsistent. In two of the six experiments the group 2 chickens harbored more worms than the group 1 chickens. When the average, total number of worms from groups 1 and 2 were compared, the
first group was noted to harbor an average of 1.3 worms more. This small difference indicated a lack of correlation between the speed of hatching and the degree of resistance. The data in Table 2 were taken from chickens infected with Ascaridia during the sixth week of age and autopsied 21 days later. In five of the six experiments the average weight records were higher among the chickens which hatched the earliest. The group 2 chickens had a total, average weight 16 grams higher than those in group 1. Pertaining to the average worm numbers harbored by the chickens in each experiment (Table 2), the group 2 chickens harbored consistently fewer ascarids than did the group 1 birds. These small
SPEED OF HATCHING AND RESISTANCE OF CHICKS TO ASCARIDIA
705
TABLE 2.—The effect of early and late hatching upon the weight records and the numbers of "Ascardia galli" harbored in older chickens Av. weight (gms.) Group*
1 2
Chick number
At start
Number of chickens harboring worms
At finish
Total worm number harbored
Av. worm number harbored
24 24
68 73
Experiment 1 885 997
32 24
1.3 1.0
25 22
71 74
Experiment 2 1,026 1,016
40 22
1.6 1.0
21 21
64 66
1,015 1,069
12 12
84 44
4.0 2.1
23 21
65 67
Experiment 4 1,001 1,049
16 11
62 34
2.7 1.6
20 20
68 71
Experiment 5 1,019 1,032
14 10
50 44
2.5 2.2
21 23
69 72
Experiment 6 1,008 998
11 9
66 54
3.1 2.3
69 51
334 222
2.5 1.7
Totals 1 2
134 131
68 71
1,008 1,026
Group 1 hatched late, Group 2 hatched early.
differences were not significant, and failed to show any correlation between speed of hatching and susceptibility to ascariasis in older chickens. The chickens in experiments 5 and 6 in Table 1 harbored fewer worms than the chickens in the remaining experiments. This may be explained on the basis that the infective ova used in the last two experiments were from cultures with a lower viability. From experience it has been observed that in every flock of chickens experimentally infected with infective ascarid ova, there are always some which are naturally immune and regardless of the age of the host when infected or the size of the infective dose, do not become infected. From the results of this investi-
gation it is apparent that the natural immunity was the greatest among the chicks which hatched the earliest, because fewer of these chicks harbored worms. SUMMARY
An experiment was performed to learn if speed of hatching affected the resistance of chickens toward infection by Ascaridia galli. The results indicated that the chickens which hatched the earliest grew more rapidly than those which hatched late. The speed of hatching did not correlate with the numbers of worms harbored. The natural immunity among the early hatched chicks was higher than it was among those hatching late, because fewer birds in the former category harbored worms.
706
NEWS AND NOTES REFERENCES
Ackert, J. E., and T. D. Beach, 1933. Resistance of chickens to the nematode, Ascaridia lineata, affected by dietary supplements. Tr. Am. Micr. Soc. 52: 51-58. ——— and S. A. Edgar, 1938. Goblet cells and age resistance to parasitism. J. Parasitol. (Supp.) 24: 13-14. , L. L. Eisenbrandt, J. H. Wilmoth, B. Glading and I. Pratt, 1935a. Comparative resistance of five breeds of chickens to the nematode Ascaridia lineata (Schneider). J. Agric. Res. 607-624. —, W. L. Fisher and N. B. Zimmerman, 1927. Resistance to parasitism affected by the fatsoluble vitamin A. J. Parasitol. 13: 219-220. , D. A. Porter and T. D. Beach, 1935b. Age resistance of chickens to the nematode Ascaridia lineata (Schneider). J. Parasitol. 21:205-213. , and L. A. Spindler, 1929. Vitamin D and resistance of chickens to parasitism. Am. J. Hyg. 9: 292-307. , A. C. Todd and W. A. Tanner, 1938. Growing larvae Ascaridia lineata (nematode) in vitro. Tr. Am. Micr. Soc. 57: 292-296.
and J. H. Wilmoth, 1934. Resistant and susceptible strains of White Minorca chickens to the nematode Ascaridia lineata (Schneider). J. Parasitol. 20: 323-324. Frick, L. P. and J. E. Ackert, 1948. Further studies on duodenal mucus as a factor in age resistance of chickens to parasitism. J. Parasitol. 34: 192206. Henderson, E. W. and L. R. Champion, 1948. Correlation between speed of hatching and growth rate of chickens. Poultry Sci. 27: 667. Herrick, C. A., 1926. Studies on the resistance of chickens to the nematode, Ascaridia perpicillum. Am. J. Hyg 6: 153-172. Riedel, B. B. and J. E. Ackert, 1947. Further studies on hydrogen-ion concentration as a factor in age resistance to the fowl ascarid. J. Parasitol. (Suppl.) 33: 19-20. and , 1950a. The resistance of chickens to ascarids as affected by protein supplements of soybean oil meal and skim milk. Poultry Sci. 29:437-443. —•—— and , 1950b. Quantity and source of proteins as factors in resistance of chickens to ascarids. J. Parasitol. In press.
News and Notes {Continued from page 684)
throughout the nation. Peters Hall, built at a cost of approximately $660,000, is a three-story Tshaped building. One wing measures 192 feet, the other 106 feet in length. It is faced in brick with stone trim, with several large brick panels set into the walls. It will be used for classrooms, laboratories and offices by both the animal and poultry husbandry divisions. Included in the structure is a 100 by 53 foot auditorium, seating 400. The basement will house laboratories to be used by both divisions. The ground floor will be devoted to animal husbandry classrooms, offices and a library for both staff members and graduate students. The second floor, as well as part of the base-
ment, will be given over to facilities for the poultry division. FLORIDA NOTES Julian S. Moore has been appointed Extension Poultryman, Florida College of Agriculture, Gainesville. TEXAS NOTES Professor D. H. Reid, who retired a few years ago as Head of the Poultry Department, Agricultural and Mechanical College of Texas, College Station, was honored recently by leaders of the poultry industry and allied fields at the time of his final broadcast on the Texas Farm and Home Program. Prof. Reid who had been on the air for 14 years with his weekly
{Continued on page 711)
E
VIDENCE has been presented which indicated that the resistance of chickens to infection by the large roundworm may be affected by several factors. Among these factors are genetic constitution (Ackert and Wilmoth, 1934; and Ackert et al., 1935a) and diet (Ackert and Beach, 1933; Ackert et al.-, 1927; Ackert and Spindler, 1929; and Riedel and Ackert, 1950a). Age as a factor of resistance was reported by Herrick (1926); Ackert et al. (1935b); and Riedel and Ackert (1950b). Histological studies made by Ackert and Edgar (1938) disclosed a progressive increase of goblet cells in the chicken duodenum. This increase of the number of goblet cells correlated with the increase of age resistance established formerly by Herrick (1926). The mucus secreted by the goblet cells was tested (Ackert, Todd and Tanner, 1938; and Frick and Ackert, 1948) and the results showed that the growth of young Ascaridia was retarded when placed in nutrient media containing autoclaved mucin from older chickens. Hydrogen-ion concentration as a factor in age resistance to the fowl ascarid was studied by Riedel and Ackert (1947). The fact that the worm habitat in chickens 17 to 35 weeks of age had about the same hydrogen-ion concentration as did that of young birds one to 8 weeks of age eliminated hydrogen-ion concentration as a factor of age resistance. Recently, Henderson and Champion
(1948) found that within breeds there was a tendency for chicks which hatched earliest to be the largest at the end of an 8-week period. As a result of their observations an investigation was undertaken to note if speed of hatching may influence the resistance of the chick toward infection by Ascaridia galli. METHODS
The chicks used in this investigation were selected from several hatchings of Rhode Island Reds after separating each hatch into an early, intermediary, and late period. To make certain that the speed of hatching between the early and late chicks varied considerably, the intermedial period, from which no chickens were taken, was always of 10 or more hours duration. The chickens in each experiment were banded and weighed within one week after hatching. The chicks were individually infected with 300 embryonated Ascaridia galli ova and autopsied 21 days later. The nematodes harbored in the intestinal lumen of each chick were collected and counted and the numbers of worms harbored by each bird were used as the criterion in determining the correlation between the degree of resistance to infection by Ascaridia galli and speed of hatching. RESULTS AND DISCUSSION
The data in Tables 1 and 2 show the effect of speed of hatching upon the weight 703
704
BERNARD B. RIEDEL TABLE 1.—The effect of early and late hatching upon the weight records and the numbers of "Ascardia galli" harbored in younger chickens Number of birds harboring worms
Av. weight (gms.)
G
™P**
1 2
SSr
At start
At finish
Total worm number
Av. worm number harbored
30 31
60
52
Experiment 1 238 247
16 14
460 360
15.3 11.9
26 20
64 69
Experiment Z 20 240 19 253
826 856
31.8 42.8
29 24
58 60
Experiment 3 247 25 21 259
728 555
25.1 23.1
23 23
65 68
Experiment 4 244 21 260 20
644 578
28.0 25.1
22 23
69 71
Experiment 5 251 21 262 12
129 29
5.9 1.3
25 24
62 65
Experiment 6 17 239 15 253
58 96
2.3 4.0
2,845 2,474
18.4 17.1
Totals 1 2 ;
155 145
63 66
245 257
120 101
Group 1 hatched late, Group 2 hatched early.
records and the average numbers of Ascaridia galli harbored by growing chickens. In the first part of this investigation in which the chicks were infected at less than 10 days of age and autopsied 21 days later (Table 1), a consistent correlation existed between the speed of hatching and the average weight records. The chickens which hatched the earliest (Group 2) had a total, average weight of 12 grams higher than that of the chicks which hatched late (Group 1). With respect to Ascaridia the results were inconsistent. In two of the six experiments the group 2 chickens harbored more worms than the group 1 chickens. When the average, total number of worms from groups 1 and 2 were compared, the
first group was noted to harbor an average of 1.3 worms more. This small difference indicated a lack of correlation between the speed of hatching and the degree of resistance. The data in Table 2 were taken from chickens infected with Ascaridia during the sixth week of age and autopsied 21 days later. In five of the six experiments the average weight records were higher among the chickens which hatched the earliest. The group 2 chickens had a total, average weight 16 grams higher than those in group 1. Pertaining to the average worm numbers harbored by the chickens in each experiment (Table 2), the group 2 chickens harbored consistently fewer ascarids than did the group 1 birds. These small
SPEED OF HATCHING AND RESISTANCE OF CHICKS TO ASCARIDIA
705
TABLE 2.—The effect of early and late hatching upon the weight records and the numbers of "Ascardia galli" harbored in older chickens Av. weight (gms.) Group*
1 2
Chick number
At start
Number of chickens harboring worms
At finish
Total worm number harbored
Av. worm number harbored
24 24
68 73
Experiment 1 885 997
32 24
1.3 1.0
25 22
71 74
Experiment 2 1,026 1,016
40 22
1.6 1.0
21 21
64 66
1,015 1,069
12 12
84 44
4.0 2.1
23 21
65 67
Experiment 4 1,001 1,049
16 11
62 34
2.7 1.6
20 20
68 71
Experiment 5 1,019 1,032
14 10
50 44
2.5 2.2
21 23
69 72
Experiment 6 1,008 998
11 9
66 54
3.1 2.3
69 51
334 222
2.5 1.7
Totals 1 2
134 131
68 71
1,008 1,026
Group 1 hatched late, Group 2 hatched early.
differences were not significant, and failed to show any correlation between speed of hatching and susceptibility to ascariasis in older chickens. The chickens in experiments 5 and 6 in Table 1 harbored fewer worms than the chickens in the remaining experiments. This may be explained on the basis that the infective ova used in the last two experiments were from cultures with a lower viability. From experience it has been observed that in every flock of chickens experimentally infected with infective ascarid ova, there are always some which are naturally immune and regardless of the age of the host when infected or the size of the infective dose, do not become infected. From the results of this investi-
gation it is apparent that the natural immunity was the greatest among the chicks which hatched the earliest, because fewer of these chicks harbored worms. SUMMARY
An experiment was performed to learn if speed of hatching affected the resistance of chickens toward infection by Ascaridia galli. The results indicated that the chickens which hatched the earliest grew more rapidly than those which hatched late. The speed of hatching did not correlate with the numbers of worms harbored. The natural immunity among the early hatched chicks was higher than it was among those hatching late, because fewer birds in the former category harbored worms.
706
NEWS AND NOTES REFERENCES
Ackert, J. E., and T. D. Beach, 1933. Resistance of chickens to the nematode, Ascaridia lineata, affected by dietary supplements. Tr. Am. Micr. Soc. 52: 51-58. ——— and S. A. Edgar, 1938. Goblet cells and age resistance to parasitism. J. Parasitol. (Supp.) 24: 13-14. , L. L. Eisenbrandt, J. H. Wilmoth, B. Glading and I. Pratt, 1935a. Comparative resistance of five breeds of chickens to the nematode Ascaridia lineata (Schneider). J. Agric. Res. 607-624. —, W. L. Fisher and N. B. Zimmerman, 1927. Resistance to parasitism affected by the fatsoluble vitamin A. J. Parasitol. 13: 219-220. , D. A. Porter and T. D. Beach, 1935b. Age resistance of chickens to the nematode Ascaridia lineata (Schneider). J. Parasitol. 21:205-213. , and L. A. Spindler, 1929. Vitamin D and resistance of chickens to parasitism. Am. J. Hyg. 9: 292-307. , A. C. Todd and W. A. Tanner, 1938. Growing larvae Ascaridia lineata (nematode) in vitro. Tr. Am. Micr. Soc. 57: 292-296.
and J. H. Wilmoth, 1934. Resistant and susceptible strains of White Minorca chickens to the nematode Ascaridia lineata (Schneider). J. Parasitol. 20: 323-324. Frick, L. P. and J. E. Ackert, 1948. Further studies on duodenal mucus as a factor in age resistance of chickens to parasitism. J. Parasitol. 34: 192206. Henderson, E. W. and L. R. Champion, 1948. Correlation between speed of hatching and growth rate of chickens. Poultry Sci. 27: 667. Herrick, C. A., 1926. Studies on the resistance of chickens to the nematode, Ascaridia perpicillum. Am. J. Hyg 6: 153-172. Riedel, B. B. and J. E. Ackert, 1947. Further studies on hydrogen-ion concentration as a factor in age resistance to the fowl ascarid. J. Parasitol. (Suppl.) 33: 19-20. and , 1950a. The resistance of chickens to ascarids as affected by protein supplements of soybean oil meal and skim milk. Poultry Sci. 29:437-443. —•—— and , 1950b. Quantity and source of proteins as factors in resistance of chickens to ascarids. J. Parasitol. In press.
News and Notes {Continued from page 684)
throughout the nation. Peters Hall, built at a cost of approximately $660,000, is a three-story Tshaped building. One wing measures 192 feet, the other 106 feet in length. It is faced in brick with stone trim, with several large brick panels set into the walls. It will be used for classrooms, laboratories and offices by both the animal and poultry husbandry divisions. Included in the structure is a 100 by 53 foot auditorium, seating 400. The basement will house laboratories to be used by both divisions. The ground floor will be devoted to animal husbandry classrooms, offices and a library for both staff members and graduate students. The second floor, as well as part of the base-
ment, will be given over to facilities for the poultry division. FLORIDA NOTES Julian S. Moore has been appointed Extension Poultryman, Florida College of Agriculture, Gainesville. TEXAS NOTES Professor D. H. Reid, who retired a few years ago as Head of the Poultry Department, Agricultural and Mechanical College of Texas, College Station, was honored recently by leaders of the poultry industry and allied fields at the time of his final broadcast on the Texas Farm and Home Program. Prof. Reid who had been on the air for 14 years with his weekly
{Continued on page 711)