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The Effects of the Northern Fowl Mite, Ornithonyssus sylivarium1 on Egg Production and Body Weight of Caged White Leghorn Hens
The Effects of the Northern Fowl Mite, Ornithonyssus sylivarium1 on Egg Production and Body Weight of Caged White Leghorn Hens JOYCE A. DeVANEY Veterinary Toxicology and Entomology Research Laboratory, Agricultural Research Service, USDA, College Station, Texas 77840 (Received for publication June 15, 1978) ABSTRACT Egg production of caged White Leghorn hens with heavy (>1000) populations of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), was 5 to 15% less than egg production of control hens. Body weight was depressed in hens infested with mites before the hens came into full egg production but not when hens were infested after that time. Feed consumption was not affected by mite populations.
The northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), a hematophagous mite found on chickens as well as other avian species, is the most important external parasite of poultry in the United States. Because the mite feeds on blood, can build up large populations in a very short time, and is irritating to poultrymen, efforts have been made to control this mite since it was first reported in the United States (Wood, 1920). However, relatively little work has been done on the biology, ecology, or host-parasite relationships. Cameron (1938), Chamberlain and Sikes (1950), and Combs and Lancaster (1965) have contributed to our present understanding of the basic biology of the mite. In studies on roosters, Matthysse et al. (1974) found mites distributed over the entire body causing microcytic, normochromic anemia with severe mite populations. However, DeVaney et al. (1977) did not detect anemia in roosters with extra heavy mite populations but did detect body weight losses. They also found decreases in seminal fluid, sperm concentrations, and levels of serum testosterone of mite-infested roosters when compared with mite-free roosters. Much of the literature states that mite-infested hens show decreased egg production, irritability, anemia, loss of weight, and scabs which spoil the appearance of dressed carcasses (Wood, 1920; Payne, 1930; Blount, 1947; Furman, 1952; Knapp and Krause, I960; Benbrook, 1965). However, Loomis et al. (1970) using a Hyline strain in California did not find
1
Acarina: Dermanyssidae.
1979 Poultry Sci 58:191-194
significant differences in egg production means among older hens, pullets, or any one of eight different family lines rated "negatively, moderately, or heavily mite infested." On the other hand, using high an'd low arginine strains developed by R. Cole at Cornell University, Matthysse et al. (1974) found a 9.8% decrease in egg production in one experiment but no significant effect on egg production with "smallto-moderate infestations" of northern fowl mites. This study was designed to determine the effects of uncontrolled northern fowl mite populations on egg production, body weight, and feed consumption of Ideal 236 hens throughout an entire laying cycle. MATERIALS AND METHODS Forty-eight 22-week-old commercially grown White Leghorn hens (Ideal 236) were used in each of two studies. All birds were paired by weight; then 24 birds were used as controls for each study and the remaining 24 were infested with mites by mechanically aspirating 500 to 2000 mites from a carrier bird and immediately placing this number of mites on the back or vent of each hen. The two groups of hens for each study were maintained in individual cages in separate rooms as previously described by DeVaney (1976). In the first study, March 1975 through March 1976, the hens were infested on March 20, 1975. In the second study, July 1976 through June 1977, the hens were infested on September 24, 1976. During both studies, each hen was removed from her cage once each week for weighing. After weighing, the mite population was estimated visually by parting the feathers and carefully 191
Downloaded from http://ps.oxfordjournals.org/ by guest on January 30, 2015
INTRODUCTION
DeVANEY
192
FIG. 1. Mean egg production of hens infested and uninfested with northern fowl mites from March 1975 through March 1976.
FIG. 2. Mean body weight of hens infested and uninfested with northern fowl mites from March 1975 through March 1976.
RESULTS AND DISCUSSION
Downloaded from http://ps.oxfordjournals.org/ by guest on January 30, 2015
In the first study, hens were infested with northern fowl mites two weeks after they had begun laying. Subsequently mite populations increased rapidly on all treated hens. By the end of April, only four hens had a moderate population of mites (Figure 1 and Figure 2); all the others had heavy to extra heavy populations. An average rating of heavy was then maintained until the end of June 1975; the rating was moderate from July through December 1975. However, on December 11, 1975, a light population of mites was found on three of
the control hens. Rather than treating these hens with a pesticide, all "control" hens were infested with mites as described to determine whether mites would cause decreased egg production or body weight in older hens. One month later, the mean mite population of this previous control group was heavy. During April and May, 1975, hen-day egg production for the mite-infested birds was 71 and 78% compared with 86 and 87% for the control hens (Figure 1). April egg production difference was significant at P = . 1 . Thereafter, there was no appreciable difference in egg production. The mean body weight of mite-infested hens (Figure 2) was consistently lower than the mean body weight of the control hens. Significant differences (P = .05) in body weight occurred from May through December 1975. However, one month after the control group was infested with mites in December, the mean body weight of these hens had decreased by ca. 100 g. There was no significant difference between the weight of the two groups at the end of the study. In the second study, hens were not infested with mites until they had come into full egg production. Mite populations increased very rapidly, and for the first three months, the rating was heavy for the entire treated group. Egg production (Figure 3) of treated hens was 81, 78, and 75% in October, November, and December respectively compared with 86, 84, and 86% for the control hens. November and December egg productions were significantly different at P = .1 and P = .05, respectively. After this time, mite populations decreased
observing mites in the vent area, legs, breast, and ventral aspect of the neck. The following index was used in rating the infestations: 0— no mites, 1-very light (1 to 10 mites/hen), 2— light (11 to 10 mites/hen), 3—moderate (101 to 1000 mites/hen), 4-heavy (1001 to 10,000 mites/hen), and 5-extra heavy (> 10,000 mites/hen). The mites were actually counted when populations were rated light or less but were estimated when the populations were moderate or heavier. In the second study, feed consumption was determined on a weekly basis. The hen-day egg production for each month was compared by a completely randomized analysis of variance, with the error term representing the variation in egg production among hens of the same treatments. Hen body weight for each month of the two groups was compared by means of a completely random analysis of variance using weekly averages as observational units.
193
EFFECTS OF NORTHERN FOWL MITE ON EGG PRODUCTION INFESTED
100
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rapidly a n d t h e r e was n o significant difference in egg p r o d u c t i o n b e t w e e n groups. Body weight of t h e infested and uninfested hens (Figure 4 ) was n o t significantly different. Average daily feed c o n s u m p t i o n records also showed n o significant difference b e t w e e n t h e t w o groups. Results of t h e studies s h o w t h a t b o d y weight m a y be depressed with m i t e p o p u l a t i o n s . This weight loss is currently n o t considered of econ o m i c i m p o r t a n c e with spent caged White Legh o r n hens. However, w h e n m i t e p o p u l a t i o n s become heavy, a p r o d u c e r can expect a 5 t o 1 5 % decrease in egg p r o d u c t i o n a n d this effect m a y be greater w h e n t h e h e n s are coming into egg p r o d u c t i o n or w h e n t h e r e are o t h e r stress factors. This decrease w o u l d w a r r a n t control of n o r t h e r n fowl mites o n caged layers. However, results of this study indicated t h a t control m a y n o t b e n e e d e d after p o p u l a t i o n s of mites are declining and rated as m o d e r a t e or less (< 1,000 mites/hen) providing t h e r e are no o t h e r stress factors present. Hall and Gross ( 1 9 7 5 ) f o u n d t h a t cockerels artificially selected for l o w levels of plasma corticosterone response t o social stress and maintained in a low social interaction environm e n t rapidly developed large p o p u l a t i o n s of n o r t h e r n fowl mites. Cockerels selected for high levels of plasma corticosterone response t o stress and housed in a high social stress environm e n t developed smaller p o p u l a t i o n s of mites. O t h e r stress factors, such as diet changes, adverse environmental or lighting conditions, a n d disease m a y also affect m i t e p o p u l a t i o n s . These factors need t o b e investigated t o aid in practi-
/
JLJ.
1 O
1
1
1
1
1
N 1976
FIG. 4. Mean body weight of hens infested and uninfested with northern fowl mites from July 1976 through June 1977.
cal c o n t r o l r e c o m m e n d a t i o n which could be determined by poultrymen. ACKNOWLEDGMENTS T h e a u t h o r w o u l d like t o t h a n k Billy F . Hogan, J o h n Brock, Maurice W. Connell, a n d J o y c e Parker of this laboratory for their technical assistance.
REFERENCES Benbrook, E. C , 1965. External parasites of poultry. In Diseases of poultry. 5th ed. Iowa State University Press, Ames, IA. 1382 pp. Blount, W. P., 1947. Diseases of poultry. William and Wilkings Co., Baltimore, Maryland. 562 pp. Cameron, D., 1938. The northern fowl mite (Liponyssus sylviarum C. & F., 1877). Can. J. Res. 1 6 : 2 3 0 254. Chamberlain, R. W., and R. K. Sikes, 1950. Laboratory rearing methods for three common species of bird mites. J. Parasitol. 36:461-465. Combs, Jr., R. L., and J. L. Lancaster, Jr., 1965. The biology of the northern fowl mite. Arkansas Agr. Exp. Sta. Rep. Ser. 138 pp. DeVaney, J. A., 1976. Effects of the chicken body louse, Menacantbus stramineus, on caged layers. Poultry Sci. 55:430-435. DeVaney, J. A., M. H. Elissalde, E. G. Steel, B. F. Hogan, and H. D. Petersen, 1977. Effects of the northern fowl mite, Omithonyssus sylviarum (Canestrini & Fanzago), on White Leghorn roosters. Poultry Sci. 56:1585-1590. Furman, D. P., 1952. Control of the northern fowl mite. J. Econ. Entomol. 45:926-930. Hall, R. D., and W. B. Gross, 1975. Effects of social stress and inherited plasma corticosterone levels in chickens or populations of the northern fowl mite, Ornitbonyssus sylviarum. J. Parasitol. 61:1096— 1100. Knapp, F. W„ and G. F. Krause, 1960. Control of the
Downloaded from http://ps.oxfordjournals.org/ by guest on January 30, 2015
FIG. 3. Mean egg production of hens infested and uninfested with northern fowl mites from July 1976 through June 1977.
1400
194
DeVANEY
northern fowl mite Ornitbonyssus sylviarum (Canestrini & Fanzago), with Ronnel, Bayer L13/59 and Bayer 21/199. J. Econ. Entomol. 5 3 : 4 - 5 . Loomis, E. C , E. L. Bramhall, J. A. Allen, R. A. Ernst, and L. L. Dunning, 1970. Effects of the northern fowl mite on White Leghorn chickens. J. Econ. Entomol. 63:1885-1889. Matthysse, J. G., C. J. Jones, and A. Purnasirl, 1974.
Development of northern fowl mite populations on chickens, effects on the host, and immunology. Serch. Agri. 4(9). 39 pp. Payne, L. F., 1930. Feather mites and their control. Bull. Alabama Polytech. Inst. 2 5 : 6 1 - 6 3 . Wood, H. P., 1920. Tropical fowl mite in the United States with notes on the life history and control. U.S. Dept. Agri. Circ. 79.
Downloaded from http://ps.oxfordjournals.org/ by guest on January 30, 2015
The northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), a hematophagous mite found on chickens as well as other avian species, is the most important external parasite of poultry in the United States. Because the mite feeds on blood, can build up large populations in a very short time, and is irritating to poultrymen, efforts have been made to control this mite since it was first reported in the United States (Wood, 1920). However, relatively little work has been done on the biology, ecology, or host-parasite relationships. Cameron (1938), Chamberlain and Sikes (1950), and Combs and Lancaster (1965) have contributed to our present understanding of the basic biology of the mite. In studies on roosters, Matthysse et al. (1974) found mites distributed over the entire body causing microcytic, normochromic anemia with severe mite populations. However, DeVaney et al. (1977) did not detect anemia in roosters with extra heavy mite populations but did detect body weight losses. They also found decreases in seminal fluid, sperm concentrations, and levels of serum testosterone of mite-infested roosters when compared with mite-free roosters. Much of the literature states that mite-infested hens show decreased egg production, irritability, anemia, loss of weight, and scabs which spoil the appearance of dressed carcasses (Wood, 1920; Payne, 1930; Blount, 1947; Furman, 1952; Knapp and Krause, I960; Benbrook, 1965). However, Loomis et al. (1970) using a Hyline strain in California did not find
1
Acarina: Dermanyssidae.
1979 Poultry Sci 58:191-194
significant differences in egg production means among older hens, pullets, or any one of eight different family lines rated "negatively, moderately, or heavily mite infested." On the other hand, using high an'd low arginine strains developed by R. Cole at Cornell University, Matthysse et al. (1974) found a 9.8% decrease in egg production in one experiment but no significant effect on egg production with "smallto-moderate infestations" of northern fowl mites. This study was designed to determine the effects of uncontrolled northern fowl mite populations on egg production, body weight, and feed consumption of Ideal 236 hens throughout an entire laying cycle. MATERIALS AND METHODS Forty-eight 22-week-old commercially grown White Leghorn hens (Ideal 236) were used in each of two studies. All birds were paired by weight; then 24 birds were used as controls for each study and the remaining 24 were infested with mites by mechanically aspirating 500 to 2000 mites from a carrier bird and immediately placing this number of mites on the back or vent of each hen. The two groups of hens for each study were maintained in individual cages in separate rooms as previously described by DeVaney (1976). In the first study, March 1975 through March 1976, the hens were infested on March 20, 1975. In the second study, July 1976 through June 1977, the hens were infested on September 24, 1976. During both studies, each hen was removed from her cage once each week for weighing. After weighing, the mite population was estimated visually by parting the feathers and carefully 191
Downloaded from http://ps.oxfordjournals.org/ by guest on January 30, 2015
INTRODUCTION
DeVANEY
192
FIG. 1. Mean egg production of hens infested and uninfested with northern fowl mites from March 1975 through March 1976.
FIG. 2. Mean body weight of hens infested and uninfested with northern fowl mites from March 1975 through March 1976.
RESULTS AND DISCUSSION
Downloaded from http://ps.oxfordjournals.org/ by guest on January 30, 2015
In the first study, hens were infested with northern fowl mites two weeks after they had begun laying. Subsequently mite populations increased rapidly on all treated hens. By the end of April, only four hens had a moderate population of mites (Figure 1 and Figure 2); all the others had heavy to extra heavy populations. An average rating of heavy was then maintained until the end of June 1975; the rating was moderate from July through December 1975. However, on December 11, 1975, a light population of mites was found on three of
the control hens. Rather than treating these hens with a pesticide, all "control" hens were infested with mites as described to determine whether mites would cause decreased egg production or body weight in older hens. One month later, the mean mite population of this previous control group was heavy. During April and May, 1975, hen-day egg production for the mite-infested birds was 71 and 78% compared with 86 and 87% for the control hens (Figure 1). April egg production difference was significant at P = . 1 . Thereafter, there was no appreciable difference in egg production. The mean body weight of mite-infested hens (Figure 2) was consistently lower than the mean body weight of the control hens. Significant differences (P = .05) in body weight occurred from May through December 1975. However, one month after the control group was infested with mites in December, the mean body weight of these hens had decreased by ca. 100 g. There was no significant difference between the weight of the two groups at the end of the study. In the second study, hens were not infested with mites until they had come into full egg production. Mite populations increased very rapidly, and for the first three months, the rating was heavy for the entire treated group. Egg production (Figure 3) of treated hens was 81, 78, and 75% in October, November, and December respectively compared with 86, 84, and 86% for the control hens. November and December egg productions were significantly different at P = .1 and P = .05, respectively. After this time, mite populations decreased
observing mites in the vent area, legs, breast, and ventral aspect of the neck. The following index was used in rating the infestations: 0— no mites, 1-very light (1 to 10 mites/hen), 2— light (11 to 10 mites/hen), 3—moderate (101 to 1000 mites/hen), 4-heavy (1001 to 10,000 mites/hen), and 5-extra heavy (> 10,000 mites/hen). The mites were actually counted when populations were rated light or less but were estimated when the populations were moderate or heavier. In the second study, feed consumption was determined on a weekly basis. The hen-day egg production for each month was compared by a completely randomized analysis of variance, with the error term representing the variation in egg production among hens of the same treatments. Hen body weight for each month of the two groups was compared by means of a completely random analysis of variance using weekly averages as observational units.
193
EFFECTS OF NORTHERN FOWL MITE ON EGG PRODUCTION INFESTED
100
WITH
MITES
9-24-7*
l
90 80
~^>».
70 £
MITE
50
_
r>
- 1 J
40
-
"*"*v^_
30
i 20
1
10
\-
MITE
O
N
D
:
J
F
M
A
M
160 0
1500
r'\
-
4 S
-
j S
5
INDEX
j•
A
It****"" I
60
J
rapidly a n d t h e r e was n o significant difference in egg p r o d u c t i o n b e t w e e n groups. Body weight of t h e infested and uninfested hens (Figure 4 ) was n o t significantly different. Average daily feed c o n s u m p t i o n records also showed n o significant difference b e t w e e n t h e t w o groups. Results of t h e studies s h o w t h a t b o d y weight m a y be depressed with m i t e p o p u l a t i o n s . This weight loss is currently n o t considered of econ o m i c i m p o r t a n c e with spent caged White Legh o r n hens. However, w h e n m i t e p o p u l a t i o n s become heavy, a p r o d u c e r can expect a 5 t o 1 5 % decrease in egg p r o d u c t i o n a n d this effect m a y be greater w h e n t h e h e n s are coming into egg p r o d u c t i o n or w h e n t h e r e are o t h e r stress factors. This decrease w o u l d w a r r a n t control of n o r t h e r n fowl mites o n caged layers. However, results of this study indicated t h a t control m a y n o t b e n e e d e d after p o p u l a t i o n s of mites are declining and rated as m o d e r a t e or less (< 1,000 mites/hen) providing t h e r e are no o t h e r stress factors present. Hall and Gross ( 1 9 7 5 ) f o u n d t h a t cockerels artificially selected for l o w levels of plasma corticosterone response t o social stress and maintained in a low social interaction environm e n t rapidly developed large p o p u l a t i o n s of n o r t h e r n fowl mites. Cockerels selected for high levels of plasma corticosterone response t o stress and housed in a high social stress environm e n t developed smaller p o p u l a t i o n s of mites. O t h e r stress factors, such as diet changes, adverse environmental or lighting conditions, a n d disease m a y also affect m i t e p o p u l a t i o n s . These factors need t o b e investigated t o aid in practi-
/
JLJ.
1 O
1
1
1
1
1
N 1976
FIG. 4. Mean body weight of hens infested and uninfested with northern fowl mites from July 1976 through June 1977.
cal c o n t r o l r e c o m m e n d a t i o n which could be determined by poultrymen. ACKNOWLEDGMENTS T h e a u t h o r w o u l d like t o t h a n k Billy F . Hogan, J o h n Brock, Maurice W. Connell, a n d J o y c e Parker of this laboratory for their technical assistance.
REFERENCES Benbrook, E. C , 1965. External parasites of poultry. In Diseases of poultry. 5th ed. Iowa State University Press, Ames, IA. 1382 pp. Blount, W. P., 1947. Diseases of poultry. William and Wilkings Co., Baltimore, Maryland. 562 pp. Cameron, D., 1938. The northern fowl mite (Liponyssus sylviarum C. & F., 1877). Can. J. Res. 1 6 : 2 3 0 254. Chamberlain, R. W., and R. K. Sikes, 1950. Laboratory rearing methods for three common species of bird mites. J. Parasitol. 36:461-465. Combs, Jr., R. L., and J. L. Lancaster, Jr., 1965. The biology of the northern fowl mite. Arkansas Agr. Exp. Sta. Rep. Ser. 138 pp. DeVaney, J. A., 1976. Effects of the chicken body louse, Menacantbus stramineus, on caged layers. Poultry Sci. 55:430-435. DeVaney, J. A., M. H. Elissalde, E. G. Steel, B. F. Hogan, and H. D. Petersen, 1977. Effects of the northern fowl mite, Omithonyssus sylviarum (Canestrini & Fanzago), on White Leghorn roosters. Poultry Sci. 56:1585-1590. Furman, D. P., 1952. Control of the northern fowl mite. J. Econ. Entomol. 45:926-930. Hall, R. D., and W. B. Gross, 1975. Effects of social stress and inherited plasma corticosterone levels in chickens or populations of the northern fowl mite, Ornitbonyssus sylviarum. J. Parasitol. 61:1096— 1100. Knapp, F. W„ and G. F. Krause, 1960. Control of the
Downloaded from http://ps.oxfordjournals.org/ by guest on January 30, 2015
FIG. 3. Mean egg production of hens infested and uninfested with northern fowl mites from July 1976 through June 1977.
1400
194
DeVANEY
northern fowl mite Ornitbonyssus sylviarum (Canestrini & Fanzago), with Ronnel, Bayer L13/59 and Bayer 21/199. J. Econ. Entomol. 5 3 : 4 - 5 . Loomis, E. C , E. L. Bramhall, J. A. Allen, R. A. Ernst, and L. L. Dunning, 1970. Effects of the northern fowl mite on White Leghorn chickens. J. Econ. Entomol. 63:1885-1889. Matthysse, J. G., C. J. Jones, and A. Purnasirl, 1974.
Development of northern fowl mite populations on chickens, effects on the host, and immunology. Serch. Agri. 4(9). 39 pp. Payne, L. F., 1930. Feather mites and their control. Bull. Alabama Polytech. Inst. 2 5 : 6 1 - 6 3 . Wood, H. P., 1920. Tropical fowl mite in the United States with notes on the life history and control. U.S. Dept. Agri. Circ. 79.
Downloaded from http://ps.oxfordjournals.org/ by guest on January 30, 2015