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Effects of the Northern Fowl Mite, Ornithonyssus sylviarum (Canestrini and Fanzago)1, on Fertility and Hatchability of Eggs from Artificially Inseminated White Leghorn Hens
BREEDING AND GENETICS Effects of the Northern Fowl Mite, Ornithonyssus sylviarum (Canestrini and Fanzago) 1 , on Fertility and Hatchability of Eggs from Artificially Inseminated White Leghorn Hens JOYCE A. DeVANEY Veterinary Toxicology and Entomology Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, College Station, Texas 77840 (Received for publication January 16, 1978)
INTRODUCTION Artificial insemination is currently used very extensively in the turkey industry and is used increasingly in the broiler breeder industry. Little is known, however, about the effects that external parasites have on the fertility and/or hatchability of eggs. Rhodes (1975) found that Chorioptes bovis (Hering) on the scrotum of rams caused seminal degeneration that increased with the severity of the lesions caused by this mange mite. DeVaney et al. (1977) found that heavy infestations of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), on White Leghorn roosters significantly decreased the volume of seminal fluid produced, the total viable sperm, and the levels of serum testosterone. However, sperm motility, general morphology, and the ratio of live to dead sperm were not affected by increases in mite populations. Sperm concentrations were lower, but not significantly different than concentrations in the controls. The purpose of this study was to determine the effects of northern fowl mites on fertility and hatchability of eggs collected from miteinfested hens that had been artificially inseminated with semen from mite-infested roosters.
MATERIALS AND METHODS White Leghorn hens and roosters (20-weekold) were obtained, housed, individually caged, and maintained as described by DeVaney (1976). Forty-eight hens and 48 roosters were
'Acarina: Dermanyssidae. 1978 Poultry Sci 57:1189-1191
used for each test, and those to be infested with northern fowl mites (24/sex/test) were isolated from the controls (24/sex/test). Different groups of hens were used for each of the three tests, whereas the same roosters were used for all three tests. Both the roosters and the hens were 35 weeks old at the start of Test 1; hens in Tests 2 and 3 were 32 and 42 weeks old, respectively, at the beginning of those tests. All chickens to be infested with the northern fowl mites were infested by mechanically aspirating 500 to 2000 mites of various ages from a carrier chicken. These were then placed on the back and/or vent area of each bird. Two to three weeks before Test 1, the hens and roosters to be used in that test were infested with mites to ensure that mite population would be heavy when the hens were first artificially inseminated. Hens in Test 2 and Test 3 were similarly infested before those tests began. Mite populations and body weights were determined for each chicken every week (DeVaney et al, 1977). The mite index used in this study was light (0 to 100 mites/bird), moderate (101 to 1,000 mites/bird), and heavy (>1,000 mites/bird). Semen was collected from the roosters by the massaging technique of Burrows and Quinn (1939). Semen from the infested roosters was pooled and then used to inseminate the infested hens; likewise, pooled semen from the control roosters was used to inseminate the control hens. Each hen was inseminted with .05 ml of the pooled semen once a week for 12 consecutive weeks. Eggs were collected daily, and those from 3
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Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on June 27, 2015
ABSTRACT Egg production of White Leghorn hens infested with the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), was as much as 15% lower than egg production of control hens. However, when these hens were artificially inseminated with semen from mite infested roosters, neither fertility nor hatchability was affected by the mite infestation.
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DeVANEY
RESULTS AND DISCUSSION Mite populations were heavy on the hens at the beginning of each of the three tests (Fig. 1); in fact it was not until the 11th week in Test 1 and the 9th week in Test 2 that 50% of the hens had less than a heavy population of mites. At no time in Test 3 did 50% of the hens have less than a heavy population of mites. A heavy population was maintained also on over 50% of the roosters except for the 1st week in Test 1
FIG. 1. The percent of roosters and hens infested with light (<100), moderate (101 to 1,000), and heavy (> 1,000) northern fowl mite populations.
and the last week of Test 3. Rooster and hen weight loss resulting from mite infestations was similar to that reported by DeVaney et al. (1977) and DeVaney (1978). Egg production, the percentage of fertile eggs, and the percentage of hatch did not differ significantly among the three tests, so these data were combined (Fig. 2). Mite infested hens laid significantly fewer eggs throughout the study than did the control hens (Fig. 2A). Also, hens with the heaviest mite populations frequently did not lay during peak mite populations. Furthermore, when the mite populations were very heavy in the vent area, certain roosters would not produce semen and some hens would not respond for artificial insemination. However, neither the fertility (Fig. 2B) nor the hatchability (Fig. 2C) of eggs were affected by mite infestations. According to Munro (1938), Taneja and Gowe (1962), Van Krey and Seigel (1976), the .05 ml of semen
FIG. 2. The percent of egg production (A), the percent of fertile eggs (B) and the percent of egg hatch (C) of control and mite-infested hens artificially inseminated with semen from control and miteinfested roosters, respectively.
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on June 27, 2015
consecutive days were held at 10 C and set once a week. All eggs were candled at 4, 7, 14, and 18 days of incubation to determine fertility and embryonic death. Eggs showing no embryonic development after 4 days of incubation were broken out, and infertility or early embryonic death was visually determined. Percent egg production was calculated on a hen-day basis, percent fertile eggs and percent hatch were determined from the total number of eggs set. Then all data were analyzed by using analysis of variance. The split-plot model used was Yn = a + Mj + ik Wj + (M W)jj + 6}jki where M = mite effect and W = week effect. Mite infestations and weeks we considered fixed effects in this model.
NORTHERN FOWL MITE AND REPRODUCTION used for each insemination was an excess a m o u n t n e e d e d to maintain fertility. Therefore, this may have prevented fertility from decreasing despite t h e lower serum t e s t o s t e r o n e levels and decreased total viable sperm (DeVaney et al., 1977) and t h e inability t o inseminate each hen every week shown t o result from mite infestations in roosters. ACKNOWLEDGEMENTS
REFERENCES Burrows, W. H., and J. P. Quinn, 1939. Artificial insemination of chickens and turkeys. U.S. Dept. Agr. Ore. 525. DeVaney, J. A., 1976. Effects of the chicken body
louse. Menacantbus stramineus, on caged layers. Poultry Sci. 55:430-435. DeVaney, J. A., 1978. Effects of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzango), on egg production and body weight of caged White Leghorn hens. Poultry Sci. (In press). DeVaney, J. A., M. H. Elissalde, E. G. Steel, B. F. Hogan, and H. D. Petersen, 1977. Effect of the northern fowl mite Ornithonyssus sylviarum (Canestrini and Fanzago), on White Leghorn roosters. Poultry Sci. 56:1585-1590. Munro, S. S., 1938. The effect of dilution and density on the fertilizing capacity of fowl sperm suspension. Can. J. Res. 16:281-299. Rhodes, A. P., 1975. Seminal degeneration associated with chorioptic mange of the scrotum of rams. Aust. Vet. J. 51:428-432. Taneja, G. C , and R. S. Gowe, 1962. Effect of varying doses of undiluted semen on fertility and hatchability in the domestic fowl. J. Reprod. Fertil. 4:161-174. Van Krey, H. P., and P. B. Siegel, 1976. A revised artificial insemination schedule for broiler breeder hens. Poultry Sci. 55:725-728.
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on June 27, 2015
T h e a u t h o r would like t o t h a n k J o y c e Parker and J o h n Brock of this l a b o r a t o r y for their technical assistance.
1191
INTRODUCTION Artificial insemination is currently used very extensively in the turkey industry and is used increasingly in the broiler breeder industry. Little is known, however, about the effects that external parasites have on the fertility and/or hatchability of eggs. Rhodes (1975) found that Chorioptes bovis (Hering) on the scrotum of rams caused seminal degeneration that increased with the severity of the lesions caused by this mange mite. DeVaney et al. (1977) found that heavy infestations of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), on White Leghorn roosters significantly decreased the volume of seminal fluid produced, the total viable sperm, and the levels of serum testosterone. However, sperm motility, general morphology, and the ratio of live to dead sperm were not affected by increases in mite populations. Sperm concentrations were lower, but not significantly different than concentrations in the controls. The purpose of this study was to determine the effects of northern fowl mites on fertility and hatchability of eggs collected from miteinfested hens that had been artificially inseminated with semen from mite-infested roosters.
MATERIALS AND METHODS White Leghorn hens and roosters (20-weekold) were obtained, housed, individually caged, and maintained as described by DeVaney (1976). Forty-eight hens and 48 roosters were
'Acarina: Dermanyssidae. 1978 Poultry Sci 57:1189-1191
used for each test, and those to be infested with northern fowl mites (24/sex/test) were isolated from the controls (24/sex/test). Different groups of hens were used for each of the three tests, whereas the same roosters were used for all three tests. Both the roosters and the hens were 35 weeks old at the start of Test 1; hens in Tests 2 and 3 were 32 and 42 weeks old, respectively, at the beginning of those tests. All chickens to be infested with the northern fowl mites were infested by mechanically aspirating 500 to 2000 mites of various ages from a carrier chicken. These were then placed on the back and/or vent area of each bird. Two to three weeks before Test 1, the hens and roosters to be used in that test were infested with mites to ensure that mite population would be heavy when the hens were first artificially inseminated. Hens in Test 2 and Test 3 were similarly infested before those tests began. Mite populations and body weights were determined for each chicken every week (DeVaney et al, 1977). The mite index used in this study was light (0 to 100 mites/bird), moderate (101 to 1,000 mites/bird), and heavy (>1,000 mites/bird). Semen was collected from the roosters by the massaging technique of Burrows and Quinn (1939). Semen from the infested roosters was pooled and then used to inseminate the infested hens; likewise, pooled semen from the control roosters was used to inseminate the control hens. Each hen was inseminted with .05 ml of the pooled semen once a week for 12 consecutive weeks. Eggs were collected daily, and those from 3
1189
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on June 27, 2015
ABSTRACT Egg production of White Leghorn hens infested with the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), was as much as 15% lower than egg production of control hens. However, when these hens were artificially inseminated with semen from mite infested roosters, neither fertility nor hatchability was affected by the mite infestation.
1190
DeVANEY
RESULTS AND DISCUSSION Mite populations were heavy on the hens at the beginning of each of the three tests (Fig. 1); in fact it was not until the 11th week in Test 1 and the 9th week in Test 2 that 50% of the hens had less than a heavy population of mites. At no time in Test 3 did 50% of the hens have less than a heavy population of mites. A heavy population was maintained also on over 50% of the roosters except for the 1st week in Test 1
FIG. 1. The percent of roosters and hens infested with light (<100), moderate (101 to 1,000), and heavy (> 1,000) northern fowl mite populations.
and the last week of Test 3. Rooster and hen weight loss resulting from mite infestations was similar to that reported by DeVaney et al. (1977) and DeVaney (1978). Egg production, the percentage of fertile eggs, and the percentage of hatch did not differ significantly among the three tests, so these data were combined (Fig. 2). Mite infested hens laid significantly fewer eggs throughout the study than did the control hens (Fig. 2A). Also, hens with the heaviest mite populations frequently did not lay during peak mite populations. Furthermore, when the mite populations were very heavy in the vent area, certain roosters would not produce semen and some hens would not respond for artificial insemination. However, neither the fertility (Fig. 2B) nor the hatchability (Fig. 2C) of eggs were affected by mite infestations. According to Munro (1938), Taneja and Gowe (1962), Van Krey and Seigel (1976), the .05 ml of semen
FIG. 2. The percent of egg production (A), the percent of fertile eggs (B) and the percent of egg hatch (C) of control and mite-infested hens artificially inseminated with semen from control and miteinfested roosters, respectively.
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on June 27, 2015
consecutive days were held at 10 C and set once a week. All eggs were candled at 4, 7, 14, and 18 days of incubation to determine fertility and embryonic death. Eggs showing no embryonic development after 4 days of incubation were broken out, and infertility or early embryonic death was visually determined. Percent egg production was calculated on a hen-day basis, percent fertile eggs and percent hatch were determined from the total number of eggs set. Then all data were analyzed by using analysis of variance. The split-plot model used was Yn = a + Mj + ik Wj + (M W)jj + 6}jki where M = mite effect and W = week effect. Mite infestations and weeks we considered fixed effects in this model.
NORTHERN FOWL MITE AND REPRODUCTION used for each insemination was an excess a m o u n t n e e d e d to maintain fertility. Therefore, this may have prevented fertility from decreasing despite t h e lower serum t e s t o s t e r o n e levels and decreased total viable sperm (DeVaney et al., 1977) and t h e inability t o inseminate each hen every week shown t o result from mite infestations in roosters. ACKNOWLEDGEMENTS
REFERENCES Burrows, W. H., and J. P. Quinn, 1939. Artificial insemination of chickens and turkeys. U.S. Dept. Agr. Ore. 525. DeVaney, J. A., 1976. Effects of the chicken body
louse. Menacantbus stramineus, on caged layers. Poultry Sci. 55:430-435. DeVaney, J. A., 1978. Effects of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzango), on egg production and body weight of caged White Leghorn hens. Poultry Sci. (In press). DeVaney, J. A., M. H. Elissalde, E. G. Steel, B. F. Hogan, and H. D. Petersen, 1977. Effect of the northern fowl mite Ornithonyssus sylviarum (Canestrini and Fanzago), on White Leghorn roosters. Poultry Sci. 56:1585-1590. Munro, S. S., 1938. The effect of dilution and density on the fertilizing capacity of fowl sperm suspension. Can. J. Res. 16:281-299. Rhodes, A. P., 1975. Seminal degeneration associated with chorioptic mange of the scrotum of rams. Aust. Vet. J. 51:428-432. Taneja, G. C , and R. S. Gowe, 1962. Effect of varying doses of undiluted semen on fertility and hatchability in the domestic fowl. J. Reprod. Fertil. 4:161-174. Van Krey, H. P., and P. B. Siegel, 1976. A revised artificial insemination schedule for broiler breeder hens. Poultry Sci. 55:725-728.
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on June 27, 2015
T h e a u t h o r would like t o t h a n k J o y c e Parker and J o h n Brock of this l a b o r a t o r y for their technical assistance.
1191