- Email: [email protected]
Importance of the Bursa of Fabricius in Resistance to Disease1
1224
C. F. PETERSEN AND E. A. SAUTER enzyme and water treated barley on the performance of breeding hens. Poultry Sci. 37: 1229. Potter, L. M., M. W. Stutz and L. D. Matterson, 1965. Metabolizable energy and digestibility coefficients of barley for chicks as influenced by water treatment or by presence of fungal enzyme. Poultry Sci. 44: 565-573. Preece, I. A., and A. S. Ashworth, 1950. Cytolysis in germinating barley. II. Preliminary study of enzyme relationships. J. Inst. Brewing 56: 40-47. Rose, R. J., and G. H. Arscott, 1962. Use of barley in high energy broiler rations. 5. Poultry Sci. 4 1 : 124-130. Snedecor, G. W., 1956. Statistical Methods, Sth ed., Iowa State University Press, Ames, Iowa. Stutz, M. W., and L. D. Matterson, 1961. Metabolizable energy of barley for chicks as influenced by water treatment or by presence of fungal enzymes. Poultry Sci. 40: 1462. Willingham, H. E., L. S. Jensen and J. McGinnis, 1958. Studies on the role of enzyme supplements and water treatment on the nutritional value of barley. Poultry Sci. 37: 1253. Willingham, H. E., K. C. Leong, L. S. Jensen and J. McGinnis, 1960. Influence of geographical area of production on the response of different barley samples to enzyme supplements or water treatment. Poultry Sci. 39: 103-108. Willingham, H. E., 1964. Mechanisms of improvement in nutritional value of barley by water treatment. Poultry Sci. 43: 1376.
Importance of the Bursa of Fabricius in Resistance to Disease1 1. RESISTANCE TO CERTAIN VIRUS DISEASES REAGAN SADLER2 AND S. A. EDGAR Department of Poultry Science, Agricultural Experiment Station, Auburn University, Auburn, Alabama (Received for publication December 15, 1967)
N RECENT YEARS most attempts to determine the role of the bursa of Fa1 Portion of thesis submitted by the senior author in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Auburn University. s Present address: Central Laboratory, Forest, Mississippi.
bricius have been immunological studies. Glick et al. (1956), using Salmonella typhimurium as the antigen, demonstrated antibody titers in 86% of the non-bursectomized birds tested and in only 11% of the bursectomized birds. Chang et al. (1957, 1959) showed that bursectomy of young chickens prior to 5 weeks of age re-
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
response to enzyme supplements. Poultry Sci. 42: 1266. Fritz, J. C , F. D. Wherton and L. J. Classen, 1959. The effect of enzymes in high fiber poultry feeds. Poultry Sci. 38: 1205. Fry, R. E., J. B. AUred, L. S. Jensen and J. McGinnis, 1957a. Influence of water treatment on nutritional value of barley. Proc. Soc. Expt. Biol. Med. 95: 249-251. Fry, R. E., J. B. AUred, L. S. Jensen and J. McGinnis, 1957b. Influence of cereal grain component of the diet on the response of chicks and poults to dietary enzyme supplements. Poultry Sci. 36: 1120. Jensen, L. S., R. E. Fry, J. B. AUred and J. McGinnis, 1957. Improvement in the nutritional value of barley for chicks by enzyme supplementation. Poultry Sci. 36: 919-921. Laerdal, O. A., H. R. Bird, M. L. Sunde and P. H. Phillips, 1959. Improvement in the nutritional value of some barleys by the addition of malt or enzyme supplements. Poultry Sci. 38: 1221. Leong, K. C , L. S. Jensen and J. McGinnis, 1958. Effect of water treatment and enzyme additions on the metabolizable energy of pearled barley. Poultry Sci. 37: 1220. Leong, K. C , L. S. Jensen and J. McGinnis, 1962. Effect of water treatment and enzyme supplementation on the metabolizable energy of barley. Poultry Sci. 4 1 : 36-39 . Nelson, F. E., and D. C. Hutto, 1958. The effect of
BURSA AND RESISTANCE TO VIRUS DISEASE
fect was noted regardless of whether bursectomy was performed at 1 or 29 days of age or whether the infectious virus was administered at 1 or 28 days of age. The present investigation was undertaken to determine the role of the bursa in development of immunity and resistance against fowl pox virus and Newcastle disease virus. MATERIALS AND METHODS
Two inbred and one commercial line of S. C. White Leghorns were used in this study. One of the inbred lines was developed at Auburn University for resistance to cecal coccidiosis and hereafter is designated as R-line. The other inbred line was developed at the Regional Poultry Research Laboratory, East Lansing, Michigan, for susceptibility to visceral and neural lymphomatosis (Waters et al., 1954). Hereafter this bird is referred to as Line 15. A popular commercial line of S. C. White Leghorns was used for comparative purposes. Experiment 1.—Two strains of fowl pox virus were used, one for vaccination and another for challenge, in an attempt to determine the role of the bursa in development of immunity to fowl pox. One group of birds was bursectomized at 1 day of age (Bt), another at 14 days of age (B 14 ), and another group was not bursectomized (NB). The technique of bursectomy was that described by Glick (1955). There were 32 R-Line birds in each of the three groups. Sixteen of the birds in each group were vaccinated at 6 weeks of age with a commercial fowl pox vaccine, and 16 were not vaccinated. At 12 weeks of age, 8 of the vaccinates and 8 of the non-vaccinates from each group were challenged with another strain of the same virus (Georgia strain) but more virulent than the commercial strain. A like number of birds served as non-vaccinated, non-challenged controls.
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
duced the production of antibody to S. typhimurium antigen and sheep red blood cells. Since this early work, further evidence has been presented indicating that the bursa of Fabricius is important in antibody production (Glick, 1960; Graetzer et al., 1963; Mueller et al., 1962; and Isakovic etal., 1963). The importance of the bursa of Fabricius in resistance to disease has been investigated only to a limited extent. Chang et al. (1959) found that bursectomized, broiler-type chickens suffered greater mortality from S. typhimurium infection than normal birds. Also, bursectomized birds failed to develop immunity to S. typhimurium antigen. Perek and Drill (1962) found that when birds were challenged with virulent S. typhimurium following their immunization with this organism there was a low rate of mortality in the bursectomized group as compared with none in the intact group. They concluded that the low mortality was because of the relatively high level of antibodies found in both groups of birds. Kemmes and Pethes (1963) found that 2to 4-week-old bursectomized birds developed significantly less antibody than did intact controls during the first weeks of Leptospira icterohemorrkagiae infection. Also, they found that leptospiras persisted for a longer period (mainly in the kidneys) in infected bursectomized birds than in intact birds. Fatalities from leptospirosis and chronic carriers were more common among bursectomized than among non-bursectomized birds. Challey (1962) reported markedly greater mortality because of Eimeria tenella infection among 4j-week-old bursectomized Single Comb White Leghorns than among intact birds. Peterson et al. (1964) found that surgical removal of the bursa of Fabricius from inbred S. C. White Leghorns prevented the development of visceral lymphomatosis ordinarily induced by RPL 12 virus. This ef-
1225
1226
R. SADLER AND S. A. EDGAR
birds were available, equal numbers of bursectomized and non-bursectomized birds were placed in separate pens and infected, with a like number of birds serving as controls. Experimental data were treated statistically by the Wilcoxon (1949) rapid analysis of variance technique. RESULTS Experiment 1.—A slight depression in growth occurred during the second week following vaccination with fowl pox virus (Table 1). Growth depression was greater among vaccinated birds bursectomized at 14 days of age (B14-V) than in vaccinated birds bursectomized at 1 day of age (Bj-V) or those not bursectomized (NBV). However, these differences were not significant. There were no significant differences in growth on a weekly basis between bursectomized and non-bursectomized birds that were challenged without previous exposure to the agent, or that were vaccinated and challenged (Table 2). None of the challenged-vaccinated bursectomized or intact birds exhibited "takes," which indicated that all vaccinated birds had developed imTABLE 1.—Effect of fowl pox vaccination on growth of bursectomized and non-bursectomized, 6-week-old, R-Line Single Comb White Leghorns {experiment 1)
Group 1
NB-NV NB-V B I4 -NV Bu-V Bi-NV Bi-V 1
Birds2
No. 16 16 16 16 16 16
Average gain at days after vaccination 7
14
21
28
gm. 110 115 91 106 129 115
gm. 214 212 195 187 223 201
gm. 323 345 295 302 363 330
gm. 422 442 413 420 471 439
NB-non-bursectomized. NV-non-vaccinated. V-vaccinated. Bu-bursectomized at 14 days of age. Bi-bursectomized at 1 day of age. 2 Eight replicates of 2 birds per replicate.
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
All birds were weighed weekly throughout both vaccination and challenge periods to determine effect of the virus on growth. Each bird was also checked in the wing web for a pox "take," which would indicate the susceptible or immune status of the host. Experiments 2 and 3.—Commercial and Line-IS birds were bursectomized at 5 days of age and challenged in the wing web at 6 weeks of age with 6 stabs of Georgia pox virus. Infected and control birds were weighed at weekly intervals following inoculation and growth rate was determined. Birds were examined for pox lesions at 7 and 14 days postinoculation. Experiment 4.—This experiment was an attempt to determine the role of the bursa in the development of immunity to Newcastle disease virus. R-Line birds were bursectomized at 5 days of age and half of each group (B and NB) were isolated from other groups of the experiment. At 6 weeks of age, the isolated birds were vaccinated intranasally with combination, commercially available Newcastle-bronchitis virus vaccine. The remaining birds were not vaccinated and served as controls. Both vaccinated and control birds were weighed weekly for a period of 3 weeks. Three weeks following vaccination half the vaccinated birds and half the control birds (B and NB, respectively) were challenged intranasally with 1 minimum lethal dose of the Gilbert-Boney strain of Newcastle disease virus. The remaining birds were not challenged and served as controls. Following challenge, birds were weighed weekly for a 2-week period and percentage mortality was calculated. Data obtained during the immunization period were analyzed, but those obtained during the challenge period were not. Design and Analysis of Data.—All experimental birds were randomized into batteries prior to each experiment. If sufficient
1227
BURSA AND RESISTANCE TO VIRUS DISEASE
TABLE 2.—Importance of the bursa of Fabricius in development of immunity to fowl pox as measured by growth in R-line, Single Comb White Leghorns (experiment 1)
Group 1
I5irds2
NB-NV-NCh NB-NV-Ch NB-V-NCh NB-V-Ch B,-NV-NCh BrNV-Ch B,-V-NCh B,-V-Ch Bu-NV-NCh Bu-NV-Ch Bu-V-NCh Bu-V-Ch 1
No. 8 8 8 8 8 8 8 8 8 8 8 8
Average gain at days after challenge 7
14
21
28
gin. 100 96 99 81 101 86 63 82 72 41 102 80
gm. 220 139 192 184 220 126 175 196 201 70 208 197
gm. 290 202 281 254 303 215 226 254 246 153 286 249
gm. 336 273 357 325 354 315 280 319 319 195 348 296
Ch = challenged. NCh = non-challenged. Bi = bursectomized at 1 day of age and Bi4 at 14 days of age. 2 Eight replicates of 1 bird per replicate.
TABLE 3.—Comparative resistance of bursectomized (at 5 days of age) and non-bursectomized Line 15— S. C. While Leghorns challenged with fowl pox virus at 6 weeks of age (experiment 2)
Group1
NB-NCh NB-Ch B 5 -NCh B5-Ch 1 2
Birds2
No. 12 12 8 8
Average gain at days after challenge 7
14
21
28
gm. 80 63 69 48
gm. 181 114 161 96
gm. 289 208 267 176
gm. 362 296 376 326
Ch = challenged. NCh=non-challenged. Eight replicates of 1 or 2 birds per replicate.
Growth of challenged Line-15 birds (NBCh and B5-Ch, Table 3) and commercial line birds (NB-Ch and B-Ch, Table 4), was severely depressed by the infection as compared with normal growth by non-challenged controls (NB-NCh and B-NCh, Tables 3 and 4). However, a comparison of B5-Ch and NB-Ch birds revealed no significant difference in growth. The bursectomized birds appeared to recover from the infection at a faster rate than non-bursectomized birds. Experiment 3.—In this experiment, only the commercial bird was used (Table 5). Differences in growth between respective bursectomized and non-bursectomized birds were not significant at any time during the experiment. However, the B5-Ch birds TABLE 4.—Comparative resistance of bursectomized and non-bursectomized 6-week-old, commercial line S. C. White Leghorns to fowl pox infection (experiment 2)
Group
NB-NCh NB-Ch B6-NCh B5-Ch 1
Birds 1
No. 12 12 12 12
Average gain at days after challenge 7
14
21
28
gm. 92 55 113 74
gm. 193 121 189 125
gm. 291 227 308 227
gm. 359 321 388 336
Six replicates of 2 birds per replicate.
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
munity prior to challenge. All challenged, non-vaccinates exhibited takes. However, Bi4-V-Ch birds grew at a significantly slower rate than those vaccinated but not challenged (B14-V-NCh). Growth of all non-vaccinated challenged birds was depressed (Table 2). However, BM-NV-Ch birds appeared to be more susceptible to the challenge infection than either Bx-NV-Ch or NB-NV-NCh birds. Also, Group Bi-NV-Ch birds recovered at a somewhat faster rate than those in the other two groups. The non-vaccinated challenged birds could be ranked as follows according to the rate of growth following challenge: Bi, NB and B 14 by the third and fourth week following challenge. Experiment 2.—Both commercial and Line-15 birds were bursectomized at S days of age and challenged in the wing web at 6 weeks of age with 6 stabs of Georgia fowl pox virus. None of the birds were vaccinated prior to challenge. Results were essentially the same for the commercial strain and Line-15 birds (Tables 3 and 4).
1228
R. SADLER AND S. A. EDGAR
TABLE 5.—Comparative resistance of bursectomized and non-bursectomized 6-week-old commercial line S. C. White Leghorns to fowl pox infection (experiment 3)
Group
NB-NCh NB-Ch B6-NCh B6-Ch 1
Birds'
No. 16 16 16 16
Avera ge gain at days after challenge 7
14
21
28
gm. 147 78 110 91
gm. 267 149 235 147
gm. 358 214 311 229
gm. 441 295 419 309
tended to recover more quickly than NBCh birds, as in Experiment 2. (Tables 3 and 4). Experiment 4.—The results of effect of immunization with Newcastle disease vaccine on the growth of bursectomized and non-bursectomized R-Line S. C. White Leghorns are given in Table 6. Growth of the vaccinated birds (B5-V and NB-V) was more severely depressed (significant) than growth of their respective non-vaccinates, but both the B-V and NB-V birds appeared to be depressed to about the same degree, and the difference was not significant. Results of the effect of challenge on growth and livability are summarized in Table 7. There was little difference in growth between challenged, bursectomized and non-bursectomized birds that had been vaccinated (NBV-Ch and B5-V-Ch). Most of the growth
DISCUSSION
Cho (1963) found that the level of antibody to Newcastle disease virus (Bx strain) in bursectomized birds was equal to that of intact birds at 2 and 4 weeks after vaccination. He concluded that the bursa plays no role in the antibody response to the Bi strain of Newcastle disease. Also, Ipson and Glick (1964) found that both bursectomized and non-bursectomized birds developed about equally high serum neutralization titers to Newcastle disease virus. The results of two immunological trials of the study dealing with Bx strain of Newcastle disease and fowl pox viruses are TABLE 7.—Importance of the bursa of Fabricius in the development of immunity to Newcastle disease as measured by growth and mortality in R-line S. C. White Leghorns (experiment 4)
TABLE 6.—Effect of Newcastle disease vaccination on growth of bursectomized and non-bursectomized R-line S. C. White Leghorns (experiment 4)
Group
NB-NV NB-V B6-NV B5-V 1
Birds 1
No. 14 14 14 14
Group
Average gain at day 5 after challenge 7
14
21
gm. 123 101 103 88
gm. 236 176 224 174
gm. 351 287 306 277
Seven replicates of 2 birds per replicate.
NB-NV-NCh NB-NV-Ch NB-V-NCh NB-V-Ch Bs-NV-NCh Bs-NV-Ch B5-V-NCh Bj-V-Ch 1
Birds
No. 5 9 8 6 7 7 8 8
1
Average gain at days after challenge 7
14
gm. 59 -65 107 81 69 16 90 46
gm. 162 82 233 182 181 -7 204 160
Mortality
No. 0 5 0 0 0 6 0 0
Pet 0 56 0 0 0 86 0 0
Seven replicates of 1 or 2 birds per replicate.
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
Eight replicates of 2 birds per replicate.
depression occurred during the first week after challenge, and by end of the second week, the growth rates were about the same for all challenged groups except B5-NV-Ch, in which only 1 bird remained alive. Also, all birds previously vaccinated and challenged (NB-V-Ch and B-V-Ch) had developed protective immunity against the challenge virus, as indicated by absence of mortality in these groups. There were 56 and 86% mortality among challenged, nonvaccinated groups NB-NV-Ch and B-NVCh, respectively.
BURSA AND RESISTANCE TO VIRUS DISEASE
SUMMARY
Removal of the bursa of Fabricius at 1 or 5 days of age had no significant effect on resistance or development of immunity to fowl pox virus. However, chicks bursectomized at 14 days of age were more susceptible to fowl pox virus than non-bursectomized birds or those bursectomized at 1 day. Removal of the bursa at 5 days of age did not prevent the development of immunity to Newcastle disease virus.
ACKNOWLEDGMENTS
The assistance of the Regional Poultry Research Laboratory, East Lansing, for furnishing hatching eggs of Line IS and of Dr. W. L. Johnson for furnishing eggs of R-Line is gratefully acknowledged. REFERENCES Challey, J. R., 1962. The role of the bursa of Fabricius in adrenal response and mortality due to Eimeria tenetta infections in the chicken. J. Parasitol. 48: 352-357. Chang, T. S., M. S. Rheins and A. R. Winter, 1957. The significance of the bursa of Fabricius in antibody production in chickens. 1. Age of chickens. Poultry Sci. 36: 735-739. Chang, T. S., M. S. Rheins and A. R. Winter, 1959. The significance of the bursa of Fabricius in antibody production in chickens. 3. Resistance to Salmonella typhimurium infection. Poultry Sci. 38: 174-176. Cho, B-R., 1963. The effect of bursectomy of chickens in antibody response to Newcastle disease virus. J. Am. Vet. Res. 24: 832-834. Glick, B., 1955. Growth and function of the bursa of Fabricius in the domestic fowl. Ph.D. dissertation, Ohio State U. Glick, B., T. S. Chang and R. G. Jaap, 1956. The bursa of Fabricius and antibody production. Poultry Sci. 35: 224-225. Glick, B., 1960. Extracts from the bursa of Fabricius—a lymphoepithelial gland of the chicken —stimulate the production antibodies in bursectomized chickens. Poultry Sci. 39: 1097-1101. Graetzer, M. A., W. P. Cote and H. R. Wolfe, 1963. The effect of bursectomy at different ages on precipitin and natural hemagglutinin production in the chicken. J. Immunol. 9 1 : 576-581. Ipson, J. R., and B. Glick, 1964. Personal communication. Isakovic, K., B. D. Jankovic, L. Popeskovic and D. Milosevic, 1963. Effect of neonatal thymectomy, bursectomy and thymobursectomy on hemagglutinin production of chickens. Nature, 200: 273-274. Kemmes, F., and G. Pethes, 1963. Further evidence for the role of the bursa of Fabricius in antibody production in chickens. Zeitschrift fur immunitats und allergieforschung. 125: 446-458. Mueller, A. P., H. R. Wolfe, R. K. Meyer and R. Aspinall, 1962. Further studies on the role of
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
in agreement with the findings of the above workers. The bursa was not necessary for development of immunity to either virus. Apparently antibodies against these viruses are produced at some site other than the bursa. Because differences in growth or mortality between bursectomized and non-bursectomized non-vaccinated birds exposed to Newcastle disease virus or fowl pox virus were not significant, the bursa is apparently not important in development of resistance to these diseases. However, birds bursectomized at 2 weeks of age were apparently more susceptible to fowl pox vaccination than those bursectomized at 1 day of age or than those not bursectomized. The reason for the above phenomenon is not known at present. Possibly the bursa may not be functionally important in resistance to certain viral diseases until a certain age. Peterson et al. (1964) found that bursectomized birds were less susceptible to tumor formation caused by leukosis (visceral lymphomatosis virus) than non-bursectomized birds. In some fowl pox trials reported here (Experiments 2 and 3), the growth of birds bursectomized at 5 days of age was less depressed by vaccination than that of non-bursectomized birds. The results presented here suggest the possibility that the bursa may be an important site of fowl pox virus growth in the host.
1229
1230
R. SADLER AND S. A. EDGAR
the bursa of Fabricius in antibody production. J. Immunol. 88: 354-360. Perek, M., and A. E. Drill, 1962. The role of the bursa of Fabricius in developing immunity in chickens treated with Salmonella typhimwium and Spriochaeta gallinarum. British Vet. J. 118: 390-393. Peterson, R. D. A., B. R. Burmester, T. N. Fredrickson, H. G. Purchase and R. A. Good, 1964. Effect of bursectomy and thymectomy on the
development of visceral lymphomatosis in the chicken. J. Nat. Cancer Inst. 32: 1343-1354. Waters, M. F., B. R. Burmester and W. G. Walter, 1954. Genetics of experimentally induced erythroblastosis in chickens. J. Nat. Cancer Inst. 20: 1245-1256. Wilcoxon, F., 1949. Some rapid approximate statistical procedures. American Cyanamid Company, New York.
H. S. SIEGEL1 AND L. N. DRURY 2 Southeast Poultry Research Laboratory, ARS-VSDA, Athens, Georgia 30601 (Received for publication December 15, 1967)
I
NCREASED air movement facilitates convective heat exchange between the surface of the body and the surrounding air (Whittow, 1965; Siegel and Drury, 1968). Thus, if ambient temperatures remain below body temperature, increasing the air movement helps to alleviate some of the deleterious effects of high environmental temperatures (Lee et al., 1945; Wilson et al., 1957). The growth rates of broilers raised in diurnally cycling hot environments have been shown to be related to air velocity (Drury, 1966). Respiratory evaporation becomes more important as a means of heat loss in birds as the ambient temperature approaches body temperature. In chickens, panting commences when the core temperature reaches approximately 42°C. (Whittow, 1965), and a rapid increase in body temperature results in an increased heart rate (Linsley and Burger, 1964). Our previous studies with young chickens provided evidence that in environmental temperatures up to 40°C, the enhancement of convec1 2
Animal Husbandry Research Division. Agricultural Engineering Research Division.
tive heat loss by increased air velocity partially replaces respiratory evaporation as a means of heat loss thus delaying or preventing the onset of hyperthermic respiratory and cardiac responses (Siegel and Drury, 1968). This paper considers the effect of increased air velocity when environmental temperatures exceed body temperature. EXPERIMENTAL METHODS
Details of the air velocity facility have been published (Drury and Siegel, 1966). Two birds were confined in wire cages in each of six subchambers mounted over a main duct which was evacuated by a large fan. Air velocities in each of the subchambers were adjusted independently through the use of perforated inlet plates and damper-controlled outlets. The entire unit was situated in a large room which serves as a plenum whose air temperature was programmed according to the experimental design. Body temperatures, heart rates and respiratory rates were measured by methods previously described (Siegel and Drury, 1968). Southeast Poultry Research Labora-
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
Physiological Responses to High Lethal Temperature and Air Velocity in Young Fowl
C. F. PETERSEN AND E. A. SAUTER enzyme and water treated barley on the performance of breeding hens. Poultry Sci. 37: 1229. Potter, L. M., M. W. Stutz and L. D. Matterson, 1965. Metabolizable energy and digestibility coefficients of barley for chicks as influenced by water treatment or by presence of fungal enzyme. Poultry Sci. 44: 565-573. Preece, I. A., and A. S. Ashworth, 1950. Cytolysis in germinating barley. II. Preliminary study of enzyme relationships. J. Inst. Brewing 56: 40-47. Rose, R. J., and G. H. Arscott, 1962. Use of barley in high energy broiler rations. 5. Poultry Sci. 4 1 : 124-130. Snedecor, G. W., 1956. Statistical Methods, Sth ed., Iowa State University Press, Ames, Iowa. Stutz, M. W., and L. D. Matterson, 1961. Metabolizable energy of barley for chicks as influenced by water treatment or by presence of fungal enzymes. Poultry Sci. 40: 1462. Willingham, H. E., L. S. Jensen and J. McGinnis, 1958. Studies on the role of enzyme supplements and water treatment on the nutritional value of barley. Poultry Sci. 37: 1253. Willingham, H. E., K. C. Leong, L. S. Jensen and J. McGinnis, 1960. Influence of geographical area of production on the response of different barley samples to enzyme supplements or water treatment. Poultry Sci. 39: 103-108. Willingham, H. E., 1964. Mechanisms of improvement in nutritional value of barley by water treatment. Poultry Sci. 43: 1376.
Importance of the Bursa of Fabricius in Resistance to Disease1 1. RESISTANCE TO CERTAIN VIRUS DISEASES REAGAN SADLER2 AND S. A. EDGAR Department of Poultry Science, Agricultural Experiment Station, Auburn University, Auburn, Alabama (Received for publication December 15, 1967)
N RECENT YEARS most attempts to determine the role of the bursa of Fa1 Portion of thesis submitted by the senior author in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Auburn University. s Present address: Central Laboratory, Forest, Mississippi.
bricius have been immunological studies. Glick et al. (1956), using Salmonella typhimurium as the antigen, demonstrated antibody titers in 86% of the non-bursectomized birds tested and in only 11% of the bursectomized birds. Chang et al. (1957, 1959) showed that bursectomy of young chickens prior to 5 weeks of age re-
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
response to enzyme supplements. Poultry Sci. 42: 1266. Fritz, J. C , F. D. Wherton and L. J. Classen, 1959. The effect of enzymes in high fiber poultry feeds. Poultry Sci. 38: 1205. Fry, R. E., J. B. AUred, L. S. Jensen and J. McGinnis, 1957a. Influence of water treatment on nutritional value of barley. Proc. Soc. Expt. Biol. Med. 95: 249-251. Fry, R. E., J. B. AUred, L. S. Jensen and J. McGinnis, 1957b. Influence of cereal grain component of the diet on the response of chicks and poults to dietary enzyme supplements. Poultry Sci. 36: 1120. Jensen, L. S., R. E. Fry, J. B. AUred and J. McGinnis, 1957. Improvement in the nutritional value of barley for chicks by enzyme supplementation. Poultry Sci. 36: 919-921. Laerdal, O. A., H. R. Bird, M. L. Sunde and P. H. Phillips, 1959. Improvement in the nutritional value of some barleys by the addition of malt or enzyme supplements. Poultry Sci. 38: 1221. Leong, K. C , L. S. Jensen and J. McGinnis, 1958. Effect of water treatment and enzyme additions on the metabolizable energy of pearled barley. Poultry Sci. 37: 1220. Leong, K. C , L. S. Jensen and J. McGinnis, 1962. Effect of water treatment and enzyme supplementation on the metabolizable energy of barley. Poultry Sci. 4 1 : 36-39 . Nelson, F. E., and D. C. Hutto, 1958. The effect of
BURSA AND RESISTANCE TO VIRUS DISEASE
fect was noted regardless of whether bursectomy was performed at 1 or 29 days of age or whether the infectious virus was administered at 1 or 28 days of age. The present investigation was undertaken to determine the role of the bursa in development of immunity and resistance against fowl pox virus and Newcastle disease virus. MATERIALS AND METHODS
Two inbred and one commercial line of S. C. White Leghorns were used in this study. One of the inbred lines was developed at Auburn University for resistance to cecal coccidiosis and hereafter is designated as R-line. The other inbred line was developed at the Regional Poultry Research Laboratory, East Lansing, Michigan, for susceptibility to visceral and neural lymphomatosis (Waters et al., 1954). Hereafter this bird is referred to as Line 15. A popular commercial line of S. C. White Leghorns was used for comparative purposes. Experiment 1.—Two strains of fowl pox virus were used, one for vaccination and another for challenge, in an attempt to determine the role of the bursa in development of immunity to fowl pox. One group of birds was bursectomized at 1 day of age (Bt), another at 14 days of age (B 14 ), and another group was not bursectomized (NB). The technique of bursectomy was that described by Glick (1955). There were 32 R-Line birds in each of the three groups. Sixteen of the birds in each group were vaccinated at 6 weeks of age with a commercial fowl pox vaccine, and 16 were not vaccinated. At 12 weeks of age, 8 of the vaccinates and 8 of the non-vaccinates from each group were challenged with another strain of the same virus (Georgia strain) but more virulent than the commercial strain. A like number of birds served as non-vaccinated, non-challenged controls.
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
duced the production of antibody to S. typhimurium antigen and sheep red blood cells. Since this early work, further evidence has been presented indicating that the bursa of Fabricius is important in antibody production (Glick, 1960; Graetzer et al., 1963; Mueller et al., 1962; and Isakovic etal., 1963). The importance of the bursa of Fabricius in resistance to disease has been investigated only to a limited extent. Chang et al. (1959) found that bursectomized, broiler-type chickens suffered greater mortality from S. typhimurium infection than normal birds. Also, bursectomized birds failed to develop immunity to S. typhimurium antigen. Perek and Drill (1962) found that when birds were challenged with virulent S. typhimurium following their immunization with this organism there was a low rate of mortality in the bursectomized group as compared with none in the intact group. They concluded that the low mortality was because of the relatively high level of antibodies found in both groups of birds. Kemmes and Pethes (1963) found that 2to 4-week-old bursectomized birds developed significantly less antibody than did intact controls during the first weeks of Leptospira icterohemorrkagiae infection. Also, they found that leptospiras persisted for a longer period (mainly in the kidneys) in infected bursectomized birds than in intact birds. Fatalities from leptospirosis and chronic carriers were more common among bursectomized than among non-bursectomized birds. Challey (1962) reported markedly greater mortality because of Eimeria tenella infection among 4j-week-old bursectomized Single Comb White Leghorns than among intact birds. Peterson et al. (1964) found that surgical removal of the bursa of Fabricius from inbred S. C. White Leghorns prevented the development of visceral lymphomatosis ordinarily induced by RPL 12 virus. This ef-
1225
1226
R. SADLER AND S. A. EDGAR
birds were available, equal numbers of bursectomized and non-bursectomized birds were placed in separate pens and infected, with a like number of birds serving as controls. Experimental data were treated statistically by the Wilcoxon (1949) rapid analysis of variance technique. RESULTS Experiment 1.—A slight depression in growth occurred during the second week following vaccination with fowl pox virus (Table 1). Growth depression was greater among vaccinated birds bursectomized at 14 days of age (B14-V) than in vaccinated birds bursectomized at 1 day of age (Bj-V) or those not bursectomized (NBV). However, these differences were not significant. There were no significant differences in growth on a weekly basis between bursectomized and non-bursectomized birds that were challenged without previous exposure to the agent, or that were vaccinated and challenged (Table 2). None of the challenged-vaccinated bursectomized or intact birds exhibited "takes," which indicated that all vaccinated birds had developed imTABLE 1.—Effect of fowl pox vaccination on growth of bursectomized and non-bursectomized, 6-week-old, R-Line Single Comb White Leghorns {experiment 1)
Group 1
NB-NV NB-V B I4 -NV Bu-V Bi-NV Bi-V 1
Birds2
No. 16 16 16 16 16 16
Average gain at days after vaccination 7
14
21
28
gm. 110 115 91 106 129 115
gm. 214 212 195 187 223 201
gm. 323 345 295 302 363 330
gm. 422 442 413 420 471 439
NB-non-bursectomized. NV-non-vaccinated. V-vaccinated. Bu-bursectomized at 14 days of age. Bi-bursectomized at 1 day of age. 2 Eight replicates of 2 birds per replicate.
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
All birds were weighed weekly throughout both vaccination and challenge periods to determine effect of the virus on growth. Each bird was also checked in the wing web for a pox "take," which would indicate the susceptible or immune status of the host. Experiments 2 and 3.—Commercial and Line-IS birds were bursectomized at 5 days of age and challenged in the wing web at 6 weeks of age with 6 stabs of Georgia pox virus. Infected and control birds were weighed at weekly intervals following inoculation and growth rate was determined. Birds were examined for pox lesions at 7 and 14 days postinoculation. Experiment 4.—This experiment was an attempt to determine the role of the bursa in the development of immunity to Newcastle disease virus. R-Line birds were bursectomized at 5 days of age and half of each group (B and NB) were isolated from other groups of the experiment. At 6 weeks of age, the isolated birds were vaccinated intranasally with combination, commercially available Newcastle-bronchitis virus vaccine. The remaining birds were not vaccinated and served as controls. Both vaccinated and control birds were weighed weekly for a period of 3 weeks. Three weeks following vaccination half the vaccinated birds and half the control birds (B and NB, respectively) were challenged intranasally with 1 minimum lethal dose of the Gilbert-Boney strain of Newcastle disease virus. The remaining birds were not challenged and served as controls. Following challenge, birds were weighed weekly for a 2-week period and percentage mortality was calculated. Data obtained during the immunization period were analyzed, but those obtained during the challenge period were not. Design and Analysis of Data.—All experimental birds were randomized into batteries prior to each experiment. If sufficient
1227
BURSA AND RESISTANCE TO VIRUS DISEASE
TABLE 2.—Importance of the bursa of Fabricius in development of immunity to fowl pox as measured by growth in R-line, Single Comb White Leghorns (experiment 1)
Group 1
I5irds2
NB-NV-NCh NB-NV-Ch NB-V-NCh NB-V-Ch B,-NV-NCh BrNV-Ch B,-V-NCh B,-V-Ch Bu-NV-NCh Bu-NV-Ch Bu-V-NCh Bu-V-Ch 1
No. 8 8 8 8 8 8 8 8 8 8 8 8
Average gain at days after challenge 7
14
21
28
gin. 100 96 99 81 101 86 63 82 72 41 102 80
gm. 220 139 192 184 220 126 175 196 201 70 208 197
gm. 290 202 281 254 303 215 226 254 246 153 286 249
gm. 336 273 357 325 354 315 280 319 319 195 348 296
Ch = challenged. NCh = non-challenged. Bi = bursectomized at 1 day of age and Bi4 at 14 days of age. 2 Eight replicates of 1 bird per replicate.
TABLE 3.—Comparative resistance of bursectomized (at 5 days of age) and non-bursectomized Line 15— S. C. While Leghorns challenged with fowl pox virus at 6 weeks of age (experiment 2)
Group1
NB-NCh NB-Ch B 5 -NCh B5-Ch 1 2
Birds2
No. 12 12 8 8
Average gain at days after challenge 7
14
21
28
gm. 80 63 69 48
gm. 181 114 161 96
gm. 289 208 267 176
gm. 362 296 376 326
Ch = challenged. NCh=non-challenged. Eight replicates of 1 or 2 birds per replicate.
Growth of challenged Line-15 birds (NBCh and B5-Ch, Table 3) and commercial line birds (NB-Ch and B-Ch, Table 4), was severely depressed by the infection as compared with normal growth by non-challenged controls (NB-NCh and B-NCh, Tables 3 and 4). However, a comparison of B5-Ch and NB-Ch birds revealed no significant difference in growth. The bursectomized birds appeared to recover from the infection at a faster rate than non-bursectomized birds. Experiment 3.—In this experiment, only the commercial bird was used (Table 5). Differences in growth between respective bursectomized and non-bursectomized birds were not significant at any time during the experiment. However, the B5-Ch birds TABLE 4.—Comparative resistance of bursectomized and non-bursectomized 6-week-old, commercial line S. C. White Leghorns to fowl pox infection (experiment 2)
Group
NB-NCh NB-Ch B6-NCh B5-Ch 1
Birds 1
No. 12 12 12 12
Average gain at days after challenge 7
14
21
28
gm. 92 55 113 74
gm. 193 121 189 125
gm. 291 227 308 227
gm. 359 321 388 336
Six replicates of 2 birds per replicate.
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
munity prior to challenge. All challenged, non-vaccinates exhibited takes. However, Bi4-V-Ch birds grew at a significantly slower rate than those vaccinated but not challenged (B14-V-NCh). Growth of all non-vaccinated challenged birds was depressed (Table 2). However, BM-NV-Ch birds appeared to be more susceptible to the challenge infection than either Bx-NV-Ch or NB-NV-NCh birds. Also, Group Bi-NV-Ch birds recovered at a somewhat faster rate than those in the other two groups. The non-vaccinated challenged birds could be ranked as follows according to the rate of growth following challenge: Bi, NB and B 14 by the third and fourth week following challenge. Experiment 2.—Both commercial and Line-15 birds were bursectomized at S days of age and challenged in the wing web at 6 weeks of age with 6 stabs of Georgia fowl pox virus. None of the birds were vaccinated prior to challenge. Results were essentially the same for the commercial strain and Line-15 birds (Tables 3 and 4).
1228
R. SADLER AND S. A. EDGAR
TABLE 5.—Comparative resistance of bursectomized and non-bursectomized 6-week-old commercial line S. C. White Leghorns to fowl pox infection (experiment 3)
Group
NB-NCh NB-Ch B6-NCh B6-Ch 1
Birds'
No. 16 16 16 16
Avera ge gain at days after challenge 7
14
21
28
gm. 147 78 110 91
gm. 267 149 235 147
gm. 358 214 311 229
gm. 441 295 419 309
tended to recover more quickly than NBCh birds, as in Experiment 2. (Tables 3 and 4). Experiment 4.—The results of effect of immunization with Newcastle disease vaccine on the growth of bursectomized and non-bursectomized R-Line S. C. White Leghorns are given in Table 6. Growth of the vaccinated birds (B5-V and NB-V) was more severely depressed (significant) than growth of their respective non-vaccinates, but both the B-V and NB-V birds appeared to be depressed to about the same degree, and the difference was not significant. Results of the effect of challenge on growth and livability are summarized in Table 7. There was little difference in growth between challenged, bursectomized and non-bursectomized birds that had been vaccinated (NBV-Ch and B5-V-Ch). Most of the growth
DISCUSSION
Cho (1963) found that the level of antibody to Newcastle disease virus (Bx strain) in bursectomized birds was equal to that of intact birds at 2 and 4 weeks after vaccination. He concluded that the bursa plays no role in the antibody response to the Bi strain of Newcastle disease. Also, Ipson and Glick (1964) found that both bursectomized and non-bursectomized birds developed about equally high serum neutralization titers to Newcastle disease virus. The results of two immunological trials of the study dealing with Bx strain of Newcastle disease and fowl pox viruses are TABLE 7.—Importance of the bursa of Fabricius in the development of immunity to Newcastle disease as measured by growth and mortality in R-line S. C. White Leghorns (experiment 4)
TABLE 6.—Effect of Newcastle disease vaccination on growth of bursectomized and non-bursectomized R-line S. C. White Leghorns (experiment 4)
Group
NB-NV NB-V B6-NV B5-V 1
Birds 1
No. 14 14 14 14
Group
Average gain at day 5 after challenge 7
14
21
gm. 123 101 103 88
gm. 236 176 224 174
gm. 351 287 306 277
Seven replicates of 2 birds per replicate.
NB-NV-NCh NB-NV-Ch NB-V-NCh NB-V-Ch Bs-NV-NCh Bs-NV-Ch B5-V-NCh Bj-V-Ch 1
Birds
No. 5 9 8 6 7 7 8 8
1
Average gain at days after challenge 7
14
gm. 59 -65 107 81 69 16 90 46
gm. 162 82 233 182 181 -7 204 160
Mortality
No. 0 5 0 0 0 6 0 0
Pet 0 56 0 0 0 86 0 0
Seven replicates of 1 or 2 birds per replicate.
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
Eight replicates of 2 birds per replicate.
depression occurred during the first week after challenge, and by end of the second week, the growth rates were about the same for all challenged groups except B5-NV-Ch, in which only 1 bird remained alive. Also, all birds previously vaccinated and challenged (NB-V-Ch and B-V-Ch) had developed protective immunity against the challenge virus, as indicated by absence of mortality in these groups. There were 56 and 86% mortality among challenged, nonvaccinated groups NB-NV-Ch and B-NVCh, respectively.
BURSA AND RESISTANCE TO VIRUS DISEASE
SUMMARY
Removal of the bursa of Fabricius at 1 or 5 days of age had no significant effect on resistance or development of immunity to fowl pox virus. However, chicks bursectomized at 14 days of age were more susceptible to fowl pox virus than non-bursectomized birds or those bursectomized at 1 day. Removal of the bursa at 5 days of age did not prevent the development of immunity to Newcastle disease virus.
ACKNOWLEDGMENTS
The assistance of the Regional Poultry Research Laboratory, East Lansing, for furnishing hatching eggs of Line IS and of Dr. W. L. Johnson for furnishing eggs of R-Line is gratefully acknowledged. REFERENCES Challey, J. R., 1962. The role of the bursa of Fabricius in adrenal response and mortality due to Eimeria tenetta infections in the chicken. J. Parasitol. 48: 352-357. Chang, T. S., M. S. Rheins and A. R. Winter, 1957. The significance of the bursa of Fabricius in antibody production in chickens. 1. Age of chickens. Poultry Sci. 36: 735-739. Chang, T. S., M. S. Rheins and A. R. Winter, 1959. The significance of the bursa of Fabricius in antibody production in chickens. 3. Resistance to Salmonella typhimurium infection. Poultry Sci. 38: 174-176. Cho, B-R., 1963. The effect of bursectomy of chickens in antibody response to Newcastle disease virus. J. Am. Vet. Res. 24: 832-834. Glick, B., 1955. Growth and function of the bursa of Fabricius in the domestic fowl. Ph.D. dissertation, Ohio State U. Glick, B., T. S. Chang and R. G. Jaap, 1956. The bursa of Fabricius and antibody production. Poultry Sci. 35: 224-225. Glick, B., 1960. Extracts from the bursa of Fabricius—a lymphoepithelial gland of the chicken —stimulate the production antibodies in bursectomized chickens. Poultry Sci. 39: 1097-1101. Graetzer, M. A., W. P. Cote and H. R. Wolfe, 1963. The effect of bursectomy at different ages on precipitin and natural hemagglutinin production in the chicken. J. Immunol. 9 1 : 576-581. Ipson, J. R., and B. Glick, 1964. Personal communication. Isakovic, K., B. D. Jankovic, L. Popeskovic and D. Milosevic, 1963. Effect of neonatal thymectomy, bursectomy and thymobursectomy on hemagglutinin production of chickens. Nature, 200: 273-274. Kemmes, F., and G. Pethes, 1963. Further evidence for the role of the bursa of Fabricius in antibody production in chickens. Zeitschrift fur immunitats und allergieforschung. 125: 446-458. Mueller, A. P., H. R. Wolfe, R. K. Meyer and R. Aspinall, 1962. Further studies on the role of
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
in agreement with the findings of the above workers. The bursa was not necessary for development of immunity to either virus. Apparently antibodies against these viruses are produced at some site other than the bursa. Because differences in growth or mortality between bursectomized and non-bursectomized non-vaccinated birds exposed to Newcastle disease virus or fowl pox virus were not significant, the bursa is apparently not important in development of resistance to these diseases. However, birds bursectomized at 2 weeks of age were apparently more susceptible to fowl pox vaccination than those bursectomized at 1 day of age or than those not bursectomized. The reason for the above phenomenon is not known at present. Possibly the bursa may not be functionally important in resistance to certain viral diseases until a certain age. Peterson et al. (1964) found that bursectomized birds were less susceptible to tumor formation caused by leukosis (visceral lymphomatosis virus) than non-bursectomized birds. In some fowl pox trials reported here (Experiments 2 and 3), the growth of birds bursectomized at 5 days of age was less depressed by vaccination than that of non-bursectomized birds. The results presented here suggest the possibility that the bursa may be an important site of fowl pox virus growth in the host.
1229
1230
R. SADLER AND S. A. EDGAR
the bursa of Fabricius in antibody production. J. Immunol. 88: 354-360. Perek, M., and A. E. Drill, 1962. The role of the bursa of Fabricius in developing immunity in chickens treated with Salmonella typhimwium and Spriochaeta gallinarum. British Vet. J. 118: 390-393. Peterson, R. D. A., B. R. Burmester, T. N. Fredrickson, H. G. Purchase and R. A. Good, 1964. Effect of bursectomy and thymectomy on the
development of visceral lymphomatosis in the chicken. J. Nat. Cancer Inst. 32: 1343-1354. Waters, M. F., B. R. Burmester and W. G. Walter, 1954. Genetics of experimentally induced erythroblastosis in chickens. J. Nat. Cancer Inst. 20: 1245-1256. Wilcoxon, F., 1949. Some rapid approximate statistical procedures. American Cyanamid Company, New York.
H. S. SIEGEL1 AND L. N. DRURY 2 Southeast Poultry Research Laboratory, ARS-VSDA, Athens, Georgia 30601 (Received for publication December 15, 1967)
I
NCREASED air movement facilitates convective heat exchange between the surface of the body and the surrounding air (Whittow, 1965; Siegel and Drury, 1968). Thus, if ambient temperatures remain below body temperature, increasing the air movement helps to alleviate some of the deleterious effects of high environmental temperatures (Lee et al., 1945; Wilson et al., 1957). The growth rates of broilers raised in diurnally cycling hot environments have been shown to be related to air velocity (Drury, 1966). Respiratory evaporation becomes more important as a means of heat loss in birds as the ambient temperature approaches body temperature. In chickens, panting commences when the core temperature reaches approximately 42°C. (Whittow, 1965), and a rapid increase in body temperature results in an increased heart rate (Linsley and Burger, 1964). Our previous studies with young chickens provided evidence that in environmental temperatures up to 40°C, the enhancement of convec1 2
Animal Husbandry Research Division. Agricultural Engineering Research Division.
tive heat loss by increased air velocity partially replaces respiratory evaporation as a means of heat loss thus delaying or preventing the onset of hyperthermic respiratory and cardiac responses (Siegel and Drury, 1968). This paper considers the effect of increased air velocity when environmental temperatures exceed body temperature. EXPERIMENTAL METHODS
Details of the air velocity facility have been published (Drury and Siegel, 1966). Two birds were confined in wire cages in each of six subchambers mounted over a main duct which was evacuated by a large fan. Air velocities in each of the subchambers were adjusted independently through the use of perforated inlet plates and damper-controlled outlets. The entire unit was situated in a large room which serves as a plenum whose air temperature was programmed according to the experimental design. Body temperatures, heart rates and respiratory rates were measured by methods previously described (Siegel and Drury, 1968). Southeast Poultry Research Labora-
Downloaded from http://ps.oxfordjournals.org/ at Dalhousie University on June 19, 2015
Physiological Responses to High Lethal Temperature and Air Velocity in Young Fowl