Influence of Temperature on the Immune Response of Birds1 PAUL THAXTON Department of Poultry Science, North Carolina State University, Raleigh, North Carolina 27650 (Received for publication March 21, 1978) INTRODUCTION
INFLUENCE OF HIGH ENVIRONMENTAL TEMPERATURES
Thaxton et al. (1968) were the first to demonstrate experimentally that high environrrfental temperatures affect the development of a specific immune response in the chicken. New Hampshire chicks were exposed to heat (41—43 C) for a 30 min period during each of four consecutive hours at various times starting 24 hr before to immediately after immunization with a sheep red blood cell (SRBC) antigen. The ensuing humoral immune response was reduced (Table 1). However, in other experiments chickens were exposed to single 30 min. periods of heat on each of nine consecutive days and 12 hr after the third daily heating the birds were immunized with SRBC. Twelve hours after the last heating the birds were bled and anti-SRBC antibody levels were determined. This chronic heating regime did not affect the circulating levels of antibody (Table 2). Additional information concerning the effects of chronic high environmental temperatures on humoral immunity in the chicken has been presented recently (Subba Rao and Glick, 1977b). Chicks were reared from hatching until four weeks of age at constant temperatures of 32.2 C, 40.6 C, or in a cyclic temperature environment, i.e., over each 12 hr period temperatures cycled between 7.2 and 32.2 C. The anti-SRBC antibody levels of the birds reared at high, as well as in the cyclic temperature conditions, were reduced significantly (Fig. 1).
Because it was shown that continuous exposure to elevated temperatures reduces immune responsiveness and multiple daily exposures does not, the critical factors must be the duration and timing of the heat treatment with 1 Paper No. 5465 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, regard to the time of immunization. A further inference is that during the pre-induction and North Carolina 27650. 1430
1978 Poultry Sci 57:1430-1440
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 30, 2015
The influence that the environment exerts on the general health and productivity of poultry is a concern of long standing. Pasteur et al. (1878) demonstrated a relationship between body temperature and the resistance of the fowl to anthrax, even though the role of environmental temperature and body temperature was not understood at that time. Since Pasteur's earliest observation, an extensive body of literature has evolved which indicates that the environment influences the chicken's ability to withstand infectious diseases. Hutt (1958), in his excellent text, presented a clear picture of how the environment, as it is perceived genetically by birds, conditions resistance and/or susceptibility to common infectious diseases. Environmental factors other than temperature affect immunity in birds. Among such factors are: microbial toxins (Pier and Heddleston, 1970; Pier et al, 1971; Michael et al, 1973; Thaxton et al, 1974a), hypoxia (Tengerdy, 1970), heavy metals (Thaxton and Parkhurst, 1973; Morgan et al, 1975), non-ionic radiation (McRee et al, 1977), pesticides (Glick and Whatley, 1966; Glick, 1972, 1974; Latimer and Siegel, 1974; Subba Rao and Glick, 1977a), mechanical stress (Schmidt et al, 1976), social interactions (Siegel and Gross, 1965; Gross and Siegel, 1965; Gross and Colmano, 1967, 1969, 1970; Siegel and Latimer, 1975), restraint (Thaxton and Briggs, 1972), and nutrients (Tengerdy and Heinzerling, 1972; Tengerdy, 1976; Tengerdy and Brown, 1977). However, a correlation of the multiple factors of the environment that influence immunity in birds is beyond the scope of this review. This effort will be directed to a delineation of
the influence of one environmental factor, temperature, on immunity in the chicken.
ENVIRONMENTAL TEMPERATURE AND IMMUNITY
TABLE 1 .—Influence of acute exposures to high environmental temperature (41—43 C) on humoral immunity?-'"'0
Treatment
AntiSRBC titers (Log 2 values)
Non handled control Heat a t - 2 4 , - 2 3 , - 2 2 , - 2 1 Heat a t - 1 2 , - 1 1 , - 1 0 , - 9 Heat at 0 , + 1 , + 2 , + 3
9.00 A 4.00 B 4.87B 5.00 B
Antibody titers at 7 days post-SRBC challenge. From: Thaxton, Sadler, and Glick, 1968. Poultry Sci. 47:264-266. AB Means in a column possessing different superscripts in this and all following tables are significantly different (P
INFLUENCE OF HIGH ENVIRONMENTAL TEMPERATURES
Thaxton et al. (1968) were the first to demonstrate experimentally that high environrrfental temperatures affect the development of a specific immune response in the chicken. New Hampshire chicks were exposed to heat (41—43 C) for a 30 min period during each of four consecutive hours at various times starting 24 hr before to immediately after immunization with a sheep red blood cell (SRBC) antigen. The ensuing humoral immune response was reduced (Table 1). However, in other experiments chickens were exposed to single 30 min. periods of heat on each of nine consecutive days and 12 hr after the third daily heating the birds were immunized with SRBC. Twelve hours after the last heating the birds were bled and anti-SRBC antibody levels were determined. This chronic heating regime did not affect the circulating levels of antibody (Table 2). Additional information concerning the effects of chronic high environmental temperatures on humoral immunity in the chicken has been presented recently (Subba Rao and Glick, 1977b). Chicks were reared from hatching until four weeks of age at constant temperatures of 32.2 C, 40.6 C, or in a cyclic temperature environment, i.e., over each 12 hr period temperatures cycled between 7.2 and 32.2 C. The anti-SRBC antibody levels of the birds reared at high, as well as in the cyclic temperature conditions, were reduced significantly (Fig. 1).
Because it was shown that continuous exposure to elevated temperatures reduces immune responsiveness and multiple daily exposures does not, the critical factors must be the duration and timing of the heat treatment with 1 Paper No. 5465 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, regard to the time of immunization. A further inference is that during the pre-induction and North Carolina 27650. 1430
1978 Poultry Sci 57:1430-1440
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 30, 2015
The influence that the environment exerts on the general health and productivity of poultry is a concern of long standing. Pasteur et al. (1878) demonstrated a relationship between body temperature and the resistance of the fowl to anthrax, even though the role of environmental temperature and body temperature was not understood at that time. Since Pasteur's earliest observation, an extensive body of literature has evolved which indicates that the environment influences the chicken's ability to withstand infectious diseases. Hutt (1958), in his excellent text, presented a clear picture of how the environment, as it is perceived genetically by birds, conditions resistance and/or susceptibility to common infectious diseases. Environmental factors other than temperature affect immunity in birds. Among such factors are: microbial toxins (Pier and Heddleston, 1970; Pier et al, 1971; Michael et al, 1973; Thaxton et al, 1974a), hypoxia (Tengerdy, 1970), heavy metals (Thaxton and Parkhurst, 1973; Morgan et al, 1975), non-ionic radiation (McRee et al, 1977), pesticides (Glick and Whatley, 1966; Glick, 1972, 1974; Latimer and Siegel, 1974; Subba Rao and Glick, 1977a), mechanical stress (Schmidt et al, 1976), social interactions (Siegel and Gross, 1965; Gross and Siegel, 1965; Gross and Colmano, 1967, 1969, 1970; Siegel and Latimer, 1975), restraint (Thaxton and Briggs, 1972), and nutrients (Tengerdy and Heinzerling, 1972; Tengerdy, 1976; Tengerdy and Brown, 1977). However, a correlation of the multiple factors of the environment that influence immunity in birds is beyond the scope of this review. This effort will be directed to a delineation of
the influence of one environmental factor, temperature, on immunity in the chicken.
ENVIRONMENTAL TEMPERATURE AND IMMUNITY
TABLE 1 .—Influence of acute exposures to high environmental temperature (41—43 C) on humoral immunity?-'"'0
Treatment
AntiSRBC titers (Log 2 values)
Non handled control Heat a t - 2 4 , - 2 3 , - 2 2 , - 2 1 Heat a t - 1 2 , - 1 1 , - 1 0 , - 9 Heat at 0 , + 1 , + 2 , + 3
9.00 A 4.00 B 4.87B 5.00 B
Antibody titers at 7 days post-SRBC challenge. From: Thaxton, Sadler, and Glick, 1968. Poultry Sci. 47:264-266. AB Means in a column possessing different superscripts in this and all following tables are significantly different (P
