EFFECTS OF EARLY IMMUNE STRESS AND CHANGES IN DIETARY METABOLIZABLE ENERGY ON THE DEVELOPMENT OF NEWLY-HATCHED TURKEYS .2. SELECTED CHARACTERISTICS OF IMMUNE FUNCTION

Two 21-d experiments were conducted to document the effects of an earl y immunologic stress and changes in dietary ME(n) on selected characte ristics of immune function of newly hatched turkeys. Eight treatments were included in each experiment. Treatments were the results of compl ete factorial arrangements of two types of injection and four isonitro genous diets. Turkeys in both experiments were injected i.p. with .5, .5,and .2 mL of saline (SAL) or .5, .5, and .2 mL of a solution of Esc herichia coli lipopolysaccharide (LPS) (100 mug LPS/mL SAL) at 1, 3, a nd 5 d of age, respectively. In Experiment 1, two diets were formulate d to contain 2,800 kcal ME(n)/kg. One was a corn-soybean meal based di et (CSBM) and the other contained 8% Solkafloc(R) (SKF). A third diet (3,100 kcal ME(n)/kg) was formulated by substituting 8% sucrose (SUC) for the 8% SKF. The fourth diet (HE) included in Experiment 1 was form ulated to contain 3,700 kcal ME(n)/kg. The CSBM and SUC diets and two additional diets were tested in Experiment 2. The latter were the CSBM diet containing 74.5 mg ibuprofen/kg (IBU) and a corn-soybean meal di et formulated to contain 3,100 kcal ME(n)/kg (CS31). Concentrations of plasma IgG and jejunal IgG and IgA were not affected by injection or diet. Age-related changes in Ig concentrations were consistently obser ved in Experiments 1 and 2. Injection with LPS reduced the number or r esponse of blood leukocytes to mitogens at 8 d of age (P < .01), as co mpared with samples from turkeys injected with SAL. Leukocytes in whol e blood samples from turkeys fed the HE diet responded less to LPS sti mulation than those fed the SUC diet (P < .01). Injection with LPS did not markedly affect the characteristics of immune function studied, a nd feeding a diet with 3,100 kcal ME(n)/kg and 28.5% crude protein did not measurably affect the characteristics of immune function of young turkeys.