Epitopes for chicken monoclonal antibodies in spleens of selected Japanese quail lines.

A line of Japanese quail selected for high plasma cholesterol is highly susceptible to diet-induced atherosclerosis. Lymphocyte epitopes recognized by mouse anti-chicken monoclonal antibodies (c-mAb), TCR-1, TCR-2, TCR-3. CD-3, CD-4, CD-8, and BU-1a/b were reacted with spleens from quail selected for high (HL) and low (LL) plasma total cholesterol and their nonselected controls (CL). Cross reactivity to c-mAb and effect of line and gender were immunohistochemically evaluated. Chicken spleens were positive controls. Quail were immunologically stimulated with either sheep red blood cells (SRBC) or Brucella abortus 2 weeks before spleens were removed. Quail spleen epitopes of all lines recognized TCR-3 and CD-8 c-mAb, but no other c-mAb. Number of reacting cells and staining intensity to the TCR-3 c-mAb were greater in the HL than in the LL regardless of the stimulating Ag or dose used. For the CD-8 c-mAb, there were no differences among lines in birds receiving SRBC. In B. abortus-immunized birds, sex x line interactions indicated that males of the HL and CL had lower responses than females but LL males were not different than females. TCR-3 and CD8 c-mAb may be useful in studying immunological mechanisms for atherosclerosis in Japanese quail.

Changes in the profiles of circulating white blood cells, corticosterone, T3 and T4 during the initiation of humoral immunity in immature male chickens.

Eight-week-old male White Leghorn chickens were injected intravenously with either 0.1 ml of Brucella abortus (BA) or saline. Blood samples were collected before injection, 1 hr, 3 hr, 6 hr, 12 hr, 24 hr, and then daily for the following 6 days after the injection. Total white blood cells (WBC), differential counts and corticosterone (CS), T3 and T4 levels were measured in all blood samples. These data represented the results obtained from the primary response. To obtain data for the secondary response, the same birds were injected 4 weeks following the first challenge and the same procedure was followed. During primary and secondary responses, circulating lymphocytes and monocytes decreased significantly 3 hr following BA injection and then increased steadily and reached a peak approximately 5 days post-BA injection, however, circulating heterophils increased significantly 6-12 hr and returned to normal levels 2 days post-BA injection. Serum corticosterone increased significantly 3 hr following BA injection. Serum T3 decreased significantly 3 to 12 hr then increased significantly 2 days following BA injection. There were no significant changes in any of the measurements following saline injection. Correlations between circulating hormones and white blood cells were calculated and are reported. These results indicate that an early step in the initiation of humoral immunity is probably an increase in serum CS. This increase in CS is followed by a decrease in circulating lymphocyte and monocyte numbers. These decreases may be the result of lymphocyte trapping in secondary lymphoid organs. This series of events may occur to modulate and activate the immune response.

Effect of genetic selection and MHC haplotypes on lymphocyte proliferation and interleukin-2 like activity in chicken lines selected for high and low antibody production against sheep red blood cells.

Chickens from third generation matings of lines of chickens selected for high (HA) and low (LA) antibody production to sheep red blood cells (SRBC) and typed for MHC genotypes B13/13, B13/21, and B21/21 were used in this study. Chickens from both lines carried all the three genotypes B13/13, B13/21, and B21/21. To study T- and B-lymphocytes mitogenic activity, 12-week-old female chickens were injected intravenously with 0.2 ml of 9% SRBC and spleens were collected at 0, 6 h, and 6 day post-antigen injection (pAg). Isolated lymphocytes were incubated with either Concanavalin-A (Con-A) for T-cell activity, or Pokeweed mitogen (PWM) for B-cell activity and thymidine 3H uptakes were measured. To study the Interleukin-2 (IL-2)-like activity in the same lines and genotypes, splenic lymphocytes from 12-week-old chickens were passed through nylon wool columns to enrich the T-cell population. After a 24 h incubation with Con-A, the conditioned media (CM) were collected. The CM were tested for IL-2 like activity by determining whether they altered the proliferation of Con-A stimulated T cells. This proliferation effect was then compared to that of a reference conditioned media (RCM) prepared from K-strain birds and that were used as the standard for the assay. There was no significant difference (p > 0.05) in IL-2 like activity between HA and LA lines, however, the LA was significantly higher than HA (p < 0.05) in T- and B-cell mitogenic activity. The genotype B13/13 had significantly higher (p < 0.05) IL-2 like activity than the B21/21. The genotype B13/13 was also significantly higher (p < 0.05) in T- and B-cell mitogenic activity than the B21/21. At 0 h, pAg T- and B-mitogenic activity was significantly higher (p < 0.05) than 6 h. In summary, our results indicate that although the birds were selected for high antibody production to SRBC, their lymphocyte mitogenic activity was lower than those selected for low antibody production. Hence, humoral and cell-mediated immune responses appear to be under different genetic controls, and that selection for greater humoral response may be at the expense of cellular responses. Our results also suggest differences in IL-2 like activity production between chickens carrying different MHC B-haplotypes, and that genetic control of such activity is possibly linked to the MHC genes.

Evaluation of the heterophil/lymphocyte ratio as a measure of stress in chickens.

The number of lymphocytes in chicken blood samples decreased and the number of heterophils increased in response to stressors and to increasing levels of corticosterone in the chicken feed. The ratio of heterophils to lymphocytes was less variable than the number of heterophil or lymphocyte cells, and the range of values for this ratio was greater than the range of values for heterophils and lymphocytes among control and experimental groups. The heterophil/lymphocyte ratio appears to be a more reliable indicator of levels of corticosterone in the feed and to social stress than were the plasma corticosteroid levels.

Ethics in research.

Unethical conduct in research can be divided into five categories: 1) falsification of data, in which the researcher manipulates results, provides data without experimentation, or biases the results to give a false impression of their value; 2) failure to credit others (former colleagues, students, associates) for research results or ideas; 3) plagiarism, use of other's published material (ideas, graphs, or tabular data) without permission or credit; 4) conflicts of commitment or interest in which work or ownership in a private firm in some way conflicts or detracts from the duties to the institution they represent or allows private gain through the individual's employment at the institution; 5) biased experimental design or interpretation of data to support public or private groups that have provided financial support for research. Although none of these should be condoned or tolerated by the scientific community, the latter two are probably more serious, because they are insidious, hard to prove, and, in the long run, result in the loss of public confidence in science.

Growth, feed conversion, and carcass composition in females of four broiler crosses fed starter diets with different energy levels and energy to protein ratios.

Body weight, feed conversion, and carcass composition were studied in females of four commercial broiler crosses that differed in weight at 7 wk of age. The birds were fed starter diets for the first 3 wk containing different energy levels but the same protein level (Experiment 1) or varying energy or protein to equilibrate energy:protein ratios (Experiment 2). Experiment 1 was conducted in floor pens; Experiment 2 in batteries. All birds received a common grower diet from 4 to 7 wk of age. No significant cross by starter diet interactions were found for body weight, feed conversion, carcass weight, or protein percentages. In the floor experiment, 3- and 7-wk body weights were lower in birds receiving the highest energy starter than in those receiving lower energy starters; in the battery experiment, body weights were unaffected by energy of the starter. Feed conversion was lower in the birds receiving the high-energy starter in both experiments. Carcass weights essentially paralleled live weights in both experiments; however, percentage of protein in carcasses of 7-wk-old broilers was unaffected by starter diets. Feeding a high-energy starter for the first 3 wk posthatch resulted in higher carcass fat percentages at 7 wk of age but lower absolute and relative abdominal fat pad weights. The significant cross by starter diet interactions indicated that the fastest growing broilers responded to the high-energy starter diet by a significant reduction in abdominal fat without an overall reduction in carcass fat.

Partial purification and characterization of chicken corticosteroid-binding globulin.

Affinity chromatography of pooled chicken serum yielded a solution in which 45% of the protein was corticosteroid-binding globulin (CBG). Further purification by single passes through hydroxylapatite and Biogel A-.5m resulted in a final product with about 91% purity. The molecular weight was 56,000 daltons as determined by gel filtration and 63,000 as determined by sodium dodecysulfate-polyacrylamide gel electrophoresis. The amino acid composition was similar to that of mammalian CBG's when compared on the basis of total amino acid residues of each type. However, the avian CBG was much lower than mammalian CBG in half-cystine residues. The corticosteroid-binding ability of the purified CBG was increased up to tenfold by treatment with dithiothreitol (DTT). Of several cations tested, Mg2+, Ca2+, Zn2+, and Mn2+ exhibited some synergism with DTT, but were ineffective by themselves; Cu2+ was inhibitory. The association constant toward corticosterone at 4 degrees was 3.6 X 10(-7) M-1. Unlike mammalian CBG, which does not bind dexamethasone, the chicken CBG binds dexamethasone with almost the same affinity as corticosterone.

Effect of sex hormones on the retention of dieldrin in the fat of growing chickens.

The effects of the bird's sex, castration, and sex hormone replacement on the retention of dieldrin in the carcass fat of growing chickens given low levels of dieldrin in the feed (1 mg/kg) were investigated. Confirmed were previous results that "best-fit" curves for depletion after noncontaminated feed was provided were represented by an equation of the form, y = aX-b, and that, with the approach of sexual maturity, males tend to retain greater concentrations of dieldrin in the carcass fat than females. This sex difference was partly a diluting effect of higher carcass fat deposition in females as compared to males. Additionally, when dieldrin feeding was discontinued after 10 weeks of age, androgen replacement in castrates restricted the clearance of dieldrin from the fatty tissue, and estrogen replacement did not further increase clearance over that of nontreated castrates.

Divergent selection in Japanese quail for the plasma cholesterol response to ACTH.

Two lines of Japanese quail were divergently selected for high and low plasma cholesterol levels after three daily injections with 2 IU of adrenocorticotropen (ACTH)/100 g of body weight. Plasma cholesterols were obtained at 31 days of age, just before the first injection, and at 34 days of age, after the last injection. After eight generations of selection, the plasma cholesterol level after ACTH injections in the high line was 34% greater than the level in the control line, whereas the low line level was approximately 14% less than that in the control. Selection differentials were significantly greater in the high line than in the low line. The realized heritability for plasma cholesterol before ACTH treatment calculated by regression of progeny on mid-parent was .25 in the high line and .16 in the low line.

Effect of adrenocorticotropin on binding of endogeneous corticosteroid by chicken bursal cells.

An intravenous injection of ACTH stimulated a maximal increase in the serum concentration of corticosterone within 60 to 65 min. This increase was closely paralleled by the amount of corticosterone which was bound to be cytoplasmic and nuclear fractions of chicken bursal cells.

Impact of cage density on pullet performance and blood parameters of stress.

The effects of cage density on pullet live performance and blood indices of stress were evaluated in two commercial White Leghorn strains housed at 38, 32, 26, and 20 birds per cage from Day 1 to 6 wk of age, and 19, 16, 13, and 10 birds per cage from 6 to 18 wk. Cage densities of 26 and 13 birds per cage represent a U.S. standard of 142 and 284 cm2 per bird that is often applied in commercial pullet rearing. Cage density treatments include confounding cage, feeder, and drinker spaces per bird as might be encountered in commercial practice when growing more pullets per cage. Body weight was significantly reduced at greater bird densities in both strains; however, one strain was affected as early as 6 wk of age, whereas in the other strain, body weight was not reduced significantly until 18 wk. Feed intake was increased by more than 13% in both strains at the lowest density treatment (20 birds per cage) from Day 1 to 2 wk but reduced by more than 9% by higher cage densities during the remainder of the study. Feed conversion (FC) ratio was similarly improved (i.e., reduced) when more pullets were housed per cage, and increased when fewer birds were placed per cage compared to the standard. Despite a significant reduction in feed intake and a corresponding loss of body weight, cage density treatments had no significant affect on hemagglutinin titers to sheep red blood cell antigen, percentage heterophils (H), lymphocytes (L), or the H:L ratio. However, pullet age and strain differences were observed for all blood parameters. Overall, treatments allowing more cage, feeder, and drinker spaces per bird than the U.S. commercial standard provided no body weight advantage, and allowed for greater feed intake and poorer FC at several ages.

Short-term effects of sodium pentobarbital on blood gases and chemistry in young chickens.

Sodium pentobarbital, in its commercially prepared propylene glycol-ethanol-saline vehicle, was given intravenously to 8-week-old male and female Athens Randombred chickens, and either the vehicle alone or 0.8% saline was given to similar groups. One minute after injection, blood samples were taken for blood pH, pCO2, HCO3 minus, corticosterone, total protein, or cholesterol levels. The pO2 was significantly lower in the pentobarbital-anaesthetized birds than in those given saline or the vehicle only. Plasma glucose of birds given the vehicle was elevated over that of those given pentobarbital or saline. Triglycerides were significantly higher in plasma of birds given pentobarbital or the vehicle. This increase appeared related to the presence of the glycol moiety in the vehicle.

Serum lipoproteins in chickens after administration of adrenocorticotropin or exposure to high temperature.

The effects of intramuscular injections of adrenocorticotropin (ACTH) or short-term exposures to high environmental temperature (44 to 46 C) were determined on the relative amounts of lipoproteins in the serum of 6 to 7-week-old White Rock chickens. In addition, the influence of the sex of the bird and fasting vs. ad libitum feeding on these lipoproteins was measured. The relative amount of high density lipoprotein (HDL) was lowered by ACTH, and heat exposure lowered both HDL and very low density lipoprotein (VLDL). Fasting completely eliminated VLDL and lowered low density lipoprotein (LDL) but had little effect on HDL. The temperature treatments significantly increased serum corticosteroid levels in both sexes in birds fed ad libitum but only in the males of fasted birds. Fasting for 15 hr did not significantly affect serum corticosteroid levels.

Effects of corticotropin and heat on corticosteroid-binding capacity and serum corticosteroid in White Rock chickens.

The effects of the administration of corticotropin (ACTH) or high environmental temperature on serum maximum corticosteroid-binding capacity (MCBC) and serum corticosteroid concentrations were studied in 6- to 8-wk-old White Rock chickens. Highly significant increases in serum corticosteroids produced by either intramuscular or intravenous injections of ACTH were followed by significant reductions in MCBC within 24 hr. A single high-temperature episode (46 C) caused a significant increase in serum corticosteroids when blood was sampled immediately following exposure to heat; however, serum corticosteroids were not significantly increased following two heat episodes spaced 11 hr apart. Exposure to high temperature did not alter MCBC levels.

Effect of age and sex on the association constant and binding capacity of chicken serum for corticosteroid.

In two experiments, the blood of White Rock chickens was collected at 6 intervals from the time they were 2 to 140 days old. The effects of age, sex of the bird, and removal of exogenous steroids (stripping) on the association constant (Ka), and the binding capacity (CBGBC) for corticosterone in the serum were measured. The Ka of the serum declined when the chickens were between 84 and 140 days old. Stripping increased the Ka only when all chickens were 2 days old and when the females were 140 days old. The CBGBC was highest in all chickens when they were 28 to 56 days old. In general, CBGBC was higher in serum of males than in that of females, but was reduced to a greater extent by stripping in males than in females. These results indicate that the bound to free ratio for corticosteroids should be highest when the chickens are 28 to 56 days old, when both Ka and CBGBC are highest.

Inactivated Newcastle disease vaccines: influence of virus concentration on the primary immune response.

Inactivated vaccines of high potency could play a valuable role in Newcastle disease control programs. We determined the influence of virus concentration and method of concentration on the immune response of chidkens to inactivated vaccines. We used the LaSota strain of virus concentrated by either ultracentrifugation of polyethylene glycole precipitation. Virus concentration has a significant effect (P less than or equal to .01) on serum antibody levels at 2, 3, 4, and 6 weeks after vaccination; but during this same period, the antibody response was not significantly influenced by method of concentration. Virus concentration increased beyond 2000 hemagglutination units did not significantly increase (P greater than or equal to .05) the magnitude of the antibody response.

DDT and metabolite accumulation in adrenal, liver, and brain of broiler chickens.

Four-week old broiler chickens were fed rations with varying levels of technical grade DDT for a 4-week period. DDT and metabolite concentrations were measured in adrenal, liver, and brain. Accumulations per gram of tissue were greatest in the adrenals, followed by those in the liver, then in the brain. All birds fed 2700 p.p.m. of DDT died with 12 days after beginning feeding, and moderate signs of toxicity, such as ataxia and trembling, appeared in those fed 900 p.p.m. Although both DDT metabolites, p,p'-DDE and p,p'-DDD, were found in the tissues, the higher levels of the former indicated that the aerobic conversion of DDE occurs more readily than the anaerobic conversion. Significant quantities of o,p'-DDT appear only in tissues of birds fed high levels of the technical grade DDT.

Modification of corticosterone and glucose responses by sympatholytic agents in young chickens during acute heat exposure.

In four experiments, immature Athens Randombred (ARB) chickens were maintained at a moderate temperature, (24 degrees C., 45% R.H.). In Exps. 1 and 2 reserpine was given intramuscularly (0.75 mg./kg.) 12 hours before the heating episode was begun; in Exp. 3, propranolol was given intravenously (4 mg./kg.) 2 hours before heating; and in Exp. 4, dihydroergotamine was given intramuscularly (4 mg./kg.) 6 hours before heating. Rserpine and propranolol elevated plasma corticosterone before the heating episode began, but dihydorergotamine did not. Reserpine also raised plasma glucose levels before heating, but propranolol and dihdroergotamine did not. During the heating episodes, plasma glucose and plasma corticosterone increased in non-drug-treated birds; the increases were then followed by significant declines. In birds treated with reserpine, propranolol, and dihydroergotamine, however, elevated plasma corticosterone was maintained throughout the period of heating. Propranolol and dihydroergotamine also stabilized plasma glucose at higher levels during heating, but reserpine permitted the late period decline similar to that of non-drug-treated birds. These results indicate an adrenal cortical insufficiency during heat stroke and death in young chickens.

Interaction of high temperature and Salmonella pullorum antigen concentration on serum agglutinin and corticosteroid responses in white rock chickens.

In three experiments, 6- to 7-week-old chickens were exposed to one or two standard heating episodes and were injected immediately afterward with different concentrations of heat-killed Salmonella pullorum antigen (Ag) or phosphate-buffered saline. The standard heat episode consisted of three .5-hr exposures of 44 to 46 C with .5-hr periods of 22 C between exposures. Nonheated chickens were maintained at 22 C. When two heating episodes were used, there was a 12-hr interval between episodes. Sera from blood collected at 0 through 15 days postimmunization (PI) were titrated for total agglutinins and assayed for corticosteroids in all three experiments. Additionally, in Experiment 3, sera were titrated for 2-mercaptoethanol-resistant (2-MER) antibody. Total agglutinins were suppressed from 5 through 13 days PI by one heating episode in birds receiving lower doses of Ag but not in those receiving higher doses. When birds were exposed to two heat episodes, 12 hr apart, total agglutinin titers were suppressed in birds receiving the low Ag dose during the induction phase (4 to 5 days PI) only. During the declining phase (7 to 14 days PI), the effect was reversed, and titers were significantly lower in heated birds receiving the higher dosage. These results are similar to those previously obtained with ACTH (adrenocorticotropin). Determination of 2-MER antibody indicated that IgM was probably suppressed during the induction of the immune response but that IgG was suppressed during the declining phase of the response. Serum corticosteroid concentrations were significantly increased immediately after exposure to high temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of adrenocorticotropin hormone injections on glucocorticoid receptors in chicken thymocytes.

The concentration of corticosteroid receptors in chicken thymocytes was determined by Scatchard analysis at various times after adrenocorticotropin hormone (ACTH) injection. Plasma corticosteroid was measured concurrently. As expected, circulating corticosteroid was significantly elevated by one or two im injections of ACTH and at .5 or 2 hr after a single iv injection. Concomitantly, there was about a 50% decline in the cellular concentration of cytoplasmic receptor sites. Although there was significantly more circulating steroid after two im injections than after one, and more at 2 hr than at .5 hr after a single iv injection, there was no significant difference between the concentrations of the cytoplasmic receptor in either case. The concentration of nuclear receptors was not altered by the ACTH injections employed.