Search PubMed⌕ Search

Biomedical subjects

J P Thaxton

Publications and source records attributed to J P Thaxton.

At least 19 recordsLinked to original sources
PubMed1992

Yolk sac absorption and initiation of growth in broilers.

A series of three experiments was conducted to determine the role of the yolk sac in initiation of growth in broilers. In Experiment 1, absorption of the yolk sac was found to precede initiation of growth in newly hatched broilers by approximately 24 h. Because the yolk sac is essential for early initiation of growth, in Experiments 2 and 3 it was removed and diets with incremental fat levels of 3, 6, and 10% were fed to assess whether fat was essential for optimal growth during the neonatal period. Results suggest that dietary fat has its greatest effect on growth after 10 days of age. Therefore, initiation of growth may be more closely dependent upon other nutrients.

Absorption↗
PubMed1988

Ontogeny of antibody response to Brucella abortus in turkeys.

No differences were detected between large White Nicholas and small White Hybrid turkeys in antibody (AB) titers in birds vaccinated with Brucella abortus. Maximal AB titers occurred by 6 weeks of age and remained high throughout life. B. abortus elicits an AB response when injected at day of hatch while bursectomy at day of hatch and 2 days of age significantly depressed this response. There was an apparent immunological maturation process occurring to B. abortus in the bursa of Fabricius which contained for approximately 6 weeks.

Age Factors↗
PubMed1988

Serum enzymes in hemorrhaged Japanese quail after microwave irradiation during embryogeny.

1. Japanese quail eggs were exposed to 2.45 GHz continuous wave microwave radiation at an incident power density of 5 mW/cm2 and a specific absorption rate of 4.03 mW/g during the first 12 days of embryogeny. 2. After hatching, serum biochemical changes in response to hemorrhagic stress were measured following a hemorrhage of 30% of the calculated total blood volume. 3. Lactate dehydrogenase, beta-glucuronidase, acid phosphatase, glucose and protein were not affected by microwave irradiation during embryogeny either before or after hemorrhage. 4. Microwave irradiation in ovo affected the response of serum glutamic oxaloacetic transaminase activity to hemorrhagic stress in Japanese quail.

Acid Phosphatase↗
PubMed1988

Hematological effects of ethyl methanesulfonate, paraquat and phenylhydrazine in Japanese quail.

1. Juvenile Coturnix coturnix japonica males were injected intravenously with 2, 20 or 200 mg ethyl methanesulfonate (EMS)/kg body wt; 0.2, 2 or 20 mg paraquat (PARA)/kg body wt; or 0.6, 6 or 60 mg phenylhydrazine (PHZ)/kg body wt; and hematologic variables were measured at 0 (non-injected), 24 and 72 hr post-injection. 2. EMS, PARA and PHZ-induced hemolytic anemia began within 24 hr post-injection. 3. Recovery from anemia began within 72 hr post-injection of EMS or PARA, but PHZ injected quail continued to show a marked anemia at that time. 4. EMS and PARA induced lymphocytopenia, monocytopenia and heterophilia, while PHZ induced lymphocytosis, monocytopenia and heteropenia after injection. 5. These results suggest that the anemia induced by EMS and PARA was dissimilar from that induced by PHZ, that all chemicals affected leukopoiesis and that Japanese quail can mount a marked recovery from the hematologic affects of PARA, a widely used herbicide, in a short interval after intoxication.

Anemia, Hemolytic↗
PubMed1988

Effect of adrenocorticotropin and dietary ascorbic acid on the graft-versus-host reaction capacity of chickens.

Two trials using the splenomegaly assay were conducted to assess the effects of adrenocorticotropin (ACTH) and dietary ascorbic acid (AA) on the ability of chickens to mount a graft-vs.-host reaction (GVHR). Broiler chicks served as blood donors. Birds received AA at levels of 0, 150, or 300 mg/kg of feed (ppm). At 6 wk of age, donor birds from each AA group received either three intramuscular injections of ACTH in gelatin at 12-h intervals, comparable injections of the gelatin, or no injections. Thirteen-day-old Single Comb White Leghorn embryos served as recipients. Two recipient embryos per donor were injected in a chorioallantoic vein with either whole blood (Trial 1) or saline-washed and reconstituted blood cells (Trial 1). Eggs were further incubated for 6 days, at which time the embryos were killed and each spleen excised. Relative spleen weights were expressed as milligrams of spleen/100 g embryonic body weight. Significant differences in relative spleen weight or donor plasma corticosterone (CS) levels did not occur in Trial 1. In Trial 2, regardless of AA treatment, relative spleen weights of embryos that received blood cells from donors treated with ACTH were significantly lower than controls. Donor CS was significantly lower in birds that received ACTH. These results indicate that, when washed and reconstituted blood cells are injected into recipients and donor plasma CS is decreased, GVHR capacity is suppressed in ACTH-treated donors.

Adrenocorticotropic Hormone↗
PubMed1988

Effect of cortisol on cutaneous basophil hypersensitivity to phytohemagglutinin in chickens.

Three independent trials were conducted to determine if cutaneous basophil hypersensitivity (CBH) to the mitogen phytohemagglutinin (PHA-P) was affected by the injection of cortisol in broiler cockerels. Trials 1 and 2 were similar, and Trial 3 imposed a period of heat stress in combination with cortisol. At 6 wk of age, chicks were injected intramuscularly with 2 mg of cortisol in a corn oil vehicle/500 g body weight at 48, 36, 24, and 12 h prior to challenge with PHA-P. Controls received an equal amount of corn oil on the same schedule. Each chick received .05 mL of PHA-P (100 micrograms) in the right wattle and an equal volume of saline in the left wattle. The CBH was assessed by measuring the thickness of wattles at various times from 0 to 48 h after challenge with PHA-P. Wattle indices were calculated. Birds were necropsied at 48 h post-PHA-P, and bursa of Fabricius, spleen, and both adrenals excised and weighed. Cortisol produced a significantly greater CBH response in Trials 1 and 2 as indicated by higher wattle indices at 48 h and at 6 h in Trial 3. Regression analysis indicated significantly greater intercepts for the cortisol responses in Trials 1 and 3 and a significantly greater linear component for the cortisol response in Trial 2. Body weights and relative bursa and spleen weights were reduced significantly by cortisol, whereas relative adrenal weights were increased significantly in Trials 2 and 3. These data indicated that cortisol enhanced CBH to the mitogen PHA-P in broiler cockerels. This is in contrast to reported immunosuppressive effects of other glucocorticoids.

Animals↗
PubMed1987

Reproduction of Japanese quail after microwave irradiation (2.45 GHz CW) during embryogeny.

Japanese quail (Coturnix coturnix japonica) embryos were irradiated continuously in ovo with 2.45-GHz continuous wave radiation during the first 12 days of embryogenesis at an incident power of 5 mW/cm2 and a specific absorption rate of 4.03 mW/g. The internal temperature of irradiated and nonirradiated (sham) eggs was 37.5 +/- 0.3 degrees C, which is the optimum temperature for incubating quail eggs. At 35 days after hatching irradiated and sham-irradiated males were paired with irradiated or sham-irradiated females and daily records of reproductive performance were collected through 224 days of age. Progeny were hatched from each of the male-female pairs, and progeny reproductive performance was measured from 35 through 168 days of age. Hatchability was not affected by irradiation during embryogeny. Mortality after hatching, egg production, egg weight, fertility, hatchability of eggs produced, and reproductive performance of the progeny were not affected by irradiation during embryogeny. These observations indicate that irradiation of quail embryos with low-level microwave radiation does not affect the reproductive capacity of the hatchlings or of progeny produced from quail irradiated during incubation.

Animals↗
PubMed1987

Leukocyte numbers in hemorrhaged Japanese quail after microwave irradiation in ovo.

1. Coturnix coturnix japonica eggs were exposed to 2.45-GHz continuous wave microwave radiation at an incident power density of 5 mW/cm2 (and a specific rate of 4 mW/g) during the first 12 days of embryogeny. After hatching, hematological changes in response to an acute hemorrhage were measured in exposed and nonexposed (control) juveniles of both sexes. 2. Exposure did not affect erythroid cell numbers either before or after hemorrhage. 3. Exposure affected the recovery of lymphocyte and heterophil numbers after hemorrhage, but the effect was sex-limited. 4. These data indicate that microwave irradiation during embryogeny in ovo affects the ability of Japanese quail to recover from an acute and voluminous hemorrhage and that these radiation effects are sex-limited and consistent with a previous report.

Animals↗
PubMed1987

Hematological response of hemorrhaged Japanese quail after blood volume replacement with saline.

1. Hematological responses to hemorrhage by phlebotomy with and without replacement of blood volume with saline were measured in juvenile and adult male Coturnix coturnix japonica. 2. Recovery of total peripheral erythrocyte numbers and total peripheral leukocyte numbers occurred within 72 hr postphlebotomy in both treatment groups. 3. Saline replacement of blood volume following hemorrhage increased the total numbers and differential percentages of circulating reticulocytes at 72 hr postphlebotomy above the reticulocyte values of phlebotomized quail receiving no saline in both adult and juvenile Japanese quail.

Animals↗
PubMed1987

Blood volume recovery in hemorrhaged Japanese quail.

1. Blood volume and plasma biochemical changes and feed and water consumption in response to a hemorrhage by phlebotomy of 30% of the calculated total blood volume with and without replacement of blood volume with physiological saline were determined in juvenile male Coturnix coturnix japonica. 2. Plasma protein and osmolality decreased rapidly posthemorrhage and did not recover by 72 hr posthemorrhage. 3. Plasma glucose, Na+ and K+ increased within 1 hr postphlebotomy. Plasma Na+ returned to nonphlebotomized levels within 6 hr postphlebotomy. 4. Saline replacement of blood volume resulted in hypervolemia within 3-5 min postphlebotomy. 5. Phlebotomized quail receiving no saline recovered blood volume to 0 hr (nonphlebotomized) levels within 1 hr postphlebotomy.

Animals↗
PubMed1987

Leukocyte numbers during the humoral and cell-mediated immune response of Japanese quail after microwave irradiation in ovo.

1. Coturnix coturnix japonica eggs were exposed to 2.45-GHz continuous wave microwave radiation at an incident power density of 5 mW/cm2 (SAR = 4 mW/g) during the first 12 days of embryogeny. After hatching, leukocyte differential changes were measured in response to an injection with Alectoris graeca chukar red blood cells (CRBC) and in response to a phytohemagglutinin (PHA) injection in irradiated and nonirradiated (sham) quail of both sexes. 2. Microwave irradiation did not affect anti-CRBC hemagglutinin titers, PHA-evoked dermal swelling or leukocyte numbers and percentages. 3. In both the irradiated and sham irradiated males, lymphocyte percentages decreased while heterophil percentages increased after CRBC or PHA injection. 4. In ovo irradiation with microwaves did not alter the time course of either a humoral immune response or a cell-mediated immune response in Japanese quail.

Animals↗
PubMed1987

Effect of adrenocorticotropin and dietary ascorbic acid on cutaneous basophil hypersensitivity to phytohemagglutinin in chickens.

Two trials were conducted to assess the effects of adrenocorticotropin (ACTH) and dietary ascorbic acid (AA) on cutaneous basophil hypersensitivity (CBH) to phytohemagglutinin (PHA-P) in chickens. Broiler chicks received AA at levels of 0, 150, or 300 mg/kg of feed (ppm) continuous from hatching. At 6 to 7 wk of age, birds from each AA group received either 2 IU ACTH/100 g of body weight, 4% gelatin, or no ACTH or gelatin injections. Injections were given 12 h prior to, at the time of, and at 12 and 24 h after an intradermal wattle injection with PHA-P. Responses to PHA-P were determined as wattle indices. Injections of ACTH reduced body weight gain in both trials and decreased relative bursa weight in Trial 1. Injections of ACTH and dietary AA increased plasma cholesterol in both trials. Peak CBH wattle response occurred at 24 h post PHA-P injection. Injections of ACTH decreased mean wattle index at 18 and 36 h post PHA-P injection in Trial 1 and 18 and 24 h post PHA-P injection in Trial 2. The addition of AA ameliorated the ACTH-mediated suppression of CBH in a dose-related manner.

Adrenocorticotropic Hormone↗
PubMed1987

Effects of adrenocorticotropin and dietary ascorbic acid on delayed type hypersensitivity to human gamma globulin in chickens.

Three trials were conducted to assess the effects of adrenocorticotropin (ACTH) and dietary ascorbic acid (AA) on delayed type hypersensitivity (DTH) to human gamma globulin (HGG) in chickens. Broiler chicks received AA at 0, 150, or 300 mg/Kg of feed (ppm) continuously from hatching, were sensitized at 5 wk of age to HGG emulsified in complete Freund's adjuvant, and 2 wk postsensitization, were challenged with an intradermal injection of HGG into a wattle. Birds from each AA group received ACTH at either HGG sensitization, challenge, or both. There were uninjected controls and a vehicle control group, which received gelatin at both sensitization and challenge. The ACTH and gelatin injections were given at 12-h intervals beginning 12 h prior to HGG. Responses to DTH were determined as wattle indices. In all three trials, birds that received ACTH at challenge exhibited a DTH response at 18 and 24 h postchallenge that suppressed, compared with that of controls. Birds that received ACTH at sensitization had a greater wattle response than that of birds that received ACTH at challenge, and this effect was enhanced by dieting AA. In Trial 2, birds that received ACTH at sensitization had a greater wattle response at 18 h post HGG challenge than that of controls. Total leucocyte numbers were unaffected; however, heterophil:lymphocyte ratios were lower in birds that received ACTH at sensitization than in birds that received ACTH at challenge and birds that received ACTH at challenge had fewer lymphocytes. Whether given at challenge or at sensitization, ACTH decreased plasma AA when measured at those times. The 300 ppm level of AA increased plasma AA concentration. Adrenal gland and wattle AA levels were unaffected; however, spleen AA concentration was lower in birds given ACTH at challenge.

Adrenocorticotropic Hormone↗
PubMed1986

Response of Japanese quail to hemorrhagic stress after exposure to microwave radiation during embryogeny.

Coturnix coturnix japonica eggs were exposed to 2.45 GHz continuous wave microwave radiation at an incident power density of 5 mW/cm2 (SAR = 4 mW/g) during the first 12 days of embryogeny. After hatching, hematologic changes in response to an acute hemorrhage were measured in exposed and nonexposed (control) juveniles and adults of both sexes. Reticulocyte numbers and percentages were depressed below control numbers at 24 hr postphlebotomy in exposed adult females. Lymphocyte numbers were depressed below control levels at 24 hr postphlebotomy in exposed juvenile and adult males. At 72 hr heterophil numbers were depressed in exposed juvenile and adult males. These data suggest that microwave irradiation during embryogeny affects the ability of Japanese quail to recover from an acute and voluminous hemorrhage and that these radiation effects are small.

Aging↗
PubMed1986

Interaction of mercury and water deprivation on the hematology of chickens.

Four-week-old male chickens were subjected to one of the following treatments: 0 ppm mercury (Hg) plus water ad libitum, 0 ppm Hg plus limited water (LW), 500 ppm Hg plus water ad libitum, and 500 ppm Hg plus LW. Exposure was for each of the following time intervals: 0-3, 0-6, 0-9, 0-12, and 0-15 d. LW significantly increased red blood cell (RBC) numbers, hematocrit (HCT), mean corpuscular volume (MCV), and hemoglobin (Hb) level and significantly decreased mean corpuscular hemoglobin (MCH) level within 3 d of treatment. Mercury produced variable results, with no significant trends developing during the treatment period. The effects caused by Hg appeared to be masked by the effects of dehydration. The birds receiving water ad libitum had numerically greater RBC numbers and HCT and Hb levels than birds receiving water ad libitum that was contaminated with Hg, while the effects caused by Hg in the groups that received limited water were not consistent. Each group was given a recovery period of 14 d, during which time all birds received uncontaminated water and feed ad libitum. The hematologic effects caused by Hg and water deprivation did not return to a normal condition. Reduced RBC numbers, HCT, and Hb levels were observed at the end of the recovery period in the birds that were exposed to Hg and/or water deprivation.

Animals↗
PubMed1985

Hematological response of Japanese quail to acute hemorrhagic stress.

Hematological and serum biochemical changes in response to hemorrhagic stress were determined in both sexes of juvenile and adult Coturnix coturnix japonica over 3 day period following a mechanical hemorrhage of 30% of the calculated total blood volume. There was an initial shift posthemorrhage towards greater numbers of more mature erythrocytes and fewer circulating reticulocytes. Reticulocytosis was indicated 48-72 hr posthemorrhage. Glucose and lactic acid dehydrogenase levels increased after hemorrhage. Serum beta-glucuronidase was elevated only in adults. Japanese quail seemed to recover from hemorrhage more rapidly than had been reported for chickens, other birds and mammals.

Aging↗
PubMed1985

Role of ascorbic acid in chicks exposed to high environmental temperature.

This study was conducted to determine if ascorbic acid (AA) 1) increases resistance to high environmental temperature in young chickens and 2) alters heat-induced changes in several physiological responses. Groups of male chicks received either a standard ration containing 1,000 mg/kg (ppm) of AA or the ration without AA. Chicks were brooded for 3 wk and then maintained at 22 +/- 0.8 degrees C. At 4 wk of age, both AA-supplemented and control chicks were exposed to 30 min of heating (43 +/- 0.1 degrees C and 40 +/- 2% rh) on each of 3 consecutive h in an environmentally controlled chamber. Chicks were challenged with sheep erythrocytes (1 ml, 10(5) cells, iv) 12 h postheating. Heating reduced plasma potassium, body weight gain, relative bursa and spleen weights, and anti-sheep erythrocyte levels. Heating increased cloacal temperature, plasma protein, corticosteroid levels, and mortality. AA ameliorated many of these stress-related responses.

Animals↗