thiouracil and Poultry-Diseases

Three experiments were conducted to evaluate the thyroid and adrenal response in groups of birds with altered heat tolerance. Groups of chickens that had been handled on each of 4 days and a nonhandled control group were bled on the 5th day with or without heating for 1 hr at 50 C. Handling did not affect the thyroid response as indicated by thyroxine (T4) or triiodothyronine (T3) levels. Corticosterone levels were lower in handled birds than nonhandled birds after heating. In a second experiment, groups of broilers were fed a diet containing .2% thiouracil or a control diet. After 2 weeks they were bled either with or without 1 hr of heating at 50 C. The T3 and T4 levels were reduced by thiouracil feeding both with and without heating, but adrenal function was not affected. In Experiment 3, T3 and T4 levels were compared for four lines of Japanese quail. The nongrowth-selected line had higher T3 and T4 levels than growth-selected lines but did not have elevated levels of T3 or T4 in response to heat stress. The growth-selected lines (T, S, and P) responded to heating with increased T3 and T4 levels. Levels of T4 in Line T (selected on a thiouracil diet) after heating were significantly higher than all other lines.

Topics: Adrenal Cortex; Animals; Bird Diseases; Chickens; Coturnix; Food Additives; Hot Temperature; Male; Poultry Diseases; Quail; Stress, Physiological; Thiouracil; Thyroid Gland; Thyroxine; Triiodothyronine

Two experiments were conducted to examine the effects of feeding a diet containing .1% thiouracil to two lines of New Hampshire chickens differing in growth rate and relative bursa size. Body weight, serum 3,5,3'-triiodothyronine, and thyroxine were reduced by the thiouracil treatment. The primary total anti-sheep red blood cell (SRBC) titer in Experiment 1 was higher for thiouracil-fed (TF) chicks at 7 days postprimary immunization (PPI). In Experiment 2, the total anti-SRBC titers were higher for control chicks 3 days PPI; but from 5 to 10 days PPI, TF chicks had higher titers. During the secondary response in both experiments, the total anti-SRBC titers were not consistently higher for one dietary group over the other from 3 to 10 days postimmunization. Mercaptoethanol-resistant antibody titers were not significantly different between the two dietary groups in either experiment during the primary and secondary responses. Thiouracil-fed chicks had higher immunoglobulin G (IgG) and M (IgM) concentrations in serum during both the primary and secondary responses in Experiment 2. Although there was no genotype effect on antibody production to SRBC, serum immunoglobulins were different between lines. Small bursa line (SBL) chickens had higher serum IgG while the IgM concentrations of chicks from the Lester J. Dreesen strain were greater than those of SBL.

Topics: Animals; Antibody Formation; Chickens; Hypothyroidism; Immunoglobulin G; Immunoglobulin M; Mercaptoethanol; Poultry Diseases; Thiouracil; Thyroxine; Triiodothyronine

The involvement of the thyroid gland in the response of young chickens to heat stress was studied. Mean survival times when exposed to 50 C were significantly shorter for 3-week-old broiler male chickens injected with 40 micrograms L-thyroxine (T4)/100 g body weight compared to chickens injected with 30, 20, or 0 microgram of T4/100 g body weight. A significant reduction in heat stress survival time was obtained when T4 was injected 12, 18, or 24 hr before heat stress but not 6 hr before. Triiodothyronine (T3) reduced heat stress survival time when administered 12 to 24 hr before the stress but not when given 6 hr before. Chickens made hypothyroid by radiothyroidectomy had significantly longer heat stress survival times than controls. Likewise, chickens fed a diet containing .2% thiouracil 10 days before heat stress at 28 days had significantly longer survival times than control birds.

Topics: Animals; Body Weight; Chickens; Hot Temperature; Male; Poultry Diseases; Stress, Physiological; Thiouracil; Thyroid Gland; Thyroxine; Triiodothyronine

1. Hepatic lipid content, lipogenic enzyme activity and plasma lipid concentration were measured in chicks reared at 21 degrees or 34 degrees C and after thyroxine (T4), thiouracil (TU), propylthiouracil (PTU), dienestrol diacetate (DD) or PTU with DD had been given for 14 d. 2. At 34 degrees C there was a significant increase in the total liver lipid and triglyceride content. 3. Injections of T4 decreased liver lipid content whereas it was increased by feeding PTU or DD. The effects of PTU were more pronounced at 21 degrees C while those of DD were more pronounced at 34 degrees C. 4. There were significant interactions between temperature, thyroid status and synthetic oestrogen treatments on total lipid and triglyceride content of the liver. Fatty liver with marked steatosis could be produced through synergic actions of PTU and DD in chicks maintained at 21 degrees C.

Topics: Animals; Chickens; Dienestrol; Estradiol Congeners; Fatty Liver; Lipid Metabolism; Liver; Male; Poultry Diseases; Propylthiouracil; Temperature; Thiouracil; Thyroid Gland; Thyroxine; Triglycerides

Four lines of White Leghorns previously selected for fast and slow gain from 5 to 9 weeks of age in a hot (32.2 C) and in a cold (21.1 C) selection environment were grown from 5 to 9 weeks in the same two temperature environments. Samples of 32 females from each line of the third generation grown in each temperature environment from 5 to 9 weeks of age were divided into two groups; one received .2% thiouracil in the diet for a 5-day period and the other did not. The temperature was then increased to 40.6 C until 52.8% of all birds had died. The percentages of mortality of lines, rearing environments, and thiouracil treatments were then analyzed. An increase of 64.8% mortality from acute heat stress for birds reared in the cold environment was significant, but the differences among the four selected lines were not. The presence of thiouracil in the diet significantly reduced mortality from heat stress by 16.4%. There were no significant interactions between thiouracil treatments and selected lines or rearing environments.

Topics: Acclimatization; Administration, Oral; Animals; Chickens; Female; Hot Temperature; Poultry Diseases; Stress, Physiological; Temperature; Thiouracil

Adult White Plymouth Rock hens were submitted to a heat shock of 42.2 C. It was demonstrated that .1% thiouracil fed for 4 weeks prior to heat stress significantly increased survival time. Administration of DL-thyroxine administered at the rate of 4 micrograms/100 g body weight injected on day of testing did not alter survival time. However, survival under heat shock was significantly reduced if DL-thyroxine was administered daily for 3 days prior to testing. White Rocks exhibited significantly longer survival time under heat shock than Single Comb White Leghorns, and females of both breeds exhibited significantly longer survival time their male counterparts. Treatment with DL-thyroxine greatly reduced the survival time differences between breeds and sex. The implications of these findings for applied breeding programs are discussed.

Topics: Animals; Chickens; Female; Hot Temperature; Male; Poultry Diseases; Shock; Thiouracil; Thyroxine

The effect of two levels each of methionine (0.0 and 0.07 percent), thiouracil (0.0 and 0.05 percent), dienestrol diacetate (0.0 and 0.007 percent), and thyroactive casein (0.0 and 0.0125 percent) on the performancy, organ changes, and liver composition in 640 pullets of two strains was studied in a 24 factorial arrangement of treatments. Egg production, egg characteristics, feed conversion, organ weights, and liver composition were parameters measured. Supplemental methionine increased the phosphorus content of liver fat in strain A, but other parameters in the two strains were mot affected by the increase in dietary methionine. The thiouracil increased weight grains, gram of fat per total liver, percent of liver fat, thyroid weight, and heart weight but decreased the phosphorus content of liver fat. Nine typical cases of fatty liver syndrome with large liver hematomas occurred in the thiouracil treated birds and one case occurred in an untreated pullet. Dienestrol diacetate did not affect egg production, egg characteristics, organ weights, and liver composition in the two strains. Thyroprotein decreased weight gain, abdominal fat, liver weight. liver fat, thyroid weight, and percent red cells, but decreased percent blood sports in eggs and adjusted weights of the kidney and heart in both strains.

Topics: Adipose Tissue; Animal Feed; Animals; Caseins; Chickens; Dienestrol; Eggs; Fatty Liver; Female; Hematoma; Hemorrhage; Iodoproteins; Lipid Metabolism; Liver; Liver Diseases; Methionine; Phenols; Phosphorus; Poultry Diseases; Syndrome; Thiouracil

Topics: Animal Feed; Animals; Body Weight; Dietary Proteins; Drug Resistance; Hot Temperature; Poultry Diseases; Quail; Selection, Genetic; Stress, Physiological; Thiouracil

Topics: Administration, Oral; Animal Feed; Animals; Cestode Infections; Chickens; Hemoglobins; Hyperplasia; Hypertrophy; Hypothyroidism; Leukocyte Count; Lipids; Poultry Diseases; Thiouracil; Thyroid Gland

Topics: Administration, Oral; Animal Feed; Animals; Body Weight; Chickens; Escherichia coli Infections; Male; Organ Size; Oxygen Consumption; Poultry Diseases; Thiouracil; Thyroid Gland; Thyroxine

Topics: Animal Feed; Animals; Chickens; Dietary Proteins; Poultry Diseases; Thiouracil; Thyroxine; Vitamin A; Vitamin A Deficiency