The effect of 5-fluorouracil treatment of chicks: a cell depletion model for the study of avian polymorphonuclear leukocytes and natural host defenses.

Two-week-old Leghorn chicks injected intravenously with 5-fluorouracil (5-FU) were found to have a three- to fivefold reduction (P < .05) in circulating polymorphonuclear leukocytes (PMN) 5 to 10 days later. The reduction in PMN was dose-dependent with a dosage of 200 mg/kg body weight of 5-FU, causing suppression of PMN to almost undetectable levels.

Immunoprophylaxis of Salmonella enteritidis infection by lymphokines in Leghorn chicks.

Chickens were treated prophylactically with the soluble products from Con A-stimulated T-lymphocytes from Salmonella enteritidis-infected chickens in order to investigate the effect of such prophylactic treatment on organ invasion by S. enteritidis. At 18 days of age, chicks were injected intraperitoneally with one of the following: A) the Amicon YM 10 ultrafiltrate from immunized chickens, B) the Amicon YM 10 ultraretentate material from immunized chickens, or C) the Amicon YM 10 ultraretentate material from control nonimmune chickens.

Genus-specific detection of salmonellae using the polymerase chain reaction (PCR).

Oligonucleotide primers for the polymerase chain reaction (PCR) that enable genus-specific detection of members of the genus Salmonella were developed. The primers amplify a 496-bp genetic sequence of members of the genus Salmonella. Amplification of DNA extracted from all other genera of the family Enterobacteriaceae and various other gram-positive aerobic and anaerobic bacteria yielded negative results.

Development of defined cultures of indigenous cecal bacteria to control salmonellosis in broiler chicks.

An in vitro continuous-flow (CF) culture system was utilized to isolate and maintain a defined mixed culture of indigenous cecal bacteria from adult broilers. The protective effects of the defined CF culture and dietary lactose on Salmonella typhimurium colonization were evaluated in broiler chicks. The CF culture was administered to chicks by crop gavage on the day of hatch.

Research note: differential chemotaxis of Physarum polycephalum to Salmonella gallinarum and Salmonella pullorum.

The chemotactic and chemotropic responses of the plasmodial stage of the slime mold Physarum polycephalum were used to distinguish Salmonella gallinarum and Salmonella pullorum from 10 Salmonella serovars that are commonly isolated from domestic poultry. Utilizing an in vitro plasmodium agar plate assay method, P. polycephalum was attracted to S.

Effect of dietary lactose on cecal morphology, pH, organic acids, and Salmonella enteritidis organ invasion in Leghorn chicks.

The effect of 14 or 19 days of 10% dietary lactose administration on Salmonella enteritidis (SE) colonization and histological, morphometric, and organic acid changes of the ceca were investigated. At Day 13 or 18, chicks were challenged with 10(8) cfu of SE. Chicks were killed and cultured 24 h later.

Effect of ascorbate on luteinizing hormone stimulated progesterone biosynthesis in chicken granulosa cells in vitro.

1. Utilizing hen granulosa cells from the two largest (F1 and F2) follicles, we have examined the effect of sodium ascorbate (AS) on luteinizing hormone (LH) stimulated progesterone (PR) biosynthesis. 2.

Alterations in thyroid metabolism are associated with improved posthatch growth of chickens administered bovine growth hormone in ovo.

Effects of in ovo administration of growth hormone (GH) on growth and thyroidal function of chickens were investigated in two experiments. In Experiment 1, fertile eggs were injected on day 11 of embryogenesis with vehicle (0.03 M NaHCO3, 0.

Protective effect of used poultry litter and lactose in the feed ration on Salmonella enteritidis colonization of leghorn chicks and hens.

The effect of dietary administration of lactose and used poultry litter, containing cecal and fecal droppings from adult broilers, was evaluated for protective effects against Salmonella enteritidis colonization in leghorn chicks and 16-week-old hens. The addition of used litter as 5% of the feed ration significantly decreased (P < 0.01) Salmonella cecal and organ colonization in the chicks.

Effect of prolonged administration of dietary capsaicin on Salmonella enteritidis infection in leghorn chicks.

The effect of 14 or 19 days of dietary capsaicin (18 ppm) on Salmonella enteritidis infection and histological, morphometric, and pH changes of the ceca was investigated. At day 13 or day 18, chicks were challenged with 10(8) colony-forming units of S. enteritidis.

Detection and partial characterization of an anti-steroidogenic peptide from the humoral immune system of the chicken.

Phenomenological association of alterations of immune system function at the time of puberty (e.g. involution of the chicken bursa of Fabricius) has led to postulation that the humoral immune system may negatively affect the hypothalamo-adenohypophyseal-gonadal axis of the neonate.

Research note: effect of in ovo 17-beta-estradiol or tamoxifen administration on sexual differentiation of the external genitalia.

The effect of in ovo administration of tamoxifen or 17 beta-estradiol on external sexual dimorphism in chickens was investigated. In two trials, fertile eggs were injected with either tamoxifen (200 micrograms per egg) or vehicle (100 microL corn oil) on Day 1 of incubation, or with 17 beta-estradiol (20 micrograms per egg) or vehicle on Day 11 of incubation. Sexes were determined by visual inspection of the external genitalia and by gonadal identification at Day 1 posthatch.

Intraosseous infusion using the osteoport implant in the caprine tibia.

We evaluated the in vivo animal tolerance to intraosseous infusion via the Osteoport pediatric implant (model 2005PSO, Lifequest Medical, San Antonio, TX, U.S.A.

Effect of used litter from floor pens of adult broilers on Salmonella colonization of broiler chicks.

The effect of used pine-shaving litter from broiler floor pens on Salmonella colonization resistance was evaluated in broiler chicks. One-day-old chicks were placed in floor pens on fresh unused litter or on used litter. All chicks were challenged orally with 10(4) S.

Effect of nitrofurazone or novobiocin on Salmonella enteritidis cecal colonization and organ invasion in Leghorn hens.

Nitrofurazone (433 mg/liter drinking water) administration to leghorn laying hens for 72 hours with a 48-hour withdrawal period before nitrofurazone-sensitive Salmonella enteritidis challenge resulted in a S. enteritidis culture-positive rate significantly (P less than 0.05) higher than that of unmedicated controls when hens were cultured 6 days following challenge.

Evaluation of vectorelectrocardiographic analysis of young broiler chickens as a predictive index for susceptibility to ascites syndrome.

Vectorelectrocardiographic (VCG) analysis was performed on 50 male broiler chicks (1 week of age) before placement in a hypobaric chamber. During 5 weeks of exposure to hypobaric hypoxia (simulated altitude of 2900 m), all recorded mortality (38%) was due to the development of ascites syndrome. There was a positive correlation (r = 0.

Use of electrocardiographic analysis for investigation of ascites syndrome in broiler chickens.

This study was conducted (at high altitude [1969 meters]) to determine whether chicks predisposed to cardiac failure and ascites could be identified and followed during growout with non-invasive electrocardiographic (ECG) techniques. ECG recordings were made on 40 chicks at 1 week of age. All recordings were analyzed by quantifying the amplitude in millivolts of the R-, S-, and T-waves in each of the recordings.

Characterization of dissimilar steroid productions by granulosa, theca interna and theca externa cells during follicular maturation in the turkey (Meleagris gallopavo).

Unlike the established models for steroidogenesis in the rat and human, we have previously demonstrated that in the turkey progesterone (P), androgen (A), and estrodiol (E) are primarily produced by the granulosa, theca interna, and theca externa cells, respectively. In the present study, experiments were conducted to further characterize steroid productions by these cell types during follicular maturation. In Experiments 1 and 2, granulosa cells and theca internal cells, respectively, from the larger (F1) and fifth largest (F5) preovulatory follicles were incubated (1 x 10(5) cells/ml) with ovine luteinizing hormone (oLH) or porcine follicle stimulating hormone (pFSH) for 5 hr.

Ovarian steroid production in vitro during gonadal regression in the turkey. II. Changes induced by forced molting.

In the turkey, the onset of incubation behavior is associated with altered ovarian steroidogenesis, ovarian regression, decreased, LH secretion, and increased serum prolactin (Prl) levels. To clarify the relative contribution of circulating LH and Prl to the initiation of ovarian regression, laying hens were exposed for 0, 3, 7, or 14 days to a forced molting procedure (exposure to reduced day length of 6L:18D and removal of feed and water for the initial 3 days) that induces ovarian regression and decreased LH levels but does not increase Prl levels. On each of these days, hens were killed and granulosa and theca interna cells from the largest (F1) and fifth largest (F5) preovulatory follicles and total cells from the small white follicles (SWF) were incubated for 5 h in the presence or absence of ovine LH (oLH; 0-1,000 ng/ml).

Effects of zinc toxicity on thyroid function and histology in broiler chicks.

Mechanisms of zinc (Zn) toxicity are incompletely understood and data regarding potential endocrine alterations in Zn toxicity are scarce. To examine mechanisms of Zn toxicity, day-old chicks were pair-fed diets containing 5280 ppm (Hz) or 73 ppm (CON) Zn. Impaired postnatal growth, independent of feed consumption, and multiple endocrinopathies were observed following short-term (1-2 weeks) exposure to the high Zn diet.

Effect of anaerobic cecal microflora and dietary lactose on colonization resistance of layer chicks to invasive Salmonella enteritidis.

The effect of oral inoculation with anaerobic cultures of cecal microflora and providing lactose in the feed on colonization resistance to invasive Salmonella enteritidis was evaluated in newly hatched leghorn chicks. Salmonella colonization of the ceca, tissue invasion and organ colonization, horizontal transmission, and seroconversion were significantly decreased (P less than 0.01) in chicks inoculated with cecal flora.

Dietary modification of yolk lipid with menhaden oil.

Due to the numerous proposed cardiovascular benefits associated with consumption of omega-3 fatty acids, marketing of an egg enriched by omega-3 fatty acid may benefit the egg producer. Effects on yolk composition of a standard laying hen diet enriched with 3% menhaden oil (test diet), versus an isocaloric (control) diet containing no added fat, were evaluated for 18 wk. Dietary menhaden oil did not alter egg production, egg weight, total yolk fat, or yolk cholesterol.

Identification of two lipid binding proteins from liver of Gallus domesticus.

1. Two low molecular weight (approximately 14,000 Da) proteins exhibiting lipid binding activity were purified from liver cytosol and identified as non-specific lipid binding protein (ns-LTP) and fatty acid binding protein (L-FABP). 2.

Isolation and characterization of a fatty acid binding protein in adipose tissue of Gallus domesticus.

1. Fatty acid binding protein (A-FABP) was isolated from chicken adipose cytosol. 2.

Thermal stress reduces serum luteinizing hormone and bioassayable hypothalamic content of luteinizing hormone-releasing hormone in hens.

Studies were conducted to evaluate the effects of acute (24 h) thermal stress on anterior pituitary function in hens. Circulating levels of luteinizing hormone (LH) were measured and the ability of the pituitary to respond to luteinizing hormone-releasing hormone (LHRH) challenge was determined. Moreover, bioassayable hypothalamic LHRH content was assessed by using dispersed anterior pituitary cells.