Modification of the lipid profile and antioxidant status of the blood plasma of turkey hens fed mixtures with raw or extruded linseed.

The aim of the study was to determine the most beneficial proportion of raw linseed in complete feed mixtures for turkey hens on the basis of lipid and redox indicators in the blood. In experiment 1, the turkey hens received the complete mixture with 2%, 4% or 6% linseed. On the basis of the results obtained in experiment 1, we selected the most effective proportion of linseed, which was given to the birds in the group receiving a 4% linseed additive. In experiment 2, the birds were fed mixtures with a 4% addition of raw or extruded linseed. The use of 4% raw linseed was found to improve production effects (improvement of weight gain, and lower feed conversion ratios), while extruded linseed in the diet of turkey hens did not affect growth performance. The use of linseed (4% and 6%) as a feed component for turkey hens led to an increase in indicators of antioxidant potential, that is the total antioxidant potential of the plasma, vitamins E and C, bilirubin and creatinine. A benefit resulting from the use of linseed, particularly in the amounts of 2% and 4% was a marked improvement in lipid indicators in the blood. The reduced percentage of unsaturated fatty acids (n-3) following the use of extruded linseed resulted in a decrease in lipid peroxidation (lower content of malondialdehyde, superoxide and vitamins C and E in the blood). The most effective dose and form of linseed in the diet of turkey hens is 4% raw linseed.

A comparison of Mott cell morphology of three avian species. II. - Bad behavior by plasmacytes?

Mott cells are atypical plasmacytes recognized microscopically by endoplasmic reticulum (ER) distensions (Russell bodies) a result of retained secretory product (antibody). Originally associated with parasitism, they are observed in a broad spectrum of immunopathology, sometimes involving hypergammaglobulinemia. Few descriptions of Mott cells appear in avian literature. The purpose of the manuscript is to provide examples identified by light microscopy in three poultry species. Transmission electron micrographs (TEM) of plasmacytes from the turkey oviduct mucosa are included for comparison with Mott cell light microscopic images. Wright's stained blood and bone marrow from commercial and specific pathogen free (SPF) chickens, ducks, and turkeys are the sources. Mott cell positive samples commonly occurred with leukocytosis or leukemoid reactions, polymicrobial bacteremia, and fungemia. Atypical granulocytes and leukocytes regularly accompanied Mott cells. It is proposed that circulating Mott cells are "sentinels" indicative of stress, dyscrasia, and pathology. Moreover, Mott cells, like other atypia, complicate the interpretation of simple heterophil/lymphocyte (H/L) ratios. As Mott cells are defective plasmacytes these observations address hematology, immunology, pathology, and welfare issues.

Antioxidant status of blood and liver of turkeys fed diets enriched with polyunsaturated fatty acids and fruit pomaces as a source of polyphenols.

It was hypothesized that dietary polyphenol-rich fruit pomaces can improve the antioxidant status of both diets and the tissues of turkeys fed such diets. Turkeys were fed diets containing a cellulose preparation (C) or 5% dried apple pomace (AP), blackcurrant pomace (BCP), strawberry pomace (SP) and seedless strawberry pomace (SSP). Blood and liver biochemical parameters were determined in 7 birds from each experimental group slaughtered at 15 weeks of age, after 5 weeks of feeding diets containing soybean oil and linseed oil (approx. 1:1 ratio). Dietary linseed oil added to diets at 2.5% lowered the n-6/n-3 PUFA ratio from approx. 7:1 to below 2:1, thus reducing the antioxidant properties of diets measured using DPPH, ABTS and photo-chemiluminescence assays, compared with diets containing only soybean oil and administered to birds in the first phase of feeding. Fruit pomaces, in particular SSP with the highest polyphenol content (32.81 g/kg) and the highest antioxidant activity (256.4 µM Trolox/g), increased the antioxidant capacity of turkey diets. In comparison with the control group, the dietary treatments with fruit pomaces improved blood antioxidant parameters, including catalase activity (groups AP and BCP), the total antioxidant capacity of hydrophilic (group AP) and lipophilic (groups AP, SP, and SSP) compounds, peroxide levels (groups AP and SSP) and antioxidant capacity measured by the FRAP (ferric reducing antioxidant power of plasma) assay (groups AP, BCP and SSP). Significantly lower concentrations of both vitamin E and thiobarbituric acid reactive substances (TBARS) were noted in the livers of turkeys fed all diets with dried fruit pomaces.

Antioxidant status of turkey breast meat and blood after feeding a diet enriched with histidine.

The objective of this study was to investigate the effects of 1) spray dried blood cells rich in histidine and 2) pure histidine added to feed on the antioxidant status and concentration of carnosine related components in the blood and breast meat of female turkeys. The experiment was performed on 168 Big7 turkey females randomly assigned to 3 dietary treatments: control; control with the addition of 0.18% L-histidine (His); and control with the addition of spray dried blood cells (SDBC). Birds were raised for 103 d on a floor with sawdust litter, with drinking water and feed ad libitum. The antioxidant status of blood plasma and breast muscle was analyzed by ferric reducing ability (FRAP) and by 2,2-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging ability. The activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) was analyzed in the blood and breast meat, with the content of carnosine and anserine quantified by HPLC. Proximate analysis as well as amino acid profiling were carried out for the feed and breast muscles. Growth performance parameters also were calculated. Histidine supplementation of the turkey diet resulted in increased DPPH radical scavenging capacity in the breast muscles and blood, but did not result in higher histidine dipeptide concentrations. The enzymatic antioxidant system of turkey blood was affected by the diet with SDBC. In the plasma, the SDBC addition increased both SOD and GPx activity, and decreased GPx activity in the erythrocytes. Feeding turkeys with an SDBC containing diet increased BW and the content of isoleucine and valine in breast muscles.

DIAGNOSING LYMPHOPROLIFERATIVE DISEASE VIRUS IN LIVE WILD TURKEYS (MELEAGRIS GALLOPAVO) USING WHOLE BLOOD.

Lymphoproliferative disease virus (LPDV) is a retrovirus that infects wild and domestic turkeys ( Meleagris gallopavo ). The first cases of LPDV in the United States were diagnosed in 2009, and subsequent surveillance has revealed the virus to be widespread in wild turkey populations throughout the eastern half of the country. More research is needed to determine whether LPDV is having a negative effect on turkey populations, but progress has been impeded by the lack of a simple method for diagnosing the virus in living birds. Infected animals may appear asymptomatic, and diagnostics currently rely on tissue or bone marrow, which can be difficult to obtain. This study investigated the reliability of polymerase chain reaction (PCR) to detect LPDV in whole blood, compared with previous methods using buffy coat (concentrated white blood cells) and bone marrow. Paired samples of whole blood and buffy coat were collected from 137 live turkeys and paired samples of whole blood and bone marrow were collected from 32 turkeys postmortem. Compared with buffy coat, whole blood had 97% sensitivity and 100% specificity. When compared with bone marrow, whole blood had 100% sensitivity and 89% specificity. Both comparisons had a high degree of agreement using Cohen's kappa statistic. Based on these results, PCR of whole blood provides detection of LPDV in living birds that is on par with both buffy coat and bone marrow.

Use of Deslorelin Acetate Implants to Mitigate Aggression in Two Adult Male Domestic Turkeys (Meleagris gallopavo) and Correlating Plasma Testosterone Concentrations.

Two adult, male domestic turkeys were treated with implants of deslorelin acetate, a gonadotropin-releasing hormone agonist, to reduce intermale aggression and aggression directed toward the animal care team at a zoologic institution. The turkeys were manually restrained and either two 4.7-mg or two 9.4-mg implants were placed within the pectoral musculature on 3 occasions over the course of approximately 1.5 years. Plasma testosterone concentrations were measured by radioimmunoassay every 2 weeks for the first month after a new implant placement and then monthly thereafter. Testosterone concentrations remained low and aggressive behavior was decreased for a period of several months after implant placement. At necropsy of both birds, no adverse gross or histologic lesions were noted at the implantation sites in the pectoral musculature or within the gonadal tissue. Deslorelin acetate implants are a treatment modality to consider for mitigation of aggression in male domestic turkeys.

The effect of yeast Yarrowia lipolytica on the antioxidant indices and macro-and microelements in blood plasma of turkey hens.

The aim of the study was to assess the effect of different amounts of Yarrowia lipolytica yeast on the redox response and content of macro- and microelements in the blood plasma of turkey hens. The experiment was carried out on 240 turkey hens aged from 1 to 16 weeks. The birds were randomly assigned to 3 experimental groups of 80 birds each. Group I served as a control (K) and did not receive any experimental compounds. The turkey hens from the experimental groups (YL3 and YL6) were administered dried Yarrowia lipolytica yeast in their feed mixtures in the amount of 3% (YL3) or 6% (YL6). Yarrowia lipolytica yeast in the feed mixtures for the turkey hens did not induce oxidation reactions in the organism of the birds. However, an increase in catalase activity and a reduction in the level of LOOH, MDA and vitamin C were observed in the blood plasma of the turkey hens whose diet was supplemented with YL yeast. In the case of other indices, such as superoxide dismutase activity and total antioxidant potential (FRAP), the additive caused no significant changes. Administering Yarrowia lipolytica yeast to turkey hens may stimulate the enzymatic response of the antioxidant system (e.g. increasing catalase activity), mainly by increasing the concentration of iron in the plasma.

Vasoactive intestinal peptide and its role in continuous and seasonal reproduction in birds.

Native Thai chicken, an equatorial species breeds throughout the year, whereas turkeys are seasonal temperate zone breeder whose reproductive cycle is terminated by the onset of photorefractoriness. This study investigated VIPergic activity throughout a reproductive cycle in both species, hypothesizing that the differential expression of vasoactive intestinal peptide (VIP) would provide an insight into the differing reproductive strategies of the two species. Distribution of VIP neurons in the native Thai chicken and a comparison of VIPergic activity in the nucleus inferioris hypothalami (IH) and nucleus infundibuli hypothalami (IN) were investigated. VIP immunoreactivity was found throughout the native Thai chicken brain, predominantly located within the IH-IN. The pattern of VIP distribution in the native Thai chicken supports the findings reported in temperate zone species. Unlike the turkey, where there is a dissociation between VIPergic activity and prolactin levels during photorefractoriness, in the native Thai chicken, which do not express photorefractoriness, changes in VIP immunoreactive (VIP-ir) neurons within the IH-IN were directly correlated with prolactin throughout the reproductive cycle. VIPergic activity reached its lowest level after hatching of the chicks in the native Thai chicken, while in the turkey VIPergic activity was lowest only after exposure to a short day photoperiod and the acquisition of photosensitivity. This suggests that VIP neurons in the IH-IN may play a pivotal role in regulating the reproductive cycle and its differential expression following hatching of the young may, in part, account for the difference in reproductive mode between equatorial, continually breeding, non-photoperiodic birds and seasonally breeding, photoperiodic birds.

Ornithine alpha-ketoglutarate increases mineralization and mechanical properties of tibia in turkeys.

Skeletal disorders in rapidly growing poultry are commonplace. This study was performed to investigate the effect of ornithine alpha-ketoglutarate (OKG) administration during the last 7 weeks of life on structural properties, mineralization, and mechanical endurance of skeleton in turkeys at slaughter. Healthy HB Medium Bronze female turkeys were randomly assigned to two weight-matched groups at the age of 12 weeks. OKG was administered orally to the experimental group (N=17) at the dose of 0.4 g/kg body weight per day, while the control group (N=16) received an equal dose of the vehicle. The turkeys were slaughtered at the age of 19 weeks and the tibiae were isolated for analysis. The effect of OKG on skeletal system development in turkeys was evaluated in relation to both geometrical and mechanical properties as well as quantitative computed tomography (QCT). Free amino acids concentrations were assessed with the use of ion-exchange chromatography. Significantly increased bone mineral density of the trabecular and the cortical bone of tibia in the turkeys given OKG for the last 7 weeks of production cycle were observed (P<0.05). OKG administration improved mechanical endurance of the tibia estimated by the three-point bending test (P<0.01). Plasma amino acid analyses showed increased level of aspartate, proline, alanine, valine, isoleucine, leucine, and ornithine (all P<0.05) after OKG treatment, whereas cystathionine concentration was decreased (P=0.03). Obtained results indicate that oral OKG administration has beneficial effects on skeletal development in fast growing turkeys and this effect is connected with increased amino acid synthesis. These observations may serve to improve skeletal properties in birds, especially when considering that skeletal disorders often affect the tibia and the proper function of the skeletal system plays an essential role in animal welfare and poultry production.

Duration of the reproductive period decreases the frequency of preovulatory luteinizing hormone surges in heavy weight-sire line turkey hens.

The frequency of preovulatory luteinizing hormone (LH) surges is an important determinant of ovulation and oviposition rates in turkeys. Egg production rate is relatively poor in heavy weight-sire line type turkey hens and declines with advancing duration of the reproductive period. The purpose of this study was to measure frequency and characteristics of preovulatory LH surges in turkey hens of a heavy weight-sire line type early, at peak of egg production (Early), and late, after egg production rate had declined (Late), in a reproductive period. The Early hens were photostimulated with a continuous photoperiod [24 h light (L):0 h dark (D)] at 40 weeks of age and sampled during peak egg production at about 47 weeks of age. The Late hens were photostimulated at 40 weeks of age with a long day photoperiod (14L:10D). After a 27-week egg production period, the Late hens were switched to the 24L:0D photoperiod and sampled at 74 weeks of age. Continuous lighting was used during blood sampling to allow the rhythm of preovulatory LH surges to free run. All hens were cannulated 3-5 days before starting sampling and hourly blood samples were collected for 200 h. All hens were necropsied and ovarian and oviductal morphologies were measured after serial bleeding. The Late hens had a longer interval between intra-clutch preovulatory LH surges than the Early hens, and a higher incidence of atretic ovarian follicles. The Early hens had higher baseline and surge amplitude LH concentrations but lower progesterone (P4) surge amplitude concentrations than the Late hens. The duration of preovulatory LH surges, incidence of "blind" preovulatory LH surges, baseline P4 concentrations, and overall estradiol-17beta (E2) concentrations were not different between Early and Late hens. In conclusion, a longer interval between preovulatory LH surges, lower LH baseline and surge amplitude concentrations, a higher incidence of atretic follicles, and higher P4 surge amplitude concentration were associated with the decline in egg production late in the reproductive period in a heavy weight-sire line of turkey hens.

The relative importance of vasoactive intestinal peptide and peptide histidine isoleucine as physiological regulators of prolactin in the domestic turkey.

In mammals, prolactin (PRL) secretion is regulated by vasoactive intestinal peptide (VIP) and peptide histidine isoleucine (PHI). In birds, however, VIP is considered a PRL-releasing factor (PRF), while the role of PHI is unknown. The purpose of this study was to compare the effects of turkey PHI (tPHI) and turkey VIP (tVIP) on PRL secretion in vitro, and to study their physiological significance in vivo through active immunization against tPHI and tVIP. In vitro studies were conducted using pituitary cell cultures from female turkeys. In the in vivo study, female turkeys were immunized with keyhole limpet hemocyanin (KLH; control), synthetic tPHI conjugate (KLH-tPHI), or synthetic tVIP conjugate (KLH-tVIP). Both tVIP and tPHI stimulated PRL secretion from anterior pituitary cells in a dose response manner. However, tPHI was 100-fold less potent than tVIP in stimulating maximum PRL secretion in vitro. In addition, the highest dose (10(-4) M) of tPHI inhibited its own PRL-releasing activity as well as that of VIP-stimulated PRL release. Whereas, circulating PRL levels and nesting activity remained low and unchanged during the photo-induced reproductive cycle (i.e., experimental period) in tVIP-immunized birds, control and tPHI-immunized turkeys showed a significant increase in plasma PRL levels and in the incidence of incubation behavior over time following photostimulation. These findings, taken together with earlier results, indicate that VIP is the sole physiological PRF in the turkey (avian species).

Fumonisin and beauvericin induce apoptosis in turkey peripheral blood lymphocytes.

Fumonisins, a family of mycotoxins produced by Fusarium verticillioides (synonym Fusarium moniliforme Sheldon) and F. proliferatum, have been associated with various deleterious effects in different animal species. Serological, hematological and pathological effects and mortality have previously been observed in broiler chicks fed F. proliferatum culture material containing known concentrations of fumonisin, moniliformin and beauvericin. Turkey peripheral blood lymphocytes were exposed in vitro for 72 hours to fumonisin B1 (FB1), fumonisin B2 (FB2), hydrolyzed fumonisin B1 (HFB1), moniliformin and tricarballylic acid (TCA) (0.01-25 microg/ml). A decrease in cell proliferation, as determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] bioassay, occurred in the order: FB2 > FB1 > HFB1, with IC50 = 0.6 microM, 1 microM and 10 microM, respectively. Internucleosomal DNA fragmentation and morphological features characteristic of apoptosis were observed following exposure to fumonisin B1 and beauvericin; cytoplasmic condensation and membrane blebbing were seen by light microscopy. Tricarballylic acid and moniliformin did not interfere with cell proliferation. Results suggested that fumonisin B1 and beauvericin may affect immune functions by suppressing proliferation and inducing apoptosis of lymphocytes.

Concentration change patterns of luteinizing hormone and progesterone and distribution of hierarchical follicles in normal and arrested laying turkey hens.

Young photosensitive turkey hens of a line selected for increased egg production (Egg line) were photostimulated with constant light [24 h light:0 h darkness] at 30 wk of age. Egg laying became arrested in 6 of 12 the hens after only 2 to 3 wk of laying. Ovarian morphology and changes in concentrations of plasma hormones [luteinizing hormone (LH), progesterone (P4), and estradiol-17beta (E2)] over 10 d of serial bleeding were compared between the arrested laying and normal laying hens. The number of ovarian follicles heavier than 1.0 g was much greater in arrested laying hens, and some of the arrested laying hens presented a polycystic ovarian follicle condition. The oviducts of the arrested laying hens were fully developed and were similar in weight to those of normal laying hens. In arrested laying hens the plasma concentration of LH was relatively low (1.72 +/- 0.30 ng mL(-1)) and without preovulatory surges. In normal laying hens the baseline concentration of LH was 2.60 +/- 0.71 ng mL(-1), and the interval between LH surges was 26.8 h. In the arrested laying hens, the plasma concentration of P4 was relatively high (4.66 +/- 1.28 ng mL(-1)) and without preovulatory surges. In normal laying hens the baseline concentration of P4 between surges was 1.76 +/- 0.24 ng mL(-1). Plasma E2 concentrations were not different between normal laying and arrested laying hens. In conclusion, ovulations and ovipositions ceased in the arrested laying hens, but the entrance of follicles into the follicular hierarchy and hierarchical growth continued, leading to an accumulation of numerous mature follicles in the ovary. In addition, some of the accumulated mature follicles might have resumed growing, leading to the formation of cystic ovarian follicles.

Comparison of gonadal hormone levels in turkey embryos incubated in long-term shell-less culture and in ovo.

Changes in concentrations of 17beta-estradiol (E2) and androgenic hormones were measured in turkey embryos incubated in long-term, shell-less culture (ex ovo) and in ovo. Blood samples were obtained from both sets of embryos on Days 14, 16, 18, 20, and 22 and from embryos incubated in ovo on Days 24, 26, and 28. Ex ovo and in ovo embryos showed no differences in either hormone within sexes, with one exception. On Day 14 of incubation, the ex ovo females had higher (P < 0.05) E2 levels (55.6+/-5.1 pg/mL) than the in ovo females (32.2+/-2.3 pg/mL); however, this result might have been due to the small sample size (n = 3) for ex ovo females. No significant differences were found in androgen concentrations between sexes in ovo on Days 24, 26, and 28 of incubation. However, on Days 24, 26, and 28, in ovo females showed highly significant differences (P < 0.01) in E2 compared with males of the same age. These results indicate a similar developmental pattern for the endocrine system in ovo and ex ovo through Day 22 of incubation. Further, there were sex differences in E2 that are likely to be critical for sexual differentiation that emerges late in embryonic development.

Are P2Y1 purinoceptors expressed in turkey erythrocytes?

Since the beginning of purinoceptor research turkey erythrocytes have been widely used as the model systems for studying the pharmacology of P2Y1 nucleotide receptors. In this report the statistical analysis of the activity parameters of several purinoceptor agonists and antagonists in the turkey erythrocytes and P2Y1 receptor transfected cells is presented. As a results of this analysis several differences in the ligand activity orders measured in these biological systems were found. These data indicate that the receptors expressed in turkey erythrocytes and P2Y1 transfected cells are probably not the same. Whether it has to do with co-expression of several purinoceptor subtypes in turkey erythrocytes or novel P2Y receptors needs the further investigation.

LH responses to chicken luteinizing hormone-releasing hormone I and II in laying, incubating, and out of lay turkey hens.

An experiment was conducted to assess the relative in vivo and in vitro activities of chicken LH-RH-I and -II in laying, incubating and out-of-lay turkey hens. The highest plasma concentrations of LH were measured in laying turkey hens, whereas hypophyseal concentrations were highest in incubating hens (I) and lowest in the laying hens at the end of the laying period (EL). Hypophyseal and plasma concentrations of LH decreased with aging in laying hens (L) and the greater decrease occurred in the hypophyses. An in vitro hypophyseal acute challenge with 2-min pulses of cLHRH I or II (10(-7) M) using a perifusion technique resulted in an increase in the release of LH in out-of-lay (OL) and incubating (I) hens, but not in laying (L) hens. Although both peptides elicited comparable responses in I hens, cLHRH II was more effective in OL hens. This difference was attributable to a greater amplitude of the response, whose duration was unchanged. Hypophyseal desensitization to a subsequent stimulation was observed in OL hens when the interval between stimulations was 30 min, but this did not occur at 60- or 120-min intervals. In vivo, the injection of cLHRH I or II, at doses of 10(-8) and 10(-10) M/kg B.W. stimulated increases in the plasma concentrations of LH, which were initiated within 1 min of injection in OL and I hens but from 5 to 20 min postinjection in L hens. The responses were dose-related and greater immediate responses were measured with cLHRH I than with cLHRH II. Also, after the injection of cLHRH II at the 10(-8) M/kg B.W. dose, the shape of the LH response consisted of an initial increase, followed by a more sustained phase during which LH concentrations were either stable (I hens) or continued to increase (L and OL hens) from 20 to 60 min after injection. In contrast, the injection of cLHRH I at doses of 10(-8) or 10(-10) M/kg or cLHRH II at a dose of 10(-10) M/kg in I and OL hens, produced a peak of LH concentrations in plasma within 5 min and thereafter declined gradually. The difference in the in vivo responses to LHRH I and II could not be attributed to a greater potency of cLHRH II, but to a more prolonged action. In summary, the responses to both forms of chicken LH-RH varies markedly with the stage of the reproductive cycle (L, I, and OL) and differs between the in vivo and in vitro situations. Although cLHRH II may be more active than cLHRH I, controversy still surrounds its precise physiological role.

Fluorescein isothiocyanate staining and characterization of avian heterophils.

Fluorescein isothiocyanate (FITC) was found to stain cytoplasmic granules of avian heterophilgranulocytes. In tissue sections, the fluorescent granulocytes were predominantly distributed adjacent to trabecular bones. The fluorescein stained granulocytes were abundant in synovial fluids of chickens with synovitis. A significant correlation was observed in the percent of fluorescein labeled granulocytes in blood smears and the percent of heterophils determined using an automated counting method, in unstained blood from normal and Escherichia coli-infected turkeys. The fluorescein-binding heterophils purified from chickens showed a time dependent increases in the oxidation of 2',7'-dichlorofluorescin diacetate (DCF-DA) and the reduction of nitroblue tetrazolium (NBT) which were indicative of changes in oxidative burst in response to phorbol 12-myristate 13-acetate (PMA), Salmonella typhimurium lipopolysaccharide (LPS), and zymosan A (ZA). These heterophil-activating agents, also, caused significant degranulation at 16 h post-treatment, as indicated by the loss fluorescence. There were microscopically visible alterations in the cell shapes and a decrease in the density of granules due to treatment with LPS, PMA or ZA. In addition, these cells also showed phagocytic response which was evident at 30 min of incubation with fluorescent latex particles. Both chicken and turkey heterophils produced interleukin-6 in vitro at 24 h in response to LPS but not to PMA, FMLP or ZA. The chicken heterophils showed spontaneous production of matrix metalloproteinases (MMP) which was significantly enhanced by treatment with LPS, PMA, and ZA; however, LPS appeared to be most effective in inducing MMP production. These results demonstrate that the functions of heterophils can be differentially regulated by different activating agents and the fluorescein binding property of these cells may be useful for their histochemical identification.

Iron starvation of Bordetella avium stimulates expression of five outer membrane proteins and regulates a gene involved in acquiring iron from serum.

Iron starvation of Bordetella avium induced expression of five outer membrane proteins with apparent molecular masses of 95, 92, 91.5, 84, and 51 kDa. Iron-responsive outer membrane proteins (FeRPs) of similar sizes were detected in six of six strains of B. avium, suggesting that the five FeRPs are common constituents of the outer membrane of most, if not all, strains of B. avium. Iron-regulated genes of B. avium were targeted for mutagenesis with the transposon TnphoA. Two mutants with iron-responsive alkaline phosphatase activities were isolated from the transposon library. The transposon insertion did not alter the iron-regulated expression of the five FeRPs in mutant Pho-6. The mutant Pho-20 exhibited a loss in expression of the 95-kDa FeRP and the 84-kDa FeRP. Both Pho-6 and Pho-20 were able to use free iron as a nutrient source. However, Pho-20 was severely compromised in its ability to use iron present in turkey serum. The data indicated that the mutation in Pho-20 affected expression of one or more components of an uptake machinery that is involved in acquisition of iron from organic ferricomplexes.

Effect of storage of chicken and turkey blood on the lymphocyte responses to concanavalin A and pokeweed mitogen.

The effect of storage of whole blood of chicken and turkeys on the mitogen responses of lymphocytes to concanavalin A (con A) and pokeweed mitogen was investigated. It was found that, despite slight differences in optimum storage conditions with respect to mitogens, species and age of birds, blood could be stored for 24 h at 4 degrees C without significant reduction in the lymphoproliferative responses. However, even during the initial 24 h storage of blood at 4 degrees C, the levels of reduction in stimulation index (SI) values following con A stimulation, ranged from 27% for 3-4 week-old turkeys to 60% for 3-4 week-old white leghorn chickens.

Changes in plasma concentrations of luteinizing hormone, progesterone, and testosterone in turkey hens during the ovulatory cycle.

Changes in luteinizing hormone (LH), progesterone, and testosterone concentrations were determined in blood samples taken every 10 min for 26 hr during an ovulatory cycle in laying turkey hens. During the 26-hr sampling period, one peak of both LH and progesterone and numerous peaks of testosterone were detected. The concentration of LH in plasma increased from basal level (2.44-4.0 ng/ml) to maximum level (8.57-24.3 ng/ml) over 1 to 2 hr and then declined over 3 to 5 hr to a basal level. The duration of the descending portion of the peak was about double that of the ascending portion. The concentration of progesterone increased rapidly from a basal level of 1.18-1.65 ng/ml to a peak of 6.18-11.87 ng/ml and then maintained a plateau before rapidly declining to basal level. The concentration of testosterone increased from a basal level of 0.06-0.09 ng/ml to a peak level of 0.13-0.30 ng/ml. All maximum levels of testosterone preceded those of LH, and all maximum levels of LH preceded those of progesterone. The durations of the progesterone peaks were longer than those of the LH peaks. Progesterone concentrations returned to basal level after LH had returned to basal level, although the initial increase in progesterone concentration was earlier, later, or at the same time as LH. Peak durations of testosterone were variable. The preovulatory surges of LH and progesterone of five of nine sets of samples started at the end of the scotophase and ended during the beginning portion of the photophase. In three of nine sets both the start and the end occurred druing the scotophase and in one of nine sets during the photophase. It was concluded from this study that the patterns of secretion of LH, progesterone, and testosterone were similar in that the preovulatory surge was superimposed on a relatively stable basal level, while the temporal relationships of the ovulatory surges of these hormones were variable. The preovulatory surges were more tightly associated with ovulation rather than with photoperiod. Neither progesterone nor testosterone might be an initiator of the LH surge prior to ovulation.