Control Poults Research Articles

The effect of infrared beak treatment on the welfare of turkeys reared to 12 weeks of age

This study aimed to determine the effects of infrared beak treatment on the behavior and welfare of male and female turkeys reared to 12 wk of age. To do this, poults (236 males and 324 females) were assigned to one of 2 beak treatments: infrared beak treated on day of hatch (IR) or sham untreated control (C). Data collected included heterophil/lymphocyte (H/L) ratio, pecking force, feather cover, behavioral expression, and beak histology. Data were analyzed as a 2 × 2 factorial of beak treatment and gender, in a completely randomized design and analyzed using PROC MIXED (SAS 9.4). H/L ratio (indicative of a stress response) did not differ between treated and control poults during early life, except at 20 d of age when H/L ratio was higher for C poults than IR poults. Pecking force, measured as a method of monitoring pain, was different only at 1 wk of age, when IR poults pecked with more force than C poults. Feather cover was better in IR poults at 12 wk of age. Differences in behavior between treatments were minor over the 12-wk period. Overall, infrared beak treatment of commercial turkeys had minimal negative impacts on behavior and welfare. The results suggest that stress may be reduced in flocks that are beak treated and that the procedure itself does not cause a pain response.

Isolation and Identification of Lactic Acid Bacteria Probiotic Culture Candidates for the Treatment of Salmonella enterica Serovar Enteritidis in Neonatal Turkey Poults.

Simple SummarySalmonella spp. continues to be one of the most important foodborne bacterial pathogens. S. enterica serotype Enteritidis (SE) that emerged as an important human illness during the 1980s is currently one of the most common non-typhoidal Salmonella serotypes worldwide. Poultry and their products (eggs and meat) are considered as one of the most important source of SE infection in humans. Due to restrictions in the addition of antibiotics in the feed of animals intended for human consumption, alternatives to these antibiotics have been sought. Probiotics have shown to reduce infection in turkey poults. However, studies are lacking to show how these probiotics influence the intestinal microbiome as well as how this microbiome is related to a lower infection by Salmonella. In the present study the effect of a Lactobacillus spp.-based probiotic on SE colonization was evaluated in two separate experiments. In both trials, a significant reduction in the incidence and log10 cfu/g of SE were observed in poults treated with the probiotic when compared with control poults (p ≤ 0.05). Results showed that the application of this probiotic culture could reduce SE cecal colonization in day-of-hatch turkey poults, although further research is needed to elucidate the mechanism of this response.The effect of Lactobacillus spp.-based probiotic candidates on Salmonella enterica serovar Enteritidis (SE) colonization was evaluated in two separate experiments. In each experiment, sixty-one day-of-hatch female turkey poults were obtained from a local hatchery. In both experiments, poults were challenged via oral gavage with 104 cfu/poult of SE and randomly allocated to one of two groups (n = 30 poults): (1) the positive control group and (2) the probiotic treated group. Heated brooder batteries were used for housing each group separately and poults were allowed ad libitum access to water and unmedicated turkey starter feed. 1 h following the SE challenge, poults were treated with 106 cfu/poult of probiotic culture via oral gavage or phosphate-buffered saline (PBS) to control groups. A total of 24 h post-treatment, poults were euthanized and the ceca and cecal tonsils from twenty poults were collected aseptically for SE recovery. In both trials, a significant reduction in the incidence and log10 cfu/g of SE were observed in poults treated with the probiotic when compared with control poults (p ≤ 0.05). The results of the present study suggest that the administration of this lactic acid-producing bacteria (LAB)-based probiotic 1 h after an SE challenge can be useful in reducing the cecal colonization of this pathogen in neonatal poults.

Propolis supplementation attenuates the negative effects of oxidative stress induced by paraquat injection on productive performance and immune function in turkey poults

Paraquat (PQ) is used as a herbicide in agriculture and causes oxidative and inflammatory damage to animal tissues. The current study was conducted to investigate the positive effects of dietary propolis (PR), as a potent naturally produced antioxidant, on growth performance and immune function of turkey poults exposed to oxidative stress induced by PQ injection. Native male turkey poults (n = 120, 49-d-old) were randomly assigned into 4 groups: poults received a basal diet with a daily subcutaneous PQ injection of 5 mg/kg BW for 7 consecutive days (PQ group), an experimental diet containing 1 g/kg PR with a daily subcutaneous PQ injection for 7 days (PR+PQ group), or received the experimental PR diet with a daily subcutaneous injection of 0.5 mL sterile saline for 7 days (PR group); while the control poults received a basal diet with a daily subcutaneous saline injection for 7 consecutive days (C group). The productive performance in the PQ group showed a significant (P < 0.05) reduction in the weight gain (WG) and feed intake (FI), and impaired feed conversion ratio (FCR). Propolis supplementation in the PR+PQ group significantly ameliorated the PQ effects on WG and FCR. Turkey poults of the PQ and PR+PQ groups had a significant augmentation in the blood malondialdehyde (MDA), tumor necrosis factor-α (TNFα), and corticosterone levels, and in contrast, a significant reduction in the triiodothyronine (T3), when compared to the C group. While propolis significantly reduced the MDA and corticosterone, and increased the T3 levels in the PR+PQ group compared to the PQ group. Furthermore, the dietary PR supplementation significantly limited the PQ-suppressive effects on cell- and humoral-mediated immunity and lymphocyte proliferation of turkey poults. In addition, propolis supplementation in the PR and PR+PQ groups markedly reversed the PQ-induced DNA fragmentation and heat shock protein 70 (Hsp70) over-expression in blood cells. It can be concluded that PR could improve turkey immunity and performance, particularly under inflammation and oxidative stress induced by PQ exposure.

AN ASSESSMENT OF ECHOCARDIOGRAPHY AS A DIAGNOSTIC TOOL FOR DILATED CARDIOMYOPATHY IN TURKEY (&lt;i&gt;MELEAGRIS GALLOPAVO&lt;/i&gt;)

Our understanding of the etiology of Dilated Cardiomyopathy (DCM), which affects about 5% of turkeys, is limited. This limitation may be due to the lack of an easy-to-use diagnostic tool with well-defined parameters and does not involve necropsy. This lack of a widely tested non-necropsy method makes it difficult for a large-scale study of the genetic factors that underlie DCM. Here, we Evaluated Echocardiography (ECHO) for its ease and reliability for identifying DCM-affected turkeys from hatch to four weeks-of-age. The parameters evaluated included Left Ventricular Internal-Diastolic (LVIDd), Internal-Systolic Dimension (LVISd), Interventricular Septum End-Diastolic (IVSEd), Interventricular Septum End-Systolic (IVSEs), Left Ventricular Wall End-Systolic (LVWEs) and Left Ventricular Wall End-Diastolic (LVWEd). To induce DCM, feed containing 700 ppm of Furazolidone (Fz) was fed to turkey poults from one to 28 days-of-age. The LVIDd and LVISd were the most consistent indicators of DCM. Both parameters revealed differences between control and treatment poults of between 25 and 326% at the 4 ages at which ECHO measurements were taken. The average difference in LVIDd between control and poults fed Fz-containing diets ranged from 25% in one week-old to 80% in 4-week-old poults. At similar ages, average differences between control and poults fed Fz-containing diets in LVISd were 74 and 326% respectively. Necropsy of poults that survived to the end of the 4-week Fz-treatment confirmed these ECHO measurements in treatment and normal poults. Our data suggest that using LVIDd and LVISd as parameters make ECHO a reliable tool for identifying DCM in turkeys.

Gastrointestinal Maturation is Accelerated in Turkey Poults Supplemented with a Mannan-Oligosaccharide Yeast Extract (Alphamune)

Alphamune, a yeast extract antibiotic alternative, has been shown to stimulate the immune system, increase BW in pigs, and reduce Salmonella colonization in chickens. The influence of Alphamune on gastrointestinal tract development has not been reported. Two trials were conducted to evaluate the effects of Alphamune on gut maturation of 7- and 21-d-old turkey poults. Poults were fed a standard control unmedicated turkey starter diet or the same diet supplemented with either 1 or 2 lb/ton of Alphamune (n = 18/group). Poults were weighed on d 7 and 21, euthanized, and a 2-cm section was collected from the midpoint of the duodenum, jejunum, and ileum of each bird (9 poults/d per treatment) and fixed in a 10% formalin solution for 72 h and then stained. Twenty measurements of villus height, villus surface area, lamina propria thickness, crypt depth, and density of neutral, sialomucin, and sulfomucin goblet cells were taken per section per poult. On d 7, BW were higher for the poults given the Alphamune treatments compared with control poults; however, no differences were observed on d 21. Alphamune supplementation influenced intestinal morphology differently based on gut location. Ileum villus height, surface area, lamina propria thickness, crypt depth, and neutral, sialomucin, and sulfomucin goblet cell density were enhanced with Alphamune treatments on d 7 and 21 (P < 0.05) and in a dose-dependent manner for many of the parameters evaluated. Jejunum results were mixed. Surface area, crypt depth, and sialomucin and sulfomucin goblet cells were consistently higher for the 2 lb/ton of Alphamune groups compared with the control group on d 7 and 21. Duodenum villus height, surface area, and goblet cell density were higher for the 2 lb/ton of Alphamune groups on d 7; however, intestinal morphology of the duodenum was not different between the control and treated birds on d 21. These results suggest that feed supplemented with Alphamune can accelerate gastrointestinal maturation in turkey poults and is more pronounced in the ileum than in other portions of the small intestine.

Changes in Tissue Nitrite Concentration in the Crop of the Turkey Poult in Response to Salmonella Typhimurium Challenge

The present study examines whether Salmonella typhimurium colonization of the crop of young turkeys influences nitrite concentration in the component tissues of the crop. Nitric oxide (NO) is the principal compound in biological samples that is converted into nitrites and NO is known to be a component of the early host response to infection. Challenge with S. typhimurium increased the concentration of nitrite in the crop wall of 3-wk-old turkey poults. The magnitude of the response was reduced at 8 h and absent at 48 h after challenge. As would be expected, S. typhimurium concentrations in the crop were markedly increased following challenge, and were nondetectable in control poults.

Feeding Turkey Poults with Starter Feed and Whole Wheat or Maize in Free Choice Feeding System: Its Effects on Their Performances

This study was carried out to determine the effects of free choice feeding of starter feed and whole cereals on the growth of turkey poults. Two hundred-seventy poults (7-d old) were divided into 3 treatment groups each with 3 replications containing 15 males and 15 females. Control poults (C) were fed only on starter feed (280 g CP and 11.7 MJ ME/kg). Treatments for choice-fed turkey poults were offered a choice of a starter feed and wheat (120 g CP and 12.3 MJ ME/kg) for wheat selecting (WS) or maize (83 g CP and 13.9 MJ ME/kg) for maize selecting (MS) group in separate feeders. Final live weight (2,280.7 g for the C vs. 2,374.3 and 2,324.6 g for the WS and MS), daily gain (39.21 g vs. 40.87 and 39.99 g) and total feed intake (95.2 g vs. 103.2 and 97.9 g) in the WS poults were significantly higher (p<0.05) than those of the C group, but feed conversion ratio was not significantly different between the treatments. The proportional intakes of cereals vs. total feed intake were 11% in both the WS and MS group. The amount of protein intake in the C group (280 g CP/kg diet) was significantly (p<0.05) higher than that in WS and MS groups (263 and 259 g CP/kg diet, respectively) whilst the ME intake in the C group (11.7 MJ/kg diet) was significantly (p<0.05) lower than that in MS group (11.9 MJ/kg diet). Our results showed that turkey poults fed starter feed and whole wheat in a free choice feeding system have a higher efficiency in terms of daily gain, final live weight, and an economic advantage may be obtained from free choice feeding due to a reduced protein intake and feed cost. (Asian-Aust. J. Anim. Sci. 2006. Vol 19, No. 1 : 86-90)

Effectiveness of an Undefined Mucosal Competitive Exclusion Treatment to Control Salmonella in Turkeys During Brooding

Mucosal competitive exclusion (MCE) cultures generated from the mucosal scrapings of healthy adult turkeys were administered to commercial turkey poults. MCE-treated poults were placed on tom and hen farms with paired untreated control poults in adjacent houses. After 6 wk in the brood house, cecal droppings from control and treated flocks were collected and analyzed for the presence of salmonellae. Salmonellae were detected in 14 of 30 cecal droppings (47%) from control flocks and from only 1 of 30 (3.3%) droppings from the treated poults. This study demonstrated that mucosal competitive exclusion could be used to effectively control salmonellae in a commercial field trial of young turkey flocks.

Induction of Functional Defects in Macrophages by a Poult Enteritis and Mortality Syndrome-Associated Turkey Astrovirus

The interaction of a poult enteritis and mortality syndrome (PEMS)-turkey astrovirus-Ohio State University (TAst-OSU) with the mononuclear phagocytic system cells, namely macrophages, was examined after in vitro and in vivo exposure. In vitro exposures were performed by incubating adherent turkey macrophages with various volumes of 10(6) 50% embryo infective dose (EID50)/ml TAst-OSU stock, whereas for in vivo challenge, poults were given a 200 microl inoculum of 10(6) EID50/ml TAst-OSU stock at 7 days of age. Results show that TAst-OSU in vitro exposure reduced macrophage viability relative to controls (P < 0.05) and decreased phagocytosis (P < 0.05) and intracytoplasmic killing of Escherichia coli (P < 0.05) after a 42-48-hr exposure. Poults challenged with TAst-OSU in vivo recruited almost 50% fewer Sephadex-elicited inflammatory cells in the abdominal cavity (P < 0.05) as compared with the sham controls. Similar to in vitro exposure, macrophages isolated from in vivo TAst-OSU-challenged poults exhibited reduced percentage of phagocytic macrophages (P < 0.05) as well as fewer intracytoplasmic E. coli per phagocytic macrophage (P < 0.05). TAst-OSU-challenged poults had a greater number of viable E. coli in their spleens (P < 0.05) after an intravenous E. coli challenge as compared with the non-TAst-OSU-challenged control poults. Macrophage-mediated cytokines and metabolites were also examined during this study. Both in vitro and in vivo TAst-OSU challenge resulted in reduced interleukin (IL)-1 and IL-6 activity. On the contrary, nitrite levels in macrophage culture supernatant fraction of TAst-OSU-challenged macrophages were significantly higher (P < or = 0.05). The findings of these studies indicated that TAst-OSU challenge induced defects in macrophage effector functions, implying that PEMS-turkey astrovirus can potentially impair the immune response of turkeys, thereby leading to enhanced susceptibility of turkeys to secondary, perhaps even fatal, bacterial infections.

THE EFFECT OF DIETARY AFLATOXIN ON WILD TURKEY POULTS

Aflatoxins, toxic metabolites of Aspergillus flavus or Aspergillus parasiticus, cause poor feed utilization, decreased weight gains, depressed immune function, liver dysfunction, coagulation abnormalities, and death in a wide variety of species including humans. Conservationists have become concerned that increasingly popular wildlife feeding or baiting practices could expose wildlife to toxic amounts of aflatoxin-contaminated grains. In particular, the effects of aflatoxins on the wild turkey (Meleagris gallopova silvestris) are of concern because the conspecific domestic turkey is highly susceptible to aflatoxins. To evaluate the effect of dietary aflatoxin on wild turkeys, four groups of 4-mo-old wild turkeys were fed diets containing either 0, 100, 200, or 400 micrograms aflatoxin/kg feed for 2 wk in September and October 1996. Aflatoxin-fed poults had decreased feed consumption and weight gains as compared with control poults. Decreased liver-to-body weight ratios, liver enzyme alterations, slightly altered blood coagulation patterns, and mild histologic changes indicated low-level liver damage. Compromise of cell-mediated immunity was indicated by decreased lymphoblast transformation. The effects were apparent in all treatment groups to variable levels, but significant differences most often were found at 400 micrograms aflatoxin/kg feed. This study shows that short-term aflatoxin ingestion by wild turkeys can induce undesirable physiologic changes; therefore, exposure of wild turkeys to feeds containing aflatoxin levels of 100 micrograms aflatoxin/kg feed or more should be avoided.

D-xylose absorption as a measurement of malabsorption in poult enteritis and mortality syndrome

Severe wasting of body tissues, diarrhea, high morbidity and mortality, and stunting are all characteristics of poult enteritis and mortality syndrome (PEMS). The wasting of musculature and loss of nearly all adipose tissue suggested that even though the PEMS-infected poults were eating some feed, nutrient intake was not sufficient to meet body requirements for maintenance and growth. Because epithelial cells in the gastrointestinal tract appeared to be a target of the undefined etiological agent (or agents) that causes PEMS, a study was conducted in which PEMS-infected poults were evaluated for malabsorption through 3 wk of age. D-Xylose, a poorly metabolized pentose, was given per os as a bolus, and blood samples were obtained from the ulnar vein in the wing of control and PEMS-infected poults over a 3-h period to estimate intestinal absorption. D-Xylose absorption in control poults peaked 30 to 60 min after the oral treatment, similar to results reported earlier. The PEMS-infected poults did not show a peak in absorption. The PEMS-infected poults showed significant delays in D-xylose absorption at 4, 7, and 11 d after PEMS challenge. The severe malabsorption and metabolic deficiency problem associated with PEMS was postulated to be a direct effect of the undefined infectious agent or agents that cause the disease.

Alterations in Macrophage-Produced Cytokines and Nitrite Associated with Poult Enteritis and Mortality Syndrome

Poult enteritis and mortality syndrome (PEMS) is an acute, transmissible, infectious intestinal disease associated with high mortality and morbidity in turkey poults. Earlier studies demonstrated immune dysfunction, involving both humoral and cell-mediated immunity, associated with PEMS. The current study examined cytokines and metabolites produced by macrophages from poults exposed to PEMS agent(s). Six trials were conducted with six separate hatches of poults. Poults in the PEMS group were exposed to PEMS agent(s) via contact exposure at 7 days of age whereas uninfected poults served as control poults. Abdominal macrophages were harvested from control (uninfected) and PEMS poults at various times postexposure and cultured for 18-24 hr in the presence of Escherichia coli lipopolysaccharide. Interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) bioactivities and nitrite levels in macrophage culture supernatants were quantified. Macrophage supernatants from PEMS poults had greater IL-1-mediated stimulation index compared with the macrophage supernatants from uninfected control poults in both trials. However, this increase was significant only in trial 1. IL-6 activity tested in three separate trials was significantly higher in PEMS macrophage supernatants over the controls. On the contrary, TNF-alpha production by macrophages was decreased in PEMS macrophage culture supernatants. Nitrite levels in PEMS macrophage culture supernatants were significantly higher in two out of three trials. These findings suggest that the enhanced production of proinflammatory cytokine/metabolites by activated macrophages in PEMS poults may be responsible, at least in part, for the physiological intestinal inflammation, gut motility, and anorexia that characterize this disease.

The individual and combined effects of feeding moniliformin, supplied by Fusarium fujikuroi culture material, and deoxynivalenol in young turkey poults

The effects of feeding diets containing either 20 mg deoxynivalenol (DON)/kg, 100 mg moniliformin (M)/kg, or a combination of DON and M (20 mg/kg DON and 100 mg M/kg) were evaluated in growing turkey poults, from 1 to 21 d of age. Feed intake and BW gains were decreased (P < 0.05) by dietary treatments containing M. Feed conversion was not affected by any of the dietary treatments, and no interactive effects on performance were evident between M and DON. Absolute weights of hearts and kidneys were increased (P < 0.05) in poults fed diets containing M. Mean cell volume was decreased by the M and DON-M treatments; however, the decrease was much smaller in poults fed the combination DON-M treatment resulting in a significant (P < 0.05) DON by M interaction. Mean cell hemoglobin and mean cell hemoglobin concentrations were not affected by any of the dietary treatments. No histological lesions were seen in control poults or poults fed DON alone. Lesions associated with dietary treatments were only observed in the heart and kidney. Poults fed diets containing M alone or the DON-M combination exhibited an increased incidence of variable sized cardiomyocyte nuclei, with numerous large giant nuclei, and a generalized loss of cardiomyocyte cross striations. Isolated renal tubules in sections of kidney were noted to have mild diffuse mineralization in poults fed M and the combination DON-M treatments. None of the response variables measured were affected by DON alone. No toxic synergy was observed when these toxins were fed simultaneously to turkey poults for 21 d.

Tryptophan methylester modulation of poult responses to Bordetella avium

On the day of hatching, four groups of poults [Control, L-tryptophan methylester (LTME), Bordetella avium-infected, and B. avium-infected plus LTME] were established and placed into heated metal brooding batteries. Bordetella avium infection caused a significant depression in body temperature within 24 h after intranasal challenge with the W strain, and the hypothermia persisted through 21 d of age. L-Tryptophan methylester, a water-soluble form of tryptophan, was given by oral gavage daily in saline at a concentration of 50 mg per poult beginning 4 d after hatch. Within 2 d after initiation of LTME treatments, colonic temperature of B. avium-infected poults was elevated to the level of Controls and remained at that level throughout the experimental period. The BW of B. avium-infected poults were reduced significantly. The LTME treatment caused a significant BW increase in the B. avium-infected poults, but the increase was not to the level of Controls. The anti-sheep red blood cell antibody titers in B. avium-infected poults were not affected significantly. However, LTME treatment induced a significant increase in anti-sheep red blood cell antibody titers in both the infected and Control poults. Based upon data reported herein, it was concluded that feed intake depression associated with development of bordetellosis caused the poults to react more specifically to a mild tryptophan deficiency than to other nutrient deficiencies. The tryptophan deficiency caused a growth depression that was only partially alleviated by daily supplementation of LTME. The physiological responses to daily supplementation of LTME to B. avium-infected poults suggested that growth depression and poor performance was not limited to dietary deficiency of tryptophan.

Alterations in the Lymphocytic and Mononuclear Phagocytic Systems of Turkey Poults Associated with Exposure to Poult Enteritis and Mortality Syndrome

In vivo and in vitro mononuclear phagocytic system functions, expression of lymphocyte subset cell surface markers in the thymus and bursa of Fabricius, and lymphocyte subset dynamics during the course of poult enteritis and mortality syndrome (PEMS) were examined. PEMS is an acute, transmissible, infectious intestinal disease accompanied by high mortality and morbidity. The etiology of this multifactorial disease remains to be elucidated; however, turkey coronavirus was initially assumed to be one of the primary agents involved. Further investigation demonstrated that turkey coronavirus was not always detectable in poults exhibiting PEMS symptoms, and, thus, PEMS poults began to be identified as positive or negative for turkey coronavirus. In each trial, uninfected hatchmate controls were compared with turkey poults that were contact exposed to PEMS poults at 7 days of age. Following intravenous inoculation, control poults cleared Escherichia coli from their circulation by 60 min, whereas viable E. coli were still present in the circulation of PEMS poults at 60 min postinoculation. Inflammatory response measured by Sephadex-elicited abdominal exudate cell recruitment and the adherence potential of abdominal exudate cells was not significantly different between uninfected and PEMS poults. The percentage of glass-adherent abdominal exudate macrophages was higher in PEMS poults. However, the ability of these macrophages to phagocytize sheep red blood cells and the average number of sheep red blood cells per phagocytic macrophage were both lower compared with uninfected controls. CD4+ expression in thymic tissue of PEMS poults at 9 days postinfection was significantly lower. The CD4+:CD8+ lymphocyte ratio in peripheral blood leukocytes from coronavirus-negative PEMS poults was lower than that from both uninfected and coronavirus-positive PEMS poults at 14 days postinfection. In the spleen, the CD4+:CD8+ lymphocyte ratio was higher in coronavirus-positive PEMS poults as compared with the other treatments. In conclusion, immune system dysfunction in PEMS is associated with impaired mononuclear phagocytic system function and alterations in lymphocyte populations.

Improvement of Poult Performance Following Bordetella avium Challenge by Administration of a Novel Oxy-Halogen Formulation

The ability of a novel oxy-halogen formulation (OHF) to alter the development of bordetellosis (turkey coryza) in large white turkey poults was assessed. Bordetella avium (BA)-infected (1-day-of-age) and noninfected control poults received 0, 0.008%, or 0.016% of an OHF continuously in the drinking water. At 4, 7, 10, 14, and 17 days of age, reisolation of BA from infected poults was attempted. Infected poults receiving 0.016% OHF exhibited significantly lower cumulative BA reisolation rates (90%) when compared with infected poults receiving 0 (96.7%) or 0.008% OHF (100%). At 7, 14, and 17 days of age, infected poults in the OHF-treated groups were significantly heavier than those BA-challenged poults receiving control water. Feed utilization was significantly improved from hatch to 7 days of age in BA-infected poults receiving OHF when compared with infected poults receiving control water. Clinical symptoms were severe only in untreated, infected poults and were mild or absent in all others. Damage to the tracheal epithelium, as measured by scanning electron microscopy, paralleled the clinical signs. Tracheal epithelial damage was virtually eliminated by OHF administration in infected poults. These results suggest that OHF treatment ameliorates many of the symptoms frequently associated with bordetellosis in young turkeys.

Enhancement of humoral and cellular immunity by vitamin E after embryonic exposure

In the present study, the amnion of turkey and chicken embryos were injected 3 d prior to hatch with different levels of vitamin E (VE). In Experiments 1 and 2, turkey embryos received 10, 20, and 30 IU of VE. In Experiment 3, broiler embryos received 10 IU VE. In all three experiments, sham-injected control embryos (0 IU VE) received 300 microL of saline. In Experiments 1 and 2 (turkey embryos), 20 and 30 IU of VE reduced (P < or = 0.05) percentage hatchability below that of controls. At hatch, poults exhibited a dose related increase (P < 0.05) in plasma VE levels. Mean BW gain up to 35 d and relative bursa of Fabricius and spleen weights were not different among treatment groups. When challenged at 7 d posthatch, total (P < 0.05) and IgM (P < 0.08) anti-SRBC antibodies were higher in 10 IU VE poults than in controls. Immunoglobulin G levels did not differ among the treatment groups. Poults in the 10 IU VE group had higher (P < 0.002) numbers of Sephadex-elicited inflammatory exudate cells, as well as a greater percentage of phagocytic macrophages (P < 0.0001). Additionally, the numbers of SRBC per phagocytic macrophage were greater (P < 0.001), than in control poults at 4 wk of age. In Experiment 3, chick embryos exposed to 10 IU VE, exhibited no differences in hatchability, BW gain, or bursal and splenic weights from the sham-exposed group. However, total and IgM antibody responses against SRBC were greater (P < 0.01) in the 10 IU VE group at 7 d postinjection. A secondary SRBC challenge given at 14 d after primary injection resulted in higher total (P < 0.07) and IgG (P < 0.04) antibody responses in the 10 IU VE chicks than in the controls. Similarly, broiler chicks (10 IU VE) had more Sephadex-elicited abdominal exudate cells (P < 0.07), and greater macrophage phagocytic potential (P < 0.0001). In ovo VE exposure (10 IU) also increased nitrite production (P < 0.04) by chick macrophages. The results from this study demonstrated an enhanced antibody and macrophage response and suggest that in ovo exposure with VE may improve posthatch poult and broiler quality.

Application of Normal Avian Gut Flora by Prolonged Aerosolization onto Turkey Hatching Eggs Naturally Exposed to Salmonella

A commercial preparation of normal avian gut flora (NAGF) was aerosolized for an extended period over turkey hatching eggs during pipping and hatching to examine any protective effects against natural exposure to salmonellae. Turkey hatching eggs, produced by salmonellae-infected breeder flocks and hatched in a commercial hatchery with a history of salmonellae contamination, were used in two trials. In Trial 1, four doses of NAGF inoculum per hatching egg were aerosolized through an automated hatcher fogging system during the final 48 hr of the pipping and hatching process. In Trial 2, two doses of NAGF inoculum were aerosolized in a like manner. In both trials, poults were exposed to Salmonella montevideo during hatching, as indicated by samples collected at the time of pull. At day 7, treated poults in both trials were culture negative for salmonellae and control poults were culture positive for salmonellae. In Trial 1, control poults were infected with Salmonella brandenburg, and in Trial 2, control poults were infected with S. montevideo. These studies justify further critical evaluation of the protective effects of prolonged aerosolization of normal avian gut flora during pipping and hatching against salmonellae colonization in turkey poults.

Effects of Feeding Fumonisin B1 Present in Fusarium moniliforme Culture Material and Aflatoxin Singly and in Combination to Turkey Poults

Diets containing 200 mg fumonisin B1/kg of feed and .75 mg aflatoxin/kg of feed singly or in combination were fed to female turkey poults (Nicholas Large White) from day of hatch to 21 d of age. When compared with controls, 21-d body weight gains were reduced 10% by fumonisin B1, 39% by aflatoxins, and 47% by the combination. Relative weights (grams/100 g body weight) of the kidney and pancreas increased in poults fed the diet containing aflatoxins alone, whereas the relative weight of the liver decreased. Relative weights of the liver and pancreas increased in the poults fed the fumonisin diet. Relative weights of the kidney, pancreas, and gizzard increased in the poults fed the combination diet, whereas the relative weight of the liver decreased. Most serum constituents, hematology values, and activities of enzymes measured were altered in poults receiving the diets containing aflatoxins with or without fumonisin B1. No major histological lesions were observed in tissues from control poults or poults fed the diet containing fumonisin alone. Lesions associated with aflatoxins were only observed in the liver and occasionally in the kidney of poults fed the diets containing aflatoxins with or without fumonisin B1. The primary hepatic change was bile duct hyperplasia with some hepatocellular degeneration and necrosis and megalocytosis. Occasional necrotic and degenerating tubular epithelial cells were observed in the kidneys. The increased toxicity in poults fed the combination diet for most variables can best be described as additive, although some variables showed less than additive toxicity. Although toxicity due to fumonisin B1 was shown, it must be pointed out that these concentrations are not likely to be encountered under field conditions. However, other stress factors may be present that could alter the toxicity observed under these controlled experimental conditions.

Astrovirus Infection in Hatchling Turkeys: Alterations in Intestinal Maltase Activity

Two experiments were conducted to determine intestinal disaccharidase activity in 1-day-old commercial turkey poults inoculated with astrovirus. Small intestinal samples were collected on days 0.5, 1, 3, and 7 postinoculation (PI) in Expt. 1 and on days 7, 10, and 14 PI in Expt. 2 and evaluated for specific maltase activity (SMA). Astrovirus infection was verified on day 7 PI by immune electron microscopy of intestinal contents. Inoculated poults developed diarrhea and a transient, significant decrease in intestinal SMA. SMA was significantly (P < 0.05) lower in astrovirus-inoculated poults than in control poults throughout the entire small intestine from day 3 through day 7 PI. However, SMA had returned to normal in inoculated poults by day 10 PI and was significantly higher than control values (P < 0.05) in all sections of the small intestine, except in the proximal jejunum, by day 14 PI. Decreased SMA caused by astrovirus infection resulted in disaccharide maldigestion, malabsorption, and subsequent osmotic diarrhea. As astrovirus was cleared from the intestinal tract, SMA was restored and diarrhea was resolved.