Evaluation of XPC and prototypes on aflatoxin-challenged broilers.

Various products and prototypes were added to poultry diets during an aflatoxin challenge on growth and histological parameters. Male broiler chicks were randomly assigned to 8 treatment groups with 8 replicates/treatment and 3 birds/replicate. Treatments were as follows: 1) negative control containing no aflatoxin (NC); 2) positive control containing aflatoxin (PC); 3) 0.1% glucomannan mycotoxin standard industry ameliorator (STD); 4) 0.1% prototype A, a proprietary mixture of a Saccharomyces cerevisiae product and diatomaceous clay; 5) 0.2% prototype A; 6) 0.15% prototype B, a proprietary mixture of a S. cerevisiae product and diatomaceous clay (PB); 7) 0.0625% XPC (S. cerevisiae fermentation product); and 8) 0.125% XPC (XPC2). All treatments except NC contained 2,280 +/- 102 ng/g of aflatoxin and were fed for 28 d. Body weight and feed intake were measured weekly. Livers were collected on d 28, weighed, and used for histopathological evaluation. Beginning weights were similar across treatments, but BW were lower (P /= 0.05) different among the treatment groups. Liver weights relative to BW were higher (P /= 0.05) compared with NC. Overall, BW gain in treatment groups PB and XPC2 was not different from NC and that corresponded to protective effects against liver lesions. Benefits observed during an aflatoxin challenge when broilers were supplemented with XPC, a fermentation product that does not contain any adsorbents, may be attributed to something other than adsorption as a primary mechanism.

Acid-base balance of the domestic turkey during thermal panting.

The objectives of this research were to evaluate the effects of thermal panting in domestic turkeys on arterial blood values for the acid-base variables, pH(a), bicarbonate concentration ([HCO(-) (3)](a)), partial pressure of carbon dioxide (P(a)CO(2)), and hemoglobin concentration [Hb]. In addition, body temperature and partial pressure of oxygen (P(a)O(2)) were measured to determine the effectiveness of panting in their control. Nine adult (23 wk) broad-breasted white turkey toms, all from the same hatch and reared contemporaneously in the same facility, were acclimated to room conditions of 19 degrees C and 65% RH. After a 1-wk control period, a 3-wk heat-stress period (32 degrees C, 65% RH) was induced, for a heat-stress group of 9 turkeys. Thermal panting began at this time and continued to its end. A 1-wk recovery period followed (19 degrees C, 65% RH) during which panting ceased. An age-matched group of 8 turkeys was similarly acclimated (19 degrees C, 65% RH) but was continued at this level to the end of the experiment. During the heat-stress period, the bicarbonate concentration increased, whereas pH(a) and P(a)CO(2) did not change significantly. Body temperature changes were not significant. Parabronchial ventilation was not compromised by panting, as noted by a significant increase in P(a)O(2). Hemoglobin concentration decreases were significant. The only significant change that occurred for the age-matched group was an increase in [Hb]. Domestic turkeys, reared in confinement, have the ability to resist changes in blood pH and prevent the development of respiratory alkalosis while panting in response to thermal stress. Normal body temperature and oxygenation of the blood are also maintained.

Effects of storage time and temperature after blood sampling from turkeys on plasma concentrations of potassium, sodium, and chloride.

The objectives of this research were to study the effect of several time intervals of turkey blood storage from sampling to centrifugation on plasma K, Na, and Cl concentrations and to study the effect of ambient temperature of turkey blood storage on these same variables. In the first study, 6 consecutive blood samples were obtained from each turkey. The first sample was centrifuged immediately (control), and each of the others was respectively stored for 20, 40, 60, 120, or 360 min at 22 degrees C before centrifugation and plasma harvest. In the second study, 4 consecutive blood samples were obtained from each turkey. The first sample was centrifuged immediately (control), and each of the others was respectively stored at ambient temperatures of 9, 22, and 30 degrees C for 120 min before centrifugation and plasma harvest. Plasma K concentration declines and is significant (P < 0.01) for each of the 20, 40, 60, 120, and 360 min values. Plasma Na concentration increases and Cl decreases were not significant (P < 0.01) until 360 and 120 min, respectively. Significant (P < 0.01) reductions occurred for plasma K concentration for each of the ambient temperature values but were the least at 9 degrees C and greatest when stored at 30 degrees C. Plasma Na concentration decreased (P < 0.01) when stored at 9 degrees C. Though increased (P < 0.01) when stored at 22 and 30 degrees C, the difference was not significant (P < 0.01) between samples stored at either 22 or 30 degrees C. Plasma Cl concentration was decreased (P < 0.01) from control values, but there was no significant difference (P < 0.01) among samples stored at 9, 22, and 30 degrees C. Clot formation and its retraction from serum are unduly delayed after blood is withdrawn from turkeys because birds lack the intrinsic mechanism for blood coagulation. Accordingly, serum is not appropriate for the determination of K concentration in turkeys, and plasma harvested immediately after blood sampling is the fluid of choice for K analysis.

Salmonella prevalence in market-age turkeys on-farm and at slaughter.

The objective of this study was to compare the prevalence of Salmonella in market-age turkeys on-farm and at slaughter (i.e., before and after feed withdrawal, catching, loading, transportation, and preslaughter holding). Thirty birds were randomly selected from each of 6 commercial turkey flocks scheduled to be loaded and shipped to the abattoir during the evening of the same day. Selected birds were euthanized on the farm, and the cloacal contents, large intestine, crop, ceca, liver and gallbladder, and spleen were aseptically collected. At the abattoir, 30 birds from the same flock were randomly selected from the slaughter line, and the crop, ceca, liver and gallbladder, and spleen were collected for subsequent culture at the laboratory. All flocks studied were positive for Salmonella at slaughter. No statistical difference was found between the overall prevalence on-farm and at slaughter. At both sampling points, the overall prevalence found was 33.3%. Diverging prevalence estimates were obtained based on the different sample types collected on-farm and at slaughter. In both cases, cecal content samples had the highest relative sensitivity (73.3% on-farm and 68.3% at slaughter). This study demonstrates that the preslaughter practices of feed withdrawal, catching, loading, transportation, and holding do not significantly alter the prevalence of Salmonella in market-age turkeys. Therefore, our results suggest that it may be possible to monitor the Salmonella status of turkey production farms based on samples collected at the abattoir.

Preharvest feed withdrawal affects liver lipid and liver color in broiler chickens.

An Iowa grain processor attempted to alter the typical 12-h preharvest fasting period by giving broilers cornstarch derivative pellets and water for 6 h followed by 6 h of no feed or water. After slaughter, plant food inspectors determined that livers from the treatment group were lighter in color than normal, and consequently a significant number of chicken carcasses were condemned for human consumption. The study reported herein was conducted to determine the effects of fasting or 3 feeding programs applied before processing on liver color, liver lipids, and liver glycogen of broilers. Dietary treatment groups consisted of 1) full-fed control broilers, 2) fasted broilers, 3) maltodextrin-fed broilers, and 4) and chickens given maltodextrin and methionine. Full-fed chickens had lighter liver coloration than chickens without access to feed for 6 or 12 h immediately prior to slaughter (P < 0.05). Lightness values for livers from full-fed control chickens (L* = 54.41) were 38% higher than those for livers from fasted broilers (L* = 39.30). Lighter liver colors in full-fed broilers were associated with higher hepatic lipid concentrations (6.38%) and more total liver lipid (4.96 g/liver) than was found in broilers without feed for 12 h. In contrast, darker livers from fasted broilers had lower levels of lipid (4.42%) and less total lipid (2.68 g/liver) than the full-fed broilers. Feeding maltodextrin pellets resulted in liver colors that were lighter (P < 0.05) than those found in fasted chickens but darker (P < 0.05) than livers from full-fed broilers. If carbohydrate supplements are fed prior to slaughter, producers should notify processing plant officials so that inspectors do not interpret light livers as an abnormal physiological state.

Effect of irradiating shell eggs on quality attributes and functional properties of yolk and white.

Shell eggs were irradiated and the physico-chemical, and functional properties of egg yolk and white were determined. The color of egg yolk was not affected, but the viscosity of egg white was dramatically lowered and became watery by irradiation. The foam capacity and foam stability of egg white were significantly decreased due to protein oxidation by irradiation. However, the texture characteristics of egg white were not changed by irradiation, indicating that irradiation may not alter the thermal characteristics of egg white proteins. Sulfur volatiles were generated by irradiation but disappeared during storage under aerobic conditions. Because egg white became watery, irradiation may not be advisable for table eggs but may be useful for pasteurizing liquid egg white or liquid whole egg without significant deterioration of their quality and functionality. In particular, the dramatic decrease in the viscosity of egg white by irradiation will improve flow of liquid egg white or liquid whole egg, which could be highly useful for egg processing.

Effect of bacitracin methylene disalicylate on turkey poult performance in the presence and absence of stunting syndrome.

This study included a complete factorial arrangement of three dietary levels of bacitracin methylene disalicylate (BMD) (0, 50, and 200 g/ton) and two health conditions (none and stunting syndrome [SS]). One-day-old turkeys were dosed per os with tryptose phosphate broth or a supernatant derived from gastrointestinal tracts of poults with SS. Body weight, feed intake, feed efficiency, water intake, and hydration efficiency were determined at 5, 9, 13, 21, and 27 days of age. BMD at 200 g/ton in the feed significantly improved body weight (P < 0.005) of poults with SS at all ages, and it improved feed efficiency (P < 0.05) from 1 to 9 days of age. BMD at 50 and 200 g/ton improved hydration efficiency (P < 0.05) of poults with SS during the first 9 days of life.

Outbreak of Mycoplasma iowae infection in commercial turkey poults.

In September 1989, 17-day-old turkey poults were submitted to Iowa State University because of leg weakness and dehydration. These birds were commercial large white toms from a flock of 23,214. Lesions observed at necropsy included chondrodystrophy of the hock joints, clear fluid in hock joint spaces, valgus deformities and shortening of the tarsometatarsal bones, and curled toes. Mycoplasma iowae was isolated and identified from swabs of the air sac, cloaca, hock joint, and large intestine. Approximately 1.4% of the flock was culled between 2 and 8 weeks of age because of leg problems. M. iowae infection did not severely affect overall flock performance. Eighty-seven percent of the flock was marketed at 18 weeks of age with an average per turkey weight of 29.5 pounds.

Efficacy of aluminum hydroxide-adjuvanted Escherichia coli bacterin in turkey poults.

Aluminium hydroxide-adjuvanted Escherichia coli bacterins were evaluated for efficacy in protecting turkeys against homologous challenge. In each of six trials involving four different E. coli serotypes, poults in one group received a single subcutaneous injection at 1 day of age, poults in a second group were vaccinated twice at 1 and 14 days of age, and those in a third nonvaccinated group served as controls. Vaccinated and control turkeys were challenged at 4 wk of age and survivors were necropsied 1 wk later. Mortality and gross lesion scores of both vaccinated groups were compared with those of the nonvaccinated group. Poults vaccinated twice had significantly lower mortality and less severe gross lesions than poults receiving no vaccine prior to challenge. Immunization with one or two injections of aluminum hydroxide-adjuvanted E. coli bacterin did not impair weight gain of poults.

Stunting syndrome in turkeys. Development of an experimental model.

Experiments were conducted to establish a stunting syndrome (SS) model to facilitate research on nutritional aspects of enteric disorders of poults. One-day-old turkeys were dosed per os with tryptose phosphate broth (TPB) (controls) or inoculum (inoculated). The inoculum was prepared by homogenizing intestines from 11-day-old commercial poults diagnosed to have SS in TPB (1:0.5 [wt:wt]). Subsequently, intestines from 8-day-old inoculated poults from the previous experiment were used. Inoculation reduced growth (P less than 0.001) and feed consumption (P less than 0.001) at 8 and 14 days of age. In Expts. 1, 2, and 3, gain of inoculated poults was 60.9%, 58.8%, and 52.6% that of controls up to 8 days of age and 77.9%, 76.6%, and 80.9% that of controls from 8 to 15 days of age, respectively. Feed conversion was impaired (P less than 0.001) up to 8 days of age. The activity of maltase and sucrase in the jejunum and of pancreatic enzymes was determined every 2 days up to 13 days of age. Inoculation decreased (P less than 0.001) maltase and sucrase starting at 3 days of age (i.e., maltase activity was 17.45 and 1.70 mumols maltose hydrolyzed/hr.mg protein in control and inoculated poults, respectively). Inoculation had no effect on pancreatic lipase, amylase, or trypsin.

Cecal spirochetosis in commercial laying hens.

Cecal spirochetosis in chickens has been associated with enteric disease and reduced egg production in the United States and Europe. This report describes spirochete overgrowth of cecal mucosa in chickens from a flock of 100,000 commercial layers experiencing diarrhea and a 5% drop in egg production. Spirochetes were demonstrated in the ceca by darkfield and light microscopy. Apical surfaces of cecal enterocytes were covered by a dense layer of spirochetes aligned parallel to each other and perpendicular to the mucosal surface. Weakly beta-hemolytic, indole-negative spirochetes were isolated from the ceca on BJ media under anaerobic conditions at 42 C. Chicken cecal spirochetosis may represent an economically significant enteric disease of laying hens which has heretofore been infrequently recognized.

Hemorrhagic enteritis virus inclusions in turkey renal tubular epithelium.

Commercial turkeys from four Iowa flocks, two Illinois flocks, and three California flocks were submitted to state diagnostic laboratories because of a variety of health problems. The turkeys ranged in age from 5 to 12 weeks, included both hens and toms, and were owned by five different companies. Some flocks had previously been immunized with live hemorrhagic enteritis vaccine, and other flocks were unvaccinated. In all accessions, basophilic intranuclear inclusion bodies were observed in renal tubular epithelium by light microscopy. Transmission electron microscopy showed that the inclusions consisted of densely packed virus particles. The virions were identified as adenoviruses based upon the icosahedral morphology and average particle diameters of 72 nm. Avidin-biotin immunoperoxidase staining of formalin-fixed, paraffin-embedded kidneys was used to identify this adenovirus as hemorrhagic enteritis virus.

Urinary tract cryptosporidiosis in commercial laying hens.

Formalin-fixed kidney tissues from adult egg-laying chickens in two houses of an egg-production complex in the upper Midwest were submitted to Iowa State University for histopathologic examination. An increased incidence of visceral gout, average daily mortality 1%-2% higher than expected, and egg production within normal limits were observed in both houses. Numerous developing stages of Cryptosporidium were observed on the apical surface of epithelial cells lining renal collecting tubules and ureters. Scanning and transmission electron microscopy were used to visualize colonization of cryptosporidia, disruption of microvilli, and exfoliation of parasitized epithelial cells. Lymphoplasmacytic infiltration in the wall of ureters and hyperplasia of parasitized epithelial cells resulted in partial obstruction of ureters, which may have induced visceral gout in affected hens. This is the first report of urinary tract cryptosporidiosis occurring in adult hens in a modern commercial egg-production facility.

Postmortem detection of acute septicemia in broilers.

Septicemia is an unwholesome condition diagnosed during postmortem inspection in poultry slaughter establishments on the basis of macroscopic lesions. Early identification of septicemia has important public health implications. In this study, Pasteurella multocida, Escherichia coli, and Staphylococcus aureus septicemia were induced in broilers in order to determine if lesions of acute septicemia can be grossly detected in the visceral organs of broiler carcasses prior to the development of changes in the skeletal muscle. Increased spleen and liver weights were observed during the acute phase of septicemia. Airsacculitis, pericarditis, and perihepatitis were observed during the acute phase of P. multocida- and E. coli-induced septicemia; and arthritis was the earliest indicator of S. aureus-induced septicemia. These macroscopic lesions were sufficient to identify unwholesome septicemic broiler carcasses prior to the development of changes in the skeletal muscle of the carcass.

Intranuclear inclusions of unknown pathogenic significance from diagnostic cases in three avian species.

Intranuclear inclusions were observed with light microscopy in tissues from necropsy cases from three different species of birds. Because of the nature of these inclusions, the species affected, or their distribution, the inclusions were considered of unknown pathogenic significance. The inclusions were examined ultrastructurally. Parvovirus-like particles were observed in the intranuclear inclusions of pigeon hepatocytes and duodenal stromal cells from a quail. Finely granular eosinophilic intranuclear inclusion bodies from two unrelated pigeon cases were found to be composed of loosely organized filaments. One liver sample from a 16-week-old laying chicken had prominent eosinophilic hepatocellular intranuclear inclusions composed of electron-dense coarsely granular amorphous material.

Long-segmented filamentous organisms observed in poults experimentally infected with stunting syndrome agent.

One-day-old turkeys were inoculated per os with material shown previously to induce stunting syndrome (SS). Weight gain and feed efficiency of inoculated poults from 1 to 13 days of age were impaired (P less than 0.01) compared with uninoculated poults. Examination of the jejunal mucosa by scanning and transmission electron microscopy showed the presence of long-segmented filamentous organisms (LSFOs) in poults that had been inoculated with SS. These organisms were not seen in jejuna of uninoculated poults. Further research is needed to characterize LSFOs and to determine their involvement, if any, in the adverse effects associated with SS.

Immunohistochemical detection of Mycoplasma gallisepticum antigens in turkey respiratory tissues.

An avidin-biotin-immunoperoxidase diagnostic test was developed to facilitate rapid identification of Mycoplasma gallisepticum in respiratory tissues of turkeys. This procedure used polyclonal primary antibodies produced in rabbits. Turkeys were inoculated into the infraorbital sinus and trachea with the R strain of M. gallisepticum, Mycoplasma synoviae, Mycoplasma meleagridis, or Frey's media. The outer walls of the infraorbital sinuses, lungs, and tracheas were collected and fixed in either 10% neutral formalin or pentanedial methyl glycol at 1, 2, 3, and 4 wk postinoculation. Tissues were subdivided and remained in each fixative for 6 or 24 hr. The avidin-biotin-immunoperoxidase diagnostic test was sufficiently sensitive to detect M. gallisepticum antigen at 1, 2, 3, and 4 wk postinoculation. Staining of M. gallisepticum was significantly more intense on infraorbital sinus epithelium than on respiratory epithelium from the trachea or lung. Statistical analysis indicated that the 6-hr fixation time offered better antigen preservation than 24 hr in a fixative. There was no difference in intensity of M. gallisepticum antigen staining in tissues fixed in methyl pentanedial glycol when compared with tissues fixed in 10% neutral buffered formalin. Significant differences in staining intensity were observed between weeks. Specificity of the avidin-biotin-immunoperoxidase test was not complete. None of the tissues from the M. meleagridis and control groups showed staining. No staining was observed in the ciliated brush border of infraorbital sinus epithelial cells from turkeys infected with M. synoviae. However, weak to moderate staining was observed in several tracheas of turkeys inoculated with M. synoviae. Improved specificity of an avidin-biotin-immunoperoxidase diagnostic test to detect M. gallisepticum in respiratory tissues of turkeys probably will require the use of multiple monoclonal antibodies directed against several different epitopes specific to the cell membrane of M. gallisepticum.

Parvovirus-like enteropathy in Missouri turkeys.

A viral enteric disease of young turkeys characterized by stunting of affected birds, diarrhea, and increased mortality is described. Eosinophilic intranuclear inclusion bodies were found in the absorptive epithelial cells of the ileum. Electron microscopy of formalin-fixed tissue revealed that the intestinal inclusions contained numerous loosely packed 15-to 20-nm hexagonal particles. The size, shape, and intranuclear location have been used to tentatively identify these particles as parvoviruses.

Aspergillus fumigatus keratitis with intraocular invasion in 15-day-old chicks.

Eye infections were initially observed in single-comb white leghorn breeder chicks at 5 days of age, and morbidity increased from 0.05% to 1.5% after debeaking at 7 days of age. All chicks necropsied at 15 days of age had cheesy yellow exudate within the conjunctival sac of one eye and small (1 mm diameter) white nodular lesions in lungs and on thoracic air-sac membranes. Histopathologic examination of the eyes revealed septate fungal hyphae and inflammatory cells in the anterior chamber, cornea, and conjunctival sac. Similar fungal hyphae were present within lung granulomas. Aspergillus fumigatus was isolated from the eyes. Eye infections were the only health problem reported for several consecutive flocks on this farm. Elimination of moldy feed from the diet and environment and proper management of sawdust litter have prevented fungal ophthalmitis in subsequent flocks.

Relationship between age of flock seroconversion to hemorrhagic enteritis virus and appearance of adenoviral inclusions in the spleen and renal tubule epithelia of turkeys.

A retrospective study was conducted to evaluate the temporal relationship between flock seroconversion to hemorrhagic enteritis virus (HEV) and the appearance of adenoviral inclusions in the spleen and renal tubular epithelium. The study was conducted on samples of turkey poults submitted to the Fresno Branch of the California Veterinary Diagnostic Laboratory System during May to December 1988. The study included 78 submissions (four to eight poults per submission) of ages ranging from 6 to 15 weeks. Sera were tested for antibodies to HEV using the agar gel immunodiffusion test. Spleen and kidney samples were examined by light microscopy for the presence of inclusions in the mononuclear phagocytes of the spleen or in the renal tubular epithelium of the kidney. Logistic regression statistical analysis was used to evaluate the association between the age of the bird and the likelihood of the presence of inclusions in the spleen and kidney, as well as the likelihood of seroconversion to HEV. A significant association (P less than 0.05) was found between the presence of splenic inclusion bodies and the age of the bird. The probability of splenic inclusions was higher in younger birds (6 weeks of age), and decreased as the birds became older, approaching zero at 11 weeks of age. The kidney inclusions were significantly associated with age. The probability of detecting the inclusions increased with age, reached a maximum at 10 weeks, and then declined, approaching zero by 14 weeks. However, the probability of seroconversion to HEV increased significantly with age up to 10 weeks and then remained positive throughout the remainder of the study period.