Biomedical subjects

J N Beasley

Publications and source records attributed to J N Beasley.

At least 19 recordsLinked to original sources

PubMed2005

Respiratory infection of turkeys with Listeria monocytogenes Scott A.

The pathogenesis of L. monocytogenes strain Scott A was studied by challenging day-old male turkey poults by air sac inoculation with tryptose phosphate broth containing 10(0) cfu (control), 10(4), 10(5), and 10(6) cfu (low challenge), or 10(7) and 10(8) cfu (high challenge) of the Scott A (serotype 4b) strain of L. monocytogenes. Mortality at 2 wk postinfection (PI) ranged from 25% for low challenge to 100% for high challenge (P= 0.0001). Gross and histopathological lesions were observed in heart, liver, spleen, lung, and bursa of Fabricius of mortalities at 4 days PI. Listeria monocytogenes challenge resulted in significantly decreased relative weight of the bursa of Fabricius and increased relative weight of the spleen, and L. monocytogenes was isolated by direct plating of liver, pericardium, brain, and both left and right stifle joint synovium (knee) cultures, as well as gall bladder, yolk sac, and cecal tonsil from transfer swabs onto Listeria-selective agar. Isolates were confirmed as positive using Gram stain, biochemical tests, and the Biolog system. High challenge resulted in confirmed L. monocytogenes isolation from 48% of left knee and 59% of right knee cultures. Low challenge resulted in isolation of L. monocytogenes from 11% of both left and right knee cultures. These results suggest that L. monocytogenes Scott A colonization of turkey knee synovial tissue can initiate in day-of-age poults and that L. monocytogenes Scott A can be invasive through air sac infection.

Animals↗

PubMed1995

Experimental reproduction of proventriculitis using homogenates of proventricular tissue.

Proventriculitis is a problem affecting the processing of broiler carcasses, particularly those processed at 4 to 5 wk of age. The proventriculus and the gastric isthmus connecting the proventriculus to the gizzard are enlarged and swollen and often rupture during processing, causing carcass contamination. This study suggested that a filterable agent found in homogenated proventriculi can cause lesions similar to those seen in field cases. Proventriculitis was produced independently of an effect on growth, and only unfiltered homogenate caused stunting. Field birds with severe proventriculitis were shown to have increased body weights compared with birds without proventriculitis or with milder lesions. Intestinal weakness was not associated with proventriculitis and field birds with the most severe proventriculitis had stronger intestines. Although infectious proventriculitis has generally been reported as one of the lesions associated with stunting syndrome, these data suggest that it may have an independent etiology.

Animals↗

PubMed1995

The effect of dietary copper sulfate on infectious proventriculitis.

Oral inoculation of day-old broiler chicks with a crude homogenate of affected proventricular tissue, or the same homogenate filtered through a .2 micron filter caused proventricular lesions similar to those responsible for carcass contamination of broilers at processing. Dietary copper sulfate (CUS) has also been shown to produce similar lesions. In this study, we investigated the interaction between crude proventriculus homogenate or filtered proventriculus homogenate and 1 g/kg CUS added to a standard chicken diet. Cobb x Cobb female broiler chicks were distributed into six groups with four replicate battery pens per group. Birds were fed either a standard broiler starter diet or the same diet with 1 g/kg CUS. Each dietary treatment was inoculated per os with 1 mL of either sterile saline, unfiltered homogenate, or filtered homogenate. Both crude and filtered homogenates had a much stronger affect on proventriculus score than did Cu by itself, resulting in no interaction between either homogenate or filtrate and CUS. There was a significant and possibly antagonistic interaction on proventriculus relative weights in the CUS by filtrate group during Week 1 and a synergistic interaction in the CUS by homogenate group during Week 4. Body weights were decreased in birds fed homogenate or CUS, but not in birds fed filtrate. There was a protective effect shown by filtrate on body weight of birds fed both filtrate and CUS only during Week 1. There was a synergistic decrease in body weight of birds fed homogenate and CUS during Week 2. Overall feed conversion efficiency was significantly decreased in the homogenate treatment (P = .04) and decreased in the birds fed CUS (P = .1). There was a (4.2 vs 2.3) (P = .1) decrease in feed conversion efficiency in birds fed both homogenate and CUS. Natural exposure to low levels of the infectious agent present in the homogenates may interact with excess dietary CUS, resulting in increased proventriculus size and decrease in body weight and feed conversion efficiency.

Animals↗

PubMed1994

Age-related changes in the incidence of tibial dyschondroplasia in turkeys.

Age-related changes in the incidence and severity of tibial dyschondroplasia (TD) and its relationship to body weight and other bone pathologies were studied in turkeys from ages 2 through 15 wk. A steady increase in the incidence and severity of TD was observed from 11 wk onwards. Whereas there was no correlation between the body weight and TD in early ages, during Weeks 14 and 15 the turkeys with severe TD had significantly higher body weight relative to those without or with mild lesions. Starting from Week 13, hemorrhage was evident in the base of TD-affected growth plates of many turkeys, which increased linearly during the following weeks. Histological examination of these areas revealed mild necrosis with erosion in TD tissues accompanied by occasional bone formations, fibrosis, and the presence of multinucleate chondroclasts and large number of erythrocytes adjacent to lesions. Sporadic rod-like bacterial colonies were discernible in TD tissues and cartilage canals. These studies show 1) whereas the onset of TD may have an independent etiology, the severity of the disease may be influenced by a higher body weight; and 2) subepiphyseal hemorrhages possibly facilitate a healing-type response that leads to replacement of TD tissue by way of resorption, bone formation, and fibrosis, but simultaneously makes the tissue accessible to bacteria.

Age Factors↗

PubMed1994

The effect of microaerosolized hydrogen peroxide on bacterial and viral poultry pathogens.

The effect of microaerosolized H2O2 on bacterial and viral poultry pathogens was investigated. Bacterial cultures and viruses were dried on sterile glass Petri dishes and subjected to direct and indirect 5% (H2O2) microaerosol mist. In the trials using Escherichia coli and Staphylococcus aureus, there was complete inactivation following exposure to H2O2. Using Salmonella typhimurium, indirect exposure resulted in only partial inactivation whereas direct exposure to H2O2 gave complete inactivation. For the viruses studied, 5% H2O2 microaerosol mist completely inactivated infectious laryngotracheitis virus. Newcastle disease virus, infectious bronchitis virus, and avian influenza virus showed reduced infectivity but were not completely inactivated. Avian reovirus susceptibility varied with the method of exposure and infectious bursal disease virus was highly resistant. The use of 10% H2O2 mist, however, resulted in total inactivation of infectious bursal disease virus. The effect of 10% H2O2 on equipment and selected materials representative of a hatcher or poultry house was investigated. A solar cell calculator, a thermostat containing a microswitch, and samples of uncoated steel, galvanized steel, and uncoated aluminum were subjected to 10 fumigation cycles. No damage was detected in the calculator and the thermostat. Both the uncoated steel and the galvanized steel showed signs of oxidation. The aluminum did not show signs of oxidation.

Aerosols↗

PubMed1993

Development of PCR method specific for Marek's disease virus.

A rapid polymerase chain reaction (PCR) assay specific for Marek's Disease Virus (MDV) was developed. This assay was able to detect MDV in inoculated chick kidney cells at dilutions of 10(-5). Negative PCR results were obtained using uninoculated chick cells, Marek's Disease Vaccine (SB), Herpesvirus of Turkeys (HVT) and Fowl Laryngotracheitis Vaccine (LT). Bursae, feathers and kidneys from MDV infected chickens were positive in the PCR assay. The same tissues from normal chickens were negative. This method required only 0.5 h for sample preparatory, 3 h for PCR application and 1 h for electrophoresis. Internal probe hybridization confirmed that the PCR products are from MDV, but this hybridization will not be necessary for future MDV detection.

Animals↗

PubMed1991

Effects of dietary amino acid levels on bone development in broiler chickens.

Studies with several species suggest that dietary protein may influence bone calcification. Six pens of six male broilers in two consecutive trials were fed from 1 to 21 days either .5 or 1.0% Ca in diets with 80, 90, 100, 110, or 120% of the amino acid (AA) standards suggested by Thomas et al. in 1986 at a constant .46% nonphytate P. The BW and feed conversion rate (FCR) were determined, and bone measurements were taken. Both AA and Ca levels influenced BW with an interaction of the two factors. The Ca level, but not AA level, influenced FCR. The lower Ca level inhibited feed intake. Increasing AA levels reduced bone ash but did not affect tibia breaking strength. There was an interaction of AA and Ca on tibia ash, tibia weight, and tibia length. The higher AA levels supported normal linear growth of the tibia but decreased rate of calcification, especially in the diets with .5% Ca. In diets with marginal Ca levels, higher AA levels may reduce bone calcification.

Amino Acids↗

PubMed1989

Infection with and antibody response to Pasteurella multocida and Bordetella bronchiseptica in immature rabbits.

At 2, 4, 6, 8 and 10 weeks of age rabbits were cultured for Pasteurella multocida and Bordetella bronchiseptica from the paranasal sinuses, trachea, middle ears, lungs and liver. Sera were tested for antibodies (IgG) against P. multocida and B. bronchiseptica. Pasteurella multocida was isolated from all ages of rabbits, and B. bronchiseptica was isolated from rabbits 4 to 10 weeks old. The sinuses were colonized most often, followed by the trachea, middle ears and lungs. No bacteria were isolated from the liver. The number of rabbits with antibodies against both bacteria decreased between 2 and 6 weeks of age, indicating a fall in maternal antibodies, and increased between 6 and 8 weeks of age, suggesting an active humoral response.

Animals↗

PubMed1987

Citrinin toxicity in young chicks.

Two experiments were conducted to demonstrate the capacity of citrinin to cause dose-related increases in water consumption and urine excretion. In Experiment 1, chicks 24 days old were fed mixtures of untreated and inoculated corn containing citrinin to provide 0, 50, 100, 150, 200, and 250 micrograms of the toxin per gram of blended corn. The corn was fed for 4 hr, and water intake and urine excretion were measured. Chicks consumed 0, 1.23, 2.37, 3.68, 4.26 and 5.44 mg citrinin from the respective treatments. Compared with chicks consuming no citrinin, water intake and urine excretion of treated chicks increased (P less than .05) when chicks consumed 3.68 mg or more citrinin. Measures of the difference between water intake and urine excretion were similar for all treatments except for chicks consuming 3.68 mg citrinin; for those chicks the difference was significantly greater (P less than .05) than for chicks consuming 1.23 mg citrinin. In Experiment 2, inoculated corn was heated in a microwave oven for 1, 2, 8, and 16 min. Temperatures of the heated corn samples, when removed from the oven, were 76 C, 100 C and 105 C, respectively. Chicks that were 28 days old were fed these various samples of corn for 4 hr. Heating corn for 2 min to a temperature of 76 C caused no apparent loss of citrinin activity based on water intake and urine excretion measures. Heating the corn for 8 min to a temperature of 100 C destroyed some of the citrinin activity. Heating citrinin-contaminated corn to 105 C for 16 min destroyed the diuretic effect of the mycotoxin.

Animals↗

PubMed1985

The effect of drying method and storage time on citrinin activity in corn.

Sterilized whole corn was inoculated with a Penicillium spp.,3 a citrinin-producing fungus, and incubated at room temperature for 8 weeks. The corn was then blended and divided into two parts, which were dried either in air at room temperature (ADC) or in a forced draft oven at 60 C for 24 hr (ODC). Each batch of corn was ground and stored in plastic containers. The corn was fed to broiler chicks prior to and after 3, 6, 9, and 12 months of storage at 4 C. The inoculated corn was fed undiluted or blended with noninoculated corn to give mixtures containing one-third and two-thirds of inoculated corn. Noninoculated corn, inoculated corn, and blends of the two were fed to chicks for 5 hr as the only feed. Feed consumption, water intake, and excretion were measured at the end of the test. The citrinin contents of the ADC at 3, 6, 9, and 12 mo were 824, 599, 667, and 590 ppm and were 928, 541, 781, and 490 ppm for the ODC at the same periods. Water consumption and water excretion increased as the amount of citrinin intake increased. Neither drying method nor length of storage affected the citrinin activity in the corn. The citrinin in ODC was neither bound nor converted to a derivative that was unextractable.

Animal Feed↗

PubMed1985

Factors related to the incidence of the malabsorption syndrome.

Malabsorption syndrome has been produced in the laboratory with chicks and feed supplied by poultry integrators who had experienced the problem. Feed supplied by one company produced chicks that developed pale shanks and had apparent malabsorption of certain nutrients. One chick source also had a statistically lower pigmentation score than the other.

Animal Feed↗

PubMed1985

Effect of heat drying of corn on the extraction of citrinin.

Experiments were conducted to determine if drying citrinin-contaminated corn at varying temperatures and times either bound citrinin or converted it to a derivative that could not be extracted from the grain. Sterilized whole corn was inoculated with spores of a Penicillium spp. that produces citrinin and was incubated for 8 weeks. Following incubation, the corn was mixed and divided into three portions. In Experiment 1, one portion was dried at room temperature and the other portions were dried at 65 C for either 40 or 72 hr. In Experiment 2, one portion was air-dried and the other portions were dried at 60 C for 24 hr or 100 C for 3 hr. The corn was then ground to a texture suitable for feeding to chicks. Analysis of the corn indicated that temperature or length of drying time had no adverse effects on the extraction of citrinin from the corn. The citrinin was not rendered unextractable by either being bound because of heating or by being converted to a derivative. When fed to chicks for 5 hr, water consumption and urine excretion data indicated that there was no loss of citrinin activity because of method of drying.

Animal Feed↗

PubMed1983

Influence of temperature, moisture, and propionic acid on mold growth and toxin production on corn.

The influence of temperature and propionic acid on mold growth and toxin production on whole corn with 10, 15, or 20% added water was studied. Levels of propionic acid tested at each moisture level were 0, .025, .05, and .1%. Each flask of corn was inoculated with spores of a citrinin-producing Penicillium spp. and was then incubated for 8 weeks at a constant temperature of 5 C, at 5 C at night and room temperature during the day, or at room temperature both at night and during the day. The corn was then dried, ground, and fed to chicks to determine the presence of citrinin. Regardless of acid level or moisture content, neither mold growth nor toxin production occurred on the corn incubated at 5 C. Both mold growth and toxin production occurred on corn either partially or totally incubated at room temperature but were more prevalent in the latter. Increasing the moisture content resulted in greater mold growth and toxin production, especially on the corn incubated at room temperature. Higher levels of propionic acid were needed to prevent mold growth and toxin production as the moisture content of the corn increased.

Animals↗

PubMed1982

Digestion of dry matter and amino acids and energy utilization by chicks fed molded corn containing mycotoxins.

A study was conducted to determine the ability of chicks to digest dry matter and amino acids and to utilize the energy from uncontaminated corn and contaminated corn containing mycotoxins. The contaminated corn contained either aflatoxin from natural molding, citrinin by artificially molding with a Penicillum spp., or ochratoxin by inoculation with Aspergillus ochraceus. Compared to uncontaminated corn, none of the criteria measured was affected in corn contaminated with aflatoxin. Dry matter digestibility, amino acid digestibility, and energy utilization were reduced (P less than .05) when corn was artificially molded with the Pencillium spp. and with A. ochraceus.

Aflatoxins↗

PubMed1981

Benzoyl peroxide: percutaneous penetration and metabolic disposition.

The transepidermal penetration and metabolic disposition of 14C-benzoyl peroxide were assessed in vitro (excised human skin) and in vivo (rhesus monkey). In vitro, the benzoyl peroxide penetrated into the skin, through the stratum corneum or the follicular openings, or both, and was recovered on the dermal side as benzoic acid. In vivo, benzoic acid was recovered from urine in amounts equivalent to 45% and 98% of the radiolabel following, respectively, topical and intramuscular administration of small amounts of 14C-benzoyl peroxide. We conclude that benzoyl peroxide penetrates as such into the skin layers and is converted therein to benzoic acid, which, in turn is absorbed into the systemic circulation. Renal clearance of the metabolite is sufficiently rapid as to preclude its hepatic conjugation with glycine, since following topical administration to rhesus monkeys, no hippuric acid was found in the urine, as could have been expected had a significant amount of benzoic acid passed through the liver.

Administration, Topical↗

PubMed1981

Citrinin toxicity in growing chicks.

Male broiler chicks, from day-old to 3 weeks of age, were fed diets containing 0, 100, 220, 330, and 440 ppm citrinin produced by Penicillium lanosum grown on whole corn. Body weight decreased (P less than .05) when chicks were fed the diets containing 330 and 440 ppm citrinin. Average body weight of chicks fed the diet containing 220 ppm citrinin was 8% less than that of chicks fed no toxin. Feed utilization decreased (P less than .05) with chicks fed the diet containing 440 ppm citrinin. Analysis of thigh muscle, kidney, liver, and blood for citrinin revealed detectable amounts in the liver and blood of chicks fed 440 ppm.

Animals↗

PubMed1981

Effects of extracts of toxic fescue given orally to rats.

Fresh fescue (Festuca arundinacea) was obtained from farms where toxicity was encountered in cattle grazing the fescue. The fescue was dried in a forced draft oven at 60 degrees C and then ground. The dry ground fescue was extracted with ether and then re-extracted with either 1% sodium bicarbonate (NaHCO3), sodium hydroxide or hydrochloric acid. The residual ether was evaporated and the residue resuspended in ethyl alcohol diluted with water 1% (control) and 1 mL of the above extracts of fescue were given daily to rats, via stomach tube, beginning the seventh day after breeding. Two of the seven rats given the 1% NaHCO3 fraction of the extract of fescue gave birth to live young. One of these litters contained only five pups, with one being stillborn. Three of the seven rats aborted, one gave birth to seven stillborn pups and one female died during birth. All females fed the 1% NaHCO3 and the other extracts of the fescue gave birth to normal litters. Rats fed the ether extract which was re-extracted with 1% NaHCO3, acidified and re-extracted with ether, dried and resuspended in 1% NaHCO3 produced similar reproductive problems as those rats given the ether extract of fescue which was re-extracted only once with 1% NaHCO3. Therefore, it appears that the toxic entity(s) of fescue can be extracted and that infertility/abortion/still-birth ratio of rats may be used as a bioassay.

Administration, Oral↗

PubMed1980

The effect of feeding corn molded with Penicillium lanosum to broiler chicks.

Penicillium lanosum was isolated from broiler feed obtained from troughs in a house in which the litter was wet and the chicks were substantially smaller than expected at the time of slaughter. Corn was inoculated with the fungus, incubated for 8 weeks, dried, and incorporated in a broiler ration. The ration was fed to broiler chicks for a period of 2 weeks in order to evaluate toxicity. Experimental chicks developed diarrhea and grew slower than the controls. Gross lesions consisted of swollen kidneys and erosions in the lining of the gizzard. Histologic examination revealed mild toxic nephritis and growth of fungus in and on the surface of the gizzard lining. Penicillium lanosum was isolated from the gizzards of affected birds. Diarrhea but no gizzard lesions occurred in birds feld molded corn which had been treated with ethylene oxide. This finding indicates that this isolate of P. lanosum is both toxigenic and capable of producing gizzard erosion.

Animal Feed↗