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Biomedical subjects

R K Page

Publications and source records attributed to R K Page.

At least 19 recordsLinked to original sources
PubMed1986

The response of broiler chickens to the addition of bacitracin methylene disalicylate to diets containing salinomycin and roxarsone.

Two experiments were conducted to evaluate the response of broiler chickens to addition of bacitracin methylene disalicylate (BMD) to diets containing salinomycin. In each experiment, five tests were conducted at different locations. In Experiment 1, all diets contained 66 mg salinomycin/kg of diet for the first 42 days and either 0 or 33 mg BMD/kg of diet for the entire 49-day feeding period. In Experiment 2, all diets contained 66 mg salinomycin and 50 mg roxarsone/kg of diet for the first 42 days and either 0, 11, 33, or 55 mg BMD/kg of diet for the entire 49-day feeding period. In Experiment 1, addition of 33 mg BMD/kg of diet significantly (P less than .05) improved body weights and feed utilization. Results were similar in all five tests. In Experiment 2, addition of 11, 33, or 55 mg BMD/kg of diet significantly (P less than .05) increased body weights. In one location the addition of 55 mg BMD/kg of diet resulted in no significant difference in body weight compared with those fed the unsupplemented diet, but in all other locations the response was similar. Addition of 33 or 55 mg BMD/kg of diet resulted in improved (P less than .05) feed utilization when all tests were combined. Feed utilization was not improved in all locations by the addition of BMD.

Animal Feed↗
PubMed1985

The effect of aflatoxin on complement activity in broiler chickens.

Groups of broiler chickens were fed rations containing .625, 1.25, or 2.5 micrograms total aflatoxin/g of feed from one day to 42 days of age. Treatment groups were segregated according to sex and control groups were maintained. The chickens were bled at 14-day intervals, and serum was collected for assay of total complement (C) activity using a radial hemolytic procedure. No significant differences were found in C titers between males and females of the same age group. For the sexes combined, mean C titers of chickens fed aflatoxin were compared to mean titers of controls. For each age group, significant differences in C titers existed only between the control group and those chickens fed 2.5 micrograms/g aflatoxin. Complement is a major component of the humoral immune response and this study adds to the evidence that aflatoxin can be immunosuppressive to chickens.

Aflatoxins↗
PubMed1981

Tissue residues of dietary cadmium in wood ducks.

One-week-old wood ducks were fed cadmium in diets containing 18 or 30% protein for a period of three months. Seven drakes from each group were sacrificed, and blood, brain, muscle, kidney, liver, and wing feather tissues were collected and analyzed for cadmium. Highest cadmium concentrations were found in the kidney, liver, and feather tissues; blood, muscle, and brain cadmium residue levels were undetectable. Except in the kidney tissue, protein level of the diet did not affect cadmium residue levels. For birds that were changed to a cadmium-free, high-protein ration at 13 weeks of age, regression analysis indicated a significant decrease in cadmium residue levels for the kidney tissue only. Growth, as measured by bodyweight at 13 weeks of age, was not affected by the various cadmium treatment levels. Histopathological examination revealed lesions in the kidney tissues of the 100 ppm cadmium treatment groups, which were more severe in those birds receiving the 18% protein diet. Vacuolation of the pancreatic acinar cells was observed in all groups, but tended to occur more frequently in the higher cadmium level groups.

Animals↗
PubMed1980

Toxicity and bioaccumulation of pentachlorophenol in broiler chickens.

Hubbard-Hubbard broiler chickens were fed graded levels (0, 1, 10, 100, and 1000 ppm) of pentachlorophenol (PCP) containing less than .0023% octachlorodibenzo-p-dioxin (OCDD) for 8 weeks. Tissue samples for PCP, OCDD, and pentachloroanisole (PCA) were cleaned up via gel permeation chromatography and analyzed by gas chromatography employing electron capture detection. Kidney weights were significantly increased by the 100 ppm and 1000 ppm PCP diet. Weights of all other organs including the body weights were significantly lowered by the 1000 ppm PCP diet. Except for the control group, histopathologic examination of the liver revealed bile duct proliferation and some fatty changes in all of the 6-week-old birds. Examination of the brain, liver, gizzard, pancreas, intestine, proventriculus, spleen, kidney, lung, and heart revealed no histopathological lesions in the treated or control birds. Significant linear relationships were found between PCP accumulation in tissues and the concentration of dietary PCP. Accumulation of PCP was greatest in the kidney followed by liver, heart, leg, breast, gizzard, and fat. The high residue levels in the kidney and liver may reflect principal routes of elimination and metabolism. Following a 5 week withdrawal of PCP from the diet, PCP residues were still present in the adipose tissue of all treated birds. Residue levels in the kidney and liver were reduced at the first and third week of withdrawal, but a continuous decline was interrupted by a slight elevation in residue level at the fifth week of withdrawal from the chemical.

Animals↗
PubMed1980

Hemolytic complement activity in broiler chickens and turkeys.

Broiler chickens and turkeys were tested for hemolytic complement (C) activity at 7 or 14 day intervals beginning at one day of age and ending at 42 days of age. The mean titers for chickens on days 1, 14, 28, and 42 were 1:14, 1:14, 1:22, and 1:33, respectively. The mean C titers for turkeys on days 1, 7, 14, 21, 28, and 42 were 1:4, 1:6, 1:9, 1:10, 1:19, and 1:25, respectively. Birds were segregated as to sex so hemolytic activities could be compared. There were no significant differences between sexes in C titers in broiler chickens at any of the ages tested. This was also true of turkeys, except at 42 days of age when the C titer of the hens was significantly higher than the toms. Complement titers increased with age in both broiler chickens and turkeys.

Animals↗
PubMed1980

Comparison of inactivated and live infectious bursal disease virus vaccines in White Leghorn breeder flock.

Leghorn breeder chickens, which had received live infectious bursal disease (IBDV) virus vaccine at 12 weeks of age and had been injected subcutaneously at 20 weeks of age with an inactivated IBDV oil emulsion vaccine, produced very high antibody titers which persisted for at least 9 months and were more uniform than those obtained from breeders receiving only the live IBDV vaccine. Breeders vaccinated with the inactivated IBDV oil emulsion vaccine at 12 and 20 weeks of age had antibody titers higher than breeders which received only the live IBDV vaccine at 12 weeks of age; titers were lower than in the group which received both the live and inactivated oil emulsion IBDV vaccines. Maternal antibody levels in chickens derived from parent flocks vaccinated with the inactivated oil emulsion IBDV vaccine were higher and more uniform than in chickens derived from parent flocks vaccinated with the live IBDV vaccine. Maternal antibody persisted longer in chickens derived from parent flocks vaccinated at 20 weeks of age with the inactivated oil emulsion IBDV vaccine than in chickens vaccinated by the other procedures. The titers remained quite high up to 16 days of age.

Animals↗
PubMed1978

In vivo and in vitro studies on the effect of gentamicin sulfate on the efficacy of the turkey herpesvirus vaccine.

In vitro studies indicate that the titer of the cell-free or cell-associated turkey herpevirus (HVT) vaccine was not appreciably reduced when incubated with .1, .2, or .3 mg of gentamicin sulfate for up to 2 hr. However, the titer of both the cell-free and cell-associated HVT vaccines was reduced when incubated with .4 mg of gentamicin sulfate for 2 hr. However, in vivo studies show that the incidence of Marek's disease (MD) in chickens which were vaccinated with the cell-free or cell-associated HVT vaccine which had been incubated with ,1, .2, .3, or .4 mg of gentamicin sulfate up to 2 hr was not increased when compared to chickens receiving only the HVT vaccine. The results of other laboratory studies also show that there was no increase in the incidence of MD when comparing chickens which received either 1360 or 6360 PFU of cell-free HVT vaccine or 1250 or 5690 PFU of cell-associated HVT vaccine to those vaccinated with the same doses of cell-free or cell-associated HVT vaccine containing .2 mg of gentamicin sulfate.

Animals↗
PubMed1977

Efficacy of lincomycin feed medication for the control of necrotic enteritis in broiler-type chickens.

Necrotic enteritis was reproduced in two trials, conducted in a penned research-type broiler facility, by growing broiler-type chickens on litter obtained from a commercial poultry house which had experienced a chronic necrotic enteritis mortality problem. In each trial, various concentrations of lincomycin in feed were evaluated for effectiveness in controlling necrotic enteritis. Lincomycin was evaluated at concentrations of 2 to 100 g./ton in Trial 1 and at concentrations of 2 and 4 g./ton in Trial 2. In each trial, non-lincomycin medicated control groups were also included. Each trial included six treatment groups each consisting of four 60-bird replicates. The coccidiostat used in all groups in Trial 1 and in four of the six treatment groups of Trial 2 was the same as had been used on the farm which the litter had been obtained. No other medications were used in any groups. Clinical coccidiosis due to Eimeria brunetti and E. maxima was prevalent in both trials. Birds receiving lincomycin at a concentration of 2 g./ton, or higher, showed a significant reduction in mortality from necrotic enteritis when compared to birds in coccidiostat-control pens not receiving lincomycin medication. Clostridium perfringens was isolated from the litter in all pens and from the livers of birds dying from necrotic enteritis.

Animals↗
PubMed1977

Infectious coryza: cross-protection studies, using seven strains of Haemophilus gallinarum.

Bacterins prepared from 7 strains of Haemophilus gallinarum were used to immunized chickens for cross-protection studies. Three distinct immunotypes were distinguished. Slight protection between immunotypes was evident for some strains. Airsacculitis could be prevented by use of these bacterins; however, prevention was related to immunotype specificity. Hyaluronic acid found in 2 strains rendered them inagglutinable in homologous antiserums. Treatment with hyaluronidase rendered them agglutinable.

Agglutination Tests↗
PubMed1976

Long term studies comparing the efficacy of cell-free versus cell-associated HVT vaccines against Marek's disease.

In long-term field trials lasting approximately 12 months attempts were made to determine whether the cell-free HVT vaccine was as effective in reducing MD losses as the cell-associated HVT vaccine. Four trials were conducted in which flocks were vaccinated with either the cell-free or the cell-associated HVT vaccine. The cell-free HVT vaccine was as safe and effective in preventing MD as the cell-associated HVT vaccine. Although there were some losses due to MD in all flocks, there were also losses due to lymphoid leukosis, multiple hemangioma, liposarcoma or coccidiosis. Egg production was essentially the same in flocks vaccinated with the cell-free HVT vaccine as in those vaccinated with the cell-associated HVT vaccine.

Animals↗
PubMed1975

Efficacy of lyophilized turkey herpesvirus vaccine against Marek's disease in broilers.

Field trials involving approximately 1,250,000 chickens vaccinated with cell-free turkey herpesvirus (HVT) vaccine and 635,000 chickens vaccinated with cell-associated HVT vaccine howed both vaccines equally effective in reducing condemnations (attributable to Marek's disease) at the poultry processing plant. Vaccinated chickens were progeny of hens vaccinated at 1 day of age with cell-associated HVT vaccine. The maternal antibody did not interfere with the ability of either the cell-free or cell-associated HVT vaccine to provide protection for chickens against challenge from the virulent Marek's disease virus.

Animals↗
PubMedDate not supplied

An outbreak of type-C botulism in three-weeek-old broilers.

Botulism was diagnosed in 3-week-old broilers from clinical signs, absence of postmortem and histopathological lesions, and demonstration of toxin in the serum of comatose birds. Passive immunization of mice with Clostridium botulinum type-C antitoxin protected against a challenge with serum from comatose birds containing the Cl. botulinum toxin. Total mortality for the grow-out period exceeded 27% and was not altered by water medication with penicillin. Bacitracin at 100 g per ton reduced mortality to 5-7 birds per day.

Animals↗
PubMedDate not supplied

Teratogenic activity of Arasan fed to broiler breeder hens.

Tetramethylthiuramdisulfide (TMTD), the active ingredient in Arasan, fed to broiler breeder hens at 10, 20, or 40 ppm depressed egg production, reduced hatchability, and resulted in soft-shelled eggs. The progeny of these hens had anomalies manifested by bilaternal medial deviation of the toes, exophthalmia, and shortened femurs. Broiler breeder hens that consumed a ration containing 80 ppm of TMTD produced only soft-shelled eggs.

Abnormalities, Drug-Induced↗