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Biomedical subjects

P R Fitzgerald

Publications and source records attributed to P R Fitzgerald.

At least 19 recordsLinked to original sources
PubMed1989

Effects of intermittent and continuous administration of decoquinate on bovine coccidiosis in male calves.

Male Holstein calves were each inoculated with 350,000 sporulated oocysts of Eimeria bovis. Two calves were given decoquinate (0.5 mg/kg of body weight) continuously in dry feed for 29 days, and 2 calves each were given 0.5, 1, or 1.5 mg of decoquinate/kg on an every 2nd-or 3rd-day schedule for 29 days. Calves given decoquinate continuously did not discharge oocysts but had slightly loose feces. In general, the number of oocysts discharged increased and fecal consistency decreased as the time between feeding of medicated feed increased. Calves given 0.5 or 1.5 mg of decoquinate/kg every 3rd day discharged more oocysts and had more diarrhea than did calves given 1 mg of decoquinate/kg every 3rd day. At postinoculation day 29, calves were euthanatized. At necropsy, intestinal tissues of calves given decoquinate were mostly normal. Apparently, reduced infections along with the elapsed time were sufficient to resolve most intestinal lesions caused by the coccidia. Decoquinate was most effective when fed continuously at 0.5 mg/kg. However, when fed at 1 or 1.5 mg of decoquinate/kg every 2nd day or 1.5 mg of decoquinate/kg every 3rd day, oocyst production was reduced and clinical coccidiosis was prevented.

Administration, Oral↗
PubMed1989

Effects of inoculations with Eimeria zuernii on young calves treated with decoquinate or narasin with or without dexamethasone.

Sixteen 7-week-old Holstein male calves were inoculated with sporulated oocysts of Eimeria zuernii. Four calves (controls) were euthanatized and necropsied at 14 and 20 days after inoculation (DAI). Two calves were treated with 20 mg of dexamethasone (IM) on 13, 14, and 15 DAI and euthanatized and necropsied 17 DAI and 2 calves were given similar treatments and necropsied 20 DAI. The 8 other calves were euthanatized and necropsied 20 DAI. Two were started on the anticoccidial drug decoquinate in feed 13 DAI; 2 others were given decoquinate on the same schedule plus dexamethasone on 13,14, and 15 DAI. Two calves were given the antibiotic narasin in feed beginning 13 DAI and 2 calves were given parasin on the same schedule plus dexamethasone on 13,14, and 15 DAI. All calves, except 2 controls necropsied 14 DAI and 4 calves given decoquinate, discharged moderate-to-large numbers of oocysts in feces and had moderate-to-serve changes in fecal consistency. Histologic examinations revealed large numbers of endogenous stages in tissues of calves treated or not treated with dexamethasone. Few endogenous stages were observed in tissues from calves that were given decoquinate or decoquinate plus dexamethasone. Calves given narasin or narasin plus dexamethasone had moderate-to-large numbers of endogenous stages in the tissues.

Animals↗
PubMed1986

Effect of decoquinate on the control of coccidiosis in young ruminating calves.

Twenty-five 6-week-old Holstein male calves were each inoculated with 500,000 sporulated oocysts of Eimeria bovis. Two nontreated (control) and 3 treated calves (1.5 mg of decoquinate/kg of body weight in feed) were necropsied 7 days after inoculation. Similar groups of calves were necropsied at 12, 18, 22, and 28 days after inoculation. Treated calves were started on medicated feed 2 days before inoculation or at 7, 12, or 15 days after inoculation or were on continuous medication from the day of inoculation. Control calves were not given medication. Early schizonts were in the small intestines of control calves at 7 days after inoculation, but none was in the treated calves that were started on medicated feed 2 days before inoculation. Schizonts were present in the small intestine of both treated and control calves at 12 days after inoculation. At 18 days after inoculation, control calves had schizonts in the small intestine and gamonts and oocysts in the cecum and large intestines, but treated calves only had schizonts in the small intestine. At 22 days, control calves had schizonts in the small intestine and gamonts and oocysts in the large intestine; treated calves had schizonts in the small intestine. At 28 days, controls still had schizonts in the small intestine and gamonts and oocysts in the cecum and large intestine; the treated calves that had been on continuous medication did not have schizonts, gamonts, or oocysts in the tissues. Decoquinate apparently kills sporozoites or arrests development and release of merozoites from the schizonts when fed at 1.5 mg/kg of body weight in the feed.

Animal Feed↗
PubMed1985

Heavy metals in tissues of cattle exposed to sludge-treated pastures for eight years.

Cattle allowed to graze pastures variously treated with anaerobically digested sludge (ADS) for up to 8 years, contained higher concentrations of heavy metals and organic compounds in some tissues than did cattle not exposed to ADS. Chemical analyses were made on heart, diaphragm, liver, kidney, brain, and bone to determine the amount of Zn, Cu, Cd, Cr, Ni, Pb, Fe, and Hg. Determinations for organic compounds (polychlorinated-biphenyls, dieldrin, and heptachlor/epoxide) were made on visceral fat. Cadmium was the only metal to accumulate consistently in increased amounts. Amounts of Cd accumulated in kidneys and livers were higher in cattle exposed to ADS than in cattle not exposed to ADS. Although the amounts were higher in cattle exposed to ADS, none of the cattle had detectable evidence of disease or pathologic conditions. The mean amount of Cd in kidneys of cattle exposed to ADS was 44 vs 9 mg/kg dry weight. Amounts of other heavy metals in the body tissues were generally not unusual and were similar in both groups of cattle. Polychlorinated-biphenyl concentrations were higher in the visceral fat of cattle exposed to ADS. All cattle in both herds remained healthy, and pathologic changes that could be attributed to association with ADS were not detected. Seemingly, ADS can be used safely to produce cattle forage without endangering the health of cattle.

Adipose Tissue↗
PubMed1985

Heavy metals in fluids and tissues of fetal calves and in young calves of nursing cows exposed or not exposed to anaerobically digested wastewater sludge.

Fetal fluid, diaphragm muscle, heart, kidney, and liver from 14 four- to five-month-old calf fetuses were analyzed for Zn, Cu, Cd, Cr, Ni, Pb, and Fe. The same tissues and bone were examined from postparturient calves 30, 60, and 120 days of age. Weaned calves (8 to 9 months old) were necropsied and diaphragm muscle, heart, kidney, liver, brain, and bone were analyzed. Additional calves from cows exposed or not exposed to anaerobically digested sludge were placed in a feed yard at weaning for a feeding period of 150 days and then were killed and necropsied. Heavy metal content of the aforementioned tissues was compared with the same tissues obtained from peer calves weaned, killed, and necropsied 150 days earlier. Zinc, Cu, and Fe were up to 11 times higher in fetal livers than in control or exposed postparturient calves. These concentrations declined after birth and stabilized at approximately the concentrations observed in adult cattle at about 12 to 14 months of age. Cadmium accumulated to a greater extent in kidneys and livers of exposed calves than in control calves. However, the accumulation did not produce a detectable effect upon the functional or morphologic characteristics of the organs examined. Other metals were present at low levels and were generally not remarkably different in control and exposed animals.

Age Factors↗
PubMed1985

The relationship of Baylisascaris procyonis to Illinois raccoons (Procyon lotor).

The gastrointestinal tracts of 310 steel-trapped or hunter shot Illinois raccoons (Procyon lotor) were collected in November and December 1979 and 1980 and examined for the presence of Baylisascaris procyonis (Nematoda) in order to determine the prevalence and intensity of this ascarid and to note any differences with respect to host age and sex. The raccoons were classified as either juveniles (animals less than 1 yr old) or adults. The prevalence for all the raccoons examined was 81.9% and is the highest reported in the United States when compared to other moderate to large samples. Juvenile raccoons had a significantly higher (P less than 0.0005) prevalence (93.5%) and mean intensity (62.4) than adults (55.3%; 11.8). Male raccoons had a significantly higher (P less than 0.025) prevalence (87.6%) than females (76.4%). Adult males had a significantly higher (P less than 0.05) prevalence (66.7%) than adult females (44.9%). In the other comparisons, no significant differences (P less than 0.05) in either prevalence or intensity were found. Since juveniles are more heavily infected than adults, they most likely pose a greater threat to other animals and humans as a potential cause of visceral larva migrans. It is advisable that all young raccoons kept as pets or in captivity be systematically and routinely treated with an appropriate anthelminthic to remove adult B. procyonis from the intestine.

Age Factors↗
PubMed1984

The iron-zinc interrelationship in the chick as influenced by Eimeria acervulina infection.

Two 14-day growth trials were performed to assess the effects of Eimeria acervulina infection (duodenal coccidiosis) on the Fe-Zn interrelationship in growing chicks. In the first assay, two levels of Fe (0 and 2000 mg/kg) were added to diets that contained either 0 or 52 mg supplemental Zn (from ZnCO3) per kilogram to establish whether excess Fe would affect Zn status of healthy and coccidial-infected chicks. In the second trial, either 0 or 2000 mg Zn/kg was added to diets containing 0 or 500 mg Fe/kg to determine whether Zn could modify Fe utilization. Based on chick performance as well as plasma Zn concentration, excess dietary Fe did not antagonize Zn in either healthy or E. acervulina-infected chicks. Coccidial infection, however, increased liver Fe and decreased intestinal Fe and hemoglobin concentration. Excess dietary Zn reduced performance and Fe content of tissues in both healthy and infected chicks. Coccidial infection ameliorated the adverse effects of excess Zn on performance and tissue Zn concentration and consequently enhanced Fe status of birds fed 2000 mg Zn/kg. These data suggest that the Fe-Zn interaction is a one-directional phenomenon in the chick, i.e., excess Zn reduces Fe utilization but excess Fe does not antagonize Zn.

Animals↗
PubMed1984

Lead toxicity in the chick as affected by excess copper and zinc and by Eimeria acervulina infection.

Several experiments were performed with young chicks to evaluate lead (Pb) toxicity and its effect upon copper (Cu) and zinc (Zn) toxicosis in the presence or absence of Eimeria acervulina infection. Toxic levels of Pb (3300 mg/kg) and Cu (500 mg/kg) or Zn (2000 and 4000 mg/kg) were added to completely adequate corn-soybean meal diets, while duodenal coccidiosis was produced by multiple crop inoculations of 4 X 10(5) sporulated E. acervulina oocysts. Both Pb and Cu depressed gain and feed efficiency while concomitant coccidial infection reduced these parameters further. Moreover, E. acervulina increased the concentration of liver Cu and kidney Pb. Although Pb supplementation slightly decreased the accumulation of liver Cu, additional Cu tended to increase the deposition of Pb in the kidney in both infected and uninfected birds. Similarly, chick performance was significantly reduced by excess dietary Pb or Zn, although coccidiosis slightly ameliorated the growth depression caused by toxic levels (4000 mg/kg) of Zn. Although 4000 ppm Zn and coccidial infection reduced the deposition of Pb in the kidney, this interaction was not evident when 2000 mg/kg Zn was fed to infected chicks. It is evident that Pb toxicosis in the chick is affected little by excess dietary levels of either Cu or Zn.

Animal Feed↗
PubMed1984

Eimeria acervulina infection and the zinc-cadmium interrelationship in the chick.

The purpose of this study was to evaluate the effects of Eimeria acervulina infection (duodenal coccidiosis) on cadmium (Cd) toxicity and zinc (Zn) status in the young chick. Additions of Cd (45 mg/kg) were made to diets that contained either 0 or 52 mg/kg supplemental Zn (from ZnCO3). Duodenal coccidiosis was produced by multiple crop inoculations of 4 X 10(5) sporulated E. acervulina oocysts. Growth and efficiency of feed utilization were reduced by dietary Cd addition while concurrent coccidial infection reduced these parameters further. Addition of Cd also increased Cd content of liver and kidney and depressed hemoglobin, hematocrit, and plasma Zn content. Coccidial infection exacerbated tissue Cd deposition and depressed hematological parameters further. Although dietary Zn addition ameliorated some of the adverse effects of Cd toxicity, Cd administration tended to enhance tissue Zn deposition. Administration of Cd enhanced synthesis of metallothionein.

Animals↗
PubMed1984

Zinc utilization in the chick as influenced by dietary concentrations of calcium and phytate and by Eimeria acervulina infection.

Experiments were performed to investigate the effects of Eimeria acervulina infection (duodenal coccidiosis) on the zinc (Zn)-calcium (Ca)-phytate interrelationship in the chick. Three supplemental levels of Ca (0, .91, and 1.82%), two of Zn (0 or 52 mg/kg), and two of sodium phytate (0 or 1.2%) were evaluated as to their effects when added to completely adequate corn-soybean meal diets. Duodenal coccidiosis was produced by multiple crop inoculations of 4 X 10(5) sporulated E. acervulina oocysts. Calcium supplementation depressed gain and efficiency of feed utilization, while Zn content of tissue and plasma was also lowered. Coccidial infection tended to reduce these values further. The addition of dietary phytate also depressed performance and deposition of Zn in tissue. Both excess dietary Ca and phytate addition to the diet markedly reduced plasma Zn concentration of birds fed corn-soybean meal diets unsupplemented with Zn. Addition of 52 mg/kg Zn, however, prevented excess Ca or phytate from exerting this effect. Parasitized chicks responded markedly with increased gain and gain/feed ratios when 52 mg/kg supplemental Zn was added to a 24% protein corn-soybean meal diet containing 1.82% total dietary Ca. It is evident, therefore, that the Zn-antagonizing effect of excess Ca (in the presence of phytate) is exacerbated by duodenal coccidiosis.

Animals↗
PubMed1984

Control of bovine coccidiosis with monensin: in nonresistant newborn calves.

Newborn Holstein male calves were purchased within 3 days after birth and were removed from the local farms to the Dixon Springs Agricultural Research Center. They were hand-fed for 7 weeks and then weaned to a prepared feed. Eight groups, each of 4 calves, were housed in separate pens. In each of 4 pens (pens 2 to 5), 1 calf was inoculated with sporulated oocysts of Eimeria bovis (and was not medicated); 1 calf was inoculated and given feed with added monensin at the dosage level of 10 g/906 kg of feed; and 2 calves were inoculated and given medicated feed with added monensin at the dosage level of 20 g/906 kg or 30 g/906 kg. In the 4 other pens (6 to 9), the calves were inoculated with E zuernii and otherwise were given feed without or with added monensin as in pens 2 through 5. Another group of 5 calves (all kept in 1 pen), served as noninoculated, nonmedicated controls. At 14 days after inoculations with E bovis, the single calves in each of the 4 pens that were given the nonmedicated feed began to show clinical signs of coccidiosis and discharged increasing numbers of oocysts. The other inoculated calves (given monensin) had fewer clinical signs and discharged fewer oocysts in the feces as the level of medication in the feed increased. The calves inoculated with E zuernii developed only moderately severe infections when compared with those inoculated with E bovis. Inoculated (with E bovis) nonmedicated calves had severe reductions in feed consumption and weight, and 3 of 4 died.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1978

Ovine coccidiosis: effect of the antibiotic monensin against Eimeria ninakohlyakimovae and other naturally occurring coccidia of sheep.

Sixteen female and 16 male lambs were used in 4 groups to determine the effect of monensin on naturally occurring and experimentally induced coccidiosis. Determinations of numbers of oocysts discharged, quantities of feces discharged, feed consumption, and weight gain were made for female and male lambs in each group. The effect of experimentally induced and naturally occurring coccidiosis on the performance of each group was compared. Nonmedicated lambs, experimentally inoculated with Eimeria ninakohlyakimovae, gained the least weight. Lambs naturally infected with coccidia gained next best and inoculated lambs, in 2 groups medicated with 10 or 20 ppm of monensin in the feed, gained best. The average net gain for the 4 groups was 7.8, 9.7, 13.7, and 13.7 kg. The medicated lambs required less feed/kilogram of weight gain than did the nonmedicated lambs. In general, female lambs were more severely affected by the coccidia, consumed more feed, produced more fecal material, and gained less weight than did male lambs.

Animal Feed↗
PubMed1978

Survival of Trichinella spiralis larvae in sewage sludge anaerobic digesters.

The survival of some bacteria, viruses, protozoans, and helminths through the sewage digestion process has been a question of considerable concern among researchers throughout the world. Among the most resistant organisms are some of the pathogenic roundworms and tapeworms. Encysted larvae of Trichinella spiralis are sometimes present in animal tissues discarded as waste from slaughterhouses, restaurants or other sources. In experimental anaerobic sewage digesters, encysted larvae of T. spiralis, in rat muscle, were able to survive a maximum of 96 hr in a "batch" digester. In a digester "fed" daily with small numbers of encysted larvae, "draw-off" remained infective for white rats throughout a 16-day experimental period. Potentially infective material could be present when there is continuous "draw-off" from the anaerobic digesters.

Anaerobiosis↗
PubMed1976

Efficacy of antibiotics A204 sodium A28695A, and A204np against Coccidia of rabbits.

Three polycyclic, polyether, monocarboxylic acid antibiotics produced by and extracted from a strain of Streptomyces albus and designated A204 sodium, A28695A, or A204-np, were specifically tested for activity against hepatic and incidentally against intestinal coccidia of rabbits. All were effective in preventing infections and acceptable to young rabbits when prepared in pelleted feed. Weight gain, however, was not as good as inoculated, medicated rabbits as in noninoculated, nonmedicated controls. No gross pathologic changes were detected except in the livers of inoculated, nonmedicated controls which were severely infected on greatly enlarged. Livers of medicated rabbits were uninfected and normal in appearance and size.

Animals↗