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Biomedical subjects

M D Ruff

Publications and source records attributed to M D Ruff.

At least 55 records · Page 3Linked to original sources
PubMed1978

Disaccharidase activity in the intestinal tissue of broilers infected with coccidia.

Maltase and sucrase activities were measured in the intestine of broilers inoculated with sporulated coccidial oocysts. Infection with Eimeria acervulina, E. maxima, E. necatrix, and E. brunetti decreased disaccharidase activity in the intestinal region in which maximum infection was found compared with the activity in uninoculated controls. The maximum reduction occurred on the first or second day of patency followed by a rapid recovery in activity. Disaccharidase activity was inversely proportional to the inoculum dose.

Animals↗
PubMed1978

Effect of the anticoccidial arprinocid on production, sporulation, and infectivity of Eimeria oocysts.

Medication of broilers with arprinocid [MK-302, 9-(2-chloro-6-fluorbenzyl adenine)] had 3 distinct effects on oocysts; (1) the number of oocysts produced was decreased, (2) fewer of the oocysts sporulated, and (3) those oocysts which did sporulate were less infective than those from unmedicated birds. The drug level necessary to prevent passage of oocysts depended on the species and strain of coccidia. To essentially eliminate oocyst production (less than 5% of controls) required medication with the following levels of arprinocid: 70 ppm with Eimeria maxima; 60 ppm with E. mivati, E. E. necatrix, and E. brunetti; and 50 ppm with E. tenella. With E. acervulina, oocysts were completely eliminated by 60 ppm of arprinocid with one field strain but were still numerous at 70 ppm with a second field strain. Oocysts recovered from birds on medication often failed to sporulate. No sporulation was seen at drug levels of 30 ppm or above with E. maxima and E. mivati. The level of arpinocid required to prevent sporulation with other species depended on the strain being studied, but varied from 30 ppm to 70 ppm. The oocysts of E. acervulina, E. mivati, E. tenella, and E. brunetti recovered from medicated birds that subsequently sporulated, were less infective when inoculated into susceptible birds, than oocysts from unmedicated birds. Oocysts from low medication level with E. necatrix (30 ppm) and E. maxima (10 ppm), once sporulated, were as infective as oocysts from unmedicated control birds, even though the numbers produced were less. No differences were detected in the time oocysts were produced between medicated and unmedicated birds infected with E. acervulina, E. maxima, E. brunetti, and E. tenella.

Adenine↗
PubMed1978

Effect of coccidiosis on blood coagulation in broilers.

Severe infection with Eimeria acervulina, Eimeria maxima, Eimeria necatrix, and Eimeria tenella increased the prothrombin times in broilers compared with the times in uninfected birds. Recalcification time was not affected. The increase in prothrombin time was related to the severity of infection (as measured by lesion score), and was significant (P less than or equal to 0.05) only in the most severely infected birds. The increase was of short duration, lasting only 1 or 2 days, and first appeared on day 5 or 6 postinoculation. Restricting the feed intake of uninoculated birds to the amount of feed consumed by infected birds showed that the reduction in feed intake with coccidiosis was not responsible for the increase in prothrombin time.

Animals↗
PubMed1977

Anticoccidial activity of salinomycin in battery raised broiler chickens.

Infections with single species of Eimeria acervulina, E. mivati, E. maxima, E. tenella, E. necatrix, and E. brunetti, and the six species mixed, were utilized in three separate battery experiments to evaluate the anticoccidial efficacy of various levels of salinomycin (AHR-3096), a fermentation product of a strain of Streptomyces albus. At the 60 to 100 p.p.m. treatment levels, this compound showed significant anticoccidial activity for all parameters studied (mortality, weight gain, feed conversion, dropping scores, and lesion scores). The mortality due to coccidiosis was reduced to 0.1% in the medicated infected birds. Some activity, as measured by weight gain, was seen in the lower levels of salinomycin medication (12.5 to 50 p.p.m.), but other parameters, including mortality and lesion scores, indicated less activity than that seen with the higher treatment levels. At 100 p.p.m., there was no apparent effect on the compound on bird performance in uninfected control birds. Salinomycin at the 100 p.p.m. treatment level was statistically as effective as 121 p.p.m. monensin (reference anticoccidial) in controlling coccidiosis.

Animal Feed↗
PubMed1977

Anticoccidial activity of salinomycin in floor-pen experiments with broilers.

The anticoccidial agent salinomycin (AHR-3096) was compared at various treatment levels (60 to 100 p.p.m.) in two experiments against unmedicated and either 100 or 121 p.p.m. monensin-medicated groups to evaluate its performance under floor-pen conditions. Various methods for the initial rearing of birds and coccidial exposure were employed to test the efficacy of salinomycin against severe, moderate, and mild coccidiosis. Salinomycin at all treatment levels showed definite anticoccidial activity resulting in improved weights, feed conversion ratios, lesion scores, and mortality compared with unmedicated controls. In pens with severe coccidiosis, this compound demonstrated a significant improvement in all parameters when compared with the corresponding unmedicated controls. Salinomycin-treated pens exposed to light coccidiosis usually had a numerical increase in the parameters over the unmedicated control groups. Statistical analysis of overall main effects on mortality, weight gain, and feed conversion ratio showed no significant differences between the activity of any level of salinomycin and monensin.

Animal Feed↗
PubMed1977

Comparison of the intestinal surface damage caused by Eimeria mivati, E. necatrix, E. maxima, E. brunetti, and E. acervulina by scanning electron microscopy.

Eimeria brunetti, an intestinal coccidial parasite of poultry, caused the most severe mucosal damage when compared to E. mivati, E. necatrix, and E. maxima. The damage caused by E. brunetti was observed in the ileum and large intestine and consisted of complete villar destruction in these areas. Oocysts of E. brunetti were observed in tissue debris. E. necatrix (jejunum) enlarged isolated villi causing the lamina propria core to extrude through the villus tip. Damage to the mucosal surface is not as severe as lesions observed on the serosal surface would indicate. E. maxima (jejunum) caused epithelial sloughing and isolated patches of exposed connective tissue. Oocysts of E. maxima were observed under the surface epithelial layer. E. mivati damaged the villus tips of the duodenum and caused sloughing of the villar epithelia exposuncated and clubbed the duodenal villi. E. mivati oocysts were observed in the infected epithelia.

Animals↗
PubMed1976

Effect of dietary methionine status on response of chicks to coccidial infection.

Three experiments determined if the methionine requirement of broiler chicks was affected by coccidial infection. Chicks were fed a corn-soy or a corn-soy-pea basal diet containing 0.73% and 0.62% total sulfur amino acids (TSAA), respectively. Levels of 0 to 0.45% DL-methionine were added, with and without 0.01% monensin sodium. In two experiments, the chicks were inoculated at two weeks of age with a mixture of oocysts of E. acervulina, E. maxima, E. tenella, E. necatrix and E. brunetti. Lesion scores on the intestines and ceca, and blood carotenoid levels were determined at three weeks. The experiments were terminated at four weeks. A level of methionine greater than 0.47% and of TSAA greater than 0.83% was necessary to obtain maximum growth rate in uninoculated chicks. No evidence of dermatitis was observed. Growth rate and feed efficiency of chicks infected with coccidiosis were more severly depressed when the diet was not supplemented with methionine. Infections of coccidia and low levels of methionine, which in themselves did not produce any significant change in weight gain, did give a significant weight depression in combination. Adding monensin to the diet prevented a reduction in growth rate and feed efficiency of inoculated chicks fed adequate methionine. Monensin did not completely prevent the adverse effects of a coccidial infection, based on feed efficiency, when chicks were fed diets inadequate in methionine. Blood carotenoid levels were not affected by methionine level, but were significantly lowered by coccidial infection in the absence of monensin. Intestinal and cecal lesions in inoculated chicks were significantly reduced by including monesin in the diet. Although the coccidial infection more severly affected the performance of chicks fed diets deficient in methionine, satistical analysis of pooled data indicated no difference in the quantitative requirement of chicks for methionine. Therefore, a level of methionine and cystine adequate for optimum growth under the coccidial-free conditions should be adequate for chicks when infected with coccidia.

Animals↗
PubMed1976

Efficacy of different feeding levels of monensin in the control of coccidiosis in broilers.

The feed level of monensin which gave maximal protection from coccidial infection in broilers reared in floor pens depended on the severity of the coccidial exposure and the criteria of infection studied. With indirect seeding of pens with coccidia (light coccidial exposure), 40 ppm was as efficacious as 100 ppm in improving weight gain, lesion score, and feed conversion. Statistical analysis with direct seeding (seeder birds; severe coccidial exposure) showed that feed levels of 84 and 102 ppm gave maximal improvement of weight gain and 4-week feed conversion, respectively. Further increasing the monensin level from 100 to 121 ppm did not improve weight gain and feed conversion at 8 weeks. Conversely, the relationship of plasma pigmentation and total lesion scores to monensin feed levels indicated that increasing the dosage of monensin from 100 to 121 ppm improved the performance of the broilers on the basis of these 2 infection indicators.

Administration, Oral↗
PubMed1975

Some mechanisms of reduction of carotenoid levels in chickens infected with Eimeria acervulina or E. tenella.

The levels of plasma carotenoids were markedly reduced in broiler cockerels infected with Eimeria acervulina or E. tenella. The mechanisms of this depigmentation differed between the two species, being primarily associated with interference of absorption of xanthophyll (carotenoids) from the intestinal lumen with E. acervulina infection and with leakage through the damaged wall of the cecum with E. tenella infection. Chicks reared on an essentially carotenoid-free diet and inoculated with E. acervulina showed no detectable levels of carotenoids in the blood 48 hours after being changed to a diet containing 30 mg of xanthophyll/kg. Conversely, uninoculated chicks and chicks inoculated with E. tenella showed significant and similar increases in plasma levels of carotenoids. Chicks reared on a diet containing xanthophyll and inoculated with E. tenella showed a more rapid decrease in plasma carotenoids than did uninoculated controls when changed to a xanthophyll-free diet. In chicks fed high xanthophyll diets containing chromic oxide, no indication of malabsorption was seen in chicks infected with E. tenella compared with uninoculated controls, whereas chicks inoculated with E. acervulina showed significantly less xanthophyll absorption. Conversely, a marked increase in the xanthophyll : Cr2O3 ratio was observed in the cecal contents of chicks inoculated with E. tenella compared with uninuoculated controls or those inoculated with E. acervulina. Studies of uninoculated chicks pair-fed with chicks inoculated with E. acervulina or E. tenella indicated that the decrease in plasma carotenoids and increases in intestinal pH are not associated with the reduced intake of feed associated with infection. The studies involving uninoculated birds with reciprocal chagnes between high and low xanthophyll diets indicated that plasma carotenoids are a more rapid and sensitive means of measuring changes in pigmentation levels than are visual skin scores carotenoid levels from the skin.

Animals↗
PubMed1975

A rapid technique for the cleaning and concentration of Eimeria oocysts.

A technique using 1% sodium bicarbonate, ether and centrifugation was developed for cleaning oocyts of Eimeria tenella, E. maxima or E. mivati. The speed and efficiency of this technique was compared with the sedimentation technique currently used in many laboratories. Parameters measured were percent sporulation after cleaning and number of oocysts recovered. Suspensions of oocysts cleaned by bicarbonate and ether consistently yielded a similar or superior percent sporulation. In four of the five trials bicarbonate and ether recovered a larger number of oocysts from feces. To determine the storage stability of oocysts cleaned with bicarbonate and ether in comparison with sedimentation cleaned oocysts, suspensions of Eimeria tenella and E. mivati were stored at 4 degrees C. and atssayed initially after harvest and a three month intervals thereafter. The parameters of bird weight gain, lesion score, mortality and feed conversion were measured to test viability of oocysts. Bicarbonate and ether cleaning had no initial deleterious effect on oocyst viability. After 6 months storage, oocysts of Eimeria cleaned with bicarbonate and ether maintained viability similar or superior to oocysts cleaned by sedimentation.

Animals↗