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Biomedical subjects

W M Reid

Publications and source records attributed to W M Reid.

100 records · Page 6Linked to original sources
PubMedDate not supplied

Interaction of infectious bursal disease and coccidiosis in layer replacement chickens.

During a floor-pen study on anticoccidial programs for layer-replacement pullets, there was a natural outbreak of infectious bursal disease (IBD). The interaction of coccidiosis and IBD was characterized by: excessive deaths from coccidiosis; and apparent failure of some anticoccidial drug treatments. Immunity to coccidiosis was not blocked by the IBD infection, although immunity was less in some treatments than would be expected with the degree of coccidiosis exposure.

Animals↗
PubMedDate not supplied

Coccidiosis and intestinal pH in chickens.

The intestinal contents of white Leghorn cockerels were significantly lower in pH in birds infected with Eimeria mivati, E. maxima, or E. necatrix than in uninoculated control birds. The particular Eimeria species used affected the region of the intestine involved, the days (5-9 postinoculation) on which pH decreased, and the magnitude of the decrease. The effects on the magnitude and frequency of pH decrease were as follows: E. mivati, marked in the duodenum and jejunum, variable in the ileum; E. maxima, slight in the duodenum, variable in the jejunum and ileum; E. necatrix, no change in the duodenum, variable in the jejunum and ileum. Infection with E. tenella did not change the intestinal pH. The pH of the gizzard was occasionally higher in birds infected with E. mivati or E. necatrix than in uninoculated control birds. With all four species, on some days the pH in the ceca was higher than in the ceca of controls. These results and previous reports indicate that infection with one of the above four species or with E. acervulina or E. brunetti produces the greatest and most consistent decrease in pH in the region of the intestine where the particular species characteristically produces the severest infection.

Animals↗
PubMedDate not supplied

Efficacy of arprinocid against coccidiosis of broilers in battery and floor-pen trials.

Medication of broilers with arprinocid [9-(2-chloro-6-fluorophenylmethyl)-9H-purine-6-amine] gave protection against the effects of coccidiosis in both battery and floor-pen trials. In battery trials, efficacy was tested on single-species inoculations of Eimeria acervulina, E. mivati, E. necatrix, E. maxima, E. Brunetti, and E. tenella. Two strains of each species recently recovered from the field, were tested separately. In floor-pen trials, all six species, both field and laboratory strains, were used as a mixed infection. In batteries, 60 and 70 ppm essentially eliminated coccidiosis-induced mortality and weight depression. Effects of 50 ppm on weight gain were variable. The effectiveness of different medication levels varied between strains within a species. In floor-pen trials, 40, 60, or 80 ppm was effective in controlling mortality and weight depression, and increasing feel-conversion ratios. All levels were significantly as effective as monensin in protecting against coccidiosis. With severe exposure to coccidia, 60 and 80 ppm gave significantly lower lesion socres than did 40 ppm of arprinocid or 120 ppm monensin.

Adenine↗
PubMedDate not supplied

Development of immunity to coccidiosis in chickens administered anticoccidials in feed.

New combinations of techniques were employed for comparing the development of immunity of Eimeria tenella in chickens being medicated with 12 different anticoccidials. Broiler-type birds in batteries received a daily measured dose of E. tenella oocysts for 15 consecutive days while the drug was administered at the manufacturer's recommended level. Two or more tests of each drug gave the following ratings: strong suppression, monensin (121 ppm), salinomycin (80 ppm), lasalocid (75 ppm); moderate suppression, monensin (100 ppm), decoquinate (30 ppm), clopidol (125 ppm), and narasin (80 ppm); slight suppression, arprinocid (70 ppm), nicarbazin (125 ppm), and amprolium (125 ppm + ethopabate (4 ppm); no effect, robenidine (33 ppm), zoalene (125 ppm), and aklomide (250 ppm).

Amprolium↗
PubMedDate not supplied

Efficacy of monensin against turkey coccidiosis in laboratory and floor-pen experiments.

Monensin at 60, 80, or 100 ppm in feed reduced mortality and lesion scores while protecting against weight loss of turkeys infected with the major pathogenic species: Eimeria adenoides, E. meleagrimitis, and E. gallopavonis. With single and mixed infections in battery-cage experiments, the death rate of unmedicated turkey poults was 33-75%. Weight gains were significantly (P is less than or equal to 0.05) better with 100 ppm monensin than 60 ppm, as were also lesion scores. Under floor-pen conditions there were no significant differences among monensin treatments. Moisture content of the litter was significantly lower in all monensin-medicated pens (40%, compared with 52% moisture in pens of unmedicated controls).

Animals↗