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Biomedical subjects

R Froyman

Publications and source records attributed to R Froyman.

10 recordsLinked to original sources

Effect of dietary fluoride on performances and bone characteristics of broilers and the influence of drying and defatting on bone-breaking strength.

A trial with broiler males, housed in cages, was conducted to determine the effect of (added) dietary fluoride at 0, 200, and 400 mg/kg on performance and bone characteristics and the influence of preconditioning (drying, defatting) on bone-breaking strength. The F administration resulted in a significantly (P less than .05) lower weight gain. Feed conversion, however, was not affected. Tibial ash deposition and ash-percentage increased significantly (P less than .05) at both dietary levels of added F. Broiler males fed supplemented F had a significantly (P less than .05) higher incidence of tibial dyschondroplastic plugs and epiphyseal bone with looser structure, as judged macroscopically. Tibial bone strength was significantly (P less than .05) affected not only by dietary F level, but also by preconditioning, resulting in a significant interaction. Administration of F had a significantly negative or positive effect on breaking strength, depending on whether the measurements were carried out on fresh bones or dried (defatted) bones, respectively. This diverging response of F on breaking strength offers a valid explanation for the contradictory results in the literature, demonstrating at the same time that F supplementation of feed or drinking water should be discontinued as a method to improve bone-breaking strength.

Animals

[A hemorrhagic-anemic syndrome with dermatitis in broiler chickens].

Eleven successive deaths of broiler chickens affected with dermatitis (Staphylococcus aureus) preceded by anaemia and muscular haemorrhages, are reported as occurring in Belgium. All of these cases could be traced to a single flock of broiler breeders. The depletion of lymphoid cells in the bursa, thymus and spleen was a striking feature. Infectious Bursal Disease virus as triggering or causative agent, could not be demonstrated. The pathological changes showed a marked resemblance to similar syndromes which were recently reported in broilers (1, 2, 3, 4).

Anemia

Isolation of orthoreoviruses from psittacine birds.

Orthoreoviridae were regularly isolated from imported psittacine birds in the absence of other pathogens or in combination with salmonella. These viruses grew in embryonated eggs, in chicken embryo fibroblasts and in hepatic cell cultures. The viral isolates were classified as orthoreoviridae on the basis of their morphological and physico-chemical properties.

Animals

Coccidiosis in rabbits: a field study.

During a survey 1052 faecal samples were examined in commercial and domestic rabbitries in Belgium. Nine different species of Eimeria were recognised. E magna, E media and E perforans were very common in both production methods. E flavescens, E intestinalis and E stiedai occurred more commonly in traditionally reared rabbits. E stiedai was not recorded in commercial rabbitries. E coecicola, E irresidua and E piriformis were less common. Oocyst output was suppressed in increasing efficacy by clopidol, sulphaquinoxaline/pyrimethamine (10:1), sulphadimidine and robenidine (P less than 0.01). The use of a droppings pit reduced the level of coccidial infection significantly compared with a sledge type of cleaning mechanism (P less than 0.001).

Animal Husbandry

Flubendazole: safety regarding egg production and reproductive performance of breeder chickens.

In a comparative field trial, 5,950 meat breeder chickens were medicated via feed for 7 consecutive days with 60 ppm of the anthelmintic flubendazole. This treatment cured the birds of an infection with Ascaridia galli and Capillaria obsignata. A slight but transitory diarrhea was observed in treated chickens. The applied medication did not unfavorably affect egg production, fertility, or hatchability.

Animals

A model for testing the efficacy of enrofloxacin (Baytril) administered to turkey hens in the control of Mycoplasma iowae infection in eggs and embryos.

In a preliminary experiment, a field infection with Mycoplasma iowae was simulated by inoculating turkey eggs with various doses of two strains of M. iowae immediately before incubation. The strain and dose chosen for further study were those that best multiplied and resulted in infection of embryos from which the organism could be isolated after 25 days of incubation. Ten turkey hens free from infection with mycoplasmae were housed in isolation. The hens were given enrofloxacin in the drinking water at a concentration of 50 ppm on 3 successive days, on two occasions at intervals of 14 days. Within 48 hours of lay, their eggs were each inoculated with 0.1 ml of the selected strain and dose (10(5) colony-forming units/ml) of M. iowae. M. iowae was recovered from almost all eggs laid by hens before the initial medication but not from any of the eggs laid for several days after each period of medication. Thereafter, the organism could be recovered from a high proportion of inoculated eggs. The treatment of infected turkey laying flocks with enrofloxacin at strategic periods might be helpful in the control of this Mycoplasma by limiting both vertical and horizontal transmission.

Animals

Dose titration study of enrofloxacin (Baytril) against respiratory colibacillosis in Muscovy ducks.

Four-week-old specific-pathogen-free Muscovy ducks were inoculated with reovirus. One week later, they were inoculated intratracheally with a O78:K80 strain of Escherichia coli. The next day, they were given enrofloxacin at different doses in the drinking water. Comparison of mortality rates, weight gain, macroscopic lesions, and E. coli re-isolations among treated and untreated birds showed that a 5-day treatment course with 12.5 or 25 ppm enrofloxacin in water for 4 hours in the morning provided good therapeutic efficacy against respiratory colibacillosis.

Animals

Evaluation of enrofloxacin against egg transmission of Mycoplasma gallisepticum.

Five groups of 20 commercial leghorn hens near peak production were challenged with Mycoplasma gallisepticum, and medicated with enrofloxacin in the drinking water at 7-11, 21-25, or 7-11 and 21-25 days postchallenge (PC), a combination of lincomycin/spectinomycin at 7-11 and 21-25 days PC, or left as untreated controls. Egg production records were maintained, and all eggs produced during the 63 days following challenge were incubated for 18 days and then cultured for M. gallisepticum. All groups experienced marked egg production drops beginning about 1 week PC; production returned to near normal levels after approximately 3 weeks. Under the conditions of this study water medication did not prevent egg production losses, probably because of the delay in the onset of medication, but medication may have resulted in a more rapid recovery of egg production. Enrofloxacin was highly effective in reducing the level of egg transmission of M. gallisepticum, although a small number of eggs (0-0.3%) in the treated groups were culture positive after medication was begun. Only 1 of 2463 live embryos was culture positive after the onset of treatment. In the unmedicated control group, 12.8% of all eggs were culture positive. Lincomycin/spectinomycin also reduced egg transmission (3.4% of eggs were culture positive after treatment was initiated), but not as effectively as enrofloxacin. Most of the egg transmission occurred before the medication could have had an effect. Both enrofloxacin and lincomycin/spectinomycin reduced the number of dead-in-shell embryos.

Animals