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991.
992.
A survey of carcass condemnation at a poultry abattoir and its application to disease management 总被引:1,自引:1,他引:0
Ansong-Danquah J 《The Canadian veterinary journal. La revue veterinaire canadienne》1987,28(1-2):53-56
During a five year period, slaughter records were maintained on flocks of broiler chickens sent to a federally-inspected abattoir in New Brunswick. These records, including data regarding condemnation of both carcasses and portions of broilers, were maintained at the level of the individual producer. Annual meetings and ad hoc consultations with producers, a veterinary poultry specialist, and support groups in the poultry industry (feed mills, breeders, etc.) were used to relay to the various interested parties, information relating to disease conditions.
Following the implementation of this system, condemnation rates dropped by one full percentage point during the first three years, with a slight increase observed during the last two years of the study. At the end of the survey, condemnation rates were 20% less than those of the national average.
相似文献993.
994.
To assess respiratory function in dogs with tick paralysis, respiratory measurements were recorded on 14 dogs experimentally infested with Ixodes holocyclus. There was a progressive fall in respiratory rate with no change in tidal volume, which resulted in a significant fall in minute respiratory volume in the latter stages of the disease. The fall in respiratory rate was possibly central in origin and was accompanied by an increased alveolar-arterial oxygen tension difference, probably caused by pulmonary congestion and oedema. The "grunting" respiration seen in tick paralysis was due to closure of the vocal cords during expiration and could represent an attempt to re-expand collapsed parts of the lung. 相似文献
995.
Steinhardt PJ 《Science (New York, N.Y.)》1987,238(4831):1242-1247
Numerous examples of metallic alloys have been discovered, the atomic structures of which display an icosahedral symmetry that is impossible for ordinary periodic crystals. Recent experimental results support the hypothesis that the alloys are examples of a new "quasicrystal" phase of solid matter. Observed deviations from an ideal quasicrystal structure can be explained as "phason strains," a special class of defects predicted to be the dominant type of imperfection formed during solidification. 相似文献
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Thirty eight newly weaned hinds were randomly allocated to one of two equal groups. One group received ivermectin, the other, oxfendazole at dose rates of 0.2 mg/kg and 4.5 mg/kg, respectively. All deer were drenched four times and were grazed on pasture. Both anthelmintics reduced D. viviparus faecal larval counts to low levels 20 days after dosing, but the mean larval output and the proportion of deer shedding D. viviparus larvae at 27 and 33 days after treatment, were significantly lower in the ivermectin treated group. There was no significant difference in weight gain between the two groups throughout the trial. This study suggests that ivermectin prevents reinfection with D. viviparus for approximately 14 days longer than oxfendazole. 相似文献