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Pathogenesis of Fowlpox in Laying Hens
Avian Diseases, 1978Egg production dropped after hens were inoculated with fowlpox virus originally isolated from a natural mild infection. The drop started from the 2nd week and continued to the 5th week after inoculation. All birds developed focal lesions at the site of inoculation, and some developed secondary lesions.
D N, Tripathy, L E, Hanson
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Characterization of persistency of lay in laying hens
Biology of ReproductionAbstract Selective breeding in laying hens has resulted in a laying rate of approximately one egg per day during their first year. Due to variability within a flock, egg-laying rates decline after the first year, leading producers to cull hens.
Laurie Francoeur +3 more
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The laying hen and bone fractures
Veterinary Record, 2011THE laying hen has undergone considerable artificial selection pressure over the past century, to increase its egg output in order to provide a protein-rich food source for humans. While its wild counterpart will lay just five to six eggs per breeding season, modern breeds will lay in excess of 300 eggs per year (Lever 2011). With increased egg output,
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Calcium Logistics in the Laying Hen
The Journal of Nutrition, 1987The hourly changes in the Ca2+ content of various physiological compartments in relation to shell formation has been calculated for the domestic hen throughout a 4-d ovulatory sequence. These calculations consider the circadian rhythm in Ca2+ intake when the hen is fed a complete feed or a diet containing oyster shell, the effect of the stage of the ...
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The effects of lindane on laying hens
British Poultry Science, 1972Synopsis Feeding lindane, in capsule form, to laying hens at a rate equivalent to 100 mg/kg food for 1 or 2 weeks had little effect on egg production. Longer periods of feeding resulted in a 20 to 30% decrease in the rate of egg production. When treatment was stopped after 4 weeks, the birds recovered and egg production returned to its original rate ...
C C, Whitehead +2 more
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Fluoride tolerance of laying hens
British Poultry Science, 19971. One thousand Silver Grey Hyline hens were given drinking water containing 5 concentrations of added sodium fluoride (0, 6, 10, 14 and 20 mg/l) over a 17-week growth and 57-week laying period. The natural fluoride content of the water was 0.21 mg/l during the growing period and 0.29 mg/l throughout lay. 2. During the rearing phase, efficiency of food
C B, Coetzee, N H, Casey, J A, Meyer
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Climatic adaptation of laying hens
Tropical Animal Health and Production, 1994Three hundred Warren Isabrown female day old chicks were raised for 18 weeks in 3 distinct artificial climates described as temperate (20 degrees C, 60% RH), hot dry (32 degrees C, 40% RH) and hot humid (32 degrees C, 90% RH). At 18 weeks each group was divided into 3 and re-allocated to 3 similar air-conditioned laying rooms as during the growing ...
Njoya, J., Picard, M.
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Antifertilityeffects of clonidine in laying hens
Experientia, 1981Clonidine was anovulatory and markedly antigonadal in laying hens when infused for 1 week from minipump implants at daily rates of 1.08 mg per hen or greater. The ovaries of hens treated with clonidine responded to FSH injections which suggests that the antigonadal effect of clonidine resulted from a reduction in the output of gonadotropin by the ...
R M, Weppelman +4 more
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Utilization of Urea in Laying Hens
Archiv für Tierernaehrung, 1986K, Gruhn, A, Hennig
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