| Popis: |
1. A comparative study on the iron content in internal organs (blood, liver, spleen, kidneys and heart), carcass and feathers, as well as on the whole iron content has been carried out at different ages (4, 8, 13, 18 and 24 weeks), on two chicken breeds (shaver and New Hampshire). 2. The iron content in internal organs in shaver was higher than in New Hampshire. 3. A tendency of the iron content in the carcass to decrease with age has been observed for both breeds; values were higher for laying shaver hens. 4. The egg-producing strain, shaver, showed a greater iron status with a stable body iron content from 13 weeks on (53-55 ppm), permitting a constant laying frequency (90%) during an 18-month period, with only a small reduction of egg iron content from 33.8 to 31 ppm. 5. The whole body iron decreased progressively with age in the New Hampshire broiler strain to 42-49 ppm iron, and the laying process sharpened this tendency. A drastic reduction in laying, accompanied by a lower egg iron content (28.9 ppm iron), was observed. 6. Iron data obtained in the present paper reflect the specific genetic adaptation to egg production of the shaver strain. |
