Volume 13 (1976) Issue 4 Pages 129-135
Kanamycin was fed to laying hens for 7 days at the dietary levels of 20, 1, 000, 4, 000, 8, 000 and 16, 000μg potency/g diet, respectively, and kanamycin content in the eggs laid on the 7 th day was analyzed microbiologically using Bacillus subtilis ATCC 6633. To the 40 hens fed 16, 000μg kanamycin/g for 7 days, kanamycin-free diet was fed for another 7 days and all of the eggs laid by 5 hens out of 40 during 14 days of experimental period were analyzed for kanamycin content. On 0, 1, 2, 3, 5 and 7 days after the withdrawal of dietary kanamycin, 5 hens each were sacrificed to get samples of the liver and bile for kanamycin analysis.
No kanamycin was detected in the egg white tested. No kanamycin was detected in the egg yolk laid by the hens fed 20 and 1, 000μg kanamycin/g diet, respectively.
During feeding the diet containing kanamycin, content of kanamycin in the egg yolk increased in proportion to the dietary kanamycin level over 1, 000μg/g and in proportion to the length of kanamycin feeding.
After the withdrawal of dietary kanamycin, contents of kanamycin in the egg yolk, liver and bile increased or remained almost constant for 2 days, then decreased exponentially. The disappearance pattern of residual kanamycin in the body of laying hens was different from those of the antibiotics tested previously. Application of 3-compartment model to explain the pattern was discussed.