| 摘要 |
<p>PCT No. PCT/GB93/02565 Sec. 371 Date Aug. 23, 1995 Sec. 102(e) Date Aug. 23, 1995 PCT Filed Dec. 16, 1993 PCT Pub. No. WO94/13132 PCT Pub. Date Jun. 23, 1994A method of hatching eggs of avian species, especially chickens, which comprises carrying out at least one cycle of steps (a) and (c) as follows: (a) incubating the eggs in a first, baseline ambient environment which is normal for hatchery incubation of the eggs of the avian species in the prevailing climatic conditions and then during a sex-sensitive time window of embryonic development, (b) altering the ambient environment to shifted conditions for a period of time effective to bias the normal phenotypic sex ratio of the embryos, without significant adverse effect on the average mortality rate, and (c) thereafter restoring the incubation conditions to or towards normal and allowing the eggs to hatch. Preferably the ambient environment comprises a temperature of 37.5 DEG -38 DEG C. and the shifted conditions comprise reduced temperature, especially a temperature maintained at about 22 DEG C. for a period of from 18 to 42 hours. The method may be used to produce birds which are chromosomally male (ZZ) but phenotypically female or chromosomally female (ZW) but phenotypically male.</p> |
