| 英文描述 | Reproductive disorders in swine increase in late summer and autumn, and in Britain the percent of abortions in sows rises from a normal 1% to as high as 10% in some herds. Some herds are affected repeatedly in the fall. Fetuses tend to be of equal size, and there are no fetal lesions. May be associated with hormonal changes due to declining daylight. Other manifestation of seasonal infertility include reduced farrowing rate, prolonged weaning to estrus interval, later attainment of puberty, and possibly reduced litter size. |
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