Ageing of the unfertilized cow egg in vivo: how soon is fertility compromised?
Hunter, R.H.
Veterinary Record 124(18): 489-490
1989
ISSN/ISBN: 0042-4900 PMID: 2750032 Document Number: 338125
This paper highlights the scarcity of information on the viable lifespan of unfertilized eggs in cattle, and stresses the practical importance of having such information to determine the time of insemination. Post ovulatory degenerative changes that occur in the egg with aging are described, and it is shown that these changes do not prevent fertilization. Thus, fertilization of eggs having an abnormal chromosome complement, or fertilization by multiple spermatozoa due to breakdown of the defence mechanism against polyspermy, can occur, resulting in early embryonic death. The need for data on actual calving rates as distinct from non-return rates to throw light on this subject is emphasised.