Íslenskar landbúnaðarrannsóknir - 01.09.1981, Page 41

MEÐGÖNGUTÍMI ÍSLENSKRA KÚA 39
SUMMARY
Gestation length of Icelandic cattle.
Gunnar Ríkharðsson
and
JÓN VlÐAR JÓNMUNDSSON
Bœndaskólanum á Hvanneyri.
The mean length of4223 recorded gestat-
ions was found to be 286.5 days with a
standard deviation of 4.86 days.
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Gestation length was longest for cows
calving in February.
Heifers had two days shorter gestation
length than adult cows.
The gestation period was one day
shorter for female foetuses than male foet-
uses. Twin births gave a 4.5 days shorter
gestation period than single births.
Heritability estimated as a trait of the
dam was 0.13±0.04, but when considered
as a trait of the foetus it was 0.27±0.05.
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