Effect of Split Weaning on Sow Ovulatory Responses to Injection of Gonadotrophins during Lactation

Ovulation was induced in sows at 18 days of lactation by a team of researchers from Australia and the US but the response was too unpredictable to be considered a practical management option to increase weaning age whilst maintaining sow productivity.
calendar icon 26 February 2013
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In Journal of Swine Health and Production, Dr Roy Kirkwood of the University of Adelaide in Australia and co-authors there and at Michigan State University in the US report that, at day 18 of lactation, 21 of 42 sows had their litters reduced to five or six piglets and all sows received gonadotrophins. Remaining piglets were weaned at day 26.

More split-weaned than control sows had elevated serum progesterone two days post-weaning (47.6 per cent versus 9.5 per cent; P<0.05).

The implications of this work are, according to the researchers, that hormonal induction of ovulation at 18 days of lactation in sows is possible but that the predictability of the ovulatory response must be improved if hormonal induction of ovulation during lactation is to become an accepted management option.


Kirkwood R.N., K.C. Turner and D.L. Rutley. 2013. Effect of split weaning on sow ovulatory responses to injection of gonadotrophins during lactation. Journal of Swine Health and Production. 21(1):42–44.

Further Reading

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February 2013

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