![Sow in Estrus.](images/po00238.jpg)
Sow in Estrus.
Yorkshire sow in estrus responding to teasing by standing immobile with erect ears.
Evans LE (2009)
![Sow in Estrus.](images/po00239.jpg)
Sow in Estrus.
Hampshire sow in estrus responding to teasing by standing immobile with erect ears.
Evans LE (2009)
![Woodlot Breeding.](images/po00242.jpg)
Woodlot Breeding.
Sow in estrus seeking out the boar [in the upper left hand corner] in a woodland lot.
Evans LE (2009)
![Estrus Detection.](images/po00419.jpg)
Estrus Detection.
Boar checking for evidence of heat by pheromones.
Smith MC (2011)
![Heat Detection for A.I.](images/po00376.jpg)
Heat Detection for A.I.
Red color marking denotes that the sow has shown signs of heat today, the blue color was for yesterday.
Smith MC (2010)
![Heat Detection for A.I.](images/po00378.jpg)
Heat Detection for A.I.
Record keeping directly on the sow. These sows have been inseminated artificially (AI) or bred by the B boar. The records are transcribed at the end of the week.
Smith MC (2010)
![Heat Detection for A.I.](images/po00377.jpg)
Heat Detection for A.I.
Record keeping directly on the sow. This sow has been inseminated artificially after several N days when not in heat.
Smith MC (2010)