8/2/2011

1

Species Length of Estrous

Cycle (days)

Duration of Estrus

(Hours)

Time of Ovulation

Ewe 16-17 24-36 30-36 hr fro beginning of estrus

Goat 21 20-35 -

Sow 19-20 48-72 35-45 hr from

beginning of estrus

Cow 21-22 18-19 10-11 hr after end of

estrus

Mare 19-25 4-8 days 1-2 days before end

of estrus

Estrous Cycle, Estrus, and Ovulation in Farm ANimals