Reproductive Parameters in Bovine Species

Length of Estrus in Cattle

6-24 (15) hours

Length of Estrous Cycle

17-24 (21) days

Fertile Life of the oocyte

8-12 (20-24?) hours

Time of Ovulation, relative to Estrus

10-11 hours

Fertile Life of Sperm

30-48 hours

Time of Artificial Insemination, relative to Estrus

7-18 hours

Time of first cleavage following fertilization

20-24 hours

Length of Gestation

279-287 (283) days

Progesterone source during Gestation

CL produces progesterone and peaks around day 5 and is in control until day 15 when maternal recognition signal is sent and placenta takes over control.

% Motility (minimum)

30% motile

% Morphology (minimum)

70% intact sperm

Stage I Duration for Cow

2-6 hours

Stage I Duration for Heifer

up to 12 hours

Stage II Duration for Cow

(30 mins)-1-2 hours

Stage II Duration for Heifer

1-4 hours

Stage III Duration for Cow

6-12 hours

Induction of Parturition Requirements

Requires live fetus (dexamethasone)

Induction of Parturition Timing

Has to be induced during the last 7-14 days of gestation, give dexamethasone (20-50 mg/IM)-> induces parturition in 48 hours

Combined Induction of Parturition Dosage

20-50 mg/IM combined with 25 mg of prostaglandin F2alpha induces parturition within 35 (+- 2) hours.