Cattle Reproduction: Estrous Cycle, Heat Detection, Ovulation & Gestation
Key reproductive figures for cattle from the MSD Veterinary Manual [1][3], the estrous cycle as described by Mississippi State University Extension [4], heat detection from LSU AgCenter [5] and gestation length from eXtension [2].
Key figures
| Feature | Cattle | Source |
|---|---|---|
| Age at puberty | 10–12 months; usually first bred at approx. 14–15 months | [1] |
| Cycle | Polyestrous all year; 21 days (18–24) | [1] |
| Duration of estrus | 18 h (6–24) | [1] |
| Ovulation | 10–12 h after the end of estrus | [1] |
| Best time to breed | Insemination from mid-estrus until 6 h after the end of estrus | [1] |
| First estrus after calving | 20–60 days | [1] |
| Gestation | 279–287 days; 283 days is common for most breeds | [2] |
The MSD gestation table gives 9 months for cattle [3]. Gestation length varies with the age of the dam, breed and sex of the calf; cows carrying bull calves tend to have a slightly longer gestation [2].
The estrous cycle
- The estrous cycle of cattle is the period from one estrus (heat, the phase of sexual receptivity) to the next [4].
- The ovulated follicle turns into the corpus luteum (CL) by approximately day 5 of the cycle [4].
- Around day 17, prostaglandin F2α lyses the CL, which regresses in about three to five days [4].
- Periods when a cow or heifer does not show estrous cycles are called anestrous or acyclic [4].
Heat detection
- The only definitive sign of estrus is standing still while another animal attempts to mount [5].
- Secondary signs include a reddened, moist and slightly swollen vulva and a clear mucus discharge; roughed-up tailhead hair and missing hair or mud on the flanks suggest that mounting has occurred, and some of these signs can also be seen after estrus has ended [5].
- Standing heat lasts only about 16 hours in beef cattle and can range from 6 to 24 hours [5].
- Cattle are more likely to show estrus behaviour during darkness; when heat checks are limited to twice a day, check early in the morning and as late in the evening as practical [5].
- Cows ovulate 24 to 32 hours after the onset of estrus [5].
How the sources compare
Frequently asked questions
How long is the estrous cycle of a cow?
21 days, with a range of 18–24 days; cattle are polyestrous all year [1].
How long does a cow stay in heat?
When should a cow be inseminated?
From mid-estrus until 6 hours after the end of estrus; ovulation occurs 10–12 hours after the end of estrus [1].
When does a cow come into heat after calving?
The first estrus after parturition occurs at 20–60 days [1].
Related tools and references
More reproductive physiology
References
For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.