[JUMPMAN]

Brings a cow into estrus. I've been pondering this subject for awhile. One guy told me it has to due with the weather, another one tells me it is the amount of daylight hours that triggers a hormone (I think he's onto something). One guy even told me it had to due with the amount of precipitation your area has recieved . And the best one of all, he tell's me that it has to due with global warming .

Does it happen at the exact same time every year? Is it the smell of a cow in estrus that triggers the bull into going nuts or is it the same thing that triggers both a cow and a bull?

 

[DBL LUNG]

I was always told it was the amount of daylight hours like your friend said. Whether it's true I don't know.

 

[Volfan]

Daylight!

I attended a seminar at the local Bass Pro. The pro - staff guy that was giving the seminar told us it was the amount of daylight. As the daylight hours decrease it triggers the hormones which also begins to harden the antlers. He basically told us a buck is in rut at the instant he sheds his antlers. Although, there may not be any does in cycle at that time for the rut to be in full swing. Hope that helps...

 

[Bobmuley]

Daylight hours - it has to be "around" the same time every year.

Calves can't be born too early or the spring snows will kill them...and they can't be born too late or they won't be big and healthy enough for the next falls snow.

Other reasons for having them all bred/birth at around the same time as well such as inundating predators, etc.

 

[3DBIGBULLX]

It is daylight, and that causes ovulation, therefore, esterus!:wink:

 

[Bobmuley]

It is daylight, and that causes ovulation, PMS, and therefore, esterus!:wink:

.:wink:No wonder the bulls are in bachelor herds in August.

 

[C-NOGLE]

I agree... I have heard that animal detects low light phase or (shorter daylight patterns) and the Pineal gland is the sensory part of the brain that triggers the estrus cycle to start.
All I know for sure is it's tough to beat the second and third week of September anywhere in the western U.S.!

 

[Elk in CO]

Correctly stated,

It is Photoperiodicity. The amount, or lack of daylight that an animal experiences during a 24 hour period.

Same thing that turns the leaves colors.

EIC

 

[Ivorytooth]

Well all I know is that it is money and booze that does it for human females.

 

[Ivorytooth]

It is Photoperiodicity. The amount, or lack of daylight that an animal experiences during a 24 hour period.

Same thing that turns the leaves colors.

EIC

That's what it is.

 

[pirogue53]

That Photo..???...????... word sure is a big one.
It is mother nature's calendar backed up from the optimum time next spring/summer, which is key to calf survival. The daylight hours decreasing is incidental to this.

 

[jcs271]

They are extremely sensitive to the photo periods (lenght of daylight). That light stimulates hormones and things begin to happen. Same theory as leaving lights on in the chicken coops to lengthen their laying periods or leaving the lights on in the show horse barn so that they DO NOT grow their winter coats.

 

[mtboho]

would that go along with the moon phases> that is what I was told by a bioligist in Wyoming. that the moon phases trigger the cows to cycle.

 

[TCR1]

MTBOHO, I have heard, but not personally witnessed that full moon cycles durin the estrous period often throws the rut off.

Last year I believe we had a large amount of full moon during our season, but I didn't notice the rut being much different than normal.

Bob will probably fix me on this:nervous s

 

[Bobmuley]

MTBOHO, I have heard, but not personally witnessed that full moon cycles durin the estrous period often throws the rut off.

Last year I believe we had a large amount of full moon during our season, but I didn't notice the rut being much different than normal.

Bob will probably fix me on this:nervous s

I like a full moon...saves on batteries walking in and out.:wink:

I've never (up to this point) been adversely affected by a full moon while elk hunting. Heat....yes, full moon...no. I think elk are just like us. The days aren't long enough for all the things you NEED to get done. Only difference is the stuff they need to get done are dependent for life. Walk around some night under a full moon in September. The elk will have nighttime beds in or near their feeding areas just like when there's no moon or a quarter moon.

 

[WYBowhunter]

There is a big difference between a cow's estrous and the amount of rutting activity you see. You could have every cow on the mountain in heat but if it's 100+ degrees, you won't hear any bugles....doesn't mean there's no rut on, it just means it's not happening during the day.

They've done studies on captive elk and found that healthy cows will come into heat within 24 hours of the same time year to year regardless of moon phase or temperature. Photoperiodism is that effective. Really the only thing that can affect the estrous cycle is the condition of the animal.

Moon phase, temperature, precipitation, etc. have nothing to do with the estrous cycle but it can affect the amount of daytime rutting activity you see.

mtboho-glad to see WY is hiring such competent biologists!

 

[gotitwithmybow]

photoperiodism

The amount of time of daylight acting on the retina of the eye communicating with the pituitary glad or something like that.....