cattlepower
Well-known member
Does anyone do this with this size herd? What kind of calving window should I expect? When would I put the bulls in, for how long and is two enough or three?
fall calving for 50-55 cows
- Thread starter cattlepower
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That depends on the window you desire, which would dictate how many bulls you need to use.
If you wish a 30 day window you will probably need 2 bulls.
If you wish a 60 to 90 day window 1 bull should do the job.
The rule of thumb is 1 bull for 30 -35 cows for a 30 day window, provided all cows have already cycled/recycled and depends on the condition of the bull.
See: http://www.cattletoday.com/gestation.shtml
As for how long?
That depends on if they all have cycled/recycled or not. If they all have cycled/recycled then 30 days should do it as The entire estrous cycle averages 21 days long, but can be as short as 18 days and as long as 24 days ! Hypothetically speaking of course.
Liz
Depends:
How large is the pasture and how rough is the terrain? The larger and rougher the more bulls you need and the larger natural window you can expect.
Do your cows break into smaller groups? We'll often see herds break into two or three groups and if the pasture is large enough, they aren't very close together. I'd have at least one bull per group if they get spread out much at all.
How tight a calving window do you want? Are you ready to cull hard? If you want a tight window you need more bulls or be prepared to to accept a lesser success ratio.
We like a 45 to 50 day calving window and generally figure 1 bull per 25 or so after AI. We try to breed in smaller pastures (50 acres or less) and if the girls break into groups we add bulls. We like an odd number of bulls.
We would never trust a herd of 55 to a single bull. To much can go wrong and the cost of wrong is a lot of money.
How large is the pasture and how rough is the terrain? The larger and rougher the more bulls you need and the larger natural window you can expect.
Do your cows break into smaller groups? We'll often see herds break into two or three groups and if the pasture is large enough, they aren't very close together. I'd have at least one bull per group if they get spread out much at all.
How tight a calving window do you want? Are you ready to cull hard? If you want a tight window you need more bulls or be prepared to to accept a lesser success ratio.
We like a 45 to 50 day calving window and generally figure 1 bull per 25 or so after AI. We try to breed in smaller pastures (50 acres or less) and if the girls break into groups we add bulls. We like an odd number of bulls.
We would never trust a herd of 55 to a single bull. To much can go wrong and the cost of wrong is a lot of money.
Fire Sweep Ranch
Well-known member
Everything they said!
As far as when, we start our AI on Thanksgiving, which gives us September 1st calves. We are still in the September window, meaning if we AI now, we will still get September calves.
As far as when, we start our AI on Thanksgiving, which gives us September 1st calves. We are still in the September window, meaning if we AI now, we will still get September calves.
dwa
Active member
NC Liz 2":1d86wyil said:If you AI 55 cows and get a conception rate of 60%, that only leaves 22 cows for a bull to cover.
If one of your bulls can't cover 22 cows, in a 1 mile radius I think you may need a new bull.
Liz
Yes that is true, But the majority of those 22 will be coming back into heat at the same time. Can he/will he cover 22 in a 2-3 day period? Some bulls, maybe. Most bulls, I doubt it.
Since the original poster didn't mention AI, I will assume that is not part of the equation. I have about that many fall calving cows and I run 2 bulls with them. I put the bulls in Dec. 1st and they will start calving around Sept. 7th. I leave the bulls in for just shy of 90 days so the latest a calf will be born theoretically is Dec. 1st. 90+% will calve before the end of October, but always have 4-5 that will calf the first week or so in November.
dwa
Active member
We started a fall group last year with 59 cows. We put bull 2 bulls on Dec. 1 for 65 days. We had 52 get bred. First calf was Sept. 4th, last calf I think was around Nov. 15th.
There are many pros and cons to fall calving, but a lot has to do with the type area you are in and what type of grass you have.
There are many pros and cons to fall calving, but a lot has to do with the type area you are in and what type of grass you have.
NC Liz 2":2jpg1bap said:If you AI 55 cows and get a conception rate of 60%, that only leaves 22 cows for a bull to cover.
If one of your bulls can't cover 22 cows, in a 1 mile radius I think you may need a new bull.
Liz
I would agree in most situations a single bull easily covers 22 females. On the other hand, cows break into distinct groups and we've seen bulls go with one group and stick with that group if the girls are coming in heat one after another and leave standing cows in other groups not serviced. Eventually that bull will probably get those others serviced as well but if you're trying to hold onto a specific window you likely want more bulls in that pasture.
Our ranch is in Southern Illinois and there are a lot of old mine pastures in the area. Bulls need to be part billy goat to thrive on these pastures. They lose condition fast trying to travel the terrain. They get injured mounting cows in the oddest and most awkward places. With the movement of decent pasture to marginal row crop land I imagine there are other situations with rugged terrain reserved for breeding grounds.
I currently have a situation of 53 heifers (not AI) on 300 acres of old spoil mine pasture and this bunch breaks into three groups nearly every day. We're blocking them down onto about 100 acres and throwing three bulls at them this week. Had these been AI'd first I would probably still use three clean up bulls to ensure all three groups were covered. If I get one more calf by using an extra bull I've probably saved or made enough extra to justify using the bull.
We have plenty of bulls and we'll have a couple of bulls ready to go if anything happens to any of these three. We'll keep bulls on them for about 7 weeks. We expect to get 95% conception on this bunch.
