by Dr. Jimmy T (Gunny) LaBaume
At the end of Part I. We sad that there are three ways to cut back on breeding animals without reducing the calf crop: 1) improve herd fertility so that fewer replacement heifers are needed; 2) increase the useful life of your mamma cows and 3) find ways to cut back on the number of bulls.
Let’s talk about mamma cows and their relationship to replacement heifers.
Although a standard useful life for a breeding cow used by most ranchers who bother to budget is 7 years. However, this is a bit misleading. The average beef cow’s useful life is about 3 years (see the table below).
The average rancher (your neighbor) typically gets less than an 80% conception rate (20 open cows out of 100 at pregnancy testing). Then, of those, only 90% will actually wean a calf (i.e. there will be 8 dry cows at weaning).
Using generous assumptions: 1) we have 100 heifers of breeding age; 2) the conception rate is 90%; 3) we have no death losses, and 4) cows that do not wean a calf are culled.
The table below shows what will happen to the herd without replacements.
|Year||Opening Inventory (# of Cows)||Open(10%)||Dry(10%)||Calves Weaned||Culled (Open & Dry)||Closing Inventory (# of Cows)|
Note that, without replacements, the herd went from 100 head to 53 head in 3 years. In other words, we have to have a lot of replacement heifers and these heifers take up room that could be occupied by cows. This represents an enormous hidden cost.
In part III, we will do a similar exercise dealing with bull costs. It too is a shocker.
After: Parsons, Stanly D. Putting Profit into Ranching
Dr. Jimmy T (Gunny) LaBaume (send him mail) is President & CEO, Land & Livestock International, Inc. providing a complete line of management & consulting services to the range livestock industry.