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When to calve?

From the Ground Up with Steve Kenyon

When to calve?

Seeing as though I am calving out a custom herd of cows right now, that seems like a good topic for this month. I know there are lots of different points of view on the best time to calve. It is not for me to say who is right and who is wrong because every farm is unique.

Some calve in winter, spring, summer or fall. I personally like to calve in May, but all seasons have different advantages and disadvantages. The only thing that will tell you the truth is by running your numbers. A gross margin analysis will give you your answer. This should include all of your direct costs in the margin calculation and it should also include any profit centre overhead costs. We need to include all of our labour and equipment costs in the cow-calf profit centre, including opportunity costs and depreciation.

If we change our calving season, that changes the revenue and the costs, which will change the whole gross margin and will produce a completely different result. Every season has a different margin.

The issue I have seen many times in ranching is that we mistake higher production for higher profit. Those are two totally different numbers. Just because your weaning weights are higher, it does not necessarily mean your profit is higher. I would take profit over production every time. If you have not done a proper gross margin calculation, you are just guessing. I have seen a lot of farms that have a cow-calf profit centre, where they thought they were making money, when in reality they had a negative margin. Do your numbers! It could be the most important thing you will ever do for your farm.

I would like to share a few other concepts that I have picked up over the years, just to challenge your paradigms. One is the Cow Wheel. This is a tool that I adapted from a Ranching for Profit concept. I blended it with a gestation wheel that I picked up from a college course I took. In Ranching for Profit, they look at the highest nutrient requirements of the cow (return to estrus) and try to match that up with the time of the year when the feed quality is the best (summer).

Photo: Supplied

I was already working on a concept at the time that was totally opposite from this but gave the exact same results. I was looking at the biological cycle of the cow’s gestation where she required the least amount of nutrition (second trimester) and was lining that up with the time of the year that was the most expensive to feed in my environment (winter).

If you look at the Cow Wheel, you will see both. In the Ranching for Profit analogy, the peak nutritional need for the cow happens just after calving. She is milking and has to prepare to rebreed. If you match this up with when your grass is the best, it will set your ideal calving time around June 21.

On the flip side, I looked at when the cow needs the least amount of nutrition in her second trimester. If you line this up with the most expensive time to feed (winter: December 31 to March 31), that would put calving sometime around June 21. Cool, same results.

But I am not saying that this is my ideal time to calve. This is just a concept. The closer you calve to the longest day of the year, the lower your costs of feeding might be, but there are lots of other factors to consider. The summer heat can be very hard on sick calves. And with my regenerative grazing management practices, I prefer to calve in May, as it matches my calving with my pasture turn-out and grass production. But I definitely see the logic in the cost savings to calving and/or feeding according to the gestation cycle. It just makes sense. Markets will also play a huge role in the margin. Again, you need to look at all the numbers in the margin calculations.

Another concept that I learned many years ago was from Dick Divon. He was a very knowledgeable nutritionist who taught the Low Cost Cow-Calf School. I still have my course binder that has a graph showing the speed that a cow will return to estrus after calving, depending on the time of year that she calves. It was fascinating to me as it depended on the degree of latitude of your ranch. This was a bit different depending on where you live, but for my location, near Edmonton, Alta., if my cows were to calve in early June, they would, on average, return to estrus within 12 days of calving. Wow. Twelve days.

In comparison, if calving in February or October, it would take on average 65 days for her to return to estrus. April and August were 30 days. In a year with 365 days, an average gestation of a cow is 281 days. If it takes 65 days to return to estrus, she only has one cycle before she needs to conceive to stay in the herd. With 12 days, she has 3.5 (21-day) cycles before she has to rebreed to stay on schedule. Just a thought: this might affect your cull rate in your herd, which affects your depreciation of your herd, which is one of the biggest costs in the cow-calf profit centre. It was interesting to note that the body condition score of your cow will also affect her return to estrus by about eight days.

Now please don’t take this the wrong way. Although both of these concepts are pointing towards summer calving, I am not saying that you should calve in June. The first deciding factor for your farm is the margin. If your labour requirements are higher at a different time of year or if you have a market advantage at a different time of year, these can all affect your margin. In the end, your margin is the most important factor. I am just throwing out concepts to challenge your paradigms.

No matter when you calve, best of luck to you. I know it is a very important part of your operation.

About the author


Steve Kenyon runs Greener Pastures Ranching Ltd. in Busby, Alta. You can email him at [email protected] or call 780-307-6500.

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