Winter Calving

by Dallas Mount


Calving season has begun across cow-country and so have the stories of sleepless nights, calves being brought inside the house to warm up and heroic tales of battling the recent polar vortex across the country. Granted this weather was extremely unusual for some parts of the country, but for places where this is part of the deal I have a hard time working up much sympathy. My first reaction to all this was “Who is the one that turned the bulls out so that the calves would be born in the winter?”. Certainly, there is an element of tradition and comfort in raising cattle the way it has always been done. There are also valid reasons for winter calving, but there are compelling reasons to examine a change.

Let me be the first to say that I don’t think there is a prescription on how to run a profitable ranch. I don’t think all cow-calf operations should be calving in the spring (May-June). There are profitable ranches that calve in the winter, but they are more the exception than the rule.  

A generation ago it likely made more sense than it does now. Winter calving relies on abundant and cheap feed, labor, and machinery. The price of all these inputs relative to the value of a weaned calf have drastically changed. The decision of when to calve is critical to the profitability of a cow-calf operation so it warrants a fresh analysis.  

If you are ranching for profit, the selection of the best calving season is really a question of profitability. Show me da money. It should take less than a half-day to do a comparative gross margin analysis of a February-March calving cow herd with a May-June calving cow herd. What is the total gross margin produced by each herd? Once you have that number, take the next step and examine the ranch overheads required to maintain a herd of February-March calving cows with a herd of May-June calving cows. Which one will have the highest requirements of labor, facilities, and equipment? Make sure you overlay the quality-of-life factors on these numbers. You will want to have a WOTB (Working On The Business) meeting with your ranch team about what direction is more appealing.  

Choosing a calving season is high on the list of decisions that have a drastic effect on profitability. Your calving season will also affect many of the other aspects of your ranch from marketing, grazing, genetic program, nutrition program etc. Figuring out your calving season before you start considering breed and genetic providers is important. Also determining your enterprise mix comes before calving season.  

If this recent polar vortex is making you consider calving in a more pleasant time of the year, there are some important considerations when it comes to moving your calving season. If you move a February-March calving cow to May-June, you have just reduced her value by $200-$400/head. It might be far better for you to sell your herd of winter calvers and buy a herd of spring calvers, picking up that money as cash rather than devalue your cows. The genetics that you have selected for a winter calving cow are likely not going to fit a spring calving cow anyway. When making the switch, pay attention to forage quality just before and through the breeding season. Sometimes those making the switch find that breeding on a declining plane of forage quality can cause conception rates to suffer. If you see cows slipping condition during this critical time, shorten graze periods and consider a 45-day protein supplementation strategy during this window.

I’m not suggesting any particular calving season is right for you. If your business is producing the outcomes you want and the quality of life you desire, then why change. However, when it comes to your bull turn out date let’s not forget the pictures and memories of frozen calves and miserable people.


3 Responses to “Winter Calving”

February 24, 2021 at 8:26 am, John Marble said:

Every place, every ranch, every climate is different. In my balmy neighborhood, most people target calving season for the 45-day period that is routinely 38 F and raining. Pretty tough conditions for a new-born calf. This works out great for me, as I try to buy “late” calving cows, those that are set to pop about a week after we turn out on grass. No one else wants them. Sort of a win/win. Morbidity/mortality is extremely low.


March 15, 2021 at 9:30 pm, Ayer Ranch said:

John Marble,
Your strategy interests me. Can you offer any details about how you are acquiring these late calvers and any issues you may have had? I wonder if you have had problems with these winter calvers making too much milk when they calve in the spring. I asked a similar question in the cow depreciation article. Appreciate any input you can offer. Thanks.


March 24, 2021 at 5:34 pm, John Marble said:

Hi there.

I begin purchasing 6/7/8 month pregnant cows in mid-winter. They come one by one from our local auction yards. This is very intense and difficult work. I believe that every cow gets sent to the auction for some specific reason, but many of my new cows simply need basic health and nutrition management. Not many real issues.

As to your question about too much milk, well, hmmm. I think genetics determine how much milk a cow COULD give, while nutrition determines how much milk she WILL give. I prefer a cow with no more than moderate milk potential, as I believe that most cows in America are too big and give too much milk.

Hope that helps.


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