Topic: Importance of Pregnancy|Testing Author: Ben Bennett, DVM
I hope that this letter finds all of you doing well and staying healthy. I apologize for failing to send out a newsletter in November. Through the busyness of ultrasounding cows and holidays, getting the newsletter published slipped through the cracks.
In this month’s newsletter, I wanted to cover the importance of pregnancy testing for a commercial cow herd. What is the goal of pregnancy testing and what economic factors may drive the decision to pregnancy test or not?
When I was in veterinary school, one of my professors, an experienced veterinarian who had spent 20 + years in private practice before returning to university, asked a group of cattle-focused students, “What is the number one goal of pregnancy testing cows?”. Answers ranged from “determining the calving distribution” to “figuring out what that breedup is”. He left us all wondering when he said that none of us were correct. In reality, we were all correct, but we had identified secondary goals of pregnancy testing. He was asking us to identify the primary goal of pregnancy testing. He left us all a little confused when he said that the primary goal of pregnancy testing a commercial cow herd is to “identify the open cows”. To us, it just seemed too simple. He left that week’s small-group session with giving us the homework of doing the math to determine how much it costs to feed a cow through the winter.
So, lets do the math. There are a couple things that we have to assume, but that may change from year to year. Assumptions:
| Price for Hay | $100/ton |
| Days on Feed | 12/1-5/15 (165 days) |
| Cow Weight | 1350 lbs |
| Daily Consumption | 2.5% Body Weight |
| Preg Test – $/cow | $4.5 |
• Cow’s Daily Consumption: 1350 x 0.025 = 33.75 lbs of hay per day
• Cow’s Winter Consumption: 33.75 x 165 = 5,568.75 lbs hay per winter
• Cow’s Winter Consumption: 5,568/2000 = 2.78 (~2.8 ton) hay per winter
per cow
• Cost to feed: 2.8 ton/winter x $100/ton = $280 to feed a cow through the winter
Now let’s run a scenario. If a rancher has 400 cows, the cost to pregnancy test them all at $4.5/head would be $1,800. At pregnancy test, he discovers that he has a 5% open rate, or 20 open cows. At the above calculated rate, to feed those 20 cows through the winter would cost $5,600. By pregnancy testing his cows, the rancher saved $3,800 ($5,600-$1,800). Let’s assume that it takes 5 hours to pregnancy test the 400 cows. For his time, that rancher got compensated $760/hr to pregnancy test his cows. ($3,800/5 hrs = $760/hr). I am not sure many of us can think of something differently we could be doing to make that same amount.
Remember, these numbers are assuming that the open rate was 5% and hay is $100/ton; if either of these increases, so does the amount saved. If his open rate raises to 8%, then the expense to feed those 32 open cows through the winter would be $8,960. By pregnancy testing, his net savings would be $7,160 or $1,432/hr.
The other scenario that I know some producers use is to not pregnancy test, feed all the cows through the winter, then sell the open cows in the spring once they have put on more weight, and the cull-cow market is a little stronger. Let’s use the same assumptions that we did in the last calculation concerning price of hay, beginning cow weight and daily consumption. Additionally, on a 100% hay diet, we can assume that a mature, open cow will gain 0.75-1 lb/day. If starting in the fall with a 1350 lb cow, we can then assume that come spring, she will be about 1500 lbs. When looking at sale reports, 1350 lbs cows in the fall averaged about $64/cwt ($864/cow). Then in the spring, 1500 lbs cows averaged about $67/cwt ($1,005/cow). At 1350 lbs, that cow will consume approximately 33.5 lbs of hay per day. At $100/ton for hay, that is approximately $1.68/day to feed that cow. For simplicity sake, I will use $1.68 x 165 days = ~$277 to feed the cow through the winter. I would argue though that the days on feed for these cows is longer than the rest of the herd since we must wait until the end of the calving season to be sure that they are either open, or too late bred to fit the program. Then, it is may still be a few days or weeks before those cows make it to a sale and are off of the feed bill. But for simplicity, we will assume that the cost to feed the cow through the winter is $277.
So, let’s do the math:
• $864 (fall cull-cow value) + $277 (winter feeding cost) = $1,141 (total investment to feed an open cow through winter)
• 1,500 lbs x $0.67 = $1,005 (spring cullcow value)
• $1,005 – $1,141 = -$136 (net loss to feed open cow through winter and sell in spring)
Other factors that this calculation does not take into consideration include hay wastage (which averages about 7% with a balebuster), death loss, or additional interest on the open cows that would have been sold after pregnancy testing.
For those of you who are still interested in feeding cull cows as part of your business plan, I would argue the following. Pregnancy test your cow herd, find the open cows, implant them, and set the cows up on a balanced ration aimed to maximize average daily gain in the most economical way possible. It is not unrealistic to reach an average daily gain of 4+ lbs/day for a mature cow on feed. Pair that with the fact that the health risk is much lower than feeding bawling calves, especially if just feeding your own cows, and feeding cullcows can be a profitable business plan; but it must be done efficiently.
Now that we have established that the primary goal of pregnancy testing the cow herd is to find open cows, we can also discuss the secondary goals. Going back to the vet school conversation with my professor, many of the goals that we students had listed initially were actually secondary goals. These include, examining the overall health of the individual cows, determining average body condition, splitting pregnant cows up into early and late calving groups, identifying pregnant cows that do not fit your calving season to then sell, determining the calving distribution, and many others. Those that I see customers utilizing the most include: splitting pregnant cows into early and late calving groups, identifying pregnant cows that do not fit the calving season, determining average body condition, and generally assessing the overall health of the herd. Many of these secondary goals are driven or focused by the goals that you have set forth for your operation.
As I aim to wrap this up, I hope that it has not sounded like a sales pitch to have me pregnancy test your cow herd. I will only suggest that you spend money on products or services that either add more or save you more money than they cost. Pregnancy testing is neck-and-neck as the most valuable service that I can provide to you. Can you guess the other?
To wrap this newsletter up, I hope that it has gotten you to ponder why you have chosen the management practices that you have. If you run an operation that has traditionally pregnancy tested every year, I hope that this has cemented that decision and you continue to do so for years to come. If you have traditionally chosen not to pregnancy test, I hope that this has gotten your wheels spinning. I know that operations may have extenuating circumstances that make feeding their open cows a good decision; but I would still argue that identifying them and feeding them to maximize gain will likely be a better option. At the end of the day, sitting down and running honest numbers is the best way to point you in the direction that is best for you.
Thank you again for taking the time to read this month’s newsletter. I hope that you were able to take something from it and that you enjoy reading it. If you have ideas for future topics or have questions/concerns about this one or past newsletters, please let me know! I would love to hear them.
Merry Christmas!