My milk cow Sandy is due with her third calf in exactly one week. [cue happy dancing aaaaaand obsessively checking on her six times a day].
What I’m Doing To Prepare for Calving
- I’ve calculated her due date using my Milk Cow Gestation Calendar. Download a copy for yourself so you can accurately predict her due date and know exactly when to stop milking to give her enough time for a 60-day dry/rest period. She’s due July 1st (278 days gestation), but it could happen anytime between June 24th (271 days) and July 9th (283 days).
- I’ve cleaned out and prepped the milking shed. It’s just a corner of the barn, but I dusted all the beams and added a new layer of wood chips to the floor.
- I’ve restocked my vet kit with a couple tubes of calcium gel (supplements I’ll give her immediately after calving to prevent milk fever) and double-checked that I have the IV, tube and calcium gluconate IV solution should she come down with milk fever and need serious intervention.
- I’ve taken her off pasture and put her in a small paddock behind the barn and I’m feeding her dry hay. This is one of the most important steps I’m taking to help prevent milk fever. One unexpected but totally delightful bonus: I can see her from my bedroom window upstairs.
What Is Milk Fever?
Milk Fever, or hypocalcemia, is a temporary blood calcium deficiency. It usually occurs around calving and is one of the most common metabolic disorders among dairy cattle.
Cows only have a small amount of calcium circulating in their blood. In late pregnancy (as her body is producing colostrum) and early lactation (when her milk comes in), the calcium demand increases significantly and her blood calcium levels drop.
When she struggles or cannot adapt to the sudden draw of calcium (effectively mobilizing the calcium reserves from her gut and her bones), she will experience milk fever and exhibit symptoms such as listlessness, tremors, unsteadiness on her feet, collapse, and even paralysis. It’s a serious situation.
Is Milk Fever Preventable?
All cows will experience a degree of milk fever as her system’s sudden demand for calcium at calving causes her blood calcium levels to drop.
But there are absolutely steps you can take to help her adapt and mobilize the calcium reserves she has available so that she does not experience some of the more serious symptoms.
1. Monitor Calcium Intake / Reduce Feed Quality
High calcium intake during the dry period makes it harder for her body to respond to the sudden high demand at calving.
Sandy is an all-grass cow; she eats only grass and is 100% capable of meeting all of her own nutritional demands both during pregnancy and lactation. I don’t know exactly which plants she’s eaten day to day. I don’t measure her intake or supplement her diet. She very efficiently takes care of her own nutrition.
But what I can do is make sure that she’s on pasture with a wide variety of plants and forage. I can make sure she has plenty to choose from and she will pick and choose exactly what she needs.
And – two weeks before her due date, I took her off pasture and put her in a small paddock behind the barn. I’m feeding her dry hay from two summers ago – it’s not particularly nutritious, but it’s got a lot of fiber to help her transition.
This decrease in available nutrients (particularly calcium) in her feed primes her system to begin to draw judiciously from her body’s reserves. In other words, it helps her body “practice” mobilizing the calcium and other nutrients she needs from her bones and her gut.
Though it seems a little counter-intuitive to reduce nutrition before calving, this feeding protocol will help her system adjust the the sudden draw of calcium when her milk comes in.
2. Reduce Potassium And Sodium Intake
High levels of potassium and sodium and inhibit the bone resorption of calcium. Those additional minerals can keep her system from absorbing adequate amounts of calcium into the reserves stored in her bones.
As a pasture-grazed cow, it is very difficult to monitor her intake of potassium, but grazing her on grass re-growth (rather than fully mature grasses) can help as those have lower levels of potassium. Also – grazing areas that have not been fertilized (either conventionally or with manure) have lower levels of potassium and are a good choice for the pasture-grazed cow during her dry period.
I’ve implemented both those strategies in the areas she’s grazed during the last couple months.
Additionally, when I took her off pasture, I also stopped offering free-choice minerals. She has plenty of fresh clean water and all the dry hay she wants, but a reduction of potassium and sodium are my main goal, again priming her system to prepare for and adequately respond to the sudden demand she’s going to experience at calving.
3. Administer A Calcium Supplement At Calving
Remember – cows only have a small amount of calcium circulating in their blood at any given time. She’s already producing colostrum (and her bag is getting bigger every day) and already experiencing an increased draw of calcium from her reserves.
When she calves, that draw will increase yet again and I want to be sure she has enough calcium available in her system to keep her blood calcium levels in an acceptable range.
So I administer a tube of calcium gel as soon as possible after calving. It also contains magnesium (which helps the gut absorb calcium) and cobalt (a vital component of vitamin B12 which helps with energy metabolism and rumen health).
You could theoretically administer the calcium supplement the day before calving (it remains in the system only 12 hours), but because when she’ll calve is always a guess, I like to wait until immediately after so I know it’s available exactly when she needs it.
I’ll administer a second tube of calcium 12 hours later.
There are other ways to administer a calcium supplement – you can administer an oral drench (an old wine bottle with its long neck works well to get the liquid past her back teeth and down her throat) or a bolus (a large coated pill administered with a bolus gun – a long tube that you fit the pill into and push down her throat).
4. Ease Into The Milking Routine
When her milk comes in, that calcium draw is going to be a doozy so I want to ease into that as gently as possible.
I’ll skip the first milking and let the calf have all the colostrum he can handle.
At the second milking (about 12-18 hours after calving), I’ll take just enough to take the pressure off (about 1/2 gallon). Her udder is going to be full, but I don’t want to prime the pump too early and increase production too soon.
At the third milking (about 24-32 hours after calving), I’ll take twice as much as I did before, somewhere around a gallon. Again, I don’t want to ask too much too soon, but she is designed to produce a lot of milk and I need to take the pressure off to control the edema and prevent mastitis.
At the fourth milking (about 36-42 hours after calving), I’ll take it all. We’ve eased into the process, the calf has had plenty of colostrum to get him started off on the right foot, and she’s producing a lot of milk.
Setting Her Up For Success
With those two doses of extra calcium, the reduced quality feed and removal of free-choice minerals a couple weeks before calving, a boost of calcium supplement immediately after calving, and a gradual increase in milking over the first four milkings, I’ve done all I can to help her system adjust and adequately respond to the increased demand when her milk comes in.
It doesn’t always work. It’s not a sure thing. And I’m prepared as I can be to handle an emergency. But I feel good knowing that I have a firm grasp on the science behind milk fever and how it affects her system as a whole, as well as the steps I can take and the things I can control, to help her navigate this transition as well as possible.
If You Have A Milk Cow Ready to Calve
The more you know, the better prepared (and more confident!) you’ll be.
I’ve created a 23-page Essential Guide for When Your Milk Cow Gives Birth. Along with info about preventing milk fever and how to get started with the milking routine, you’ll learn about how to tell when she’s going to calve, helping the calf suck, and all about colostrum and what to do with it.
Download yours now so you’ll feel confident and prepared when the big day comes!
“Milk Fever in Cattle,” FarmHealthOnline.com. https://www.farmhealthonline.com/US/disease-management/cattle-diseases/milk-fever/. Accessed June 23, 2021.
“Milk Fever in Cows | Hypocalcemia,” Biomin.net. https://www.biomin.net/species/ruminants/milk-fever/. Accessed June 23, 2021.
“Trouble-shooting Milk Fever and Downer Cow Problems,” Penn State Extension. https://extension.psu.edu/trouble-shooting-milk-fever-and-downer-cow-problems. Accessed June 23, 2021.