Baby calves and the energy curve

Cow-Calf Commentary

KIMBALL, Neb. – “Jester’s dead, yee-haw!”

“Get your butts above the hard deck and return to base immediately,” said Jester.

You might remember that scene from the movie Top Gun. Maverick and Goose had just defeated their instructor, Jester, in a practice dogfight, but they had broken the hard deck in doing so, therefore they were in trouble.

So, what’s this hard deck, and what does it have to do with baby calves and the energy curve?

In the world of military aviation, the “hard deck” is a risk management scheme designed to keep people from hitting the ground in their expensive airplanes. Everybody understands it represents a cushion between a reasonably safe altitude and the Real Hard Deck, which is the ground. There’s a huge difference between busting the risk management hard deck and the Real Hard Deck.

I’ve written about energy and metabolism in cattle and newborn calves before. It works the same in people and in all living organisms. When the energy tank runs dry –when there’s not enough energy left in the living system to keep it going – the organism dies. At that point it’s simply too late to do anything. That’s the Real Hard Deck when it comes to energy.

With baby calves, sometimes they end up on the backside of the energy curve. Quite often it has to do with becoming chilled or failing to maintain adequate body temperature. Even in fine weather it can be touch and go at the very start, because babies are born with almost zero energy reserve. Basically, just enough to get up and nurse and to start metabolizing their first meal of colostrum. Colostrum is loaded with energy, and that first meal is almost always enough to light them off properly.

When it’s cold and wet out, the margin is razor thin. If the calf starts losing body heat faster than it can generate it, it’s on the wrong side of the energy curve. Body heat is obviously harder to maintain the colder the air temperature. Calves are born wet, and saturated fur provides almost no insulation to maintain body heat. A belly full of colostrum will almost always provide the energy margin needed to quickly dry the hair (at least the inner hair coat, where most of the insulating happens), and the cow’s tongue is a remarkably effective towel. But when there’s a stinging cold rain driven by the wind, heat can easily flee the calf’s body faster than it can be generated.

For instance, a calf was recently born at 3 p.m. He was a lively bull calf and was up and nursing within minutes. When I checked him at 4 p.m. he was fine.

At 6 p.m. he wasn’t. For some reason the cow had taken him out of the lee of the junipers and into the middle of the paddock.

The wind was howling a gale and the rain was turning to snow. The calf was sprawled flat out in the snow, all but unresponsive. The inside of his mouth was cold as ice. He was on the wrong side of the energy curve, hypothermic, and not long for this world.

Another calf had been born at about 1 p.m. His mom elected to take him out into the storm as well. His was a different story though, because while he was shivering and not enjoying his first day of life, he was up and about, his inner hair coat was dry, he had a toasty warm mouth, and he was pleased to scamper back into the lee of the tree line with his mom. He was on the correct side of the energy curve.

Fortunately for the first calf, close monitoring allowed me to intervene in time to preserve his life. His core temperature had fallen to 94, which is only about 6-8 degrees low. He was unresponsive but breathing well. I got him inside the house and into a tub of warm water. Within a few minutes he began to shiver and move about. A very good sign.

When hypothermia begins to set in, one of the first responses is shivering. Shivering is muscle activity, and muscle activity produces heat. It’s a good response. It’s not always a perfect response. Shivering produces heat but also gets blood flowing near the skin where, if the the hair is soaked and the body is exposed to wind, warmth is wicked instantly away. When the core temperature begins to drop the body begins to shut down peripheral circulation, shunting blood flow to the core in a last, valiant effort to stay alive. This is what had happened to the calf.

As soon as he began to look around and take notice of his surroundings I got a quart of freeze dried colostrum into his belly via a stomach tube.

Within about 20-30 minutes his core temperature came up to normal, and as his gut began to digest the colostrum all that lovely energy began to flow. I took him out of the tub and started to towel him off. To my delight he immediately struggled to his feet, instinctively searching for an udder and sustenance.

All in all, the process took about an hour. If I hadn’t intervened he would have expired during that hour. I didn’t do very much at all, but what I did directly addressed the calf’s energy shortfall. All he needed was a little externally applied energy, a belly full of internally applied energy, and about 45 minutes. Sometimes the tiniest of inputs, given at a critical time, can make all the difference.