Some species, including Homo Sapiens (That is US!) can, if the individual is healthy, tolerate sudden changes in diet without problems. But, other species, especially the herbivores (grazing animals) can suffer if the diet is changed abruptly.
The horse is a good example. Because horses depend to a great extent, upon the billions of microörganisms within their digestive tract to process what they eat, any sudden change in the diet may preclude those microörganisms’ ability to break down the consumed food.
It is these microscopic residents of the equine digestive tract, which enable the horse to do something that we humans cannot do. That is, to break down grass and other plants into chemicals, which horses, can thrive on, and even become obese from over-eating.
Having seen thousands of colic cases, many of them fatal, foundered horses, and other serious problems caused by too sudden dietary changes during my practice career, I have become obsessive, and, I confess, rather paranoid about making dietary changes in my own horses.
Now, the good part of that is that never have I had one of my own equines suffer illness as a result of a too swift change in diet.
The bad part is that other people, including my ranch employees, think that I am some sort of nut.
For example, I not only take a full week or two of gradual substitution when changing diets, such as hay to pasture, or from dry forage to green, but I even insist that a new batch of the same kind of hay be introduced very gradually. So, today, just before I wrote this, my horses have been primarily on alfalfa hay. But, I opened a bale from a different delivery (from the same dealer) and I fed them ¼ flake of the new bale and ¾ flake from the old bale.
Excessive? Yes, I admit it. Unnecessary? Well, having had many horses and mules for the past 60 years, and never had one colic or founder is good reason for me to be so cautious.
Besides, horses are very aware of changes in the source of water, or the stage of growth that the hay derived from, or any other change in what they consume, so it is worth it to me to see them feeling secure and content.
That’s the reason I make any feed change gradually. For example:
If they have been primarily on hay all winter and I am ready to introduce them to the green Spring pastures, I allow them only 5 minutes the first day, and increase it by 5 more minutes during the following days until they have been in pasture a full hour. Yes, that takes time and patience, but it also means healthy horses. If they go into a different pasture with different kinds of forage (I live in a canyon, moist at the bottom and dry above), I repeat the gradual process.
And, again, even if I buy a new load of the same kind of hay from the same feed store, I make the change gradually.
Am I obsessive? Yes! I have seen too many horses damaged by too abrupt feed changes. Thousands of sick horses, as I said earlier, and many died, or were permanently damaged as is the case in laminitis. It’s not worth the risk.
Think about wild horses. Say it is at the end of the dry season. Then at last, it rains. Soon new green grass emerges from the ground. The horses nibble it, but hunger causes them to fill up on the old abundant grass. As the new grass grows, they gradually switch on to it.
That’s why, in feeding equines, I try to emulate nature. I have seen enough colics in my long career to ever see one of my own equines experience it.
© Spalding Laboratories. All Rights Reserved.