*Originally written by EnviroEquine's Dr. Clair Thunes Ph.D and posted on enviroequine.com.
So, you’ve decided that you want to change your horses’ grain or maybe you haven’t been feeding anything but forage and now want to add something else, how do you do this safely? In fact, why should you care how you do this? Let’s start there.
Your horse’s digestive tract secretes a number of different enzymes that play specific roles in the digestion of the nutrients your horse is consuming. For example, pepsin is an enzyme secreted in the stomach necessary for the breakdown of proteins in to their component amino acids. Protease is another enzyme involved in protein digestion. Lipase is secreted by the stomach and pancreas and breaks down fats. Amylase is released in to the small intestine and breaks down simple carbohydrates.
With enzymes being so specific to the digestion of certain nutrients it is important that changes in feed or the addition of a new feed is done slowly. This allows the digestive tract time to adjust and ensures that nutrients that should be digested in the small intestine do not reach the hindgut where they might cause disruption of the microbial population.
In fact, the microbial population of the hindgut is also diet specific. Different microbes are adapted to the fermentation of specific carbohydrates or the utilization of specific fermentation by-products. For example, lactate utilizing bacteria mop up lactic acid that may be produced during microbial fermentation. If the amount of lactic acid produced exceeds the capacity of the lactate utilizing bacteria to absorb it, lactate builds up and the hindgut environment becomes more acidic. This is detrimental to other fiber fermenting bacteria that need a neutral pH.
Buildup of lactic acid is most likely to happen if horses are fed large grain meals or rapidly transitioned on to higher starch feeds such that the ability of the enzymes in the small intestine to digest that starch is overwhelmed and starch arrives in the hindgut where it is rapidly fermented.
A gradual transition to a new feed is therefore important to the well-being of the entire digestive tract and reduces the chances of developing conditions such as colic. Introduce new feeds slowly. I recommend that no more than half a pound of a new feed be added each day and if you want to be super conservative make that every other day. If transitioning from a current feed to a new one, remove half a pound of your existing feed and replace it with half a pound of your new feed every day or every other day. Do this until you have reached the total desired amount of the new feed and any existing feed is replaced.
Be sure to look carefully at the new feed’s feeding directions as they may not be the same as the feed that you have been feeding. For example, if the new feed is higher in fat, you may need fewer total pounds per day than the current feed you have been feeding. Weigh feed in order to be certain that feeding directions are being followed correctly.
With this careful attention to detail when adjusting your horse’s diet, you will reduce the risk of colic and digestive upset and help keep your equine partner on the top of their game.
For more information on transitioning your horse’s diet, contact EnviroEquine's on Equivont!