Grazing Winter Annuals

In mid-August I posted about Overseeding Permanent Pastures for Winter Grazing. Today, I'd like to follow up on that topic and discuss a bit about grazing these annual forages.

The first step in getting maximum use out of these forages is to allow them to become well established before grazing. Horses must be excluded from areas where these grasses are planted until they have developed a sufficient root system to prevent the animals from pulling them up while grazing. A good rule of thumb is to allow rye, ryegrass or oats to reach at least 6" tall before grazing, and to graze no lower than 3-4".

Another consideration is that if horses have been stalled or in a drylot with no access to pasture, then care may be warranted in introducing the animals to the pasture. The following is a paragraph from "Pasture:Evaluation and Management of Existing Pasture" written by Dr. Jenifer Nadeau, Equine Extension Specialist with the University of Connecticut. (The entire article can be found here.)

"If not grazing year round, be sure to gradually introduce horses to spring pasture.
There is no need to do this if horses are maintained on pasture year round, since the growth of pastures in the spring is not rapid enough to warrant stalling horses that are typically turned out. The only time to worry about this is if horses are stalled with no turnout and all of a sudden in the spring are going to be allowed pasture. Pasture grasses are high in sugars (sucrose, glucose, fructose and fructan) particularly during rapid growth. The simple sugars (sucrose, glucose, and fructose) can be digested in the small intestine by the horse but not the fructans, which reach the horse’s large intestine undigested. The fructans are then rapidly fermented by the action of microbial enzymes with the production of lactic acid and a decrease in cecal pH leading to colic and laminitis. The first day or two after the onset of pasture growth, try to limit grazing to 30 minutes to 1 hour. Then gradually increase the time over the next 7-10 days. Avoid grazing laminitis prone horses and ponies on spring or lush pasture that may trigger laminitis. Use a dry lot for overweight horses and ponies."

The final thought I will mention is that these annual forages benefit from rotational grazing just like your permanent pastures, and making good use of rotational grazing will greatly stretch the supply of available forage, particularly in the early part of winter when the growth of these grasses is slow, before the rapid growth with warmer weather in the late winter and early spring. Good rotational grazing will also allow you to move animals off the pasture before it is grazed too low for the plant to regenerate. After all, it's not cheap to grow these forages, the last thing you want to do is waste them.

For more information on grazing winter annual grasses, contact your local Extension office.