By Tom Noyes
I want to welcome all the readers of this new column “All About Grazing.” Just as the title says, this biweekly column will be devoted to topics on grazing management.
Right now, there are seven members of the Ohio State University Extension Forage Team who have volunteered to write columns. So there will be a variety of writing styles and topics of particular interest to the writers.
Terminology. As a way of introduction, I would like to discuss some principles and terminology you will read about in future columns.
You will see the terms “management-intensive grazing” or “management-intensive rotational grazing” used many times.
This phrase means that there is some type of management being used in the operation of the grazing system that there are several fields and the livestock are rotated from field to field on some kind of schedule.
The intensity of management utilized in a grazing system is determined by the farm manager and the type of livestock being grazed.
Usually the more intense management is employed for the livestock that require the highest level of nutrition and have the highest income potential.
Dairy is a good example, along with stocker cattle or fattening lambs.
Paddock. A paddock is a field or subdivision of a field or cell where the livestock are grazing and are rotated on some kind of schedule.
Dairy cows are usually turned out on fresh grass after every milking. Large paddocks may be subdivided using portable fence that is moved after each milking.
For livestock that do not require quite as high a level of nutrition, the period of stay or occupation in a paddock may range from 3-5 days. In no way should it be longer!
A plant that has been grazed today will be starting to re-grow within 3-5 days. We do not want the animal to graze off that re-growing plant.
The goal. Therefore the goal of a managed grazing system is to provide a livestock density sufficient in a controlled paddock size to adequately graze off the desired amount of forage in as short a period of time as possible. Then rotate the livestock to a new paddock.
The pasture rest period is very important and varies with species and time of year. In the spring, when grass and legumes are growing rapidly, rest periods can be short.
Depending on species (bluegrass and clover or ryegrass and clover), a 14-16 day rest period may be adequate. However, orchard grass and alfalfa or red clover need 20-25 days of rest.
When hot, dry weather hits in mid-summer, the pastures may need a 30-35 day rest period. At times it may be necessary to pull livestock off pasture or use a sacrifice paddock and feed supplemental feed until re-growth occurs.
Heights and residues. Lastly, in this introduction to managed grazing, the grazing heights and residues are important to the success of the system.
Some graziers like to graze half and leave half. I’m not sure that I agree with this philosophy totally.
In the spring you can graze closer than in the summer. With bluegrass, ryegrass and clover, you can graze shorter than with orchard grass and alfalfa or red clover.
The bluegrass, ryegrass and clover swards should be grazed when 6-8 inches in height with 1.5 to 2 inches residue left.
Alfalfa and orchard grass can be grazed at 10 inches and a 2-3 inches residue left.
These grazing height recommendations will result in a forage quality that provides maximum nutrition. If the nutritional requirements of the livestock are not that high, then grass can be allowed to grow taller.
The goal of all plants in the spring is to flower and go to seed. Your goal as the pasture manager is to prevent or delay this natural process as long as possible.
In a rapid growth season, though, it is almost inevitable that some pasture sections will achieve maturation. Then you will have to get out the mower, clip off the seed heads, and start over.
Much to learn. There is much to be learned when starting a managed grazing program. It’s like learning to ride a bicycle, you will crash, then get up and try again.
We have been grazing for more than 10 years now; every year is different and every year we learn something new.
I hope these grazing columns will provide some helpful and timely information that will help you improve your grazing management.
The OSU Forage Team is excited about working with Farm and Dairy to offer these columns on a regular basis.
(The author is a dairy agent for OSU Extension in Wayne County. Questions or comments can be sent in care of Farm and Dairy, P.O. Box 38, Salem, OH 44460.)