Wednesday, March 3, 2010

Forage Focus: Beginning the Grazing Season

By Rory Lewandowski, Extension Educator, Athens County, Buckeye Hills EERA

Though the weather is still wintry as I write this, it seems fair to say that this may be winter's final hurrah and that spring and the accompanying pasture growth will soon be upon us. At a recent grazing school where I was teaching along with Bob Hendershot, the NRCS state grazing and grassland specialist, Bob said that a grazing program costs about three times less than any feeding program using harvested and stored feed. That being so, it behooves the livestock owner to think about how they might get more out of their pastures and grazing programs. One area to think about is how the beginning of the grazing season will be managed. As the old saying goes, "Well begun is half done".

Factors that must be considered include pasture growth rate, condition of the sod, type of livestock that will be grazing, and number of pasture paddocks that will be utilized. At the onset I need to make clear that improving pasture use and management is dependent upon pasture divisions to a large extent. The more capability you have to subdivide pastures and create more paddocks, the more possibilities there are to better utilize pasture growth.

Livestock love the new grass growth, it is preferred to any hay that is being fed. The challenge at the very beginning of the pasture growth season is to protect the newly growing plants from being overgrazed and the sod base from getting cut up by animal hooves. If the sod is very wet and the soil is soft, it must be protected from hoof action. Churning up the sod base in the early spring to get some early spring grazing can end up reducing the yearly total production. Horses are probably the worst, because of their need to run, and they are followed by cattle whose sheer weight, especially when grouped together can quickly damage a sod base. Sheep and goats make the least impact due to their lower body weight, but again, stocking density plays a role. The point is that keeping livestock confined to a sacrifice area or heavy use feeding pad during some of those soggy early spring days can pay off dividends later in the growing season.

Livestock will graze the newly emerging and young grass plants close to soil level if permitted, and when the plant starts to regrow, they will graze it down again. This is a formula for reducing the vigor and total productivity of the pasture. We have to return once again to basic grazing management principles regarding the ending grazing height and rest period. The tendency in early spring before grass growth really explodes is to let livestock graze the grass plants too low because there still is not much tonnage being produced. Keep in mind that orchardgrass should not be grazed lower than 3 inches in height, while bluegrass and endophyte infected tall fescue can be grazed down to about 2 inches in height. Then, a rest period must be provided to allow that grass plant to recover and grow back to starting grazing height.

What that starting grazing height should be is another management decision. As spring progresses, grass growth will speed up and if the standard 8 to 10 inch starting grazing height is waited for, then some of the paddocks are going to get too tall and mature. A couple of ways of handling the flush of growth are to lower the starting grazing heights, say to the 5-6 inch range, and/or drop some of the paddocks out of the spring rotation. Some graziers refer to their spring grazing management as "topping" the grass. That is, fast rotation through paddocks where livestock are only taking a couple of inches off the top of the rapidly growing plant. Remember leaving more leaf residual is much preferred over taking off too much of the grass plant.

If paddocks are dropped out of the spring rotation, it makes it easier to manage the spring flush of growth. Once grass begins to grow rapidly, the rest period to re-grow to a 6-8 inch grazing height may be as quick as 12-18 days. If there are 8-10 pasture paddocks, this is a 1 to 2 day rotation, maybe quicker than some graziers want to manage. Dropping some paddocks out of the rotation and working with 4-5 paddocks can extend grazing time in each paddock to the 3 to 4 day time-frame. In the early spring, livestock probably should not be in any paddock more than 3-4 days anyway, since grass plants will begin to regrow within that time frame and should be protected from being grazed again.

The question will come up about what to do with those paddocks that are dropped out of the spring rotation. Options include taking a hay crop from them, simulate a grazing pass by keeping them clipped, and let them grow. The advantage of taking a hay crop is that it might be used later as a management tool, but the disadvantage is that there is some significant nutrient removal associated with a hay crop. Clipping is another expense, but does allow nutrients to be recycled back into the paddock and clipping will maintain the vegetative quality of the paddock. Letting the paddocks grow and mature could be an option if, when they are worked back into the grazing rotation they are grazed by a class of animal that has a lower nutrient need, for example dry ewes. If the stocking density is heavy enough there would not be any need to clip the paddock after the grazing pass. If the stocking density is light enough to allow selective grazing, then it may be necessary to clip the paddock after this grazing pass.

The spring grazing season is quickly approaching and a little forethought now given to developing a good start to the beginning of the grazing season will have an effect beyond the spring season.

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