My Grazing Cycle
Fall is here and once again we have to decide how long our pastures should be grazed without negatively affecting next year’s growth. In this article I will talk about my experience of when to stop grazing and when to resume in the spring.
Before I begin, I need to mention that I raise “only” about 2.5 ewes and their lambs per acre. While my carrying capacity is indeed higher, I choose to be at the lower end of what I can raise on my farm in order to be able to stockpile pasture in August and September for early winter grazing, to grow my own hay, and to not run out of grass during the growing season, even if growing conditions are less favorable.
As we approach fall, conventional wisdom is to let pasture rest so that it can store reserves in its roots and to leave residual, to not graze it too short. The residual, which becomes residue over the winter, will be needed to help it green up earlier in the spring.
The former premise to allow grass enough rest time that it can store energy in its roots is undoubtedly true. Leaving enough residual is equally important for that reason. Stockpiled grass has lots of time to store energy anyway. In fact, I move my sheep for a few weeks in the fall to graze hay fields at a couple of neighboring farms. However, I come back to each part of the pasture when it has gone truly dormant in November and December and into January. This time of year, grazing closer and leaving residue is not a concern. Once truly dormant, closer grazing does not affect my pasture’s green up in the spring negatively. However, since the dominant grass species in my pasture is orchard grass, the sheep never graze anything really close to the ground and will always leave some residue while I continue to graze rotationally until the last cell is grazed in late December or early January. So my pasture never does look short like a lawn or golf course. If you do rob your pasture of all residue during the winter months you may indeed have a later green up in the spring.
Since I do most winter feeding outside, I start offering free choice first-cutting hay when my experience tells me they might start needing some. Usually, I offer it earlier than needed. In the onset of hay feeding my flock will only nibble a little on the hay as long as the grass is tastier. That changes during the month of January when snow cover gets too high to make it worth their while to dig through.
At the onset of the growing season my flock has access to the entire farm. I use my electric nettings as a perimeter fence where I don’t have permanent fencing. That means about 113 acres of pasture are available to them and indeed during these first few days of spring my flock of approximately 500 sheep during that time of year is spread out at any one point in time over 30 or more acres throughout the day. There is still a hay feeder with a clean first-cutting grass-hay of good quality sitting out there. However, when a round bale lasts about three to four days for such a flock it can be easily stated that the sheep find enough grass to graze. While such little hay eaten is almost irrelevant when it comes to my annual hay feeding costs, it is still essential in a nutritional sense.
Grass starts growing around here during the last week of March in a good year and during the first week of April when spring is late. When I can detect a green sheen when looking over the pasture and when I see the orchard grass pushing its blades out an inch or so I have all the grass it takes to feed a flock of sheep. The first grass that grows is high in protein and energy in the form of sugars but too low in fiber. The hay helps to provide the fiber that is needed. In addition, the remaining residue from the previous year that the sheep eat with the new grass has the same effect as the hay. While sheep are capable of eating very selectively with their pointy mouths, it is impossible to avoid all residue when grazing the new grass. The free choice hay is the indicator for me when I can stop feeding hay entirely. The sheep will stop eating hay in any meaningful manner when they find enough grass. That is the point when I stop feeding hay. Another indicator is that the flock stops moving around throughout the day and stays far longer in one spot. While they are still immensely spread out, the standstill for several hours tells me there is enough grass for them that it is worth their while. Lastly, the growth of the grass becomes at some point very obvious to the observing eye, especially after a warm rain. I expect that to be by mid-April.
By about late April I will have plentiful grass. That is when I start a rotational schedule and continue a strict schedule until about late December or into early January. Once the pasture rotation has started, each cell has between three (spring) to five (summer and fall) weeks resting time.
Occasionally, I hear that early grazing means that ewes encounter a “hungry gap”, meaning they get even thinner on that early grass. Some say that this is due to the imbalance between protein and energy in favor of protein. It is then suggested that the remedy for this situation is feeding hay or even grain. I have had a contrary experience. My sheep and their lambs respond very well to this early grass and gain weight. Early grass is not only high in protein, it is also high in energy in the form of sugar. The only thing missing in early grass is fiber.
The second argument I have encountered on numerous occasion is that early grazing stunts the growth of the grass, from which it will not recover all season long. The recommendations vary from at least six (for rye grass) and up to eight inches (for orchard grass) of growth before starting grazing. This may be true if one still practices set-stock grazing. It would be a mistake to wait this long if you rotationally graze. Here is why: In this area it would be early May before the grass is this high. Given a rotational schedule of at least three weeks, it will be late May or even early June before the last piece of pasture is being grazed for the first time of the season. By then you have lost a good amount of palatability. When grazing starts that late you just can’t keep up. The grass is so far ahead in growth and developing seed stems that it will go at the expense of quality. Orchard grass will have headed out and large amounts of grass will be rejected by your sheep. Grazing early, on the other hand, will reduce the amount of seed stems, thereby reducing the amount of more competitive weeds, which are mostly readily eaten early in the season. Grasses will be stimulated to develop more tillers under early grazing pressure. I have found absolutely no negative effect of early grazing. The fact that the pasture gets later on more than its share of rest time (about five weeks in the summer) due to a rigid rotational program is in my view the essential reason why early grazing has no negative effect on the growth and yield of my pasture. A field trial in Wisconsin some years ago, conducted by Geoff Brink at the US Dairy Forage Research Center with grazing heifers showed no significant reduction in total yield when grazing pastures early just as long as the pasture received enough rest time later and was allowed to grow high enough. This is what I do. This confirms my experience with early grazing of sheep.