Vigorous growth of the spring flush is well in the past, and grass has now entered what is called the “summer slump” — the period of time during the summer when perennial grasses regrow slowly. Additionally, the energy content of these grasses has dropped significantly, greatly reducing the number of calories cows consume per pound of dry matter. Due to the lack of nutritious forage available compared to early spring, August becomes one of the toughest grazing months but yet sets pastures up for the fall grazing season. If managed poorly, fall production can be greatly reduced but if managed appropriately, pastures can produce high yields of high quality to feed herds into early winter.
Summer pastures react very differently than spring pastures. During the spring flush, pastures can be grazed in intervals as short as 10 days. However, in the summer this interval is often lengthened to 30 or even 90 days. For this reason, it is important to manage pastures based on their maturity status rather than a set calendar interval.
Yet this also poses a challenge. With lengthened regrowth intervals, it becomes easy to graze pastures before they have had the appropriate time to regrow and hence overgraze pastures. This is a compounding problem that hinders regrowth, encourages weed establishment, and removes above-ground biomass, decreasing the amount of photosynthesis and leaving the soil prone to further heat stress. It is therefore crucial to appropriately manage the number of days a herd is on each paddock.
However, if forage production appears limited for the next month, there are several options that producers can take to provide high-quality feed for their herd. The first is to create more paddocks. This means building temporary fence and may require more intensive management but will allow pastures more rest time and will better utilize available forage. This will also ensure that quality species such as orchardgrass or fescue are not overgrazed.
The second option is to utilize summer annuals such as millet or sudangrass. Unlike cool season perennials, these species thrive during the summer, grow quickly, and offer high quality tonnage even during the heat. If forage is tight this year, develop a plan for next year that incorporates summer annuals into the grazing system. Low-performing pastures are great candidates for summer annuals.
The third choice is to downsize the herd. Although not the option of choice for every producer, this could be a great time to sell calves or cull cows in order to reduce the number of animal units per acre. Then reconsider your stocking rates for next year based on summer slump production rather than the spring flush production.
The final option is to feed hay. This may seem alarming, but could be more economical than first thought. Hay is often cheaper during the summer compared to the winter. Additionally, if feeding hay now allows for higher yields during the fall, the cost of feeding hay becomes minimal and the amount of total hay fed may be minimized as well. Consider a sacrifice lot in which to feed hay, perhaps the same low-performing field that will be used for summer annuals next year.
With these options in mind, choose the one that best fits the operation. The goal during August is to maximize forage growth during the fall when pasture growth is greatest and is of increased quality.