Not to be mistaken with rotational grazing or ultra-high stock density (UHSD) grazing, high stock density (HSD) grazing is the practice of intentionally grazing livestock at higher concentrations than normal to manage soil, forages, and livestock production of a specific area.
Hugh Aljoe, director of producer relations and pasture and range consultant for the Noble Research Institute, explained the difference between rotational and HSD grazing as well as considerations to keep in mind when implementing HSD grazing in an article published in the Noble News & Views.
Aljoe explains that HSD grazing is very similar and is inclusive of UHSD grazing by definition. However, HSD grazing doesn’t have to be applied at the extremely high intensities often considered to be “mob” grazing whereby multiple moves per day are required.
In rotational grazing, stock density rises while the stocking rate remains constant.
To put this in perspective, take a herd of 50 cows grazing 500 acres. The stocking rate, which is commonly expressed in total number of mature head per acre, is 50 cows or one cow per 10 acres. If the 500 acres is divided into 10 pastures of equal size, the stock density drops to one cow per acre while the stocking rate remains the same.
If those 10 pastures where subdivided further into five paddocks, the stock density would become five cows per acre.
“Cattle have to be moved to a fresh paddock more often, depending on the amount of grazing forage that is available and the amount of forage residual desired to remain after the grazing event,” Aljoe explains.
Why should you implement HSD grazing? According to Aljoe, there are many reasons.
With HSD, a producer can intentionally manage grazing intensity to meet their desired objective. They can also limit selectivity when grazing by forcing livestock to consume plants that are less palatable or preferred.
High stock density also promotes a more uniform grazing utilization of pastures. By using strategic fencing, areas that are avoided or less grazed are utilized. Also, trampled structural components of plants from a HSD system add organic materials to the soil surface and the exposed soil surface is disturbed, which promotes new plant recruitment and production.
Over time, HSD systems can enhance total forage production, boosting the carrying capacity of your pastures and maybe even the stocking rate.
Aljoe also states that there is no optimum stock density. “Stock density is dependent on the objective to be achieved, the situation, and resources,” he elaborates. Other variables that influence stock density are the season, long-term objectives, type of soil and forages, terrain, and herd size.
Aljoe makes it clear that much is learned via trial and error but also acknowledges that the higher the stock density, the more flexible a producer needs to be with the management and the gentler the cattle need to be.
Don’t forget to consider the recovery period. It is a key aspect that is often overlooked following HSD grazing. If the application of cattle was aggressive, the recovery period may need to be longer than intended. If the area was lightly grazed, or “top grazed,” in rapid succession during a rapid growth phase, recovery will be quick.
Before elevating stock density above what is typical for a well-managed grazing program, Aljoe recommends asking yourself what you wish to achieve, and then through trial and error, determine what stock density is best to accomplish your goals.
Kassidy Buse was the 2018 Hay & Forage Grower summer editorial intern. She is from Bridgewater, S.D., and graduated from Iowa State University with a degree in animal science. Buse is currently attending the University of Nebraska-Lincoln pursuing a master’s degree in ruminant nutrition.