Determining the correct stocking rate is one of the most important decisions a livestock producer makes. It needs to be conservative, flexible, and adaptable.
A smart stocking rate plan is more than just repeating the same process as in past years. It entails matching the grazing livestock numbers to forage production and also adjusting those numbers as changes occur within and over the years.
Brian Hays, a pasture and range consultant for Noble Research Institute in Ardmore, Okla., explains the different ways producers can determine if stocking rate adjustments are needed. He recommends making changes throughout a year using your own intuitive ranch assessment and by monitoring rainfall, vegetative production, and animal performance.
“Rainfall is likely the most limiting factor determining the amount of forage that will be produced during the year,” Hays notes in a recent Noble News and Views newsletter. “Since rainfall can vary significantly in a given year and from year-to-year, intentional managers who monitor and record rainfall will begin to see if they are below or above average throughout the year. A water year table for the operation is a simple means to monitor current year rainfall in relation to the long-term, indicating the variance from average at any given time.”
Based on experience with the land and how forages respond to rainfall, you can determine if adjustments in stocking rates are needed. If rainfall is down, reduce the stocking rate; if it is high, consider stockpiling forage or adding animal units.
Hays says to monitor both bare ground and brush and weed encroachment. If these get worse over time, it’s a possible sign that stocking rate is too high or there is a lack of pasture rest or recovery before grazing begins again.
Hays also recommends recording body condition scores of cows at critical times. Cattle with body condition scores lower than 5 to 5.5 at calving and weaning may be grazing at too high of a stocking rate.
Another indicator of correct stocking rate is how much hay is being fed. “If you planned on feeding hay for three months of the year and it turns out you actually have to feed for five months, you are overstocked at least two months' worth of grazing, which comes to 16.67% of the year,” Hays notes.
Know the amount of forage being produced in pastures each year, Hays says. He suggests doing this with grazing enclosures, clipping plots, or by using a grazing stick to measure forage height throughout the growing season.
“A simple guideline to remember is we never want to graze below a 3- to 4-inch residual height in pastures with introduced forage or a 6- to 8-inch residual height in native ranges,” the consultant explains.
Hays concludes with this summative advice: “Determine stocking rates annually, monitor them seasonally, and adjust when necessary.”