In an Oklahoma State University rancher webinar, Paul Beck, associate professor of animal science at OSU, discussed the controversial concept of which is better—continuous grazing versus rotational grazing.
He began by reciting a quote from the 1922 Yearbook of Agriculture: “The cheapest source of all feed is pasture, because it furnishes a balanced ration at a low cost and cow does her own harvesting. In comparatively few cases is the fullest possible use made of pasture.”
Both grazing systems have advantages and drawbacks, but a producer has to decide which positives outweigh the negatives.
“The biggest strength of a moderately stocked continuous grazing system is diet selection,” Beck said. “The animal has the entire pasture to select the plants, plant parts and area in the pasture for the highest quality diet. This leads to a pretty good performance, and when we start looking at what that animal selects versus what the total pasture is, they’ll harvest a lot better quality diet than the average of what is out there.”
However, Beck said the ability of cattle to eat their preferred forages often leads to increased utilization of desired areas and plants.
“We have those ice cream plants, whether it’s clover in a Bermuda grass system, or tall grass species in a native system, that can get overgrazed compared to other areas,” Beck said. “That leads to low-grazing uniformity and the same pasture can be both overgrazed and underutilized at the same time.”
Additionally, animals can overutilize the forage closest to the water source or under shade because those are areas they are drawn to for comfort.
Rotational grazing is more time consuming and labor intensive because it involves splitting up pastures into smaller units so animals do not have access to the entire pasture. “This reduces the diet selection, and any time we restrict that animal through overgrazing, high stocking rates, intensification of the stocking density through rotational grazing, we decrease the diet quality,” Beck explained. “The desired plants are utilized first, but they get a break, which allows them to rebuild root stores and leaf area. We do have increased grazing distribution, but there is still sacrifice areas around water sources.”
In most cases with rotational grazing research, slightly lower performance is reported, Beck said. Rotational grazing is often difficult if water sources cannot be developed for additional rotational grazing paddocks, however for those who can find a way to provide enough sources of water and have the time to move cattle from pen to pen, it can be a successful system.
When it comes to utilization, the scales are tipped toward rotational grazing, as it forces cattle to settle for less desirable forage and allows for a more even grazing of the pasture.
Beck said continuous grazing also leads to poor use of fertilizer and has an estimated forage and land utilization of 30 to 35%. Rotational grazing improves utilization of forage and efficiency of fertilizer and land with an estimated utilization of forage of 50 to 75%.
“To produce feed for livestock, forages need sunlight, water, nutrients and time,” Beck said. “The forage top is a reflection of the root, and if we graze those too short, we can artificially create drought stress. That really came home to us in 2011 and 2012 because even if we did get a rain, our plants were so overgrazed, they were slow to respond and they didn’t have the top growth to capture run-off.”
The implications of stand loss can be a long recovery and some species have to be replanted if they are overgrazed to a certain degree. Beck said producers need to maintain stocking with low to moderate grazing intensity.
“This leaves surface residue to increase water infiltration when it does rain,” he said. “This improves root health and give plants a speedy recovery from grazing.”
Cattle producers use both grazing methods with success; at the end of the day cattlemen need to decide if adding extra time and labor to raise lower preforming cattle on healthy, evenly-grazed forage is more important to them then raising higher-performing cattle on over-grazed pasture without the hassle of moving cattle from paddock to paddock. There are no wrong answers, just different results.
Lacey Newlin can be reached at 620-227-1871 or [email protected].
