Have you ever noticed that when you see, taste or smell something awful, that you want others to share in the experience? Get a whiff of a skunk or a rotting carcass and you are likely to say, “PU! Smell that!” A friend of mine found the written equivalent of a skunk. It’s an article from Oregon State University called Grass Growth and Regrowth for Improved Management. He wanted me to get a whiff and, of course, once I did I forwarded it to Allan Crockett and Dallas Mount, the Ranching For Profit School teachers to sniff. Now I’m sharing it with you.
The article attempts to describe why a “well designed rotational grazing system” with seven paddocks was failing. With phrases like, “Leaf sheath elongation had raised the collar zones of most of the leaves to a vulnerable height such that leaves were severed beneath this meristematic zone. However, internode elongation had not yet elevated the shoot growing point, thus this important meristem remained as part of the stubble.” (If you dare to actually read the article this link will take you to it: Are you sure you want to read the OSU article? It is actually good that it is hard to read, because if someone actually did read it, they would be rewarded with bad advice!
Our first clue that something is wrong with the article is offered in the first paragraph where we are introduced to the seven paddock “well designed rotational grazing system.” There is no such thing as a well-designed 7 paddock “rotational grazing” system. It takes a minimum of eight paddocks just to stop overgrazing. With seven paddocks it is a “rotational overgrazing” system!
Eight is not enough, especially in this case. Each day the herd remains in a pasture the quantity and quality of forage in that pasture drops off. As a result, animal intake goes down and at some point, performance suffers. The pastures described in the article were being grazed with dairy cattle. Lactating dairy cows need high quality forage. When graze periods are longer than a day or two, milk yield will drop sharply. In most situations it takes at least 14-16 paddocks to support decent animal performance, but with lactating dairy cattle we probably need more like 30!
There wasn’t one word in the article about recovery periods, graze periods, stock density or stocking rate. The author did suggest that a couple of the paddocks be taken out of the rotation and be cut for hay during rapid growth. It’s not a bad idea, but it hardly addresses the root causes of poor pasture or animal performance.
The paper’s primary recommendation was that graziers follow the “long-standing rule of thumb: take half and leave half.” They claim that taking half and leaving half “would have avoided untimely ‘denuding’ and ‘decapitation.’” Huh?
The problem with taking half and leaving half, when you only have seven paddocks, is that livestock will wind up grazing half of the plants into the dirt and leaving the other half of the plants completely ungrazed! I don’t think that’s what they had in mind when they said take half and leave half. But the paper offers a solution for that too. To keep the half of the plants that didn’t get grazed from going to seed, which reduces forage quality and palatability, they suggested mowing. I thought that’s what livestock were for.
For more as to why “take half and leave half” is usually bad advice click here: Take Half & Leave Half is Bad Advice
To learn more about overgrazing, click here. Rotational Overgrazing