I'm a young crop advisor in Normandy, north west of France, exactly 15miles where André Voisin used to farm. My parents are farmer (mainly crops : potatoes, flax, beet roots, wheat...) and even if I'm not a cattle man I read all your blog with a lot of attention.
I did an internship on a farm in Colby, KS in 2008, and met Jey Fuhrer from the NRCS of Bismarck, SD when he came to France. He showed us what Gabe Brown did on his farm (http://www.sustainableranching.com/) and I was very interested about "mob grazing".
I'm reading "Grass Productivity" from André Voisin and I am a bit disapointed on some points. André Voisin (and the other who followed him ) told us to begin grazing at 9" and to go out of the pasture at 3" after 3days of stay on the same paddock. It is known that at this high the grass is at its maximum value.
You are leaving the grass to rest for a long time, wich is very good for its productivity, but according to your pictures you are coming back when the grass is very tall. Is there a nutrition reason why you are doing that ? Voisin worked mainly with dairy but he wrote that he was also right for cattle. In the spring he also recommend to run the cattle when the grass is just regrowing to top off all the plants, give some food, and not having to run after grass growth that would be too tall... what is your opinion on that ?
I read some articles on mob grazing and holistic management. I don't understand what is the advantage of having some grass trampled. I understand it can provide food for soil life, but in France I found that leaving some grass behind the cows leads to a poor regrowth, so I don't know what to think.
The flora of your field may change with mob grazing but I think you will see it along the years. I would like to thank you about your blog, I'm checking it regularly, I like the weed pictures and would be curious to see how it will turn this year.
And my response:
Thanks for the email. I grew up not far from Colby, KS…small world. Voisin’s book is very interesting and I learned an enormous amount from it. The one big thing I took away was the importance of observation. I spent many hours watching my animals graze…I would never have done that before reading “Grass Productivity”. Voisin was a master of observation.
There is a lot of talk around when to turn back into a pasture to graze it and how tall the grass should be. I just read an article in The Stockman Grassfarmer about the importance of energy versus protein and I agreed with much of what was written. When I ran stockers a few years ago and even with my cows last year, in the early spring we see one to two months of what I call “sheet cake” cow manure…the manure is very runny and green. It’s a clear sign of too much protein and I have seen the cattle perform poorly when they get to this point. It is important to keep your cow patties looking like pumpkin pie. It is a good sign that the cattle are eating a balanced diet. I would suggest to you that you observe your cattle’s manure versus the height of your grass….experiment with it. You will quickly find out what works. All grass is different, so I can’t tell you how tall your grass should be, but you will quickly learn what is too tall or too short simply based on the manure patties. As the grass get’s shorter, your protein levels will increase and your manure patties will get runnier, as it gets taller, your energy levels will increase (and protein decrease) and manure patties will firm up. So it will depend on the class of cattle that you are running (ie: stockers need more protein than cows, wet cows need more than dry cows) and the relative protein values in your grass that determine when (how tall) you should be grazing your grass. I personally like to let the grass/forage get as tall as possible (maximum grass production), it seldom seems that we are lacking in protein, but we have worked hard to get clovers started that are likely increasing the protein levels in our forages, regardless of height.
I think the trampling of the grass is absolutely a critical piece to the success of mob grazing. If you can get the grass trampled down into the soil (or at least making contact with the soil) it’s just like you have fertilized that ground. I have been amazed with the quality and quantity of regrowth we get when we do a good job of trampling the grass in. I’m not sure why you are seeing that it is hindering growth…you need to make sure that the grass is being “trampled” into the soil and you are not just leaving some grass behind. If you are leaving the cows for 3 days, you are likely NOT trampling in any grass. 3 days is way too long to leave the cows on a pasture and it would NOT be considered mob grazing. To get to mob grazing, you need to at least move your cattle every day, and preferably twice or more each. It’s the only way you can get your densities up to take advantage of a true “mob”.
Thanks again for your email and best of luck in your grazing….keep me posted as to your results!