I am currently using strip grazing to run a couple groups of cattle on corn stubble fields that I planted cover crops on in early Sept. The forage that grew since Sept is very lush and I am sure very potent feed (oats/rye/turnips). Our cows had a rough time through the summer drought and I am hoping to put condition back on them with this forage, but I also want to extend the available feed for as long as possible since our hay supply is tight. Does anyone have any advice on how practically figure how much forage to give the cows each day? I also have forage that was planted after silage corn that is now about knee high, but without the corn stalks for drymatter, I am not sure how to efficiently use the stuff without the cows wasting the nutrients due to the high water content. Right now I am thinking I should give the cows a round bale of straw to chew on while they have access to the srip grazed oats/rye/turnips? Other years the little bit of cover croping we did I just let the cows run on until the feed was gone but this year is a little different with the short hay supply. Any advice?
Depends on what sort of cows-pregnant, nursing, heifers, etc-their condition, and their size. Generally, rule of thumb is animals need to consume 3-5% of their body weight a day in dry matter. Green forage can vary widely with moisture content. If you are somewhere where it gets cold (I'm in California, it doesn't really get cold) they might need a bit more fiber to help generate more body heat so free choice straw would be good. Putting out mineral would be good too, to make sure they are getting all they need. Strip grazing is a good call so they don't waste as much of the feed by trampling it. You can take a sample area (just a square foot or so) that looks average for the field, dry it in you oven at the lowest temp possible, weigh it, and try to figure out how many lbs of dry matter is probably out there. It would at least give you an idea of if and when you would need to buy hay and how much.