It's been almost three weeks since I started grazing this field of winter-killed sorghum-sudangrass as a trial to see if it's possible to graze a field like this over part of the winter instead of feeding hay. Other people are already wintering cattle this way, so I'm not really going to discover anything earth-shattering, but I still like to try things on a small scale before I believe everything I read.
I split this field into four sections (I'm not sure if I'd call them paddocks) and after the cattle had grazed the first quarter for about a week I opened up the second section. Since I was still developing my winter-grazing eye and wasn't sure about how much grazing was still left, I got a little nervous and opened up the second part earlier than I planned, but in hindsight I think I could have waited much longer. Now, I'd just estimate how many bales of hay per acre a field would have made, then I'd simply figure out how many bales of hay I'd feed in a week (factoring in some waste. etc.), and I'd build my paddock big enough to provide a week's worth of feed (or a day, a month, etc.). This field is about 25 acres, it should have made about 3 bales per acre, so it's the equivalent of 75 bales of hay. I usually figure that it takes one 1200 lb. bale of hay to feed a 1200 lb. cow for a month, so I could possibly graze 75 cows for a month or 25 cows for three months if I had no wasted grass (So far, with trampling and waste, it looks like I'll be lucky to get the equivalent of about 50-60 bales?).
I've read accounts that claimed that the protein levels for winter-killed sorghum-sudangrass could be as high as 11%, which is more than enough protein for a dry cow and also kind of hard to believe. Most of the typical prairie hay that I typically feed is supposed to be below 8% protein (I've never had any hay tested, but I really should), so I typically feed about 2 lb. of 20% cubes per day to supplement the hay, and I've also been feeding about 2 lb. of cubes while they are on this field of sorghum-sudangrass.
When I try doing this again, I think I'd add in something like cowpeas, sunn hemp, turnips, or sunflowers (I've been reading some unexpected info about the high-protein levels of sunflowers) to get protein levels high enough so that I could eliminate the cubes completely. The money I'd save by not needing to buy cubes would easily pay for a lot of cover crop seed, plus planting a cover crop mixture would be better at building the soils in my fields. I said it before, but I'll say it again, next year is going to be the year of the cover crop mix, but that's also what I said last year.
This year it also seems like there are more blackbirds (I'm no birdwatcher, so I'm not sure on the exact identity of these birds) around than there usually are in the winter, they're both in the sorghum-sudangrass field and in the pasture next to it. I don't know if the field of sorghum-sudangrass has anything to do with it, but they seem to be doing a great job of breaking up all the cow patties by scratching through them like a huge flock of hyperactive tiny chickens.
Of course, they might also eat a bunch of grain sorghum next year before it's harvested, so I'm not sure if a bunch of blackbirds is good or bad. But, since there isn't really anything that can be done one way or another, my best guess is that they are neither good nor bad, they just are.