Silage quality

[grassfarmer]

Can anyone tell me the feed value of sow thistles in silage? I was looking at standing crop today from point of view of buying it and am unfamilier with this weed. It looked to be fairly lush - more like a dandelion stalk than a tough old Canada thistle.

[farmers_son]

Why not consider harvesting some by hand, cutting it up and taking a sample to a feed testing lab. I use Parkland Labs in Red Deer. If you talk to them they might do a rush test for you and you could have your answer today or tomorrow.

[mjohn]

Crude protein and digestability of sow thistle in mid-bloom will be equivalent to full bloom alfalfa. It will also be slightly higher in calcium and magnesium (relative to alfalfa). Sow thistle, like alfalfa, tends to accumulate potassium. It probably has considerably more water in it than the grain crop growing with it. What may look like lots of thistles may be considerably less on a dry matter basis compared to the crop. I agree with the last post, have a small amount of it tested for your own interest. Some weeds accumulate nitrates, so it might be worth a check if the sow thistle makes up a substantial portion of the crop.

[grassfarmer]

Thanks for the replies - the sow thistle probably accounts for less than 15% of the fresh crop so if we get it wilted it won't be a big component of the silage. I'll put up with it and see what kind of silage we get. Should make an interesting mix - a field seeded to alfalfa but with probably 65% volunteer wheat/barley, 15% alfalfa (plenty of plants but mostly quite short so they won't all get cut)and 5% wild oats thrown in for good measure! I think it could make a silage the cows really enjoy - should be plenty nutrition and a bit of variety.