When to cut grass

I am messing around with new scythe and haven't mowed my 1/3 acre pasture all year.  The grass is long and there are seed heads at tips.  If I mow it with scythe and make hay, will my goats eat it?  On one goat forum, she said goats don't like hay with seed heads and it has far less nutrition but someone else said their goats will.  It's also really long and not sure if that is okay for hay.  

My goats would eat it.

Goats eat what they find nutritious.   Fed to them fresh this time of year they will probably eat it very well. Dried to hay they may or may not eat it or only eat parts of it.   Goats are browsers and prefer  not to graze grass but we had great success mowing fresh each day and feeding it in a manger.  There was 4 of us that were good with a scythe so we could do that most days and got very good milk production that way . We also took them for walks in the woods to browse once a day if posible.
I recommend mowing what they will eat each day on a rotational basis.  A 2nd or 3rd cutting that is fine with out tall stalks that dries quickly may be worth saving.  When I had just 2 does it was worth doing but with a herd of 20 not practical.  I would tie 2 bailing twine to the handles of a garbage can and stomp the hay in tight then tie it and pull it out.

See my scythesharpening video in the scythe forum.

Beth, i say go for it. Scythe the pasture, dry it for hay, and let the goats decide. It's true that the highest nutrition for hay is before it's gone to seed, but of our homegrown hay, sometimes the weather doesn't cooperate and it gets cut late. The same is true for hay I buy. The goats usually don't mind the seeds and will eat the hay unless the seed stalks are thick and tough. But the waste becomes straw for bedding, so it still serves a good purpose.