Years ago I went to the Pipestone program winter lambing fieldtrips.
The first producer in that progam to MARKET a 200 percent lamb crop , was a keynote stop.Middle of lambing season for them. This was in like 2003 .
200 percent lamb crop sold, is very hard to do. That is a 230 to 240 lambing percentage or higher.
These guys lived in barn 24 a day during lambing.400 ewes or so. In the 3 hrs we were there for presentation 20 or so ewes lambed and most had trips. No grafting gates. Extra lambs went to bucket system with cold milk at birth.Never nursed a ewe.Tubed with 2 onces of clostrum and cold milk replacer.
They were convinced that thier flushing regime produceed that crop.
Lush pasture and 2 lbs of the best alfalfa hay they had. Grain raises internal body temp on ewes and that is not conducive to embry retention.
My recolection of the estrogenic effect of alfalfa, is that it is only in grazing green.Dried hay ,has very limited effect. Most alfalfa hay is cured at least 90 days before feeding, and the estrogen, like most all of the vitamins, have long since volotized into the atmosphere.