I had a set of twins last year, I fed one Shag, and one Epic. I let them both complelty slick out, and then started feeding it(about the end of june)You could see a difference in hair quality and amount of hair on the heifer on epic within 20 days, and by 45 days she had hair that I had to use a skip tooth comb on. While by 45 days with the shag I was just starting to see the same results that I was seeing with epic at 20 days.
Both the heifers were bred, and they both calved just fine and are now re-bred.
Also the heifers were just in a lean-to with two fans.