Premarin and hysterectomy

I am 52 and had a hysterectomy at 28, so I've been on lots of different kinds of estrogens in that time. Once I went on Premarin until I found out that it is made from pregnant mares' urine ( the "mar-" in the name of the med). They are confined to very small stalls and have catheters to catch all of their urine. Many of their colts are born unhealthy, which is no surprise. If this disturbs you, remember - there are LOTS of good alternatives.
I'm trying what are known as "bio-identical" estrogens next this summer.

Ihad a hysterectomy and total reconstruction, then was put on premarin. It has helped me I feel alot better when i take it but siince the first week i started i've had leg and foot cramps every night! bad ones to the point i can hardly get any sleep! i asked my gyn, and he said it does not have anything to do with the premarin and that was all. has anyone else experienced this?