also, do u think that i should rug my yearling, again, shes 15h, heavy,shirextbxcob, 16 mths old, i never rugged her last year, and she lives out 24/7, but i have very good field shelters,
Definitive no. Much healthier like that and horses have a great ability to adapt to temperature. Dont forget they like it cold. We, my horse and me came over from Switzerland, none of the 30 horses there living out (with great shelter) had ever a rug and we had temperatures well under zero for weeks.
So dont worry...