I feed Kent (now Blue Seal) Gro which is a 16% with a good amount of Lysine ..I think .85 as well. I actually feed a pretty basic grain diet as they go - the Kent Jr along with beet pulp shreds and cocosoya oil and good alfalfa or 3rd cutting grass hay. Daily wormer. Once in a while I will do the Equade body builder supplement (works great on yearlings or anything really). Below is my feed label.
A pelleted horse feed for young growing foals, lactating
mares, breeding and conditioning of show horses.
GUArANTeeD ANAlYSIS
Crude Protein, Min. ........................................................................16.0%
Lysine, Min ........................................................................................0.85%
Methionine, Min..............................................................................0.40%
Threonine, Min ................................................................................0.55%
Crude Fat, Min. ...................................................................................6.0%
Crude Fiber, Max. ............................................................................12.0%
Calcium, Min .....................................................................................0.80%
Calcium, Max ....................................................................................1.30%
Phosphorus, Min. ............................................................................0.70%
Copper, Min. ..................................................................................55 ppm
Manganese, Min ........................................................................145 ppm
Selenium, Min ............................................................................0.58 ppm
Zinc, Min .......................................................................................170 ppm
Vitamin A, Min. .......................................................................5,500 IU/lb
Vitamin D, Min ...........................................................................950 IU/lb
Vitamin E, Min ............................................................................135 IU/lb
Biotin, Min ................................................................................0.55 mg/lb