The lower crude protein and higher fiber content of SQ, may be related directly to the characteristics of the plant, which upon reaching the physiological completion of cultivation tends to lignify the stem.
According to Borghezan (2001), this is when the shoots begin to lignify, the lateral buds stop developing, and the leaves become senescent (begin to age).
This is due to the climate conditions where they grow, particularly the high degree of solar radiation, meaning they lignify rapidly while their digestibility drops below 55%.
You would use your base perennial rye or orchard grass with clover, then swap those cattle that didn't finish to soybeans or green-leaf corn or millet, or some sort of annual that doesn't lignify. (The annuals don't lignify because they're not trying to survive to the next season.) On grazed soybeans, the cattle will gain more than 2 pounds a day in summertime; on grazed corn (just eating the green leaves), we can get about 3 to 4 pounds a day."
As with other plant species, maize cells secrete peroxidases, so trying to lignify walls by adding monolignols to the culture medium would result in the formation of DHPs in solution (Brunow et al., 1993) or on the cell wall surface (Nakashima et al., 1992) rather than within the wall matrix.