Longer theoretical length of cut in whole-plant sorghum silage increased feed intake and starch digestibility in growing beef steers.

This study investigated the growth performance of beef steers fed diets primarily composed of sorghum silage differing in theoretical length of cut (TLOC). Seventy-two Angus steers (200 ± 40 kg of initial body weight) were housed in 12 pens (6 steers/pen) and utilized in a randomized complete block design for an 84-d feeding trial. The experiment compared two dietary treatments (6 pens/treatment): one containing 89% sorghum silage in dry matter (DM) basis chopped at a 15 mm TLOC and another with 89% sorghum silage (DM basis) chopped at a 7.5 mm TLOC. Both diets were supplemented with 10% cracked soybeans and 1% mineral-vitamin premix. The results indicated that steers consuming the diet with the larger particle size (15 mm TLOC) exhibited greater dry matter intake (P = 0.05) compared to those fed the shorter cut (7.42 vs. 7.26 kg/d). Additionally, growing steers fed a high forage diet with a 15-mm TLOC silage showed greater starch digestibility (P = 0.03) compared to those fed the 7.5-mm TLOC diet (92.2% vs. 88.5%, respectively). Despite these differences in intake and digestibility, average daily gain and feed efficiency did not differ between treatments. These findings indicate that producers using conventional processors may optimize energy availability and feed intake by choosing a moderate chop length (15 mm) rather than cutting the forage too finely.