EFFECT OF STEAM FLAKING OF CORN AND SORGHUM GRAINS ON PERFORMANCE OF LACTATING COWS

The objective of this study was to compare the relative feeding value of sorghum versus com grain in rolled or steam-flaked forms in diets, for lactating dairy cows. Twenty-four Holstein cows (averaging 110 DIM) were divided into four groups and fed diets of 40% grain as dry-rolled sorghum, steam-rolled com, steam-flaked sorghum, or steam-flaked com for 70 d. Compared with rolling, flaking of both grains increased yields of milk, milk protein and fat, and protein percentage of milk, but differences tended to be greater for sorghum than for com. Efficiency of feed utilization was higher for steam-flaked than for dry-rolled sorghum but was unaffected by com processing. Flaking of both grains increased total tract digestibilities of DM, OM, CP, starch, ADF, and NDF. Estimates for NE(L) were 21% higher for flaked than for rolled sorghum and 6% higher for flaked than for rolled com. No differences in performance of cows existed between com and sorghum grains. Cows fed 40% of their diet as steam-flaked sorghum or com yielded more milk and milk protein than those fed the rolled form of the grains, and no differences existed between types of grain fed.