Nutritive Value of Sorghum Silage as Influenced by Grain Content

Abstract

Sterile hybrid sorghum silage, with and without rolled sorghum grain added at feeding, and two silages, with whole and rolled sorghum grain ensiled with the sterile forage, were compared in a growth trial with 200-kg Hereford steers, a digestion trial with 200-kg dairy steers, and a lactation trial with Holstein cows. Silage dry matter consumption was least with seedless silage and almost identical for the drier, grain-containing silages and the seedless silage-sorghum grain combination. Steers gained most on rations containing rolled grain, intermediate on silage containing whole grain, and least on the grainless silage. Milk production was greater when the grain was rolled, either ensiled or fed with the seedless silage, than for the rations containing seedless silage and silage containing whole grain which resulted in equal milk production. Calculated digestible energy for lactation was greater for the seedless and rolled grain silages than for either the whole grain silage or the mixture of seedless silage and rolled grain. Steers used the whole grain-containing silage least efficiently but used all treatments more efficiently than did lactating cows. Poor animal performance with the grainless silage was associated with poor intake related to low dry matter content rather than to low digestible energy.