Complete Rations for Dairy Cattle. I. Methods of Preparation and Roughage-to-Concentrate Ratios of Blended Rations with Corn Silage

Abstract

Treatment means for dry matter intake, milk production, fat-corrected milk, milk fat test and body weight gains did not differ significantly when rations containing comparable proportions of corn silage and concentrate mixture (30% roughage and 70% concentrate) were fed ad libitum as an ensiled complete ration, a complete ration blended at feeding time, or as separate components in a switchback-type experiment. Ensiling dry matter loss and pH averaged 2.9% and 3.85 for the ensiled cpmplete ration, and 5.0% and 3.75 for the urea-treated silage. Dry matter density of the ensiled complete ration was 81% greater than that of urea-treated silages. In the second experiment, widening roughage-to-concentrate ratios of complete rations from 40:60 to 30:70 to 20:80, was accompanied by stepwise increases in milk production and non-significant increases in dry matter intake under ad libitum feeding. Solids-corrected milk production was higher on the 20:80 than on the 40:60 roughage-to-concentrate ration. Milk fat tests were lower and body weight gains higher on the 20:80 and 30:70 roughage-to-concentrate rations than on the 40:60 ration. Solids-not-fat percentages were similar on all rations. © 1975, American Dairy Science Association. All rights reserved.