Brown Midrib Sorghum or Corn Silage for Milk Production

Abstract

In two total collection digestion experiments and two milk production experiments feeding value of brown midrib sorghum silage (brm 12) was compared with corn silage. Normal sorghum (N12) also was included in the first digestion experiment. Heifers consumed more dry matter from brown midrib sorghum (2.64 versus 1.83 and 2.00 versus 1.68 kg/100kg body weight) than from corn silage for the digestion experiments. No differences were significant for dry matter digestibility between the two silages in either experiment. Protein digestion for corn silage exceeded that for brown midrib sorghum in Experiment 1 (38.3 versus 31.3%); however, this was reversed in Experiment 2 (31.0 versus 41.2%). In Experiment 1, dry matter digestibility (53.3 versus 61.4%) was lowered for normal sorghum compared to corn silage. A 24% (4.4 versus 5.8%) reduction of lignin was obtained from brown midrib sorghum to normal sorghum. The lignin percentage of brown midrib sorghum and corn silages were relatively close in all experiments.No differences were significant for actual milk production, fat-corrected milk production, milk fat percent, protein percent, or flavor scores of milk produced by cows fed corn and brown midrib silages in either milk production experiment.