Abstract

A 73-day growing study utilizing 203 crossbred steers (681 lb) and a digestion trial examined the effect o f sorghum grain particle size on rumen fermentation, ration digestibility, and performance of growing steers fed 37% grain and 63% ground alfalfa. Dry-rolled grain sorghum p article sizes in both trials were about 2000, 1500, and 1000 microns, for the coarse- (CR), medium- (MR), and fine-rolled (FR) treatments , respectively. Coarsely rolled corn (2000 microns) was included as a positive control. In the growing study, half of sorghum was treated at feeding time with an enzyme product, Digest "M". The rations were 35 to 37% dry grain plus ground alfalfa hay and supplement. Total ration dry matter, neutral detergent fiber, and starch digestibilities increased linearly (P<.02) with decreasing sorghum grain particle size. Rumen pH, ammonia and total volatile fatty acid concentrations, and acetate-to-propionate ratio were unaffected by grain type or particle size. Dry matter intake was not influenced by grain types or particle size. Steers fed FR sorghum gained 9% faster (P<.03) during the first 28 days and tended to gain faster (5%, P<.14 ) over the entire trial than those fed CR sorghum , with gains on MR sorghum being intermediate. FR sorghum produced 6% more efficient gains (P<.07) than CR, and MR grain was intermediate. Digest "M" enzyme treatment of the sorghum grain had no influence. Feed con versions of CR, MR, and FR sorghum were 93, 94, and 99% of corn. This research indicates that grain sorghum in high roughage backgrounding programs should have a maximum average particle size of 1000 microns.

Keywords: Cattlemen's Day, 1997, Kansas Agricultural Experiment Station contribution, no. 97-309-S, Report of progress (Kansas State University. Agricultural Experiment Station and Cooperative Extension Service), 783, Beef, Grain sorghum, Particle size, Processing, Digestibility, Enzyme, Growing cattle

How to Cite:

Kessen, T., Simms, D., Kuhl, G. L. & Drouillard, J. S., (1997) “Effect of grain sorghum particle size and digest “M” enzyme treatment on performance of growing steers”, Kansas Agricultural Experiment Station Research Reports 1(1), 46-49. doi: https://doi.org/10.4148/2378-5977.1934