Influence of Cracked, Coarse Ground or Fine Ground Corn on Digestion, Dry Matter Intake and Milk Yield in Holstein Cows

摘要

Plascencia, A., Gonz????lez-Vizcarra, V.M., L???3pez-Soto, M.A., May, D., Pujol, L.C., Ruiz, G.F. and Vega, S.H. 2009. Influence of cracked, coarse ground or fine ground corn on digestion, dry matter intake and milk yield in Holstein cows. J. Appl. Anim. Res., 35: 149?￠????154. Four ruminally cannulated Holstein cows (526???±41 kg) with 112 d in milk were used in a 4x4 Latin square design. To evaluate the influence of corn processing on performance and digestive function, four dietary treatments were compared: 1) steam-flaked corn ( SFC , density = 0.31 kg/l); 2) coarsely-ground corn ( DR-CG , density = 0.55 kg 11); 3) medium-coarsely ground-corn ( DR-MG , density = 0.50 kg/l) and 4) fine ground corn ( DR-FG , density = 0.45 kg/l). There were no effect (P>0.05) of coarseness of grind of dried rolled corn (DRC) on DMI, digestion or milk yield. Finely ground corn increased ruminal propionate concentration and decreased ruminal pH and acetate-to-propionate ratio. SFC increased (P<0.05) total tract digestion of OM, NDF, starch and DE content of diet. Even though, no difference in DMI and milk yield were observed among treatments, SFC increased (P<0.05) milk efficiency. It is concluded that feeding value of dry-processed corn to lactating cow diets was not enhanced by reducing the particle size of the kernels beyond to that obtained following coarse rolling.