High-Moisture Corn versus Dry corn in Combination with either Corn Silage or Hay for Lactating Cows

Abstract

Forty cows were assigned to four groups of ten each in a 2×2 factorial design and fed one of four diets: 1) high-moisture shelled corn (HMSC) + hay; 2) HMSC + corn silage; 3) dry shelled corn (DSC) + hay; and 4) DSC + corn silage. All diets were supplemented with a protein, vitamin, and mineral mixture to meet the cows’ nutritional requirements. Concentrates, hay, and corn silage were fed to all cows during a 14 day standardization, Cows were than switched to experimental rations for 21 day adjustment, and experimental data were collected in the following 84 days. Cows were offered 1kg concentrates (DSC + supplement equivalent) for each 2.75kg of milk produced. Forage was fed free choice. Results for cows fed HMSC + hay, HMSC + corn silage, DSC + hay, and DSC + corn silage averaged: DM intake (kg/day), 18.9, 16.5, 19.7, 18.1; 4% FCM, 25.5, 20.6, 23.7, 21.3; milk fat %, 3.00, 3.41, 3.47, 3.01; and acetate: propionate ratio in the rumen fluid, 2.54, 2.29, 3.08, 1.83. Cows fed DSC ate more than cows fed HMSC. Dry matter intake of Cows fed hay was greater than for cows offered corn silage. Milk fat % and 4% fat-corrected milk did not differ significantly. The acetate: propionate ratio was greater for hay-fed cows than for corn silage-fed cows, but no difference was observed between the corn grain source. Digestibility coefficients and TDN for HMSC + hay, HMSC + corn silage, DSC + hay and DSC + corn silage were: Dry matter, 69.8, 67.5, 66.9, 63.8; organic matter (OM), 71.8, 70.5, 68.2, 65.7; crude protein, 68.5, 66.7, 66.4, 63.2 acid detergent fiber, 51.7, 39.6, 54.3, 40.8; ether extract, 72.1, 72.5, 68.7, 63.9; N-free extract (NFE), 82.2, 79.6, 72.5; and total digestible nutrients (TDN), 70.8, 69.3, 67.8, 65.2. Dry matter, OM, NFE and ether extract digestibilities and TDN were higher for HMSC than for DSC diets. Dry matter and acid detergent fiber digestibilities were greater for hay than for corn silage diets.