Comparison of Soybean-Grain Sorghum Silage with Corn Silage for Lactating Cows

Abstract

Data were collected in a 3-yr experiment to compare the intake, milk production, and return above feed cost of cows fed soybean-grain sorghum silage with those of cows fed corn silage. In the last yr, soybean-grain sorghum was harvested at the flower stage of the soybean plants. In the 2nd and 3rd yr, soybeangrain sorghum was harvested at both the flower and early bean stages. In all 3 yr corn silage was harvested in the dent stage of maturity. Ten cows in early lactation were on each treatment in each of the 3 yr (80 cows) to evaluate the silages. Cows fed corn silage consumed 10, 12, and 20% more dry matter and produced 1.8, 1.9, and .8 kg more fat-corrected milk daily than those fed flower stage soybeangrain sorghum for yr 1 to 3. Cows fed corn silage consumed 3 and 14% more dry matter and produced 1.8 and 2.0 kg more fat-corrected milk than cows fed the early stage bean. Corn cost more per hectare than soybean-grain sorghum to grow each year, but the cost per unit silage produced was less. Higher daily milk production coupled with lower silage cost resulted in consistently greater return above feed cost for corn silage.