Performance of lactating dairy cows fed red clover or alfalfa silage

The objective of this study was to compare utilization of red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) by lactating dairy cows. Red clover and alfalfa were harvested and conserved as silage at two maturities in 2 consecutive yr. Each year, diets containing experimental forages and supplemental grain were fed to 16 multiparous Holstein cows in early lactation in a replicated 4 x 4 Latin square lactation trial. Lactation performance and nutrient intake responses caused by forage type (red clover vs. alfalfa), maturity (early vs. late), and equivalent acid detergent fiber (ADF) content (yr 1, late alfalfa vs. late red clover; yr 2, early alfalfa vs. late red clover) were compared. Milk yield was not different between cows fed red clover or alfalfa in yr 1, but milk yield was higher for cows fed red clover in yr 2. When cows were fed alfalfa and red clover with similar ADF content, the milk yield of cows fed red clover was lower than that of cows fed alfalfa in yr 1, and milk yields were similar between cows fed alfalfa and red clover in yr 2. Milk protein yield and percentage were lower for cows fed red clover in yr 1 and 2, respectively. Intake of ADF and neutral detergent fiber was lower for cows fed red clover in both years. When red clover contained the same ADF content as did alfalfa, cows fed red clover ate less ADF, neutral detergent fiber, and dry matter, resulting in lower milk yield potential.