ARS | Publication request: AN ANALYSIS OF THE RELATIVE VALUE OF LUCERNE AND RED CLOVER SILAGES FOR LACTATING COWS

Submitted to: International Silage Conference
Publication Type: Proceedings
Publication Acceptance Date: September 11, 2002
Publication Date: September 11, 2002
Citation: BRODERICK, G.A. AN ANALYSIS OF THE RELATIVE VALUE OF LUCERNE AND RED CLOVER SILAGES FOR LACTATING COWS. INTERNATIONAL SILAGE CONFERENCE. 2002. p. 128-129

Technical Abstract: More than 50% of the protein in lucerne silage (LS) can be converted to NPN. Red clover silage (RCS) contains less NPN. Results from five Latin square trials were analysed to determine the nutritional value of these forages. The LS and RCS were harvested using conventional methods including field wilting to 40% DM. Diets containing about 63% silage DM were fed to lactating Holsteins; 104 animal observations were made on each diet. Data were analysed using SAS. Compared to LS, RCS contained 3.0% less CP, 1.7% less ADF, and 36% versus 53% NPN (% of total N). Cows consumed 1.5 kg/d more DM when fed LS, but there were no effects of forage (P ' 0.16) on yields of milk, protein, or SNF. There were trends (P ~ 0.10) for greater weight gain and lower fat yield, and milk fat content averaged 0.15% lower (P = 0.05), on RCS. Efficiency of N utilisation was greater (P < 0.01), milk urea lower (P < 0.01), apparent digestibility of DM, OM, NDF, ADF, and hemicellulose higher (P < 0.01), and fecal DM lower (P < 0.01), on RCS. Digestible OM intake was 14.4 kg/d on LS and 14.5 kg/d on RCS, suggesting that cows ate to constant energy supply. Estimated ME contents were (MJ/kg DM) 7.9 (LS) and 8.8 (RCS). Replacing dietary LS with RCS may improve nutrient efficiency and lower environmental losses.