Comparison between Whey and Lactose as Alfalfa Haylage Additives

Abstract

Dried whey and lactose were used in alfalfa haylages to compare their relative effectiveness in fermentation and digestibility of haylages. First cutting alfalfa at 60% dry matter (DM) was chopped, treated with 0 and 2% dried whey (DM basis) and preserved in oxygen-limiting silos. Materials from the same source and with the same DM treated with 0, 1.4 and 7% lactose (DM basis) were preserved in sealed metal containers. The treatment level containing 1.4% lactose corresponded to the amount of lactose in the 2% dried whey-treated haylage. Treated haylages had lower pH and higher lactic acid contents than the untreated haylages. Acetic acid concentrations in all haylages were below 1%. Treated haylages had more digestible chemical constituents than the corresponding untreated haylages. Alfalfa hay (from same source) had lower digestibility coefficients than the haylages. Digestibilities of chemical constituents were usually highest for 7% lactose haylage. Total volatile fatty acids concentrations from rumen fluid of steers were lowest for hay and highest for 7% lactose haylage. Inconsistent treatment effects were noted on percentages of individual rumen volatile fatty acids and acetate to propionate ratio. Lactose and whey were comparable in improving fermentation and digestibilities of alfalfa haylages.