INFLUENCE OF ALFALFA/FESCUE SILAGE MIXTURES ON MILK PRODUCTION OF EARLY-LACTATION HOLSTEIN COWS

摘要

Our objective was to determine the effects of various mixtures of alfalfa (Medicago saliva, L.) and tall fescue (Festuca arundinaceae Schreb.) silages, fed to provide 1.1% of body weight as forage-neutral detergent fiber (NDF) in the diet, on milk production and composition, and associated digestion kinetic and ruminal parameters. Forage-NDF was provided from 100% alfalfa/0% fescue, 67% alfalfa/33% fescue, 33% alfalfa/67 fescue, and 0% alfalfa/100% fescue. Diets were fed to five cows in an incompleteLatin Square design (two periods). Dry matter intake increased with increasing fescue silage forage in diet (45, 54, 52, and 46 lbs/d, respectively). Milk production was also higher (P < .05) as cows consumed diets increasing in fescue silage (71, 89, 86, and 76 lbs/day, respectively for 100% alfalfa/0% fescue, 67% alfalfa/33% fescue, 33% alfalfa/67% fescue, and 0% alfalfa/100% fescue). Grain in diets increased with increasing fescue in diets, accounting for increased milk protein. Milk urea nitrogen was higher for cows fed 100% alfalfa/0% fescue silage due to alfalfa's high protein solubility and high inclusion in the diet. Lower forage to concentrate ratios of mixtures accounted for higher dry matter intake and milk production in diets high in fescue silage.