SUCROSE SUPPLEMENTATION AND FEED-INTAKE OF DAIRY-COWS IN EARLY LACTATION

Based on results from previous 14-d sequential elimination trials, whi ch indicated that cows in early lactation preferred a sucrose-sweetene d diet, 12-wk lactation trial was conducted to evaluate further the ef fects of sucrose supplementation. Twenty-four cows (16 multiparous Jer seys and 8 primiparous Holsteins) were assigned at parturition to a co ntrol or sucrose-sweetened (1.5% of dietary DM) TMR in a randomized co mplete block design. The diet included 10% corn silage, 30% alfalfa ha ylage, and 60% concentrate based on corn and soybean meal on a DM basi s and was fed to ensure 10% orts. An additional 2.3 kg of alfalfa hay were fed for the first 5 d postpartum. Covariant-adjusted (BW on the d ay of parturition) mean DMI, milk yields, 3.5% FCM yields, and percent ages of milk fat, milk protein, and SNF were unaffected by treatment a nd averaged 19.0 and 19.1 kg/d, 28.4 and 29.3 kg/d, 28.4 and 28.4 kg/d , and 3.40 and 3.30%, 3.51 and 3.28%, and 8.4 and 8.3%, respectively, for cows on control and sucrose-supplemented diets. In the absence of a choice of diets, sucrose at 1.5% of dietary DM did not enhance mean DMI over the first 12 wk postpartum; however, a transient increase in consumption of the sucrose-supplemented diet may have occurred over th e a 2-wk period after parturition. Variation in feed consumption durin g early lactation suggests that additional data are needed to examine this potential effect.