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MasterGraze Silage for Growing Holstein Heifers
MasterGraze (MG) is a new corn silage hybrid that is a grazing corn. The MasterGraze hybrid will develop grain, but harvest is recommended before grain development which results in a plant that is high in sugar and crude protein (CP). Thus, the unique nutritional attributes of MG makes it an attractive forage source for dairy heifers. Twelve growing Holstein heifers weighing 220.1 ± 28.8 kg were assigned to 1 of 2 treatments varying in type of corn silage. The Control (C) ration consisted of conventional corn silage (Dekalb®) and the MG ration consisted of MG corn silage. Corn silages were fed at 38.6% (DM basis) with 19.6% alfalfa hay and 41.8% grain mix. The experimental grain mixes consisted of ground shelled corn, soybean meal, urea, minerals and vitamins that were formulated for each corn silage’s nutritional profile. The rations were formulated to be 16% CP (DM basis) and meet or exceed all nutrient requirements for a growing Holstein heifer. Due to a limited amount of MG silage, the experiment was conducted for 5 weeks. Animals were trained and fed using the Calan feeding door system to determine daily DM intake. All heifers were fed the C corn silage during the training period and measurements were taken for 1 week to be used as a covariate. Covariate adjusted average body weights (251.5 and 242.7 kg for C and MG, respectively) were similar (P<0.24) for heifers fed both corn silages. Average dairy gains (1.22 and 1.16 kg/d) were similar for heifers fed both corn silages. Dry matter intakes were similar but, numerically lower for heifers fed MG (6.49 and 4.99 kg/d). Feed conversions were similar (0.23 and 0.34 kg gain/kg feed), but numerically greater for heifers fed MG. The limited animal numbers in this study prevented finding significant differences between treatments, however, the feed costs savings are approximately $0.09/heifer/d feeding growing dairy heifers MG corn silage given the same performance based on ration formulation. Given the numerical differences in DM intakes and feed conversions, the cost advantages are greater than $0.09/heifer/d with MG.
Keywords: Corn Silage, Dairy Heifers, MasterGraze