1355 Effects of Trigestamace on performance of lactating dairy cows

Objective of this experiment was to determine if Trigestamace (mannan-oligosaccharide, β glucans and enzyme preparation), fed for 60 d to lactating dairy cows, altered milk production, efficiency and composition in early lactation (study initiated 14 to 45 d in milk). Sixty lactating Holstein cows were stratified by previous milk production and parity (2.2 ± 0.03 lactation number) and assigned randomly to control (CON) or CON with Trigestamace included (TRT) diets. Both diets (CON, 48.1% DM, 14.4% CP; TRT 48.1% DM, 15.0% CP) contained (DM basis) 32.5% alfalfa hay, 21.2% corn silage, 13.8% ground corn, 3.8% soybean hulls, 2.6% brewers grain, 26% protein and mineral. Treatment was added at a rate of 0.032% in the diet (as fed basis) providing about 17.7 g/d of Trigestamace based on feed intake. Cows were fed using Calan gates and individual intake measured. Milk yield was recorded twice daily and milk sampled once weekly and analyzed for protein (%), fat (%), lactose (%), somatic cell count (cells/mL) and milk urea nitrogen (%). Data were analyzed as a randomized complete design. Milk yield did not differ (P = 0.50; SEM = 0.22; CON 44.5, TRT 44.2 kg/d) between diets. Dry matter intake was greater (P = 0.01; SEM = 0.11) for cows fed CON (24.6 kg/d) compared to TRT (24.2 kg/d). Milk efficiency was greater (P = 0.02; SEM = 0.007) for cows fed TRT diet (1.86 kg milk/kg DMI) compared to CON (1.83 kg milk/kg DMI). Energy corrected milk (P = 0.97; SEM = 1.44; CON 43.52, TRT 43.44 kg/d) and 3.5% fat corrected milk (P = 0.93; SEM = 1.53; CON 45.1, TRT 44.9 kg/d) did not differ between diets. Milk fat (P = 0.92; SEM = 0.09; CON 3.80%, TRT 3.78%), milk protein (P = 0.42; SEM = 0.03; CON 2.79, TRT 2.82%), lactose (P = 0.59; SEM = 0.02; CON 4.89, TRT 4.91%), milk urea nitrogen (P = 0.96; SEM = 0.32; CON 13.3, TRT 13.4%) and somatic cell count (P = 0.89; SEM = 26.8; CON 79,779, TRT 71,837 cells/mL) did not differ between diets. In conclusion, adding Trigestamace to an early lactation dairy cattle diet reduced DMI without changing milk yield, resulting in a greater milk efficiency.