Evaluation of Commercial Products to Improve GUT Health and Digestibility in Lactating Dairy Cows

Different feed additive technologies are commercially available to improve gut health and milk production of dairy cows. The study objective was to evaluate the gut health and nutrient digestibility in lactating Holstein dairy cows fed two commercial products: 1) A propriety blend of essential oils and cobalt lactate (EOC) and 2) Active dried yeast product (ADY). The study utilized a continuous 12-wk experimental period using 78 lactating dairy cows arranged in a randomized complete block design with cows split between two robotic pens (n = 40 and n = 38) each equipped with Lely Astronaut A4 robotic milkers. Both treatments received the same basal total mixed ration (TMR), with the experimental treatments added to a soyhull carrier and mixed separately into the TMR at feeding time. A pelleted concentrate was provided through the robotic milking system. Each day, individual cow performance data was downloaded using Lely Time for Cows (T4C) software. All data were analyzed using the PROC MIXED procedure of SAS. Milk production (36.1 and 37.7 kg/d for EOC and ADY, respectively) was similar (P > 0.25) for cows fed both products. Cows fed EOC had lower (P < 0.01) dry matter intake than cows fed ADY (21.8 vs 22.7 kg/d), but feed efficiency (1.65 vs 1.66 kg/kg; FE) were similar (P > 0.10) for cows fed both products. There were no differences (P > 0.10) in milk composition, such as percentage of milk fat (3.46 vs 3.30%), milk protein (2.98 vs 2.98%), lactose (4.90 vs 4.95%), MUN (13.0 vs 12.4 mg/dL) and SCC (4.98 vs 4.99 log10, cells/mL), for cows fed both products. Both products prevented Aspergillus fumigatus growth in TMR samples measured weekly. Fecal presence of Escherichia coli was lower (P < 0.02) for cows fed EOC than cows fed ADY. The digestibility of dry matter (P < 0.05), neutral detergent fiber (P < 0.04), hemicellulose (P < 0.02), calcium (P < 0.02), and phosphorus (P < 0.03) were higher for cows fed ADY than fed cows fed EOC. These data demonstrated that milk production and FE were similar for cows fed both treatments, while digestibility was higher for cows fed ADY which contains an enzyme.