DOSE-DEPENDENT EFFECTS OF A SENSORY ADDITIVE ON THE EATING BEHAVIOR OF TMR-FED DAIRY COWS

Forty four Holstein dairy cows (156 DIM, 28.9 kg/d of milk, 648 kg of BW) were assigned to a 4 x 4 Latin Square design with 25-d periods replicated 11 times to evaluate the dose response to a sensory additive (ProEfficient, PE; Lucta S.A.) on eating behavior of dairy cows fed a TMR. Cows were grouped in 11 blocks and, within blocks, randomly assigned to 4 doses of PE: 0, 15, 30, and 45 g/d. The TMR averaged 16.4% CP, 31.4% NDF, and 1.63 Mcal NEL/kg. Cows were fed ad libitum on electronic scales and eating behavior and feed consumption were recorded automatically. Data were analyzed using a model with fixed effects of dose (treatment), period, block, and the random effect of cow within block using PROC MIXED of SAS. Treatments effects were evaluated using linear, quadratic, and cubic orthogonal contrasts. Dose of PE affected (P < 0.05) eating time, intake rate, dry matter (DM) intake, and energy corrected milk (ECM) of dairy cows. Eating time responded cubically (P < 0.05) to PE dose because cows fed 30 g/d dedicated more time to eat than cows fed the other doses. There was a quadratic effect (P < 0.05) of PE dose on intake rate given that cows fed 15 and 30 g/d had lower rates than cows fed 0 and 45 g/d. Lying time was not affected (P > 0.05) by PE dose. DM intake and ECM responded cubically (P < 0.05) to PE dose because cows fed 30 g/d consumed the most DM and produced the largest amount of ECM. In summary, cows fed a TMR supplemented with 30 g/d of PE spent more time eating but at a lower rate than cows receiving other PE doses. These results confirm the positive impact of the sensory additive PE on the eating behavior of dairy cows and indicate that such an effect is most pronounced at 30 g/d. tech.service@fad.com