Effect of dietary supplementation of Condensed Molasses Soluble (Vinasse) on milk yield and apparent nutrient digestibility in lactating Holstein cows under heat stress

The current study was conducted to investigate the effect of dietary supplementing of condensed molasses soluble (Vinasse) in heat stressed midlactatingHolstein cows on milk yield and composition, apparent nutrient digestibility and economical parameters. The experiment was performed by84 Holstein lactating dairy cows (DIM: 155±25; MY: 32±3) in a completely randomized design with three treatments 1) basal diet without vinous(control), 2) diet containing 5% of vinasse (2.2 kg/head/day) and 3) diet containing 10% 0f vinasse (4.4 kg/head/day). The study was conducted in thesummer season with a temperature -humidity index of 75.1. The experiment lasted for 25 days (15 days for adaptation and 10 days for sampling). Drymatter intake of the treatment fed a 10% vinasse supplemented diet was higher than the other treatments (P<0.05). Dry matter and NDF digestibilitycoefficients were increased by increasing the level of vinasse in the diets, compared to the control (P<0.05). The economical index of income overfeed cost was the highest for the diet containing 5% of vinasse. Totally, regarding to the chemical composition of the vinasse and its beneficial impactson the performance of the cows under heat stress, using 5% of dry matter vinasse supplementation (2.2 kg wet weight/day or 1.1 kg dry matter/day)can improve nutrient digestibility and reduce feed costs without any adverse effects on dry matter intake.