Heavy Metal Residue in Milk of <i>Holstein Friesian</i> Dairy Cows Supplemented by Urea Molasses Multi-Nutrient Block Containing Cement Substituted by Tapioca Meal

Urea Molasses Multi-Nutrient Block (UMMB) is a feed supplement for dairy cows, comprising fillers and adhesives. Cement is the most commonly used adhesive in UMMB; however, it consists of inorganic materials that may lead to the precipitation of heavy metals in dairy products, such as milk. In contrast, tapioca meal exhibits similar adhesive properties and is considered a viable substitute for cement in UMMB. This research aimed to evaluate the impact of substituting cement with tapioca meal as an adhesive in UMMB on heavy metal residues, specifically lead (Pb), cadmium (Cd), and mercury (Hg), in cow's milk. A total of 20 lactating Holstein Friesian dairy cows were organized into five dietary treatments according to a completely randomized design, with four cows serving as replicates for each treatment. The dietary treatments included UMMB with 100% cement adhesive (T0); a mixture of 75% cement and 25% tapioca meal (T1); 50% cement and 50% tapioca meal (T2); 25% cement and 75% tapioca meal (T3); and 100% tapioca meal (T4). The milk's Pb, Cd, and Hg concentrations were subsequently measured. Results indicated that the treatment had a significant effect (P&lt;0.05) on Pb levels, while no significant effects (P&gt;0.05) were observed for Cd and Hg. The concentrations of Pb and Cd in the milk across all treatments ranged from 0.009 to 0.01 ppm and 0.10 to 0.11 ppm, respectively. Notably, Hg residues were not detected in the milk samples. Consequently, it can be concluded that tapioca meal is an effective alternative to cement as an adhesive in UMMB. Furthermore,