Figure 1.

Raw waste milk (WM) refers to milk that cannot be sold to the market for human consumption. The milk is obtained mainly from fresh cows and diseased cows under treatment with antibiotics or whose antibiotic withdrawal period has not elapsed, resulting in very low concentrations of these antibiotics being passed through milk. Pasteurization is often performed before feeding WM to reduce health risks in calves. Pasteurized WM reduces the number of harmful bacteria, IL-8 and increases the concentration of beneficial metabolites and volatile fatty acids (VFA). Finally, the growth performance, rumen fermentation and immune system of the calves are improved.