Because the placenta of ruminants is impermeable for antibodies, neonatal calves are born without immunity and they rely on the supply and absorption of antibodies from the first colostrum. Although farmers are aware of this, a lot of calves do not realize sufficient absorption of antibodies (IgGs) due to either low or variable IgG levels in colostrum or due to insufficient absorption of these IgGs. The aim of this study is to analyze whether colostrum contains other important components besides IgGs that can influence colostrum quality or absorption of immunoglobulins in the gut of the neonate. There are two hypotheses, for one thing we’d like to look into the role of microRNAs present in the colostrum. On the other hand, we want to investigate if the microbiome of colostrum effects the uptake of antibodies. Next, we want to investigate how the maternal diet during the last weeks of gestation (dry period in dairy cattle) can influence either the colostrum quality or the absorption efficiency. The effect of dietary protein levels in the dry period on the composition of colostrum and/or IgG absorption efficiency by the calf will be investigated. If we can prove that microRNAs and/or colostral microbiota have an influence on the IgG absorption in the calf’s intestines, new strategies to improve colostrum quality, by the addition of miRNA vesicles, beneficial bacteria or pre- and probiotica, can be developed to help the farmer in the optimization of his colostrum management.