If day-one colostrum feeding isn't hitting the mark timing-wise, this study looked at what actually changes hormonally when it's delayed. Researchers tracked GLP-1 and GLP-2, two hormones tied to glucose regulation and gut development, comparing calves fed colostrum right away against calves fed later. The takeaway lines up with what producers already assume, delaying colostrum doesn't just delay antibody transfer, it shows up in measurable hormone differences too, adding another data point to why speed matters at first feeding.
"Short communication: The effect of delayed colostrum feeding on plasma concentrations of glucagon-like peptide 1 and 2 in newborn calves" — Y. Inabu, A. Fischer, Y. Song, L.L. Guan, M. Oba, M.A. Steele, T. Sugino. J Dairy Sci. 2018;101(7):6627-6631.