A calf's colon does more than just handle waste, it's actually a major site of immune development early in life. This study used genome-wide analysis to look at how colostrum feeding strategy shapes that immune development in the colon specifically, going beyond the small intestine focus most colostrum research sticks to. For producers thinking about colostrum purely as a passive-immunity play, this adds evidence that it's shaping gut immunity more broadly, not just antibody levels in the blood.
"Genome wide transcriptome analysis provides bases on colonic mucosal immune system development affected by colostrum feeding strategies in neonatal calves." He Z, Fischer A, Song Y, Steele M, Guan LL. BMC Genomics. 2018 Aug 28;19(1):635.