Several people e-mailed privately to request a ref. for Bovine IgG and colic in breastfed infants. I'll just post to the list to save time. P.Clyne and A. Kuczycki: Human milk contains bovine IgG. Relationship to infant colic? Pediatrics 1991, 87(4):439-444. Salient points: Bovine IgG has been found to be antigenic in humans. Mothers of colicky babies had higher levels of bovine IgG in their milk than the 30 mothers of non-colicky babies in the control group. Bovine IgG has a prolonged half life. Short elimination trials of 2-7 days may not clear all the protein from mother's milk. Barbara Wilson-Clay, BSE, IBCLC Austin (priv. pract)