Urinary levels of secretory immunoglobulin A at 1 week ( 71.4 vs 26.5 ng/g creatinine , P = .04 ) and 2 weeks ( 233.8 vs 48.3 ng/g creatinine , P = .006 ) , and lactoferrin at 1 week ( 3.5 vs 0.9 g/g creatinine , P = .01 ) were significantly higher in colostrum group .