Human reproductive ecology to aid infant survival and growth. Lactational strategies vary cross-culturally, but can typically be defined by sibling sets and sex ratios, frequency of nursing, entire lactational duration, and milk composition. Milk is composed of my bioconstituents, but only a few will be outlined here. In the first days of puerperium, the first milk is thick and yellowish, also called colostrum. For weeks after that, mature milk is expressed and it has been shown that fetal-mammary gland signaling occurs even before birth in determining milk type and concentrations based on the fetus sex. Colostrum plays an important role in establishing the
Colostrum as lactoferrin and hemopexin, which binds free heme in the body. The Isle of Man had a local delicacy called "Groosniuys", a pudding made with colostrum. Hyperimmune colostrum is natural bovine colostrum collected from a population of cows immunized repeatedly with a specific pathogen. The colostrum is collected within 24 hours of the cow giving birth. Antibodies towards the specific pathogens or antigens that were used in the immunization are present in higher levels than in the population before treatment. Although some papers have been published stating that specific human pathogens were just as high as in hyperimmune colostrum, and