Investigate Effects of A2 Milk on Breastmilk Composition and Subsequent Infant Gut Health, Crying and Sleep Patterns in Healthy, Full-term Infants

Inclusion Criteria: * Mothers who are 25 to 45 years old; * Mothers who are exclusively breastfeeding with healthy and full-term infants; * Infants of these mothers who have been exclusively breastfed since birth, and their parent(s) decides to continue exclusively breastfeeding until at least 120 days of age, birth weight between 2500g and 4500g; * Willing to sign ICF before the study launched. Exclusion Criteria: * Mothers with infection or have recently taken the flu / covid vaccine in the last 4 weeks; * Infant with inborn malformation and with hereditary and/or chronic and/or inborn diseases that could interfere with the survey; * Evidence of feeding difficulties or intolerance/allergy to cow's milk (mixed-fed group only); * Conditions requiring infant feedings other than those specified in the protocol; * Significant systemic disorders (cardiac, respiratory, endocrinological, hematologic, gastrointestinal, or other); or parental refusal to participate; * Infants with an acute infection or gastroenteritis at time of enrollment; * Participation in another clinical trial; * Investigator's uncertainty about the willingness or ability of the parents to comply with the protocol requirements.