Cow mother's make more milk for their daughters than for their sons. User jerodras, in the Reddit Science subreddit, 13 Feb 2014
Holsteins Favor Heifers, Not Bulls: Biased Milk Production Programmed during Pregnancy as a Function of Fetal Sex User CompleteMoronThatsMe, in the The Agriculture reddit subreddit, 11 Feb 2014
PLOS ONE: Holsteins Favor Heifers, Not Bulls: Biased Milk Production Programmed during Pregnancy as a Function of Fetal Sex User burtzev, in the Reddit Science subreddit, 05 Feb 2014