A recent study by Kansas State University and Harvard University shows that holstein dairy cows produce more milk after giving birth to female offspring as opposed to male, according to Ciaran O’Shea, Dairy Product Specialist with ABS Ireland.

He says that this new study revealed that cows produce more milk when pregnant with heifer calves, making sexed semen potentially much more attractive than was previously thought by industry experts. 

Results of the study, available in the scientific journal PLOS One, show that female dairy cows produce more milk when pregnant with heifer calves. Cows pregnant with two daughters back-to-back produced 2.7% more milk – about 444kg more milk – over the first two lactations, than cows pregnant with two sons. This provides an even more compelling reason for dairy farmers to use sexed semen, in addition to the already-known benefits, he said, including:

  • Generating more heifers – on average 90% of calves born will be female;
  • Reduced disease risk from purchased replacements;
  • Helping control heifer replacement costs;
  • Easier calving;
  • Reduced incidence of dystocia, resulting in fewer post calving drug costs;
  • Less labour costs and reduced time input, due to reduced incidence of dystocia in heifer versus bull calves; and,
  • Lower animal health costs and an increase in saleable milk.