Prefreshening parlor walk-throughs aid milk let down
Preconditioning first-calf heifers a week or so before their first milking with parlor walk-throughs reduces anxiety and generally prevents the failure of milk let down, says Jeff Keown, University of Nebraska–Lincoln dairy specialist.
"Cows get excited in the milking parlor," Keown says. "Bringing them in a week or so before they freshen helps. They get used to milker noise, people talking and the walking surface. Keep in mind that sound reverberates much more in the parlor than in the barn. Everything’s different and heifers can become frightened."
Sensitive receptors for triggering milk let down are located in the teat skin. When stimulated, they tell the brain to release oxytocin into the bloodstream. The hormone travels to the udder, causing the muscle fibers surrounding the milk-producing cells to contract.
Maximum oxytocin concentration in the blood occurs one minute after manual stimulation begins. Within two minutes, the concentration drops dramatically, reducing let down. Stimulation times of less than one minute and more than two minutes are associated with the development of severe, chronic teat end lesions.
Routine udder preparation aids rapid milk let down. Dip, strip, dry, apply and strip, dip, dry, apply are recommended procedures. Rigorous forestripping increases milk yield, reduces unit on-time and results in healthier teat ends and less mastitis.
Avoid oxytocin shots, which can lead to addiction and reduced natural oxytocin production. "Oxytocin shots don’t affect milk quality, but the drug is restricted in some states," Keown says. "Establish a uniform work routine, smooth cow flow, good milking practices and effective time management. Cows love routine."