Later, some infusion of Illawarra, Guernsey and Holstein-Friesian bloodlines occurred. Careful interbreeding of the half-bred progeny, combined with strict selection criteria, have resulted in the AMZ breed.
Selection is for heat tolerance, tick resistance and milk production alone.
Mature purebred AMZ cows produce an average of 2,700 liters of milk over a 12 month period, while AMZ cross Friesian cows average more than this. Quality of milk is very high and protein level is approximately 3.5 to 4 percent. The AMZ carries the color markings and general shape of the Jersey, but also shows the tropical influence of the Sahiwal and Red Sindhi breeds through the ability to sweat and discard ticks from a highly mobile, loose skin. Oklahoma State University Board of Regents. All rights reserved.