 North American Piedmontese cattle are a breed of domestic beef cattle originating from an imported herd of select Italian purebred Piedmontese cattle ( Piemontese or <unk> bovina Piemontese ) . The foundation line of breeding stock was first imported from Italy into Canada in 1979 , and into the United States in the early 1980s . Piedmontese cattle are distinguished by a unique , naturally occurring gene identified as the myostatin allele mutation , or inactive myostatin gene . <unk> prohibits muscle growth whereas an inactive gene has the opposite effect . Purebred Piedmontese are homozygous , ( 2 copy ) , which means they have two identical alleles present for this unique gene . Research indicates the presence of the myostatin allele mutation produces morphological characteristics unique to the breed , such as double @-@ muscling , beef tenderness , reduced fat content and high yield . According to the North American Piedmontese Association ( NAPA ) , they are the first breed registry to base animal registration requirements on the presence of this specific gene which can be easily verified by DNA testing . 
