1 73 calories per ounce or 28 g of sirloin steak lean and fat (1/8 rim of fat). 2  268 calories in a 4 oz or 114g sirloin steak (lean only). 3  402 calories in a 6 oz or 171g sirloin steak (lean only). 4  536 calories in an 8 oz or 227g sirloin steak (lean only).
Double muscling- A genetic trait in cattle where muscles are greatly enlarged rather than duplicate muscles. Double-muscled cattle...
Piedmontese cattle carry a unique gene mutation identified as an inactive myostatin allele that causes hypertrophic muscle growth, or double muscling. Purebred Piedmontese cattle are homozygous, meaning they have two identical alleles present for this unique gene.