Recent studies show polymorphisms in the leptin gene significantly impact milk production in dairy cattle. If the leptin gene were to have a similar impact on beef cattle, calf weaning weights would be expected to increase from the increased milk production in the cows. Since weaning weight is a key component of profitability in a cow-calf operation, leptin genotyping may prove to have an economic impact in breeding cattle. However, no research has been done to link the economic impact of increased milk production to breeding cattle. Using 595 observations from genotyped cows spanning 11 years (1995-2005), calf weaning weight by genotype is estimated as a function of calf and dam characteristics and environmental effects. A MIXED procedure, utilizing data from 89 culled cows, is used to determine statistical differences in average cull age by genotype. A simulation model calculates mean annualized equivalent return by genotype and breed using the regression coefficients and residuals and 16 years of price data. results show that at least one T-allele in breeding cows increases calf weaning weight, average cull age, and annualized equivalent return compared to cows with homozygous C-alleles. These results indicate that there may be future premiums and discounts for breeding cattle based on genotype. Seedstock producers could potentially begin to segregate herds based upon genotype so that they could sell genotypic registered products. Cow-calf producers may also benefit from this knowledge by increasing the amount of TT genotype breeding cattle in their herd to maximize profits.