Diverse expression of any given trait within a breed is required to protect the breed from the unwanted consequences of selective breeding. Within the cattle industry, the fluid state of selective breeding trends, and consumer demand, creates a need for intermediate/moderate type cattle within individual breeds. These cattle have the ability to stabilize a given breed and bring it back from the extreme ends of the popular selection trends. This allows cattle breeders to change the genetics of their cattle, with relative speed, and meet consumer demands. Also, it protects individual breeds from harmful genetic mutations. This is evident in the increase in demand for intermediate cattle herds, like the Trask cattle, during the time period when most of the prominent Hereford breeders had carriers of snorter dwarfism in their herds. For this reason, it is important to preserve intermediate cattle lines like the Trask cattle, which have not conformed to popular cattle breeding trends. The genetic influence of various groups of ancestors on Trask bred bulls in current/recent herds was assessed using Wright's Relationship Coefficient (Rvxvy), and the inbreeding coefficient (Fvx). Mean inbreeding coefficients of a group of 26 representative bulls from Trask bloodlines were compared to the mean inbreeding coefficient of all cattle in the available pedigree. Mean relatedness of the same 26 bulls with 1) a group of 15 prominent ancestors in the Hereford and Polled Hereford breeds, 2) a group of 30 ancestors that had the most descendants in the pedigree, and 3) a group of 19 prominent Trask line ancestors, was compared to the entire pedigree mean relatedness with the same groups. These comparisons were tested by 1) approximating a beta distribution representing the distribution of relatedness or inbreeding coefficients and testing the mean against that approximated distribution, and 2) employing resampling methods to generate a bootstrapped distribution and compare means to those distributions. These two analysis methods produced slightly different results; the beta P-values resulted in a failure to reject the H0, and the bootstrap resulted in the rejection of the Hv0. This difference highlighted the beta distribution method's inability to account for the variation that occurs among samples drawn from a given population. The bootstrap resampling method was able to account for this variation because it draws numerous random samples to use in the calculation of the empirical P-values. Results provide a scientific assessment on the genetic influence of the Trask pedigree ancestors on the Trask bred bulls in recent/current herds. Testing against approximated beta (?) distributions may have resulted in type II errors (failure to reject the null hypothesis when it is in fact false). Mean relationship coefficients for the ancestors show the Trask herd ancestors had the closest relationship with the Trask bulls (mean Rxy = 0.208), followed by the top 30 ancestors (mean Rvxvy = 0.150), and then the key breed ancestors (mean Rxy = 0.132). The Trask herd ancestor group not only had the closest relationship to the Trask bulls, they also had the smallest relationship coefficient (mean Rxy = 0.072) with the Trask pedigree as a whole. This may indicate that the genetic distance that accumulated between the Trask cattle and the rest of the Hereford breed is due to isolation and inbreeding associated with linebreeding. The mean Fx values showed the sample of 26 Trask bulls (Fvx = 0.130) was more inbred than the animals in the Trask pedigree (Fvx = 0.056).
