Transmitting ability of twenty-three Holstein-Friesian sires /

Invited Review: Selection on Net Merit to Improve Lifetime Profit

“…Transmitting ability is the average value of genes transmitted to progeny (Yapp, 1925) and was further explained in 1926 in USDA's first attempt at a national sire summary: "The pedigree of any individual is only an indication of what the transmitting ability of that individual, for milk and butterfat production, may be. Until such time as we have pedigrees in which the sires have a sufficient number of tested daughters from tested dams, so that their breeding performance can be analyzed, as has been done with these 23 sires, predictions can not be made with certainty as to the transmitting ability of any untried individual" (Graves, 1926). That first report included data from 198 daughter-dam pairs and 23 sires, whereas US genetic evaluations now include data from >20 million cows and >100,000 sires.…”

The Progeny Test as a Method of Evaluating the Dairy Sire.

“…Thirdly, because of the major contribution from the sire to the genetic constitution of the herd, it is clear that some finer distinction has to be made in his case than that which is expressed in the progeny's "equal inheritance from sire and dam." Numerous citations can be given ( (20,22,27), and p. 824) which demonstrate the influence of individual sires in raising or lowering the yields of their daughters in a most characteristic fashion. "Prepotency" for high or low production is a very real quality, capable of explanation genetically on the differing numbers of factors for milk production possessed by individual animals.…”

“…Gowen's contributions are most numerous in this field (19) and he concludes that, in general, the sire and dam contribute equally to the milk yield and butterfat of the offspring. Graves, as a result of a study of the performance of twenty-three HolsteinFriesian sires (20), does not agree that the daughter's yield is a simple blend of the parents' inheritances, as wide variations from the expected average do occur. To discover the influence of animals more distant in the ancestry Gowen (19) has studied the pedigrees of five groups of HolsteinFriesian sires, grouped according to their possession of Advanced Registry daughters with (1) high milk yield, (2) low milk yield, (3) high butterfat yield, (4) low butterfat yield and (5) a group with no daughters in the Advanced Registry.…”

“…Many investigators consider that it is total milk yield and fat percentage which are inherited-total butterfat being the derivative. There is general agreement on one pointthat milk yield and butterfat are inherited independently, to the extent that their secretions are influenced by different genes (ii, 19,20,38). Statistical investigations upon Advanced Registry data have convinced several American workers that there is a negative correlation between milk and butterfat.…”

Effects of genetic and environmental variance on dairy sire evaluation

“…The latter are usually of only minor significance, but the other factors are often of vital importance when comparing different bulls. Graves, in 1926, suggested that sires be evaluated on the basis of:…”