A comparison of an indirect and direct method for converting sire evaluations from the united states to united kingdom improved contemporary comparison equivalents - holstein friesian

Abstract

The increasing international exchanges of semen and embryos have made it necessary to develop methods for converting bull and cow evaluations from the scale in the country of export to the scale in the country of import. Methods were Initially recommended by the International Dairy Federation (IDF, 1983) and latterly by the International Bull Evaluation Service (Interbull),(Philipsson et al, 1986).The Interbull recommended methods were compared using United Kingdom (UK) data and one, known as the Goddard method was selected for routine use (Swanson, Bellamy and Oliver, 1988). These methods dealt with direct comparisons whereby progeny test evaluations for the same bulls were available In the two countries for which a conversion was required. In situations where this information is not available or is limited, an indirect conversion involving a third country may be calculated.