Method and effects of incorporating foreign information into United Kingdom production evaluations

Abstract

Countries, which import a significant amount of semen, embryos and animals, are faced with the problem of how properly to evaluate the animals in the national evaluation system when information on the foreign parents is generally missing. Additional problems arise when the foreign parents obtain an evaluation, usually on the basis of progeny, in the country of import with the result that there are two published evaluations for the animals in question. This paper presents a post-iterative method of incorporating foreign information into home country evaluations. The foreign information is initially converted to the same scale and base as in the home country using procedures recommended by the International Bull Evaluation Service. The method consists essentially of calculating a combined evaluation for animals with home and foreign information as a weighted average of yield deviations, parent averages and progeny contributions from the foreign and home countries. The combined evaluations are used to adjust the evaluations of progeny on the basis of formulae derived from the usual mixed model equations. The same principles were used to combine reliabilities from the respective home and foreign reliabilities. The results from the application of the method to the United Kingdom (UK) Holstein Friesian population are presented. There was re-ranking of both bulls and cows, especially foreign bulls with few UK daughters.

The influence of gene-environment interactions on GHR and IGF-1 expression and their association with growth in brook charr, Salvelinus fontinalis (Mitchill)

“…We used a reduced animal model [ 58 - 61 ] for the estimation of additive quantitative genetic variance (σ2a) and best linear unbiased predictions (BLUP; [ 58 ]) of breeding value (estimated breeding value; EBV) for absolute growth for all individuals (Perry et al, unpublished). Parent-offspring relationship and growth rate (as a single-vector phenotype) were coded using PEST [ 62 ] for REML in VCE5.1 [ 61 ] with the iteration of analytical gradients [ 60 ] in the animal model…”

Strategies for comparing and combining different genetic and genomic evaluations: A review

“…Moreover, this approach did not adjust either U.S. or Canadian progeny evaluations for changes in bull EGM and did not consider foreign cows. Mrode et al (1996) derived a similar procedure to combine U.K. and converted foreign evaluations based on equations of random genetic effects and solved some of the disadvantages of Wiggans' method. Evaluations for bulls and also for cows were combined as a weighted average of PAs, yield deviations, and PCs.…”

“…Some rules were defined to estimate u PÂ if parents were unknown as Mrode et al (1996) had done. With such an approach, information from foreign parents and progeny is propagated to domestic progeny.…”