Ali 1 MOJTAHEDIN, Jamal SEIFDAVATI, Azadeh 1 BOUSTAN, ? Sara 2 AZIZYAN, Reza SEYEDSHARIFI

Bulmer Etkisinin Gözardı Edilmesinin Projeni Testinde Genetik ve Ekonomik Sonuçları ve Genomik Seleksiyon Programındaki Olumsuz Etkisinin Araştırılması

Bu çalışmada Bulmer etkisinin göz ardı edilmesinin progeni testinde genetik ve ekonomik sonuçlarının tahmini ile genomik seleksiyon programındaki olumsuz etki derecesinin araştırılması amaçlanmıştır. Bu amaçla, 70 yıla yayılan gen akış metodu temelli belirleyici bir yaklaşım kullanıldı. Çalışmada, 4 yollu seleksiyon stratejisi altında seleksiyon hedefi olarak süt üretimi kullanıldı. Progeni testinde, baba ve annelerin asimtotik genetik varyansı sırasıyla %67.59 ve %64.97 azaltıldı. Genomik seleksiyon programında, baba ve annelerin asimtotik genetik varyansı da sırasıyla %68.56 ve %63.06 azaltıldı. Genetik varyansda maksimum azalma ilk üç nesilde gerçekleşti. Progeni test programında, Bulmer etkisini göz ardı etme sonucu, her nesildeki genetik ilerleme etkisi genomik seleksiyon programından dört kat daha fazlaydı. Ancak bu fark tek tur ve 20 nesil sonrasında devamlı seleksiyon sonuçlarında anlamlı derecede azaldı. Bulmer etkisi, progeni testinin ekonomik verimliliğinde ve genomik seleksiyonda sırasıyla %51.64 ve %44.62 azalmaya neden oldu. Bu çalışmanın sonuçları progeni testi ile genomik seleksiyonun karşılaştırıldığı incelemelerde Bulmer etkisinin göz ardı edilmesinin kabul edilebilir olmadığını göstermiştir. Uzun süreli seleksiyonun genetik varyansı azaltmak suretiyle genetik seleksiyon programı ile karşılaştırıldığında progeni testinin genetik ve ekonomik yönleri üzerine daha ciddi etkileri bulunmaktadır.

Investigating the Bias Resulted from Ignoring Bulmer Effect on the Genetic and Economic Output in Progeny Test and Genomic Selection Program

This study aims to investigate the degree of bias resulted from ignoring Bulmer effect during the estimation of genetic and economic progress in progeny test and genomic selection programs. To this end, a deterministic approach based on gene flow method in a time horizon of 70 years was used. In this study, milk production was considered as the selection goal under a four-path selection strategy. In the progeny test, asymptotic genetic variance of sires and dams decreased by 67.59% and 64.97%, respectively. Also, in genomic selection program, asymptotic genetic variance in sires and dams decreased by 68.56% and 63.06%, respectively. The maximum reduction in genetic variance occurred in the first three generations. In the progeny test program, the bias of genetic progress per generation due to ignoring Bulmer effect was four times higher than genomic selection program, but this difference decreased significantly in the results of single round and continuous selection after 20 generations. Bulmer effect resulted in 51.64% and 44.62% reduction in the economic efficiency of progeny test and genomic selection, respectively. According to the results of this study, ignoring Bulmer effect in the investigations concerning comparison between progeny test and genomic selection seems to be unreasonable. Long-term selection has more severe effect on genetic and economic aspects of progeny test in comparison to genomic selection program via decreasing genetic variance.

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