Effects of a breeding scheme combined by genomic pre-selection and progeny testing on annual genetic gain in a dairy cattle population

The effectiveness of the incorporation of genomic pre-selection into dairy cattle progeny testing (GS-PT) was compared with that of progeny testing (PT) where the fraction of dam to breed bull (DB) selected was 0.01. When the fraction of sires to breed bulls (SB) selected without being progeny tested to produce young bulls (YB) in the next generation was 0.2, the annual genetic gain from GS-PT was 13% to 43% greater when h(2)  = 0.3 and 16% to 53% greater when h(2)  = 0.1 compared with that from PT. Given h(2)  = 0.3, a selection accuracy of 0.8 for both YB and DB, and selected fractions of 0.117 for YB and 0.04 for DB, GS-PT produced 40% to 43% greater annual genetic gain than PT. Given h(2)  = 0.1, a selection accuracy of 0.6 for both YB and DB, and selected fractions of 0.117 for YB and 0.04 for DB, annual genetic gain from GS-PT was 48% to 53% greater than that from PT. When h(2)  = 0.3, progeny testing capacity had little effect on annual genetic gain from GS-PT. However, when h(2)  = 0.1, annual genetic gain from GS-PT increased with increasing progeny testing capacity.