Taylor M McWhorter

• Doctor of Philosophy
• Geneticist at Council on Dairy Cattle Breeding

Johne's disease (JD) is an infectious enteric disease in ruminants, causing substantial economic loss annually worldwide. This work aimed to estimate JD's genetic parameters and the phenotypic and genetic trends by incorporating recent data. It also explores the feasibility of a national genetic evaluation for JD susceptibility in Holstein cattle i...

The physiological stress caused by excessive heat affects dairy cattle health and production. This study sought to investigate the impact of heat stress on test-day yields in United States (US) Holstein and Jersey cows and develop single-step genomic predictions to identify heat tolerant animals. Data included 12.8 and 2.1 million test-day records...

Single‐step genomic BLUP (ssGBLUP) relies on the combination of the genomic (G$$ \mathbf{G} $$) and pedigree relationship matrices for all (A$$ \mathbf{A} $$) and genotyped (A22$$ {\mathbf{A}}_{22} $$) animals. The procedure ensures G$$ \mathbf{G} $$ and A22$$ {\mathbf{A}}_{22} $$ are compatible so that both matrices refer to the same genetic base...

Single-step GBLUP (ssGBLUP) relies on the combination of genomic (G) and pedigree relationships for all (A) and genotyped animals (A22). The procedure implemented in the BLUPF90 software suite first involves combining a small percentage of A22 into G (blending) to avoid singularity problems, then an adjustment to account for the fact the genetic ba...

The widespread use of sexed semen on US dairy cows and heifers has led to an excess of replacement heifers' calves, and the sale prices for those calves are much lower than in the past. Females not selected to produce the next generation of replacement heifers are increasingly being bred to beef bulls to produce crossbred calves for beef production...