The estimation of dominance effects requires the availability of direct phenotypes, i.e., genotypes and phenotypes in the same individuals. In dairy cattle, classical QTL mapping approaches are, however, relying on genotyped sires and daughter-based phenotypes like breeding values. Thus, dominance effects cannot be estimated. The number of dairy bulls genotyped for dense genome-wide marker pane...

The objective of this study was to assess the reliability and bias estimated breeding values (EBV) from traditional BLUP with unknown parent groups (UPG), genomic EBV (GEBV) single-step (ssGBLUP) UPG for pedigree relationship matrix (A) only (SS_UPG), GEBV ssGBLUP both A among genotyped animals (A22; SS_UPG2) using 6 large phenotype-pedigree truncated Holstein data sets. complete included 80 mi...

Use of sexed semen for artificial insemination of US Holstein heifers (1.3 million breedings) and cows (10.8 million breedings) in Dairy Herd Improvement herds was characterized by breeding year, parity, service number, region, herd size, and herd milk yield. Sexed semen was used for 1.4, 9.5, and 17.8% of all reported breedings for 2006, 2007, and 2008, respectively, for heifers, and for 0.1, ...

adjusted milk yield for 305 days and two milking times along with actual first lactation records of 187138 holstein cows were used to find out the effect of record adjustment on variance components estimation and on genetic evaluation. records had been gathered by the animal breeding center of iran during years 1991 to 2006. the pedigree file included 288032 animals. a single animal model with ...

To explore the potential of cattle to produce both milk and beef, the genetic aspects of beef production among Holstein‐Friesian bulls pedigree selected for milk were studied. The data included growth records of 504 bulls (DPT) by 120 sires (SPT) pedigree selected for progeny testing by American Breeders Service, 1964 to 1971. DPT bulls with proofs had an average predicted difference for milk (...

Estimated genetic values from an animal model based on first lactation milk records for 6OOO AI Holstein sires and 1,074,971 Holstein cows born in 1981 or before were used to estimate average genetic selection differentials and generation intervals for the four paths of selection for each year of birth. Selection differentials for paths of sires of bulls, dams of bulls, sires of cows, and dams ...

Electrocardiography (ECG) may be used to recognize cardiac disorders. Levels of milk production may change the serum electrolytes which its imbalance has a role in cardiac arrhythmia. Fifty high yielding and fifty low yielding Holstein dairy cows were used in this study. Electrocardiography was recorded by base-apex lead and blood samples were collected from jugular vein for measurement of seru...

Complex vertebral malformation (CVM) is an autosomal recessive inherited defect in the Holstein breed. It causes intra-uterine mortality through the entire gestation period leading to repeat breeding and involuntary culling of cows and thereby economic losses. The defect was first reported in Denmark in 1999 and a direct DNA test for the defect has been available since February 2001. The aim of...