ABSTRACT. Pedigree information is required to estimate breeding values accurately and to ensure high rates of genetic gain. DNA markers information can be used as an alternative to traditional recording of pedigree, being SNPs the markers of choice for parentage verification.
ABSTRACT.. Heat stress reduces milk production, depresses fertility and increases the incidence of health disorders in dairy cows. Our first goal was to estimate genetic components of milk yield (MY) and somatic cell score (SCS) across lactations considering heat stress. Our second goal was to reveal genes responsible for thermotolerance. Data included 254k MY and 356k SCR test-day records of 20k Holstein cows. Multi-trait repeatability test-day models with random regressions on THI values were used to estimate variance components.
ABSTRACT. Due to the complexity of selection in beef cattle where numerous traits are involved, identification of breeding objectives and developing a selection index to improve a global goal is required. A selection index was developed to maximize genetic gain for a beef cattle operation system. Breeding objective includes calving rate, carcass weight, calving ease, feed intake, direct and maternal weaning weight. Indexes were constructed from traits which EPDs are available so it can be implement to make comparisons between animals with different genetic merit.
ABSTRACT. This study aimed to compare results of genome-wide associations obtained from various methodologies for GWAS when applied to two lines of broiler chicken. Each line contained >250k birds with 3 traits and 5k SNP60k genotypes. Methods included single-step GWAS, single marker model and BayesB. Mannhattan plots were based on variances of 20-SNP segments, as shorter segments produced noisy plots. Only a few segments explained >1 % of the additive variance.
ABSTRACT. With the increasing availability of marker information in livestock, genomic selection methods can allow breeders to preselect animals on genotypes early in life. The combination of pedigree, phenotypic and genotypic data will increase genetic progress by decreasing the generational interval and increasing the accuracy of genetic merit estimates.
The objective of this study was to apply the SSP for genomic evaluation in broiler chickens to determine if accuracy of prediction could be enhanced using phenotypic data from pedigreed animals to augment information obtained on animals genotyped (FULL).
The objective of this study was to apply the SSP for genomic evaluation in broiler chickens to determine if accuracy of prediction could be enhanced using phenotypic data from pedigreed animals to augment information obtained on animals genotyped (FULL).
The objective of this study was to investigate the effects of including RFI and calf survival in the breeding objective simultaneously with the implementation of genomic selection. This was quantified in the current UK maternal breeding programs and in an alternative young bull program in terms of the economic benefit and GHG emissions at the whole beef industry level.
The genomic selection of US Holsteins has currently been conducted with a multi-step procedure where regular EBVs are used to create genomic predictions (VanRaden, 2008). Later steps in the multi-step procedure involve only genotyped animals and use single-trait (ST) procedures.
The objectives of this research were to contrast pedigree and genotype-based relationship coefficients in a swine population, and compare the outcomes of a genetic evaluation when the standard relationships were modified by genomic coefficients.