Single-step genome-wide association studies and post-GWAS analyses for the number of oocytes and embryos in Gir cattle.

Genome-Wide Association Studies (GWAS) are used for identification of quantitate trait loci (QTL) and genes associated with several traits. We aimed to identify genomic regions, genes, and biological processes associated with number of total and viable oocytes, and number of embryos in Gir dairy cattle. A dataset with 17,526 follicular aspirations, including the following traits: number of viable oocytes (VO), number of total oocytes (TO), and number of embryos (EMBR) from 1641 Gir donors was provided by five different stock farms.

Is the temperament of crossbred dairy cows related to milk cortisol and oxytocin concentrations, milk yield, and quality?

Reactive dairy cows are more susceptible to stress, and this may result in negative effects on milk yield and quality. The aims of this study were to investigate the relationships between temperament traits and concentration of milk cortisol and oxytocin, milk yield, milkability, and milk quality in Holstein-Gyr cows. Temperament traits were assessed in 76 Holstein-Gyr cows in the milking parlor (by scoring milking reactivity and recording the numbers of steps and kicks during pre-milking udder preparation and when fitting the milking cluster) and during handling in the corral (by measuring the time to enter in the squeeze chute, ET and flight speed, FS).

Runs of homozygosity and signatures of selection for number of oocytes and embryos in the Gir Indicine cattle.

Runs of homozygosity (ROH) and signatures of selection are the results of selection processes in livestock species that have been shown to affect several traits in cattle. The aim of the current work was to verify the profile of ROH and inbreeding depression in the number of total (TO) and viable oocytes (VO) and the number of embryos (EMBR) in Gir Indicine cattle. In addition, we aim to identify signatures of selection, genes, and enriched regions between Gir subpopulations sorted by breeding value for these traits.

Genomic signatures for drylands adaptation at gene-rich regions in African zebu cattle.

Background: Indigenous Sudanese cattle are mainly indicine/zebu (humped) type. They thrive in the harshest dryland environments characterised by high temperatures, long seasonal dry periods, nutritional shortages, and vector disease challenges. Here, we sequenced 60 indigenous Sudanese cattle from six indigenous breeds and analysed the data using three genomic scan approaches to unravel cattle adaptation to the African dryland region.