Linkage disequilibrium and effective population size in Gir cattle selected for yearling weight.

Linkage disequilibrium (LD) plays an important role in genomic selection and mapping of quantitative trait loci (QTL). This study investigated the pattern of LD and effective population size (N ) in Gir cattle selected for yearling weight. For this purpose, 173 animals with imputed genotypes (from 18 animals genotyped with the Illumina BovineHD BeadChip and 155 animals genotyped with the Bovine LDv4 panel) were analysed.

Evidence of negative relationship between female fertility and feed efficiency in Nellore cattle.

The objective of this study was to evaluate phenotypic and genetic relationships between fertility traits and feed efficiency in male and female Nellore cattle. Data from 320 females born between 2004 and 2011 were used for phenotypic evaluation. These animals were evaluated for postweaning residual feed intake (RFI) and classified as negative (RFI < 0, mean = -0.