Genome-wide association studies for egg quality traits in White Leghorn layers using low-pass sequencing and SNP chip data.

Low-pass sequencing data have been proposed as an alternative to single nucleotide polymorphism (SNP) chips in genome-wide association studies (GWAS) of several species. However, it has not been used in layer chickens yet. This study aims at comparing the GWAS results of White Leghorn chickens using low-pass sequencing data (1×) and 54 k SNP chip data.

Heritability of perching behavior and its genetic relationship with incidence of floor eggs in Rhode Island Red chickens.

Background: As cage-free production systems become increasingly popular, behavioral traits such as nesting behavior and temperament have become more important. The objective of this study was to estimate heritabilities for frequency of perching and proportion of floor eggs and their genetic correlation in two Rhode Island Red lines.

Results: The percent of hens observed perching tended to increase and the proportion of eggs laid on the floor tended to decrease as the test progressed.

Heritability of ascites and the ratio of right to total ventricle weight in broiler breeder male lines.

The objectives of this study were to induce ascites in three pure male line populations by subjecting them to cold stress, and to calculate heritability estimates for ascites (ASCITES) and the ratio of right to total ventricle weight (RATIO) in these populations under cold stress. Data were collected during the winter of 1993 to 1994 from 3,436 cockerels representing three commercial broiler breeder male lines. The male lines used in this study were characterized by: rapid growth rate and good feed efficiency (RG), moderate growth, good conformation, and excellent livability (MG), and maximum white meat yield and rapid growth (YD).

Realized heritability estimates in boars divergently selected for testosterone levels(1,) (2).

Data were collected from 1982 through 1992 from 100 sires and 891 Duroc boars. Testosterone production was measured from peripheral blood samples before (PRE) and after (POST) GnRH challenge. Additionally, data were collected on testes volume at 168 d (TVOL), days to 104 kg (DAYS104), number born alive (NBA) and backfat adjusted to 104 kg body weight (FAT).

Effects of pregnant mare's serum gonadotropin on reproduction in four genotypes of gilts(1).

Effects of PMSG and genotype on various measures of reproductive efficiency were investigated. Prenatal data were obtained at 40 d of gestation from 96 gilts representing four genotypes. Data on Duroc (D), Yorkshire (Y), Synthetic (Large White × Landrace) (SYN), and Crossbred Duroc × Yorkshire (XB) gilts were collected from January, 1990 through May, 1991.