Backfat thickness is one of the major quantitative traits that affect carcass quality in beef cattle. In this study, we have fine mapped a QTL for backfat EBV on bovine chromosome 14, using an identical-by-descent haplotype-sharing analysis, in a commercial line of Bos taurus. We also examined the association between gene-specific single nucleotide polymorphism (SNP) markers of the genes diacyl...

Progeny (n = 589) of randomly mated Duroc pigs were used to determine the genetic and phenotypic relationships between individual s.c. backfat layers and i.m. fat percent (IMF) of the longissimus. Five days before slaughter, cross-sectional ultrasound images were collected at the 10th rib by a National Swine Improvement Federation-certified ultrasound technician using an ultrasound machine (Alo...

The purpose of this study was to estimate components of variance and covariance for backfat and growth rate in swine tested in central test stations in the United States. Data were collected from 26 central boar test stations from 1984 through 1990. The traits analyzed were backfat adjusted to a 104.5-kg basis and ADG adjusted to a 36-kg on-test weight. Records from 7,951 purebred Yorkshire boa...

Records on 47,360 Yorkshire, 28,762 Landrace, 14,020 Duroc, and 9,983 Hampshire pigs for backfat depth and days to 100 kg made between 1989 and 1992 in herds on the Ontario Swine Improvement Program (OSIP) were used to estimate additive genetic (animal), common environmental (litter), and residual variances and covariances of the two traits. Analysis was by the DFREML program of K. Meyer using ...

The impact of body condition at 110 d of gestation on mammary gland development, mammary gene expression, and hormonal and metabolite status of gilts was studied. Thirty-nine gilts were equally divided into 3 groups based on their backfat thickness at the end of gestation: 1) low backfat (LBF; 12-15 mm), 2) medium backfat (MBF; 17-19 mm), or 3) high backfat (HBF; 21-26 mm). Gilts had similar BW...

A study was conducted to evaluate differences in performance and in carcass composition and tissue deposition rates between purebred Duroc pigs sired by boars currently available and those sired by boars from the mid-1980s. Two lines were developed by randomly allocating littermate and half-sib pairs of females to matings by current time period (CTP) or old time period (OTP) boars. Pigs from 2 ...

Previous research has identified differences in carcass characteristics across SNP in the bovine leptin gene at slaughter, but before feedlot operators implement selection and sorting strategies, more information is needed to determine how carcass characteristics change over time. The objective of this study was to investigate the effect of 2 leptin SNP on growth curve parameters for BW and bac...

Feed efficiency is of particular importance to the beef industry, as feed costs represent the single largest variable cost in beef production systems. Selection for more efficient cattle will lead to reduction of feed related costs, but should not have adverse impacts on quality of the carcass. In this study, we evaluated phenotypic and genetic correlations of residual feed intake (RFI), RFI ad...

Presence of major genes was investigated for two growth traits, backfat thickness, and two litter size traits in the F1 and F2 population of a cross between Meishan and European "White" pig lines. Segregation analyses were performed in a Bayesian setting, estimating the contribution of background polygenes and the contribution of a possible major gene to the expression of the traits considered....

Multiple genomic scans have identified QTL for backfat deposition across the porcine genome. The objective of this study was to detect SNP and genomic regions associated with ultrasonic backfat. A total of 74 SNP across 5 chromosomes (SSC 1, 3, 7, 8, and 10) were selected based on their proximity to backfat QTL or to QTL for other traits of interest in the experimental population. Gilts were al...