Quantitative trait loci for performance traits in a broiler × layer cross

Abstract

An F(2) resource population, derived from a broiler x layer cross, was used to map quantitative trait loci (QTL) for body weights at days 1, 35 and 41, weight gain, feed intake, feed efficiency from 35 to 41 days and intestinal length. Up to 577 F(2) chickens were genotyped with 103 genetic markers covering 21 linkage groups. A preliminary QTL mapping report using this same population focused exclusively on GGA1. Regression methods were applied to line-cross and half-sib models for QTL interval mapping. Under the line-cross model, eight QTL were detected for body weight at 35 days (GGA2, 3 and 4), body weight at 41 days (GGA2, 3, 4 and 10) and intestine length (GGA4). Under the half-sib model, using sire as common parent, five QTL were detected for body weight at day 1 (GGA3 and 18), body weight at 35 days (GGA2 and 3) and body weight at 41 days (GGA3). When dam was used as common parent, seven QTL were mapped for body weight at day 1 (GGA2), body weight at day 35 (GGA2, 3 and 4) and body weight at day 41 (GGA2, 3 and 4). Growth differences in chicken lines appear to be controlled by a chronological change in a limited number of chromosomal regions.

Genome-wide association studies for small intestine length in an F2 population of chickens

“…However, few studies have investigated the genetic background of small intestine development. Previous studies have reported quantitative trait loci (QTL) in animal intestines (Ambo et al 2009;Gao et al , 2010Mignon-Grasteau et al 2015). Of these, Gao et al (2010) identified 10 QTL for the length of small intestine associated with growth traits in a F 2 population of a cross between White Duroc  Chinese Erhualian pigs.…”

“…In another study, QTL were detected at an intestine length of 481 cM (GGA1) in an F 2 population derived from an intercross of White Plymouth Rock with Silkie chickens, which suggested an association with intestinal length ). In an F 2 generation derived from a broiler  layer cross, one QTL on GGA4 was associated with intestinal length (Ambo et al 2009). Seven genome-wide significant QTL were found for duodenum length (DL), jejunum length (JL) and ileum length (IL) in F 2 chickens from a cross between D À and D þ chickens fed a wheat-based diet (Mignon-Grasteau et al 2015).…”

Mapping quantitative trait loci in Gallus gallus using principal components

“…Some QTLs mapped in this population have been described by Nones et al (2006), Ambo et al (2009) and Campos et al (2009). Procedures seeking to reduce the occurrence of false positives or negatives were not employed in these studies, except of course to adjust the level of type I error to an acceptable level.…”

Genetic parameters and mapping quantitative trait loci associated with tibia traits in broilers

“…Likewise, Nones et al (2006) mapped QTL for carcass and BW42 traits on GGA1, in the same broiler population. Ambo et al (2009), studying the same population of broilers, mapped QTL for body weight traits at 35 and 41 days of age on the GGA4, exactly in the same chromosome region where QTL for tibia width and weight were mapped (MCW0240-LEI0063). Within this chromosome region, Baron et al (2011) mapped QTL for drums and thighs; Schreiweis et al (2005) for tibia area, length, and width; and Sharman et al (2007) for tibia bone mineral density, and femur weight.…”

“…The population was designed specifically for QTL mapping studies, to obtain linkage disequilibrium and variability for performance and carcass traits (Nones et al, 2006;Ambo et al, 2009;Savegnago et al, 2011).…”