Gene expression profiling reveals candidate genes related to residual feed intake in duodenum of laying ducks1,2

Abstract

Feed represents two-thirds of the total costs of poultry production, especially in developing countries. Improvement in feed efficiency would reduce the amount of feed required for production (growth or laying), the production cost, and the amount of nitrogenous waste. The most commonly used measures for feed efficiency are feed conversion ratio (FCR) and residual feed intake (RFI). As a more suitable indicator assessing feed efficiency, RFI is defined as the difference between observed and expected feed intake based on maintenance and growth or laying. However, the genetic and biological mechanisms regulating RFI are largely unknown. Identifying molecular mechanisms explaining divergence in RFI in laying ducks would lead to the development of early detection methods for the selection of more efficient breeding poultry. The objective of this study was to identify duodenum genes and pathways through transcriptional profiling in 2 extreme RFI phenotypes (HRFI and LRFI) of the duck population. Phenotypic aspects of feed efficiency showed that RFI was strongly positive with FCR and feed intake (FI). Transcriptomic analysis identified 35 differentially expressed genes between LRFI and HRFI ducks. These genes play an important role in metabolism, digestibility, secretion, and innate immunity including (), (), (), β (), and (). These results improve our knowledge of the biological basis underlying RFI, which would be useful for further investigations of key candidate genes for RFI and for the development of biomarkers.

Effects of residual feed intake divergence on growth performance, carcass traits, meat quality, and blood biochemical parameters in small-sized meat ducks

“…As expected, extremely significant differences ( P < 0.01) were observed in the RFI and FCR between the LRFI (-22.70 and 4.64) and HRFI (19.11 and 5.73) groups, respectively. Importantly, no differences were observed in the initial BW, final BW, MBW 0.75 , and ADG between the 2 groups ( P > 0.05), which is in accordance with the results of high- and low-RFI mule ducks ( Drouilhet et al, 2016b ) and laying ducks ( Zeng et al, 2017 ). Interestingly, similar results have been reported for several other farm animals, such as cattle ( Lancaster et al, 2009 ), lambs ( Zhang et al, 2017a ), pigs ( Young et al, 2011 ; Faure et al, 2013 ; Meunier-Salaün et al, 2014 ), rabbits ( Drouilhet et al, 2016a ), and chickens ( Xu et al, 2016 ; Yi et al, 2018 ; Liu et al, 2019 ; Yang et al, 2020 ).…”

Identification of key genes and pathways associated with feed efficiency of native chickens based on transcriptome data via bioinformatics analysis

“…Herein, birds with low level RFI means consume less feed than predicted and are identified as efficient birds. For the last decades, RFI is being used to measure feed efficiency traits, which has successfully applied to the artificial selection of feed efficiency in mammal [3] and poultry [4]. Besides, RFI is a trait independent of other production traits, and the heritability of RFI is between 0.23 and 0.49 in chickens, these characteristics of RFI make it can be easily incorporated into the multi-trait selection indexes of commercial breeding companies [5].…”

Expression of genes related to lipid transport in meat-type ducks divergent for low or high residual feed intake

“…It is well documented that components of lipid metabo- lism, such as triacylglycerol transport and lipid accumulation in the liver and duodenum, may be involved in the regulation of RFI in cattle [19]. Recently, a global transcriptome analysis in the duodenum of laying ducks showed that genes involved in lipid metabolism play an important role in regulating feed efficiency [20]. Moreover, a previous study suggested that lipid metabolism in the liver and lipid absorption in the intestine were two important factors affecting feed efficiency traits [10].…”