title: Genetic parameters for residual feed intake in a random population of Pekin duck.
abstract: OBJECTIVE
  The feed intake (FI) and feed efficiency are economically important traits in ducks. To obtain insight into this economically important trait, we designed an experiment based on the residual feed intake (RFI) and feed conversion ratio (FCR) of a random population Pekin duck.
  
  
  METHODS
  Two thousand and twenty pedigreed random population Pekin ducks were established from 90 males mated to 450 females in two hatches. Traits analyzed in the study were body weight at the 42th day (BW42), 15 to 42 days average daily gain (ADG), 15 to 42 days FI, 15 to 42 days FCR, and 15 to 42 days RFI to assess their genetic inter-relationships. The genetic parameters for feed efficiency traits were estimated using restricted maximum likelihood (REML) methodology applied to a sire-dam model for all traits using the ASREML software.
  
  
  RESULTS
  Estimates heritability of BW42, ADG, FI, FCR, and RFI were 0.39, 0.38, 0.33, 0.38, and 0.41, respectively. The genetic correlation was high between RFI and FI (0.77) and moderate between RFI and FCR (0.54). The genetic correlation was high and moderate between FCR and ADG (-0.80), and between FCR and BW42 (-0.64), and between FCR and FI (0.49), respectively.
  
  
  CONCLUSIONS
  Thus, selection on RFI was expected to improve feed efficiency, and reduce FI. Selection on RFI thus improves the feed efficiency of animals without impairing their FI and increase growth rate.
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China.|Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Yunsheng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Zhan Bao
authors.initials: ZB
authors.lastname: Guo
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Xie
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Zhiying
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Shuisheng
authors.initials: S
authors.lastname: Hou
keywords: Genetic Parameters; Pekin Duck; Residual Feed Intake