Table 4

Expected responses to direct selection on excretion traits or on indirect selection on digestibility (AMEn and CDUDM) and on feed efficiency (FCR and RFI), supposing that selection intensity was 1 for all traits.

Selection on


Response1

Direct

AMEn

CDUDM

FCR

RFI


CDU-DM

0.300

0.297

0.300

-0.246

-0.238

FEW/BW

0.090

-0.159

-0.154

0.136

0.185

DEW/BW

0.200

-0.225

-0.228

0.189

0.267

FEW/FI

0.170

-0.149

-0.145

0.144

0.106

WE

0.130

0.091

0.077

-0.045

-0.037

NE/NI

0.290

-0.292

-0.295

0.234

0.135

PE/PI

0.220

-0.164

-0.175

0.142

0.025

NE/PE

0.180

-0.195

-0.202

0.171

0.086


Responses are expressed in phenotypic standard deviations of the trait.

1AMEn, apparent metabolisable energy corrected for zero nitrogen balance; CDUDM, coefficient of digestive use of dry matter; FCR, feed conversion ratio; RFI, residual feed intake; FEW/BW, DEW/BW, fresh and dry excreta weight relative to body weight at 23 d; FEW/FI, fresh excreta weight relative to feed intake; WE, water content of excreta; NE/NI, PE/PI, ratio of nitrogen and phosphorus excretion to intake; NE/PE, ratio of nitrogen to phosphorus excretion

de Verdal et al. BMC Genetics 2011 12:71   doi:10.1186/1471-2156-12-71

Open Data