Abstract
Residual feed intake (RFI) and feed conversion ratio (FCR) can be incorporated into a breeding program as traits to
select for feed efficiency. Alternatively, the direct measures used to calculate RFI and FCR can be analyzed to
determine the underlying variation in the traits that impact overall efficiency. These constituent traits can then be
appropriately weighted in an index to achieve genetic gain. To investigate feed efficiency in the turkey, feed intake
and weight gain were measured on male primary breeder line turkeys housed in individual feeding cages from 15
to 19 weeks of age. The FCR and RFI showed moderate heritability values of 0.16 and 0.21, respectively. Feed
intake, body weight, and weight gain were also moderately heritable (0.25, 0.35, and 0.18, respectively). Weight
gain was negatively correlated to feed conversion ratio and was not genetically correlated to RFI. Body weight had
a small and positive genetic correlation to RFI (0.09) and FCR (0.12). Feed intake was positively genetically
correlated to RFI (0.62); however, there was no genetic correlation between feed intake and FCR. These estimates
of heritability and the genetic correlations can be used in the development of an index to improve feed efficiency
and reduce the cost of production.
B