The development of energetic efficiency concepts followed a recognized pattern of
knowledge evolution that began with novel insights leading to creative new concepts. The …

1. Direct and correlated responses were determined after five generations in four lines of
chickens selected either for increased body‐weight gain (line W), for increased food …

The objectives of this study were to estimate (co) variance components for growth and feed
efficiency measures, and to compare selection strategies to improve economic efficiency of …

Mice were selected for one of three criteria: appetite (A), measured as 4-to 6-week food
intake, adjusted by phenotypic regression to minimize change in 4-week body weight, fat …

We conducted a two-way selection experiment in a composite rabbit population to
investigate the responses to selection for postweaning ADG and feed conversion (FC). Two …

The literature on the genetics of feeding and drinking, and the genetic methods that will be
useful for future research, are described. Four subjects which have been studied most …

A set of optimum weighting factors was derived such that the resulting linear index may be
used to select for the ratio of two component traits. In a population of mice, three selection …

Correlated responses are examined from a biological rather than from a biometrical point of
view. Selection for increased body weight in laboratory animals usually, though not always …

The metabolizable energy intake (MEI) required for maintenance and the efficiency of
utilization of metabolizable energy available for gain (MEA) were determined for a line of …

Selection based on individual feed conversion ratio was made for three generations in a
chicken population previously selected for rate of growth and for one generation in a …