Investigators often examine the factors—genetic or environmental—that determine the concentrations of secondary chemicals and growth, but few have examined both simultaneously. We used a factorial genetic design and manipulated nutrient availability to Salix sericea (Salicaceae) in order to quantify: (1) genetic variation, plasticity, and genetic variation in plasticity for growth rate and the ...

Lean growth rate (LGR) in pigs is a nonlinear biological function of growth rate and lean quantity. According to animal breeding theory, genetic progress for LGR is maximized with selection on a linear index of its component traits, but selection on direct EBV for LGR is also common. In this study, the performance of five criteria for selection on estimated LGR in pigs was evaluated through sim...

Phenotypic plasticity in response to environmental variation occurs at all levels of organization and across temporal scales within plants. However, the magnitude and functional significance of plasticity is largely unexplored in perennial species. We measured the plasticity of leaf- and shoot-level physiological, morphological and developmental traits in nursery-grown Populus deltoides Bartr. ...

A bioeconomic computer model was constructed to simulate biological and economic inputs and outputs for life cycle swine production. Parameters and relationships used in model were developed and verified by comparison with experimental results in the literature. The bioeconomic model was constructed by several modules such as growth and development, pregnancy, lactation, and replacement gilt et...

The aim of the present study was to retrospectively analyze causes of the variation in age at first mating in Swedish Landrace (L) and Swedish Yorkshire (Y) gilts. Production traits including growth rate from birth to 100kg body weight and backfat thickness at 100kg body weight were also studied. Data analyzed were obtained from 11 L and 11 Y nucleus herds and included gilts born during a 5-yea...

From the evolutionary and ecological points of view, it is essential to distinguish between the genetic and environmental components of the variability of life-history traits and of their trade-offs. Among the factors affecting this variability, the resource uptake rate deserves particular attention, because it depends on both the environment and the genetic background of the individuals. In or...