Selection on milk production and conformation traits during the last two decades in Japan

Abstract

Selection was aimed more toward increasing genetic gain in milk production than toward conformation traits over the past two decades in Japan. In contrast, actual annual genetic gain for conformation traits was equivalent to or greater than intended. Balanced selection between milk production and conformation traits tended to be favored during actual selection. Each of four paths of selection (SB, SC, DB, and DC) has played an individual and important role. With shortening generation interval in the genomic era, a young sire arises before the completion of sire's daughters' milk production records. How to integrate these four paths of selection in the genomic era is vital.

Short term selection response on growth and reproductive traits in broiler lines of chicken

“…In this study, we carried out selections which were aimed at increasing the genetic gain in body weight rather than in the body conformation traits with consequential effect on reproductive and production traits. Togashi et al (2019) directed their selection toward increasing genetic gain in milk production than towards body conformation traits. Development of stocks that outshined in production of either meat and eggs have been successful due to the knowledge of hybrid vigour coupled with large population and intense selection (Siegel, 1989).…”