HETEROSIS FOR EARLY EGG-PRODUCTION AND FEED-INTAKE IN JAPANESE-QUAIL

Early egg production, body weights and feed intake between 34 and 98 d ays of age have been compared in two lines (DD and EE) of Japanese qua il selected for egg number at 14 weeks of age and in their reciprocal crosses, for three consecutive years. Genetic type, generation and the interaction had a significant effect on body weights. At 5 weeks of a ge least squares mean of body weight was between 167 g (line DD) and 2 10 g (line EE). At 14 weeks, corresponding values were 186 and 248 g. Egg production traits were only influenced by the genetic type. Least squares mean for age at first scoring egg was between 39.6 days (cross ED) and 50.2 days (Line DD). For number of scoring eggs, it was betwe en 39.3 (line DD) and 51.4 (cross ED). Daily feed intake varied betwee n generations and genetic types, with some interaction, from 23.8 g (l ine DD) to 33.7 g (line EE). Heterosis was significant in some years f or body weights and feed intake, but with variable values, and even di fferent sign for 14 week body weight. On the opposite, heterosis was s ignificant and rather constant far egg production traits, with values ranging from -3.4 to -5.1 days for age at first scoring egg, or from 5 .7 to 6.0 for number of scoring eggs. Heterosis for daily feed intake was positive but largely not significant. Finally a multiple regressio n of feed intake on metabolic mean body weight, weight gain and egg ma ss was adjusted to the data and compared to a homologous equation obta ined with poultry.