Bio-prediction of Egg Weight and Egg Component Parts at Different Ages in Small-sized Japanese Quails using Pre-broken Egg Traits as Regressors

Abstract

The present study was conducted on eggs of Japanese quail reared on deep litter at the Teaching and Research Farm, Ekiti State University, Ado-Ekiti. Three hundred eggs were randomly selected for the measurement of egg weight (g), egg length (cm) and egg width (cm); and broken to collect data of shell weight (g), albumin weight (g) and yolk weight (g) at different ages. A number of equations were developed to predict the egg weight and post-broken traits from pre-broken traits at the different ages. The prediction equations of egg weight at different ages showed that the associations were significant (P<0.01) and positive with adjusted R2 at 22.1-25.9, 17.1-19.5 and 31.6-36.6% for egg length, egg width and egg length + width respectively. Egg shell weight was predictable with sufficient accuracy (P<0.01) from egg weight + egg length (R2 = 8.1-9.3%); egg weight + egg width (R2 = 7.7-9.1%) and egg weight + egg length + egg width (R2 = 8.8- 10.1%) across the ages. Egg albumin was predictable (P<0.01) from egg weight + egg length (R2 = 71.5-76.3%); egg weight + egg width (R2 = 71.9-77.9%) and egg weight + egg length + egg width (R2 = 73.1-79.3%). The weight of egg yolk was predictable (P<0.01) from egg weight, length and width (, R2 = 69.9-78.2%); from egg weight and width (R2 = 61.4-66.8%) and from egg weight and length (R2 = 40.0 to 48.3%). This study showed that in vivo prediction based on single trait was not as reliable compared to the use of more than one trait.