REPEATABILITY OF GROWTH TRAITS IN NIGERIAN LOCAL CHICKENS USING EARLY RECORDS

Résumé

One hundred and ninety-six records of body weight (WT), shank length (SL), keel length (KL), breast width (BW) and a principal component measure of body size (PCI) from a closed random-mated population of Nigerian local chickens of mixed sexes and genotypes were analyzed, using two records (2- and 4 - Week) from each individual. The repeatability of body weight (0.12±0.071) was low, indicating that selection for 4-week body weight may not result in higher lifetime average body weight. On the other hand, PCI had a high repeatability of 0.55±0.050, indicating that an appreciable amount of genetic improvement in lifetime average body size can be realized by using this trait as selection criterion. PCI is therefore recommended for selection purposes as it is a more reliable measure of an animal's overall body size. Although repeatabilities of SL (0.33±0.064), KL (0.38±0.061) and BW (0.21±0.068) were moderate, selection based on them singly may not be useful in improving overall body growth of an animal, unless selection is designed to improve specific body areas of prime economic value.