The use of Egg Weight and Linear Characteristics as Selection Criteria for Genetic Improvement of Albumin and Yolk Height of Nigeria Local Chicken Eggs

The study was carried out at the Federal University of Agriculture Makurdi to determine the relationship between internal and external egg characteristics of the Nigeria local chickens. A total of 300 eggs collected over a period of four weeks from the Nigerian local chickens were used for the study. Fifty five (fifty hens and five cocks) were reared in cages at the University of Agriculture Animal Teaching and Research Farm, Makurdi. Nigeria. Egg external characteristics measured were egg weight, egg width, egg length, shell thickness and shell weight. Egg weight was 49.53g, while egg width, egg length, shell thickness and shell weight were 2.46mm, 3.67mm, o.33mm and 6.08g respectively. The internal egg parameters were albumin height (8.33mm) and yolk height (17.51mm) respectively. All the external egg characteristics have significant and positive correlations with the internal egg characteristics.
The correlation between egg weight (EGGWT), egg length (EGGLGHT) and egg width (EGGWDT) were high, positive and significant (P<0.05). This implied that an increase in egg weight will lead to a corresponding increase in egg length and egg width. The relationship between egg weight and shell weight observed in this study were highly significant, thus selection targeting egg weight will also improve egg shell weight. Significant (P<0.05) correlation value was found between egg weight and albumen height. There is therefore an indication that as egg weight increases, the height of the albumen also increases, the Haugh unit which is based on the albumen height also increases. A highly significant (P<0. 01) correlation was found between egg weight and yolk height. This indicated that as egg weight increases, yolk height also increases. This study indicated that egg weight has high association with egg linear measurement and internal egg characteristics. Egg weight can be selected to exploit the correlated response to selection of egg linear parameter and internal egg traits qualities that influence hatch weight of local chickens.

Keywords: correlation, egg-characteristics, linear-measurement, improvement, selection.