ABSTRACT

 A total of 140 day-old chicks generated from cross- breeding experiment to evaluate the effect of plumage modifying genes on growth and early lay characteristics of cross- bred egg type chicken. Three genetic groups consisting ofNaked neck x Isa Brown pullets (Na x IB), Frizzle, x Isa Brown pullets (F x IB) and Normal feather x Isa Brown pullets (N x IB) were used. The experimental design employed was Randomized Complete Block design (RCBD) with genetic group as a major factor of interest and batches as block. The result of the growth performance studies revealed that Frizzle hybrid chicken birds were significantly (p<0.05) highest in day -old weight when compared to their Naked neck and Normal feather counterparts. The weekly body weights (BW) at brooding phase were significantly (p<0.05) highest with Naked neck and Frizzle at week 1 and 3 over the Normal feather birds .The weekly body weight does not follow a definite pattern because Normal feather and Naked neck hybrids were significantly (p<0.05) highest at week 6 when compared to their Frizzle counterparts. At growers phase, Naked neck and Normal feather birds were significantly (p<0.05) highest in body weight (BW) over Frizzle hybrids. While for feed conversion ratios, Naked neck and Frizzle were highest when compared to Normal feather hybrids. At point of lay, Naked neck had significantly highest body weight (BW),highest in feed conversion ratios (FCRS), average daily feed intake both at growers phase and point of lay (ADFI). At laying phase, the Naked neck birds were significantly (p<0.05) highest in body weight at first egg, the 30 days of lay, weight gain at 60 days (BWG@60), feed conversion ratios (FCRS) and average daily feed intake(ADFI) over their counterparts. For egg production traits, Naked neck hybrids chickens was significantly (p<0.05) highest in egg number (ENO) over Frizzle and Normal feather hybrid chickens, hen-day egg production (HDEP %), Frizzle and Normal feather hybrid chickens were highest compared to their Naked neck hybrid chickens .Hen-house egg production (HHEP %), Naked neck and Normal feather hybrid chickens were highest when compared to their Frizzle counterparts. Egg quality traits, were better for Naked neck individuals as well as . egg weight (EWT), egg length (EL), egg width (EWD) egg volume (EV) first egg to 60' days of egg lay , Frizzle hybrids had improved significantly age at first egg, egg shape index and egg specific gravity. Normal feather on the order hand was better in egg specific gravity at 30 and 60 days of egg lay and more efficient in feed conversion ratio when compared to those of Naked neck and their Frizzle hybrid counterparts. There was a clear evidence of maternal influence in the expression of growth and egg traits in which birds tended to follow more of the damorigin effects. Generally, cross breeding resulted in offspring with improved growth, egg production and egg quality traits. It was therefore concluded that for rapid improvement of these traits in crossbred egg-type chickens, Naked neck should be considered for rapid growth, improvement of egg production and egg quality traits while Frizzle individuals should be considered for fast growth, early sexual maturity and egg production while gene frequency which is relative abundance of genotypes in population favoured the Frizzle individuals, resulting in more heterozygote Frizzle hybrid chickens being produced in the study.