GENETIC PARAMETERS OF RHODE ISLAND RED AND WHITE CHICKENS AND THEIR RECIPROCAL CROSSES
GENETIC PARAMETERS OF RHODE ISLAND RED AND WHITE CHICKENS AND THEIR RECIPROCAL CROSSES
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Date
1998-08
Authors
GABCHE, AGNES EGHOGHO
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Abstract
The genetic parameters derived from 695 F1 progenies of two strains of Rhode Island
chickens and their reciprocal crosses were compared.
The least square analysis of variance was used in comparing the four genetic groups.
While a one-way random model was used in estimating the genetic parameters. Variables used
for analysis comprised body weight at time of hatch (B-0); four (B-4); eight (B-8); twelve(B-
12); sixteen (B-16); twenty (B-20); forty(B-40); weeks of age and at sexual maturity (BSM), age
at sexual maturity (ASM), first egg weight (FEWT), Average egg weight (AEWT), 280 days
egg production (EN280D), Average shape index (ASI), shell thickness (AST); Haugh Unit
(AHU) and yolk index (AYI) measured on each pullet.
The results indicated that strain crossing improved B-12, B-16, B-20; decreased ASM;
increased EN280D and improved ASI, AHU and AYI. The RxW cross was better than its
reciprocal cross and also show maximum heterosis in the desirable direction in the above traits.
The heretability estimates obtained ranged from -0.42 to 1.33, -0.07 to 1.10, 0.03 to
0.89, -0.18 to 1.56 for RxR, WxW, RxW and WxR genetic groups, respectively. Generally,
heritability estimates were higher in the crossbred than purebred for most body weight traits,
ASM, EN280D and some egg quality traits based on the sire's parent breed. The results are
consistent with the notion that there were genetic differences between the purebred males that
affects the production characteristics of their crossbred progeny differently than their purebred
progeny. The results indicated that non-additive genetic variation exist for various component
of egg laying production which can be exploited through selection based on cross-line
performance.
Sex-linkage effect was found to be more important than maternal effect. This indicated
that a specialised male female line is required for maximium production. The genetic
correlation was positive between early body weight (B-8,B-20) and EN280D, ASM and AEWT.
whereas EN280D and early body wieght were negatively correlated with ASM and AEWT.This
indicated that selection of chickens can be done at early age based on body weight without any
detrimental effect on ASM and EN280D.
It was concluded, based on the results that RxW cross is the best genetic group for
commercial exploitation.It's production can be improved by selection based on both pure and
crossbred progeny.
Description
A THESIS SUBMITTED TO THE POST
GRADUATE SCHOOL, AHMADU BELLO
UNIVERSITY, IN PARTIAL FULFILLMENT OF
THE REQUIREMENTS FOR MASTER DEGREE
IN ANIMAL BREEDING AND GENETICS
DEPARTMENT OF ANIMAL SCIENCE
FACULTY OF AGRICULTURE
AHMADU BELLO UNIVERSITY, ZARIA
AUGUST, 1998
Keywords
GENETIC,, PARAMETERS,, RHODE ISLAND,, CHICKENS,, RECIPROCAL CROSSES