Determination of relative economic weights of growth and egg production traits in Nigerian indigenous chicken
Keywords:Aggregate value, economic weight, egg production, native chicken hen, sselection index
The relative economic weight (REW) of a trait is the additional gain/loss from a unit change in the trait relative to other traits in an individual. They are used to calculate aggregate economic values for purposes of genetic improvement in animals. The present study was designed to evaluate the bio-economic variables of growth and 16 weeks egg production parameters: egg number (EN16) egg weight (EWT16) body weight at first egg (BWTFE), body weight at 16 week of lay (BWTE16), cost of feed, and revenue from eggs and chicken carcass, 16 feed conversion ratio (FCR ), and body weight gain (BWG16) in the Nigerian indigenous chicken, and to determine the economic weights (EW) and REW of EN16, EWT16 and BWTE16 for G0, G1, and G2 generations. A total of 250 pullets (20 week old, point of lay) from a population of heavy body weight local chickens were used for the study. The birds were housed individually in cages, fed optimally on layers mash (G and G : 100g/bird/day; G : 0 1 2 125g/bird/day) and given water ad libitum. Data included EN , EWT , BWTE , BWTFE, 16 16 16 and prices of feed, eggs and spent hens, FCR , and BWG . Data on EN , EWT , BWTE , 16 16 16 16 16 and BWTFE were compared across generations using ANOVAand with other variables were used to generate the EW of the traits. The EW were then standardized relative to that of BWTE . Results showed that EW and REW of EN , EWT , and BWTE were 7.47 and 3.15, 16 16 16 16 13.67 and 5.77 and -2.37 and -1.00, respectively in G ; 13.07 and 3.82, 23.69 and 6.93, and - 0 3.42 and -1.00, respectively in G ; 16.80 and 2.89, 30.75 and 5.28 and -5.82 and -1.00, 1 respectively in G generation. Thus EN and EWT enhanced while BWTE depressed the 2 16 16 16 worth of the hen as a layer. EWT was more important than EN and both were more 16 16 important than BWTE economically. Therefore, EWT and EN are the major bio-economic 16 variables of the local hen as an egg chicken.