Estimation of genetic and phenotypic parameters in a closed ...

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percent predicted yield, grade and age to r¡arket weíght, the coefficients
ranged from low to hígh.
The relationships between ham sur_
face and shoulder fat, mid-back fat and total back fat thickness measure*
mentswere highly negative' whíle the relationshÍp betr¿een ham surface
area and percent predicted yield was highly positive which suggested
that selection for larger hau surface area would. increase percent predicred
yield.
The high negatíve correlations between percent predicted yield and
back fat thíckness measurernents indicat.ed that selection for lower
back fat thiekness would signifícantly increase the percent predicted
yÍeld. selection for larger roin eye area, percent ham weight, ham
surface area or grade index should lead to an increase in peïcent predicted
yÍeld.
The correlations betr¿een age to markeÈ weÍght and backfat thíckness
measurements rùere highly negative except for loin fat which Índicated
that sel-ection for fasL growth rate would Íncrease back fat thickness
and decrease carcass grade index in consequence. The relationships
between age Lo market weight and grade index, ham surface area and percent
predícted yield were positive and high.
These findings suggested
that selectíon for lower back fat or hÍgher grade index or srnaller ham
surface area or higher percent predicted yield would tend to increase
age to market weight unless the traits \¡/ere combined in a selectÍon
i-ndex.