4 - Central Institute of Brackishwater Aquaculture

Natlonal Workshop-cum-Trainlng on Bioinforrnatica and Information Management in Aquaculture
Capacity to manage unbalanced data
Ability to create a SAS data set corresponding to any printed table.
8. The inbreeding procedure
The inbreed procedure calculates the covariance or inbreeding coefficients for the
pedigree. PROC INBREED IS unlque In that it handles vary large populations
The inbreed procedures has two modes of operation. One mode carries out
analysis on the assumption that all the individuals belong to the same
generation. The other mode dlvides the population Into non-overlapping
generations and analyzes each generation separately assuming that the parents
of individuals In the current generation are defined in the prevlous generation.
Proc inbreed also compute average of the covariance or Inbreeding coefficient
withln sex categories ~f the gender of individuals is known.
9. Strain comparison and heterosis estimation
The diallel cross IS an efficient design for evaluating the performance of purebred
and crossbred stocks or lines. In complete diallel cross each stock IS crossed with
itself and all other stocks. For each species that may be stripped artificially the
following mating procedure should be followed to obtain an equal contribution of
genes from each cross and from each individual within a cross For each stock,
milt from a given number of slres IS used to fertilize with an equal number of
eggs from a given number of dams of the same and of each of the other stocks.
Thus both crosses between the pure stocks and all poss~ble cross combinations
between stocks ~ncluding reciprocal are produced
A complete design may provlde estimate of additional genetic effect of each
stock, overall heterosis, general heterosis for each stock and specific heteros~s
for each cross. Following formula can also be used to determine abovementioned
aspects.
Pn = mean phenotype of all purebreds
X ,(, = mean phenotype of all crossbreds
Pj/i = mean phenotype of one purebred
= Pn+gj/I+gm ]/I (here gm IS the maternal effect)
hl.. = average heterosis for all crosses
=I hIj = X n (n 1) - Pn
hlIj = average heterosis for reciprocal cross
= xi,+X,,-P,-P,)/Z
hlj = average strain heterosis
= EhllJ(n-l)
glj = average indlvldual effect of each strain
- Pj + Pn- gm,