G
Glossary
Gametes
Mature
germ cells.
Gene
interactions
The
collaboration of several different genes in the production of one phenotypic
character.
Gene
introgression
Introduction
of a single gene to an existing breed by crossing to a new breed, and then
backcrossing to the original breed for several generations.
Generation
interval
Average
age of parents when the offspring destined to replace them are born. It should
be computed separately for male and female parents.
Genetic
defects
A
genetic defect is a disease or disorder that is inherited
genetically.
Genetic
evaluation
The
prediction of breeding values.
Genetic
proofs
The
breeding value of an animal as determined by a recognised genetic evaluation
procedure.
Genetic
variance
The
portion of phenotypic variance resulting from the presence of different
genotypes in the population.
Genetic
groups
Groups
of animals with unknown parents. Groups are formed according to age (year born),
country of origin and/or breed composition (if more than one breed is
included).
Genetic
markers
A
genetic marker is an allele, DNA marker or cytogenetic marker used as a probe to
keep track of an individual, a tissue, a cell, a nucleus, a chromosome, or a
gene.
Genotype
The
two alleles present at a locus in an individual. For a locus with only two
alleles, three genotypes are possible. For example, at the polled/horned locus
in cattle, two common alleles are P ( the dominant allele preventing growth of
horns) and p (the recessive allele allowing horn growth). The three possible
genotypes are PP (homozygous dominant), Pp (heterozygous or carrier), and pp
(homozygous recessive).
Gestation
length
The
number of days between known conception date and subsequent calving
date.
Growth
promoting implants
Chemicals
that lead to increased muscle accretion in ruminants.